Dietary fiber

提供: miniwiki
移動先:案内、検索

Dietary fiber or roughage is the portion of plant-derived food that cannot be completely broken down by human digestive enzymes.[1] It has two main components:[2]

Dietary fiber consists of non-starch polysaccharides and other plant components such as cellulose, resistant starch, resistant dextrins, inulin, lignins, chitins, pectins, beta-glucans, and oligosaccharides.[1][2]

Dietary fibers can act by changing the nature of the contents of the gastrointestinal tract and by changing how other nutrients and chemicals are absorbed.[5] Some types of soluble fiber absorb water to become a gelatinous, viscous substance which may or may not be fermented by bacteria in the digestive tract. Some types of insoluble fiber have bulking action and are not fermented.[6] Lignin, a major dietary insoluble fiber source, may alter the rate and metabolism of soluble fibers.[2] Other types of insoluble fiber, notably resistant starch, are fermented to produce short-chain fatty acids, which are physiologically active and confer health benefits.[1][3][4] Health benefit from dietary fiber and whole grains may include a decreased risk of death and lower rates of coronary heart disease, colon cancer, and type 2 diabetes.[7]

Food sources of dietary fiber have traditionally been divided according to whether they provide soluble or insoluble fiber. Plant foods contain both types of fiber in varying amounts, according to the plant's characteristics of viscosity and fermentability.[1][8] Advantages of consuming fiber depend upon which type of fiber is consumed and which benefits may result in the gastrointestinal system.[9] Bulking fibers – such as cellulose, hemicellulose and psyllium – absorb and hold water, promoting regularity.[10] Viscous fibers – such as beta-glucan and psyllium – thicken the fecal mass.[10] Fermentable fibers – such as resistant starch and inulin – feed the bacteria and microbiota of the large intestine, and are metabolized to yield short-chain fatty acids, which have diverse roles in gastrointestinal health.[11][12]

Definition

Dietary fiber is defined to be plant components that are not broken down by human digestive enzymes.[1] In the late 20th century, only lignin and some polysaccharides were known to satisfy this definition, but in the early 21st century, resistant starch and oligosaccharides were included as dietary fiber components.[1][6]

Official definition of dietary fiber varies among different institutions:

Organization Definition
Institute of Medicine[13]
(2001)		 Dietary fiber consists of nondigestible carbohydrates and lignin that are intrinsic and intact in plants. "Added Fiber" consists of isolated, nondigestible carbohydrates that have beneficial physiological effects in humans.
American Association of Cereal Chemists[14]
(2001)		 Dietary fiber is the edible parts of plants or analogous carbohydrates that are resistant to digestion and absorption in the human small intestine, with complete or partial fermentation in the large intestine. Dietary fiber includes polysaccharides, oligosaccharides, lignin, and associated plant substances. Dietary fibers promote beneficial physiologic effects including laxation, and/or blood cholesterol attenuation, and/or blood glucose attenuation.
Codex Alimentarius Commission[15]
(2014; adopted by the European Commission and 10 countries internationally)		 Dietary fiber means carbohydrate polymers with more than 10 monomeric units, which are not hydrolyzed by digestive enzymes in the small intestine of humans.
British Nutrition Foundation[1]
(2018)		 Dietary fibre refers to a group of substances in plant foods which cannot be completely broken down by human digestive enzymes. This includes waxes, lignin and polysaccharides such as cellulose and pectin. Originally it was thought that dietary fibre was completely indigestible and did not provide any energy. It is now known that some fibre can be fermented in the large intestine by gut bacteria, producing short chain fatty acids and gases.

Types and sources of dietary fiber

Nutrient Food additive Source/Comments
water-insoluble dietary fibers
β-glucans (a few of which are water-soluble)
   Cellulose E 460 cereals, fruit, vegetables (in all plants in general)
   Chitin — in fungi, exoskeleton of insects and crustaceans
Hemicellulose cereals, bran, timber, legumes
   Hexoses — wheat, barley
   Pentose — rye, oat
Lignin — stones of fruits, vegetables (filaments of the garden bean), cereals
Xanthan gum E 415 production with Xanthomonas-bacteria from sugar substrates
Resistant starch Can be starch protected by seed or shell (type RS1), granular starch (type RS2) or retrograded starch (type RS3)[3]
   Resistant starch — high amylose corn, barley, high amylose wheat, legumes, raw bananas, cooked and cooled pasta and potatoes[3]
water-soluble dietary fibers
Arabinoxylan (a hemicellulose) — psyllium[16]
Fructans replace or complement in some plant taxa the starch as storage carbohydrate
   Inulin — in diverse plants, e.g. topinambour, chicory, etc.
Polyuronide
   Pectin E 440 in the fruit skin (mainly apples, quinces), vegetables
   Alginic acids (Alginates) E 400–E 407 in Algae
      Sodium alginate E 401
      Potassium alginate E 402
      Ammonium alginate E 403
      Calcium alginate E 404
      Propylene glycol alginate (PGA) E 405
      agar E 406
      carrageen E 407 red algae
Raffinose — legumes
Xylose — monosacharide, pentose
Polydextrose E 1200 synthetic polymer, ca. 1kcal/g
Lactulose — synthetic disaccharide

Fiber contents in food

Dietary fibers are found in fruits, vegetables and whole grains. The amount of fiber contained in common foods are in the following table:[17]

Food group Serving mean Fibermass per serving
Fruit 120 mL (0.5 cup)[18][19] 1.1 g
Dark green vegetables 120 mL (0.5 cup) 6.4 g
Orange vegetables 120 mL (0.5 cup) 2.1 g
Cooked dry beans (legumes) 120 mL (0.5 cup) 8.0 g
Starchy vegetables 120 mL (0.5 cup) 1.7 g
Other vegetables 120 mL (0.5 cup) 1.1 g
Whole grains 28 g (1 oz) 2.4 g
Meat 28 g (1 oz) 0.1 g

Dietary fiber is found in plants, typically eaten whole, raw or cooked, although fiber can be added to make dietary supplements and fiber-rich processed foods. Grain bran products have the highest fiber contents, such as crude corn bran (79 g per 100 g) and crude wheat bran (43 g per 100 g), which are ingredients for manufactured foods.[17] Medical authorities, such as the Mayo Clinic, recommend adding fiber-rich products to the Standard American Diet (SAD) which is rich in processed and artificially sweetened foods, with minimal intake of vegetables and legumes.[20][21]

Plant sources of fiber

Some plants contain significant amounts of soluble and insoluble fiber. For example, plums and prunes have a thick skin covering a juicy pulp. The skin is a source of insoluble fiber, whereas soluble fiber is in the pulp. Grapes also contain a fair amount of fiber.[22]

Soluble fiber is found in varying quantities in all plant foods, including:

Sources of insoluble fiber include:

Fiber supplements

These are a few example forms of fiber that have been sold as supplements or food additives. These may be marketed to consumers for nutritional purposes, treatment of various gastrointestinal disorders, and for such possible health benefits as lowering cholesterol levels, reducing risk of colon cancer, and losing weight.

Soluble fiber supplements may be beneficial for alleviating symptoms of irritable bowel syndrome, such as diarrhea or constipation and abdominal discomfort.[24] Prebiotic soluble fiber products, like those containing inulin or oligosaccharides, may contribute to relief from inflammatory bowel disease,[25] as in Crohn's disease,[26] ulcerative colitis,[27][28] and Clostridium difficile,[29] due in part to the short-chain fatty acids produced with subsequent anti-inflammatory actions upon the bowel.[30][31] Fiber supplements may be effective in an overall dietary plan for managing irritable bowel syndrome by modification of food choices.[32]

One insoluble fiber, resistant starch from high-amylose corn, has been used as a supplement and may contribute to improving insulin sensitivity and glycemic management[33][34][35] as well as promoting regularity[36] and possibly relief of diarrhea.[37][38][39] One preliminary finding indicates that resistant corn starch may reduce symptoms of ulcerative colitis.[40]

Inulins

"「Inulin」"

Chemically defined as oligosaccharides occurring naturally in most plants, inulins have nutritional value as carbohydrates, or more specifically as fructans, a polymer of the natural plant sugar, fructose. Inulin is typically extracted by manufacturers from enriched plant sources such as chicory roots or Jerusalem artichokes for use in prepared foods.[41] Subtly sweet, it can be used to replace sugar, fat, and flour, is often used to improve the flow and mixing qualities of powdered nutritional supplements, and has significant potential health value as a prebiotic fermentable fiber.[42]

Inulin is advantageous because it contains 25–30% the food energy of sugar or other carbohydrates and 10–15% the food energy of fat. As a prebiotic fermentable fiber, its metabolism by gut flora yields short-chain fatty acids (see below) which increase absorption of calcium,[43] magnesium,[44] and iron,[45] resulting from upregulation of mineral-transporting genes and their membrane transport proteins within the colon wall. Among other potential beneficial effects noted above, inulin promotes an increase in the mass and health of intestinal Lactobacillus and Bifidobacterium populations.

Inulin's primary disadvantage is its tolerance. As a soluble fermentable fiber, it is quickly and easily fermented within the intestinal tract, which may cause gas and digestive distress at doses higher than 15 grams/day in most people.[46] Individuals with digestive diseases have benefited from removing fructose and inulin from their diet.[47] While clinical studies have shown changes in the microbiota at lower levels of inulin intake, some of the health effects require higher than 15 grams per day to achieve the benefits.[48]

Vegetable gums

Vegetable gum fiber supplements are relatively new to the market. Often sold as a powder, vegetable gum fibers dissolve easily with no aftertaste. In preliminary clinical trials, they have proven effective for the treatment of irritable bowel syndrome.[49] Examples of vegetable gum fibers are guar gum and gum arabic.

Activity in the gut

Many molecules that are considered to be "dietary fiber" are so because humans lack the necessary enzymes to split the glycosidic bond and they reach the large intestine. Many foods contain varying types of dietary fibers, all of which contribute to health in different ways.

Dietary fibers make three primary contributions: bulking, viscosity and fermentation.[50] Different fibers have different effects, suggesting that a variety of dietary fibers contribute to overall health. Some fibers contribute through one primary mechanism. For instance, cellulose and wheat bran provide excellent bulking effects, but are minimally fermented. Alternatively, many dietary fibers can contribute to health through more than one of these mechanisms. For instance, psyllium provides bulking as well as viscosity.

Bulking fibers can be soluble (e.g. psyllium) or insoluble (e.g. cellulose and hemicellulose). They absorb water and can significantly increase stool weight and regularity. Most bulking fibers are not fermented or are minimally fermented throughout the intestinal tract.[50]

Viscous fibers thicken the contents of the intestinal tract and may attenuate the absorption of sugar, reduce sugar response after eating, and reduce lipid absorption (notably shown with cholesterol absorption). Their use in food formulations is often limited to low levels, due to their viscosity and thickening effects. Some viscous fibers may also be partially or fully fermented within the intestinal tract (guar gum, beta-glucan, glucomannan and pectins), but some viscous fibers are minimally or not fermented (modified cellulose such as methylcellulose and psyllium).[50]

Fermentable fibers are consumed by the microbiota within the large intestines, mildly increasing fecal bulk and producing short-chain fatty acids as byproducts with wide-ranging physiological activities (discussion below). Resistant starch, inulin, fructooligosaccharide and galactooligosaccharide are dietary fibers which are fully fermented. These include insoluble as well as soluble fibers. This fermentation influences the expression of many genes within the large intestine,[51] which affect digestive function and lipid and glucose metabolism, as well as the immune system, inflammation and more.[52]

Dietary fibers can change the nature of the contents of the gastrointestinal tract and can change how other nutrients and chemicals are absorbed through bulking and viscosity.[2][5] Some types of soluble fibers bind to bile acids in the small intestine, making them less likely to re-enter the body; this in turn lowers cholesterol levels in the blood from the actions of cytochrome P450-mediated oxidation of cholesterol.[6]

Insoluble fiber is associated with reduced risk of diabetes, but the mechanism by which this is achieved is unknown.[53] One type of insoluble dietary fiber, resistant starch, may increase insulin sensitivity in healthy people,[54][55] in type 2 diabetics,[56] and in individuals with insulin resistance, possibly contributing to reduced risk of type 2 diabetes.[57][58][59]

Not yet formally proposed as an essential macronutrient, dietary fiber has importance in the diet, with regulatory authorities in many developed countries recommending increases in fiber intake.[2][5][60][61]

Physicochemical properties

Dietary fiber has distinct physicochemical properties. Most semi-solid foods, fiber and fat are a combination of gel matrices which are hydrated or collapsed with microstructural elements, globules, solutions or encapsulating walls. Fresh fruit and vegetables are cellular materials.[62][63][64]

  • The cells of cooked potatoes and legumes are gels filled with gelatinized starch granules. The cellular structures of fruits and vegetables are foams with a closed cell geometry filled with a gel, surrounded by cell walls which are composites with an amorphous matrix strengthened by complex carbohydrate fibers.
  • Particle size and interfacial interactions with adjacent matrices affect the mechanical properties of food composites.
  • Food polymers may be soluble in and/or plasticized by water. Water is the most important plasticizer, particularly in biological systems thereby changing mechanical properties.
  • The variables include chemical structure, polymer concentration, molecular weight, degree of chain branching, the extent of ionization (for electrolytes), solution pH, ionic strength and temperature.
  • Cross-linking of different polymers, protein and polysaccharides, either through chemical covalent bonds or cross-links through molecular entanglement or hydrogen or ionic bond cross-linking.
  • Cooking and chewing food alters these physicochemical properties and hence absorption and movement through the stomach and along the intestine[65]

Dietary fiber in the upper gastrointestinal tract

Following a meal, the stomach and upper gastrointestinal contents consist of

Micelles are colloid-sized clusters of molecules which form in conditions as those above, similar to the critical micelle concentration of detergents.[67] In the upper gastrointestinal tract, these compounds consist of bile acids and di- and monoacyl glycerols which solubilize triacylglycerols and cholesterol.[67]

Two mechanisms bring nutrients into contact with the epithelium:

  1. intestinal contractions create turbulence; and
  2. convection currents direct contents from the lumen to the epithelial surface.[68]

The multiple physical phases in the intestinal tract slow the rate of absorption compared to that of the suspension solvent alone.

  1. Nutrients diffuse through the thin, relatively unstirred layer of fluid adjacent to the epithelium.
  2. Immobilizing of nutrients and other chemicals within complex polysaccharide molecules affects their release and subsequent absorption from the small intestine, an effect influential on the glycemic index.[68]
  3. Molecules begin to interact as their concentration increases. During absorption, water must be absorbed at a rate commensurate with the absorption of solutes. The transport of actively and passively absorbed nutrients across epithelium is affected by the unstirred water layer covering the microvillus membrane.[68]
  4. The presence of mucus or fiber, e.g., pectin or guar, in the unstirred layer may alter the viscosity and solute diffusion coefficient.[66]

Adding viscous polysaccharides to carbohydrate meals can reduce post-prandial blood glucose concentrations. Wheat and maize but not oats modify glucose absorption, the rate being dependent upon the particle size. The reduction in absorption rate with guar gum may be due to the increased resistance by viscous solutions to the convective flows created by intestinal contractions.

Dietary fiber interacts with pancreatic and enteric enzymes and their substrates. Human pancreatic enzyme activity is reduced when incubated with most fiber sources. Fiber may affect amylase activity and hence the rate of hydrolysis of starch. The more viscous polysaccharides extend the mouth-to-cecum transit time; guar, tragacanth and pectin being slower than wheat bran.[69]

Fiber in the colon

The colon may be regarded as two organs,

  1. the right side (cecum and ascending colon), a fermenter.[70] The right side of the colon is involved in nutrient salvage so that dietary fiber, resistant starch, fat and protein are utilized by bacteria and the end-products absorbed for use by the body
  2. the left side (transverse, descending, and sigmoid colon), affecting continence.

The presence of bacteria in the colon produces an ‘organ’ of intense, mainly reductive, metabolic activity, whereas the liver is oxidative. The substrates utilized by the cecum have either passed along the entire intestine or are biliary excretion products. The effects of dietary fiber in the colon are on

  1. bacterial fermentation of some dietary fibers
  2. thereby an increase in bacterial mass
  3. an increase in bacterial enzyme activity
  4. changes in the water-holding capacity of the fiber residue after fermentation

Enlargement of the cecum is a common finding when some dietary fibers are fed and this is now believed to be normal physiological adjustment. Such an increase may be due to a number of factors, prolonged cecal residence of the fiber, increased bacterial mass, or increased bacterial end-products. Some non-absorbed carbohydrates, e.g. pectin, gum arabic, oligosaccharides and resistant starch, are fermented to short-chain fatty acids (chiefly acetic, propionic and n-butyric), and carbon dioxide, hydrogen and methane. Almost all of these short-chain fatty acids will be absorbed from the colon. This means that fecal short-chain fatty acid estimations do not reflect cecal and colonic fermentation, only the efficiency of absorption, the ability of the fiber residue to sequestrate short-chain fatty acids, and the continued fermentation of fiber around the colon, which presumably will continue until the substrate is exhausted. The production of short-chain fatty acids has several possible actions on the gut mucosa. All of the short-chain fatty acids are readily absorbed by the colonic mucosa, but only acetic acid reaches the systemic circulation in appreciable amounts. Butyric acid appears to be used as a fuel by the colonic mucosa as the preferred energy source for colonic cells.

Dietary fiber and cholesterol metabolism

Dietary fiber may act on each phase of ingestion, digestion, absorption and excretion to affect cholesterol metabolism,[71] such as the following:

  1. Caloric energy of foods through a bulking effect
  2. Slowing of gastric emptying time
  3. A glycemic index type of action on absorption
  4. A slowing of bile acid absorption in the ileum so bile acids escape through to the cecum
  5. Altered or increased bile acid metabolism in the cecum
  6. Indirectly by absorbed short-chain fatty acids, especially propionic acid, resulting from fiber fermentation affecting the cholesterol metabolism in the liver.
  7. Binding of bile acids to fiber or bacteria in the cecum with increased fecal loss from the entero-hepatic circulation.

An important action of some fibers is to reduce the reabsorption of bile acids in the ileum and hence the amount and type of bile acid and fats reaching the colon. A reduction in the reabsorption of bile acid from the ileum has several direct effects.

  1. Bile acids may be trapped within the lumen of the ileum either because of a high luminal viscosity or because of binding to a dietary fiber.[72]
  2. Lignin in fiber adsorbs bile acids, but the unconjugated form of the bile acids are adsorbed more than the conjugated form. In the ileum where bile acids are primarily absorbed the bile acids are predominantly conjugated.
  3. The enterohepatic circulation of bile acids may be altered and there is an increased flow of bile acids to the cecum, where they are deconjugated and 7alpha-dehydroxylated.
  4. These water-soluble form, bile acids e.g., deoxycholic and lithocholic are adsorbed to dietary fiber and an increased fecal loss of sterols, dependent in part on the amount and type of fiber.
  5. A further factor is an increase in the bacterial mass and activity of the ileum as some fibers e.g., pectin are digested by bacteria. The bacterial mass increases and cecal bacterial activity increases.
  6. The enteric loss of bile acids results in increased synthesis of bile acids from cholesterol which in turn reduces body cholesterol.

The fibers that are most effective in influencing sterol metabolism (e.g. pectin) are fermented in the colon. It is therefore unlikely that the reduction in body cholesterol is due to adsorption to this fermented fiber in the colon.

  1. There might be alterations in the end-products of bile acid bacterial metabolism or the release of short chain fatty acids which are absorbed from the colon, return to the liver in the portal vein and modulate either the synthesis of cholesterol or its catabolism to bile acids.
  2. The prime mechanism whereby fiber influences cholesterol metabolism is through bacteria binding bile acids in the colon after the initial deconjugation and dehydroxylation. The sequestered bile acids are then excreted in feces.[73]
  3. Fermentable fibers e.g., pectin will increase the bacterial mass in the colon by virtue of their providing a medium for bacterial growth.
  4. Other fibers, e.g., gum arabic, act as stabilizers and cause a significant decrease in serum cholesterol without increasing fecal bile acid excretion.
ファイル:Kids ‘n Fiber (6121371164).jpg
Kids eating dietary fiber food

Dietary fiber and fecal weight

Feces consist of a plasticine-like material, made up of water, bacteria, lipids, sterols, mucus and fiber.

  1. Feces are 75% water; bacteria make a large contribution to the dry weight, the residue being unfermented fiber and excreted compounds.
  2. Fecal output may vary over a range of between 20 and 280 g over 24 hours. The amount of feces egested a day varies for any one individual over a period of time.
  3. Of dietary constituents, only dietary fiber increases fecal weight.

Water is distributed in the colon in three ways:

  1. Free water which can be absorbed from the colon.
  2. Water that is incorporated into bacterial mass.
  3. Water that is bound by fiber.

Fecal weight is dictated by:

  1. the holding of water by the residual dietary fiber after fermentation.
  2. the bacterial mass.
  3. There may also be an added osmotic effect of products of bacterial fermentation on fecal mass.

Wheat bran is minimally fermented and binds water and when added to the diet increases fecal weight in a predictable linear manner and decreases intestinal transit time. The particle size of the fiber is all-important, coarse wheat bran being more effective than fine wheat bran. The greater the water-holding capacity of the bran, the greater the effect on fecal weight. For most healthy individuals, an increase in wet fecal weight, depending on the particle size of the bran, is generally of the order of 3–5 g/g fiber. The fermentation of some fibers results in an increase in the bacterial content and possibly fecal weight. Other fibers, e.g. pectin, are fermented and have no effect on stool weight.

Effects of fiber intake

Research has shown that fiber may benefit health in several different ways. Lignin and probably related materials that are resistant to enzymatic degradation, diminish the nutritional value of foods.[74]

Color coding of table entries:

  • Both Applies to both soluble and insoluble fiber
  • Soluble Applies to soluble fiber only
  • Insoluble Applies to insoluble fiber only
Effects[1][75]
Increases food volume without increasing caloric content to the same extent as digestible carbohydrates, providing satiety which may reduce appetite.
Attracts water and forms a viscous gel during digestion, slowing the emptying of the stomach and intestinal transit, shielding carbohydrates from enzymes, and delaying absorption of glucose,[1][76] which lowers variance in blood sugar levels
Lowers total and LDL cholesterol, which may reduce the risk of cardiovascular disease[1]
Regulates blood sugar, which may reduce glucose and insulin levels in diabetic patients and may lower risk of diabetes[1][77]
Speeds the passage of foods through the digestive system, which facilitates regular defecation
Adds bulk to the stool, which alleviates constipation
Balances intestinal pH[78] and stimulates intestinal fermentation production of short-chain fatty acids[1]

Fiber does not bind to minerals and vitamins and therefore does not restrict their absorption, but rather evidence exists that fermentable fiber sources improve absorption of minerals, especially calcium.[79][80][81] Some plant foods can reduce the absorption of minerals and vitamins like calcium, zinc, vitamin C, and magnesium, but this is caused by the presence of phytate (which is also thought to have important health benefits), not by fiber.[82]

Research

A study of 388,000 adults ages 50 to 71 for nine years found that the highest consumers of fiber were 22% less likely to die over this period.[83] In addition to lower risk of death from heart disease, adequate consumption of fiber-containing foods, especially grains, was also associated with reduced incidence of infectious and respiratory illnesses, and, particularly among males, reduced risk of cancer-related death.

An experiment designed with a large sample and conducted by NIH-AARP Diet and Health Study studied the correlation between fiber intake and colorectal cancer. The analytic cohort consisted of 291,988 men and 197,623 women aged 50–71 years. Diet was assessed with a self-administered food-frequency questionnaire at baseline in 1995–1996; 2,974 incident colorectal cancer cases were identified during five years of follow-up. The result was that total fiber intake was not associated with colorectal cancer.[84]

Although many researchers believe that dietary fiber intake reduces risk of colon cancer, one study conducted by researchers at the Harvard School of Medicine of over 88,000 women did not show a statistically significant relationship between higher fiber consumption and lower rates of colorectal cancer or adenomas.[85] Similarly, a 2010 study of 58,279 men found no relationship between dietary fiber and colorectal cancer.[86]

Dietary fiber and obesity

Dietary fiber has many functions in diet, one of which may be to aid in energy intake control and reduced risk for development of obesity. The role of dietary fiber in energy intake regulation and obesity development is related to its unique physical and chemical properties that aid in early signals of satiation and enhanced or prolonged signals of satiety. Early signals of satiation may be induced through cephalic- and gastric-phase responses related to the bulking effects of dietary fiber on energy density and palatability, whereas the viscosity-producing effects of certain fibers may enhance satiety through intestinal-phase events related to modified gastrointestinal function and subsequent delay in fat absorption. In general, fiber-rich diets, whether achieved through fiber supplementation or incorporation of high fiber foods into meals, have a reduced energy density compared with high fat diets. This is related to fiber’s ability to add bulk and weight to the diet. There are also indications that women may be more sensitive to dietary manipulation with fiber than men. The relationship of body weight status and fiber effect on energy intake suggests that obese individuals may be more likely to reduce food intake with dietary fiber inclusion.[87]

Guidelines on fiber intake

Current recommendations from the United States National Academy of Sciences, Institute of Medicine, state that for Adequate Intake, adult men ages 14–50 consume 38 grams of dietary fiber per day, men 51 and older 30 grams, women ages 19–50 to consume 25 grams per day, women 51 and older 21 grams. These are based on an observed intake level of 14 grams per 1,000 Calories among those with lower risk of coronary heart disease.[2][82]

The AND (Academy of Nutrition and Dietetics, previously ADA) recommends a minimum of 20–35 g/day for a healthy adult depending on calorie intake (e.g., a 2000 Cal/8400 kJ diet should include 25 g of fiber per day). The AND's recommendation for children is that intake should equal age in years plus 5 g/day (e.g., a 4 year old should consume 9 g/day). No guidelines have yet been established for the elderly or very ill. Patients with current constipation, vomiting, and abdominal pain should see a physician. Certain bulking agents are not commonly recommended with the prescription of opioids because the slow transit time mixed with larger stools may lead to severe constipation, pain, or obstruction.

As of 2018, the British Nutrition Foundation has recommended a minimum fiber intake of 30 grams per day for healthy adults.[88]

Fiber recommendations

United States

On average, North Americans consume less than 50% of the dietary fiber levels recommended for good health. In the preferred food choices of today's youth, this value may be as low as 20%, a factor considered by experts as contributing to the obesity levels seen in many developed countries.[89] Recognizing the growing scientific evidence for physiological benefits of increased fiber intake, regulatory agencies such as the Food and Drug Administration (FDA) of the United States have given approvals to food products making health claims for fiber. The FDA classifies which ingredients qualify as being "fiber", and requires for product labeling that a physiological benefit is gained by adding the fiber ingredient.[90] As of 2008, the FDA approved health claims for qualified fiber products to display labeling that regular consumption may reduce blood cholesterol levels – which can lower the risk of coronary heart disease[91] – and also reduce the risk of some types of cancer.[92]

Viscous fiber sources gaining FDA approval are:

Other examples of bulking fiber sources used in functional foods and supplements include cellulose, guar gum and xanthan gum. Other examples of fermentable fiber sources (from plant foods or biotechnology) used in functional foods and supplements include resistant starch, inulin, fructans, fructooligosaccharides, oligo- or polysaccharides, and resistant dextrins, which may be partially or fully fermented.

Consistent intake of fermentable fiber may reduce the risk of chronic diseases.[93][94][95] Insufficient fiber in the diet can lead to constipation.[96]

United Kingdom

In 2018, the British Nutrition Foundation issued a statement to define dietary fiber more concisely and list the potential health benefits established to date, while increasing its recommended daily intake to 30 grams for healthy adults.[1] Statement: 'Dietary fibre' has been used as a collective term for a complex mixture of substances with different chemical and physical properties which exert different types of physiological effects.

The use of certain analytical methods to quantify dietary fiber by nature of its indigestibility results in many other indigestible components being isolated along with the carbohydrate components of dietary fiber. These components include resistant starches and oligosaccharides along with other substances that exist within the plant cell structure and contribute to the material that passes through the digestive tract. Such components are likely to have physiological effects.

Diets naturally high in fiber can be considered to bring about several main physiological consequences:[1]

Fiber is defined by its physiological impact, with many heterogenous types of fibers. Some fibers may primarily impact one of these benefits (i.e., cellulose increases fecal bulking and prevents constipation), but many fibers impact more than one of these benefits (i.e., resistant starch increases bulking, increases colonic fermentation, positively modulates colonic microflora and increases satiety and insulin sensitivity).[3][4] The beneficial effects of high fiber diets are the summation of the effects of the different types of fiber present in the diet and also other components of such diets.

Defining fiber physiologically allows recognition of indigestible carbohydrates with structures and physiological properties similar to those of naturally occurring dietary fibers.[1]

Fiber and fermentation

The American Association of Cereal Chemists has defined soluble fiber this way: "the edible parts of plants or similar carbohydrates resistant to digestion and absorption in the human small intestine with complete or partial fermentation in the large intestine."[97] In this definition:

Edible parts of plants
indicates that some parts of a plant we eat—skin, pulp, seeds, stems, leaves, roots—contain fiber. Both insoluble and soluble sources are in those plant components.
Carbohydrates
complex carbohydrates, such as long-chained sugars also called starch, oligosaccharides, or polysaccharides, are sources of soluble fermentable fiber.
Resistant to digestion and absorption in the human small intestine
foods providing nutrients are digested by gastric acid and digestive enzymes in the stomach and small intestine where the nutrients are released then absorbed through the intestinal wall for transport via the blood throughout the body. A food resistant to this process is undigested, as insoluble and soluble fibers are. They pass to the large intestine only affected by their absorption of water (insoluble fiber) or dissolution in water (soluble fiber).
Complete or partial fermentation in the large intestine
the large intestine comprises a segment called the colon within which additional nutrient absorption occurs through the process of fermentation. Fermentation occurs by the action of colonic bacteria on the food mass, producing gases and short-chain fatty acids. It is these short-chain fatty acids—butyric, acetic (ethanoic), propionic, and valeric acids—that scientific evidence is revealing to have significant health properties.[98]

As an example of fermentation, shorter-chain carbohydrates (a type of fiber found in legumes) cannot be digested, but are changed via fermentation in the colon into short-chain fatty acids and gases (which are typically expelled as flatulence).

According to a 2002 journal article,[93] fiber compounds with partial or low fermentability include:

fiber compounds with high fermentability include:

Short-chain fatty acids

When fermentable fiber is fermented, short-chain fatty acids (SCFA) are produced. SCFAs are involved in numerous physiological processes promoting health, including:[98]

SCFAs that are absorbed by the colonic mucosa pass through the colonic wall into the portal circulation (supplying the liver), and the liver transports them into the general circulatory system.

Overall, SCFAs affect major regulatory systems, such as blood glucose and lipid levels, the colonic environment, and intestinal immune functions.[100][101]

The major SCFAs in humans are butyrate, propionate, and acetate, where butyrate is the major energy source for colonocytes, propionate is destined for uptake by the liver, and acetate enters the peripheral circulation to be metabolized by peripheral tissues.

FDA-approved health claims

The United States FDA allows manufacturers of foods containing 1.7 g per serving of psyllium husk soluble fiber or 0.75 g of oat or barley soluble fiber as beta-glucans to claim that regular consumption may reduce the risk of heart disease.[102]

The FDA statement template for making this claim is: Soluble fiber from foods such as [name of soluble fiber source, and, if desired, name of food product], as part of a diet low in saturated fat and cholesterol, may reduce the risk of heart disease. A serving of [name of food product] supplies __ grams of the [necessary daily dietary intake for the benefit] soluble fiber from [name of soluble fiber source] necessary per day to have this effect.[102]

Eligible sources of soluble fiber providing beta-glucan include:

  • Oat bran
  • Rolled oats
  • Whole oat flour
  • Oatrim
  • Whole grain barley and dry milled barley
  • Soluble fiber from psyllium husk with purity of no less than 95%

The allowed label may state that diets low in saturated fat and cholesterol and that include soluble fiber from certain of the above foods "may" or "might" reduce the risk of heart disease.

As discussed in FDA regulation 21 CFR 101.81, the daily dietary intake levels of soluble fiber from sources listed above associated with reduced risk of coronary heart disease are:

  • 3 g or more per day of beta-glucan soluble fiber from either whole oats or barley, or a combination of whole oats and barley
  • 7 g or more per day of soluble fiber from psyllium seed husk.[103]

Soluble fiber from consuming grains is included in other allowed health claims for lowering risk of some types of cancer and heart disease by consuming fruit and vegetables (21 CFR 101.76, 101.77, and 101.78).[102]

In December 2016, FDA approved a qualified health claim that consuming resistant starch from high-amylose corn may reduce the risk of type 2 diabetes due to its effect of increasing insulin sensitivity. The allowed claim specified: "High-amylose maize resistant starch may reduce the risk of type 2 diabetes. FDA has concluded that there is limited scientific evidence for this claim." [104]

See also

References

  1. ↑ 1.00 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 1.10 1.11 1.12 1.13 1.14 1.15 1.16 1.17 1.18 “Dietary fibre”. British Nutrition Foundation (2018年). . 26 July 2018閲覧.
  2. ↑ 2.0 2.1 2.2 2.3 2.4 2.5 (2005) Dietary Reference Intakes for Energy, Carbohydrate, fibre, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids (Macronutrients) (2005), Chapter 7: Dietary, Functional and Total fibre. US Department of Agriculture, National Agricultural Library and National Academy of Sciences, Institute of Medicine, Food and Nutrition Board. DOI:10.17226/10490. ISBN 978-0-309-08525-0. 
  3. ↑ 3.0 3.1 3.2 3.3 3.4 Lockyer, S; Nugent, A. P (2017). “Health effects of resistant starch”. Nutrition Bulletin 42: 10–41. doi:10.1111/nbu.12244. 
  4. ↑ 4.0 4.1 4.2 Keenan, M. J; Zhou, J; Hegsted, M; Pelkman, C; Durham, H. A; Coulon, D. B; Martin, R. J (2015). “Role of resistant starch in improving gut health, adiposity, and insulin resistance”. Advances in Nutrition 6 (2): 198–205. doi:10.3945/an.114.007419. PMC 4352178. PMID 25770258. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4352178. 
  5. ↑ 5.0 5.1 5.2 “Dietary fiber: how did we get where we are?”. Annu Rev Nutr 25: 1–8. (2005). doi:10.1146/annurev.nutr.25.121304.131658. PMID 16011456. 
  6. ↑ 6.0 6.1 6.2 Anderson, J. W; Baird, P; Davis Jr, R. H; Ferreri, S; Knudtson, M; Koraym, A; Waters, V; Williams, C. L (2009). “Health benefits of dietary fiber”. Nutrition Reviews 67 (4): 188–205. doi:10.1111/j.1753-4887.2009.00189.x. PMID 19335713. https://cloudfront.escholarship.org/dist/prd/content/qt8d0680bq/qt8d0680bq.pdf. 
  7. ↑ Morenga, Lisa Te; Mete, Evelyn; Winter, Nicola; Cummings, John; Mann, Jim; Reynolds, Andrew (10 January 2019). “Carbohydrate quality and human health: a series of systematic reviews and meta-analyses” (English). The Lancet 0 (10170): 434–445. doi:10.1016/S0140-6736(18)31809-9. ISSN 1474-547X. PMID 30638909. https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(18)31809-9/fulltext. 
  8. ↑ (2001) Dietary Reference Intakes, Proposed Definition of Dietary Fiber. Washington, D.C.: Institute of Medicine Press. ISBN 978-0-309-07564-0. 
  9. ↑ (2006) “8”, Present Knowledge in Nutrition, 9, Washington, D.C.: ILSI Press, 102–110. ISBN 978-1-57881-199-1. 
  10. ↑ 10.0 10.1 (2001) Dietary Reference Intakes: Proposed Definition of Dietary Fiber. Washington, D.C.: National Academy Press. ISBN 978-0-309-07564-0. 
  11. ↑ Bedford, Andrea; Gong, Joshua (13 September 2017). “Implications of butyrate and its derivatives for gut health and animal production”. Animal Nutrition 4 (2): 151–159. doi:10.1016/j.aninu.2017.08.010. PMC 6104520. PMID 30140754. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=6104520. 
  12. ↑ (2001) The Effect of Dietary Fiber on Fecal Weight and Composition, 3, Boca Raton, Florida: CRC Press, 184. ISBN 978-0-8493-2387-4. 
  13. ↑ “Dietary Reference Intakes: Proposed Definition of Dietary Fiber”. Institute of Medicine (US), Panel on the Definition of Dietary Fiber and the Standing Committee on the Scientific Evaluation of Dietary Reference Intakes, National Academies Press (2001年). . 18 November 2017閲覧.
  14. ↑ “The Definition of Dietary Fiber; An AACC Report published in Cereals Food World, 46 (3) pp. 112-126”. American Association of Cereal Chemists (2001年3月). . 27 July 2018閲覧.
  15. ↑ Jones JM (2014). “CODEX-aligned dietary fiber definitions help to bridge the 'fiber gap'”. Nutrition Journal 13: 34. doi:10.1186/1475-2891-13-34. PMC 4007020. PMID 24725724. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4007020. 
  16. ↑ Fischer MH, Yu N, Gray GR, Ralph J, Anderson L, Marlett JA. (2004) The gel-forming polysaccharide of psyllium husk (Plantago ovata Forsk). Carbohydr Res. 2004 Aug 2;339(11):2009–17.
  17. ↑ 17.0 17.1 “Search, USDA Food Composition Databases”. Nutrient Data Laboratory. USDA National Nutrient Database, US Department of Agriculture, Standard Release 28 (2015年). . 18 November 2017閲覧.
  18. ↑ U.S. Government Printing Office—Electronic Code of Federal Regulations
  19. ↑ U.S. Food and Drug Administration—Guidelines for Determining Metric Equivalents of Household Measures
  20. ↑ Bloomfield, HE; Kane, R; Koeller, E; Greer, N; MacDonald, R; Wilt, T (November 2015). “Benefits and Harms of the Mediterranean Diet Compared to Other Diets”. VA Evidence-based Synthesis Program Reports.. PMID 27559560. https://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0089086/pdf/PubMedHealth_PMH0089086.pdf. 
  21. ↑ “Nutrition and healthy eating: Fiber”. Mayo Clinic (2017年). . 18 November 2017閲覧.
  22. ↑ “Chemical composition and potential health effects of prunes: a functional food?”. Crit Rev Food Sci Nutr 41 (4): 251–86. (May 2001). doi:10.1080/20014091091814. PMID 11401245. 
  23. ↑ “Value of a tomato byproduct as a source of dietary fiber in rats”. Plant Foods Hum Nutr. 56 (4): 335–48. (2001). doi:10.1023/A:1011855316778. PMID 11678439. http://www.kluweronline.com/art.pdf?issn=0921-9668&volume=56&page=335. 
  24. ↑ Friedman G (September 1989). “Nutritional therapy of irritable bowel syndrome”. Gastroenterol Clin North Am. 18 (3): 513–24. PMID 2553606. 
  25. ↑ “Probiotics and prebiotics in chronic inflammatory bowel diseases”. World J. Gastroenterol. 12 (37): 5941–50. (October 2006). doi:10.3748/wjg.v12.i37.5941. PMC 4124400. PMID 17009391. オリジナルの13 September 2008時点によるアーカイブ。. https://web.archive.org/web/20080913162939/http://www.wjgnet.com/1007-9327/12/5941.asp. 
  26. ↑ Guarner F (April 2005). “Inulin and oligofructose: impact on intestinal diseases and disorders”. Br J Nutr 93 Suppl 1: S61–65. doi:10.1079/BJN20041345. PMID 15877897. http://journals.cambridge.org/abstract_S0007114505000826. 
  27. ↑ “An oral supplement enriched with fish oil, soluble fiber, and antioxidants for corticosteroid sparing in ulcerative colitis: a randomized, controlled trial”. Clin Gastroenterol Hepatol 3 (4): 358–69. (April 2005). doi:10.1016/S1542-3565(04)00672-X. PMID 15822041. 
  28. ↑ “Intestinal anti-inflammatory activity of dietary fiber (Plantago ovata seeds) in HLA-B27 transgenic rats”. Clin Nutr. 22 (5): 463–71. (October 2003). doi:10.1016/S0261-5614(03)00045-1. PMID 14512034. 
  29. ↑ (1997) Dynamics of Clostridium difficile infection. Control using diet, Advances in Experimental Medicine and Biology, 63–75. DOI:10.1007/978-1-4899-1828-4_8. ISBN 978-1-4899-1830-7. 
  30. ↑ “Short-chain fatty acids: bacterial mediators of a balanced host-microbial relationship in the human gut”. Wien. Klin. Wochenschr. 114 (8–9): 289–300. (May 2002). PMID 12212362. 
  31. ↑ “Differential effects of short-chain fatty acids on proliferation and production of pro- and anti-inflammatory cytokines by cultured lymphocytes”. Life Sciences 73 (13): 1683–90. (August 2003). doi:10.1016/S0024-3205(03)00490-9. PMID 12875900. 
  32. ↑ MacDermott RP (January 2007). “Treatment of irritable bowel syndrome in outpatients with inflammatory bowel disease using a food and beverage intolerance, food and beverage avoidance diet”. Inflamm Bowel Dis 13 (1): 91–96. doi:10.1002/ibd.20048. PMID 17206644. 
  33. ↑ Robertson, M. Denise; Wright JW; Loizon E; Debard C; Vidal H; Shojaee-Moradie F; Russell-Jones D; Umpleby AM (28 June 2012). “Insulin-sensitizing effects on muswcle and adipose tissue after dietary fiber intake in men and women with metabolic syndrome”. Journal of Clinical Endocrinology & Metabolism 97 (9): 3326–32. doi:10.1210/jc.2012-1513. PMID 22745235. 
  34. ↑ Kevin, Maki; Pelkman CL; Finocchiaro ET; Kelley KM; Lawless AL; Schild AL; Rains TM (April 2012). “Resistant starch from high-amylose maize increases insulin sensitivity in overweight and obese me”. Journal of Nutrition 142 (4): 717–23. doi:10.3945/jn.111.152975. PMC 3301990. PMID 22357745. http://jn.nutrition.org/content/142/4/717.long. 
  35. ↑ Johnston, KL; Thomas EL; Bell JD; Frost GS; Robertson MD (April 2010). “Resistant starch improves insulin sensitivity in metabolic syndrome”. Diabetic Medicine 27 (4): 391–97. doi:10.1111/j.1464-5491.2010.02923.x. PMID 20536509. 
  36. ↑ Phillips, Jodi; Muir JG; Birkett A; Lu ZX; Jones GP; O’Dea K (July 1995). “Effect of resistant starch on fecal bulk and fermentation-dependent events in humans”. American Journal of Clinical Nutrition 62 (1): 121–30. doi:10.1093/ajcn/62.1.121. PMID 7598054. http://www.ajcn.org/content/62/1/121.short. 
  37. ↑ Ramakrishna, BS; Venkataraman S; Srinivasan P; Dash P; Young GP; Binder HJ (February 2000). “Amylase-resistant starch plus oral rehydration solution for cholera”. The New England Journal of Medicine 342 (5): 308–13. doi:10.1056/NEJM200002033420502. PMID 10655529. 
  38. ↑ Raghupathy, P; Ramakrishna BS; Oommen SP; Ahmed MS; Priyaa G; Dziura J; Young GP; Binder HJ (2006). “Amylase-resistant starch as adjunct to oral rehydration therapy in children with diarrhea”. Journal of Pediatric Gastroenterology and Nutrition 42 (4): 362–68. doi:10.1097/01.mpg.0000214163.83316.41. PMID 16641573. http://journals.lww.com/jpgn/pages/articleviewer.aspx?year=2006&issue=04000&article=00004&type=abstract. 
  39. ↑ Ramakrishna, Balakrishnan S.; Subramanian V; Mohan V; Sebastian BK; Young GP; Farthing MJ; Binder HJ (2008). “A randomized controlled trial of glucose versus amylase resistant starch hypo-osmolar oral rehydration solution for adult acute dehydrating diarrhea”. PLoS ONE 3 (2): e1587. Bibcode 2008PLoSO...3.1587R. doi:10.1371/journal.pone.0001587. PMC 2217593. PMID 18270575. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2217593.  テンプレート:Open access
  40. ↑ James, S.. “P208. Abnormal fibre utilisation and gut transit in ulcerative colitis in remission: A potential new target for dietary intervention”. Presentation at European Crohn's & Colitis Organization meeting, Feb 16–18, 2012 in Barcelona, Spain. European Crohn's & Colitis Organization. . 25 September 2016閲覧.
  41. ↑ “Applications of inulin and oligofructose in health and nutrition”. J Biosci 27 (7): 703–14. (December 2002). doi:10.1007/BF02708379. PMID 12571376. http://www.ias.ac.in/jbiosci/dec2002/703.pdf. 
  42. ↑ Roberfroid MB (1 November 2007). “Inulin-type fructans: functional food ingredients”. J. Nutr. 137 (11 Suppl): 2493S–2502S. doi:10.1093/jn/137.11.2493S. PMID 17951492. http://jn.nutrition.org/cgi/pmidlookup?view=long&pmid=17951492. 
  43. ↑ “A combination of prebiotic short- and long-chain inulin-type fructans enhances calcium absorption and bone mineralization in young adolescents”. Am J Clin Nutr 82 (2): 471–76. (2005). doi:10.1093/ajcn.82.2.471. PMID 16087995. 
  44. ↑ “Effects of dietary fibers on magnesium absorption in animals and humans”. J Nutr 133 (1): 1–4. (2003). doi:10.1093/jn/133.1.1. PMID 12514257. 
  45. ↑ “Dietary inulin affects the expression of intestinal enterocyte iron transporters, receptors and storage protein and alters the microbiota in the pig intestine”. Br J Nutr 99 (Sep): 1–9. (2007). doi:10.1017/S0007114507825128. PMID 17868492. 
  46. ↑ Grabitske, Hollie A.; Slavin, Joanne L. (2009). “Gastrointestinal Effects of Low-Digestible Carbohydrates”. Critical Reviews in Food Science and Nutrition 49 (4): 327–60. doi:10.1080/10408390802067126. PMID 19234944. 
  47. ↑ Shepherd, Susan J.; Gibson, Peter R. (2006). “Fructose Malabsorption and Symptoms of Irritable Bowel Syndrome: Guidelines for Effective Dietary Management”. Journal of the American Dietetic Association 106 (10): 1631–39. doi:10.1016/j.jada.2006.07.010. PMID 17000196. 
  48. ↑ Liber, A.; Szajewska, H. (2013). “Effects of inulin-type fructans on appetite, energy intake, and body weight in children and adults: systematic review of randomized controlled trials”. Ann Nutr Metab 63 (1–2): 42–54. doi:10.1159/000350312. PMID 23887189. 
  49. ↑ “High-fiber diet supplementation in patients with irritable bowel syndrome (IBS): a multicenter, randomized, open trial comparison between wheat bran diet and partially hydrolyzed guar gum (PHGG)”. Dig Dis Sci 47 (8): 1697–704. (2002). doi:10.1023/A:1016419906546. PMID 12184518. 
  50. ↑ 50.0 50.1 50.2 Gallaher, Daniel D. (2006). Dietary Fiber. Washington, D.C.: ILSI Press, 102–10. ISBN 978-1-57881-199-1. 
  51. ↑ Keenan, M. J.; Martin, R. J.; Raggio, A. M.; McCutcheon, K. L.; Brown, I. L.; Birkett, A.; Newman, S. S.; Skaf, J. et al. (2012). “High-Amylose Resistant Starch Increases Hormones and Improves Structure and Function of the Gastrointestinal Tract: A Microarray Study”. Journal of Nutrigenetics and Nutrigenomics 5 (1): 26–44. doi:10.1159/000335319. PMC 4030412. PMID 22516953. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4030412. 
  52. ↑ Simpson, H. L.; Campbell, B. J. (2015). “Review article: dietary fibre–microbiota interactions”. Alimentary Pharmacology & Therapeutics 42 (2): 158–79. doi:10.1111/apt.13248. PMC 4949558. PMID 26011307. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4949558. 
  53. ↑ “Metabolic effects of dietary fiber consumption and prevention of diabetes”. J Nutr 138 (3): 439–42. (2008). doi:10.1093/jn/138.3.439. PMID 18287346. 
  54. ↑ Robertson, M. Denise; Currie JM; Morgan LM. Jewell DP; Frayn KN (2003). “Prior short-term consumption of resistant starch enhances postprandial insulin sensitivity in healthy subjects”. Diabetologia 46 (5): 659–65. doi:10.1007/s00125-003-1081-0. PMID 12712245. 
  55. ↑ Robertson, M. Denise; Bickerton AS; Dennis AL; Vidal H; Frayn KN (2005). “Insulin-sensitizing effects of dietary resistant starch and effects on skeletal muscle and adipose tissue metabolism”. The American Journal of Clinical Nutrition 82 (3): 559–67. doi:10.1093/ajcn.82.3.559. PMID 16155268. http://www.ajcn.org/cgi/content/full/82/3/559. 
  56. ↑ Zhang, Wen-qing; Wang Hong-wei; Zhang Yue-ming; Yang Yue-xin (March 2007). “Effects of resistant starch on insulin resistance of type 2 diabetes mellitus patients”. Chinese Journal of Preventive Medicine 41 (2): 101–04. PMID 17605234. 
  57. ↑ Johnston, KL; Thomas EL; Bell JD; Frost GS; Robertson MD (2010). “Resistant starch improves insulin sensitivity in metabolic syndrome”. Diabetic Medicine 27 (4): 391–97. doi:10.1111/j.1464-5491.2010.02923.x. PMID 20536509. 
  58. ↑ Maki, Kevin C.; Pelkman CL; Finocchiaro ET; Kelley KM; Lawless AL; Schild AL; Rains TM (April 2012). “Resistant starch from high-amylose maize increases insulin sensitivity in overweight and obese men”. Journal of Nutrition 142 (4): 717–23. doi:10.3945/jn.111.152975. PMC 3301990. PMID 22357745. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3301990. 
  59. ↑ Robertson, M. Denise; Wright JW; Loizon E; Debard C; Vidal H; Shojaee-Moradie F; Russell-Jones D; Umpleby AM (28 June 2012). “Insulin-sensitizing effects on muscle and adipose tissue after dietary fiber intake in men and women with metabolic syndrome”. Journal of Clinical Endocrinology & Metabolism 97 (9): 3326–32. doi:10.1210/jc.2012-1513. PMID 22745235. 
  60. ↑ ((EFSA Panel on Dietetic Products, Nutrition, and Allergies, European Food Safety Authority)) (2010). “Scientific Opinion on Dietary Reference Values for carbohydrates and dietary fiber”. EFSA Journal 8 (3): 1462. doi:10.2903/j.efsa.2010.1462. http://orbit.dtu.dk/en/publications/efsa-panel-on-dietetic-products-nutrition-and-allergies-nda-scientific-opinion-on-dietary-reference-values-for-carbohydrates-and-dietary-fibre(759dfd84-f9e3-4d0a-be84-b16650ea65de).html. 
  61. ↑ “Are functional foods redefining nutritional requirements?” (PDF). Appl Physiol Nutr Metab 33 (1): 118–23. (2008). doi:10.1139/H07-134. PMID 18347661. 27 February 2012時点によるアーカイブ。. テンプレート:Citation error. http://article.pubs.nrc-cnrc.gc.ca/ppv/RPViewDoc?issn=1715-5312&volume=33&issue=1&startPage=118. 
  62. ↑ Hermansson AM. Gel structure of food biopolymers In: Food Structure, its creation and evaluation.JMV Blanshard and JR Mitchell, eds. 1988 pp. 25–40 Butterworths, London.
  63. ↑ Rockland LB, Stewart GF. Water Activity: Influences on Food Quality. Academic Press, New York. 1991
  64. ↑ “Physical properties of dietary fibre that influence physiological function: a model for polymers along the gastrointestinal tract”. Am J Clin Nutr 55 (2): 436–42. (1992). doi:10.1093/ajcn/55.2.436. PMID 1310375. 
  65. ↑ Eastwood MA. The physiological effect of dietary fiber: an update. Annual Review Nutrition, 1992:12 : 19–35
  66. ↑ 66.0 66.1 Eastwood MA. The physiological effect of dietary fiber: an update. Annual Review Nutrition. 1992. 12:19–35.
  67. ↑ 67.0 67.1 Carey MC, Small DM and Bliss CM. Lipid digestion and Absorption. Annual Review of Physiology. 1983. 45:651–77.
  68. ↑ 68.0 68.1 68.2 “Do viscous polysaccharides reduce absorption by inhibiting diffusion or convection?”. Eur J Clin Nutr 42 (4): 307–12. (1988). PMID 2840277. 
  69. ↑ Schneeman BO, Gallacher D. Effects of dietary fibre on digestive enzyme activity and bile acids in the small intestine. Proc Soc Exp Biol Med 1985; 180 409–14.
  70. ↑ Hellendoorn EW 1983 Fermentation as the principal cause of the physiological activity of indigestible food residue. In: Spiller GA (ed) Topics in dietary fiber research. Plenum Press, New York, pp. 127–68
  71. ↑ “Cholesterol-lowering effects of dietary fiber: a meta-analysis”. Am J Clin Nutr 69 (1): 30–42. (1999). doi:10.1093/ajcn/69.1.30. PMID 9925120. http://ajcn.nutrition.org/content/69/1/30.full. 
  72. ↑ “Studies on the adsorption of bile salts to non-absorbed components of diet”. Biochim. Biophys. Acta 152: 159–66. (1968). doi:10.1016/0005-2760(68)90018-0. 
  73. ↑ Gillissen and Eastwood; Eastwood, Martin A. (1995). “Taurocholic acid adsorption during non-starch polysaccharide fermentation: an in vitro study”. British Journal of Nutrition 74 (2): 221–27. doi:10.1079/BJN19950125. 
  74. ↑ Boerjan, Wout; Ralph, John; Baucher, Marie (2003). “Ligninbiosynthesis”. Annual Review of Plant Biology 54: 519–46. doi:10.1146/annurev.arplant.54.031902.134938. PMID 14503002. 
  75. ↑ “Fiber”. MedlinePlus, US National Library of Medicine (2018年7月9日). . 27 July 2018閲覧.
  76. ↑ Gropper, Sareen S. (2008). Advanced nutrition and human metabolism, 5th, Cengage Learning. ISBN 978-0-495-11657-8. 
  77. ↑ Food and Nutrition Board, Institute of Medicine of the National Academies (2005). Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids (Macronutrients). National Academies Press, 380–82. 
  78. ↑ Spiller, Gene (27 June 2001). Influence of fiber on the ecology of the intestinal flora. CRC Press. ISBN 978-0-8493-2387-4. Retrieved on 22 April 2009. 
  79. ↑ Greger JL (July 1999). “Nondigestible carbohydrates and mineral bioavailability”. J. Nutr. 129 (7 Suppl): 1434S–35S. doi:10.1093/jn/129.7.1434S. PMID 10395614. 
  80. ↑ “Mechanisms underlying the effects of inulin-type fructans on calcium absorption in the large intestine of rats”. Bone 37 (5): 728–35. (November 2005). doi:10.1016/j.bone.2005.05.015. PMID 16126464. 
  81. ↑ “Inulin and oligofructose and mineral metabolism: the evidence from animal trials”. J. Nutr. 137 (11 Suppl): 2513S–23S. (Nov 2007). doi:10.1093/jn/137.11.2513S. PMID 17951495. 
  82. ↑ 82.0 82.1 Linus Pauling Institute at Oregon State University
  83. ↑ “Dietary fiber intake and mortality in the NIH-AARP Diet and Health Study”. Arch Intern Med 171 (12): 1061–68. (14 February 2011). doi:10.1001/archinternmed.2011.18. PMC 3513325. PMID 21321288. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3513325. 
  84. ↑ “Dietary fiber and whole-grain consumption in relation to colorectal cancer in the NIH-AARP Diet and Health Study”. Am J Clin Nutr 85 (5): 1353–60. (2007). doi:10.1093/ajcn/85.5.1353. PMID 17490973. http://ajcn.nutrition.org/content/85/5/1353.long. 
  85. ↑ “Dietary fiber and the risk of colorectal cancer and adenoma in women”. N Engl J Med 340 (3): 169–76. (January 1999). doi:10.1056/NEJM199901213400301. PMID 9895396. 
  86. ↑ Simons CCJM (October 2010). “Bowel Movement and Constipation Frequencies and the Risk of Colorectal Cancer Among Men in the Netherlands Cohort Study on Diet and Cancer”. Am J Epidemiol 172 (12): 1404–14. doi:10.1093/aje/kwq307. PMID 20980354. http://aje.oxfordjournals.org/content/early/2010/10/27/aje.kwq307.full. 
  87. ↑ Britt Burton-Freeman, Amgen, Incorporated, Thousand Oaks, CA. "Symposium: Dietary Composition and Obesity: Do We Need to Look beyond Dietary Fat?"
  88. ↑ Hooper, B; Spiro, A; Stanner, S (2015). “30 g of fibre a day: An achievable recommendation?”. Nutrition Bulletin 40 (2): 118–129. doi:10.1111/nbu.12141. 
  89. ↑ Suter PM (2005). Carbohydrates and dietary fiber, Handbook of Experimental Pharmacology, 231–61. DOI:10.1007/3-540-27661-0_8. ISBN 978-3-540-22569-0. 
  90. ↑ Aubrey, Allison (2017年10月23日). “The FDA Will Decide Whether 26 Ingredients Count As Fiber” (英語). National Public Radio. https://www.npr.org/sections/thesalt/2017/10/23/558761819/the-fda-will-decide-if-these-26-ingredients-count-as-fiber . 2017閲覧. 
  91. ↑ Health claims: fruits, vegetables, and grain products that contain fiber, particularly soluble fiber, and risk of coronary heart disease. Electronic Code of Federal Regulations: US Government Printing Office, current as of 20 October 2008
  92. ↑ Health claims: fiber-containing grain products, fruits, and vegetables and cancer. Electronic Code of Federal Regulations: US Government Printing Office, current as of 20 October 2008
  93. ↑ 93.0 93.1 “Nondigestible oligo- and polysaccharides (dietary fiber): their physiology and role in human health and food”. Comp Rev Food Sci Food Safety 3 (3): 73–92. (2002). doi:10.1111/j.1541-4337.2002.tb00009.x. 
  94. ↑ “Protein, fiber and blood pressure: potential benefit of legumes”. Clin Exp Pharmacol Physiol. 35 (4): 473–76. (April 2008). doi:10.1111/j.1440-1681.2008.04899.x. PMID 18307744. 
  95. ↑ “Water-soluble dietary fibers and cardiovascular disease”. Physiol. Behav. 94 (2): 285–92. (May 2008). doi:10.1016/j.physbeh.2008.01.001. PMID 18302966. 
  96. ↑ “What Is Constipation?”. WebMD (2017年). . 19 November 2017閲覧.
  97. ↑ AACC International. “The Definition of Dietary Fiber”. 2007年9月28日時点のオリジナルよりアーカイブ。. 2007閲覧.
  98. ↑ 98.0 98.1 “Colonic health: fermentation and short chain fatty acids”. J Clin Gastroenterol 40 (3): 235–43. (March 2006). doi:10.1097/00004836-200603000-00015. PMID 16633129. http://meta.wkhealth.com/pt/pt-core/template-journal/lwwgateway/media/landingpage.htm?an=00004836-200603000-00015. 
  99. ↑ “Short-chain fatty acids and total parenteral nutrition affect intestinal gene expression”. J Parenter Enteral Nutr. 26 (3): 145–50. (2002). doi:10.1177/0148607102026003145. PMID 12005453. 
  100. ↑ “Short-chain fatty acids: ready for prime time?”. Nutr Clin Pract. 21 (4): 351–66. (August 2006). doi:10.1177/0115426506021004351. PMID 16870803. http://ncp.sagepub.com/cgi/pmidlookup?view=long&pmid=16870803. 
  101. ↑ “Prebiotics, probiotics, and synbiotics affect mineral absorption, bone mineral content, and bone structure”. J. Nutr. 137 (3 Suppl 2): 838S–46S. (1 March 2007). doi:10.1093/jn/137.3.838S. PMID 17311984. http://jn.nutrition.org/cgi/pmidlookup?view=long&pmid=17311984. 
  102. ↑ 102.0 102.1 102.2 FDA/CFSAN A Food Labeling Guide: Appendix C Health Claims, April 2008
  103. ↑ Soluble Fiber from Certain Foods and Risk of Coronary Heart Disease, U.S. Government Printing Office, Electronic Code of Federal Regulations, Title 21: Food and Drugs, part 101: Food Labeling, Subpart E, Specific Requirements for Health Claims, 101.81 [1]
  104. ↑ “Petition for a Health Claim for High-Amylose Maize Starch (Containing Type-2 Resistant Starch) and Reduced Risk Type 2 Diabetes Mellitus (Docket Number FDA2015-Q-2352)”. Office of Nutrition and Food Labeling, Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration (2016年12月12日). . 22 March 2018閲覧.

テンプレート:Phytochemicals テンプレート:Carbohydrates テンプレート:Dietary supplement テンプレート:Diets



「http:///http:///mymemo.xyz/mymemo.xyz/wiki/index.php?title=Dietary_fiber&oldid=276998」から取得