WO1994001122A1

WO1994001122A1 - Food composition containing soluble fiber and taurine and method to lower serum cholesterol

Info

Publication number: WO1994001122A1
Application number: PCT/US1993/006399
Authority: WO
Inventors: Kenneth C. Hayes
Original assignee: Brandeis University
Priority date: 1992-07-14
Filing date: 1993-07-07
Publication date: 1994-01-20
Also published as: AU4667493A

Abstract

This invention provides for a food product enriched with a composition of taurine and a soluble fiber, i.e., psyllium, wherein the soluble fiber is present in an amount ranging from about 2 wt.% to about 30 wt.%, based on the dry weight of the composition. Ready-to-eat cereals and other grain-based foods and beverages can be produced with taurine and psyllium components. The concentration of taurine to be administered should be approximately 100 to 1000 mg/day or alternatively at least 0.003 % of the food product. The concentration of soluble fiber in the finished product should be at least 2 % by dry weight basis and preferably no more than 25 - 30 % by dry weight basis, more preferably about 5 to about 19 % and most preferably from 11 to about 14 %.

Description

Food Composition Containing Soluble Fiber and Taurine and Method to Lower Serum Cholesterol

FIELD OF THE INVENTION

This invention relates to food products enriched with a composition containing taurine and soluble fiber. The composition may be administered to humans and animals susceptible to or afflicted with hypercholesterolemia to lower serum cholesterol. The invention also relates to the production of food products, including but not limited to breakfast cereals, and assorted grain-based products, in which the combination of soluble fiber, such as psyllium, and taurine, incorporated in the product, operates to increase bile acid excretion and to lower serum cholesterol.

BACKGROUND OF THE INVENTION

The liver plays a central role in the metabolism of cholesterol. It is the primary site of cholesterol metabolism and the principal organ modulating cholesterol excretion from the body. A portion of cholesterol in the liver is converted to highly polar bile acids, which are thereafter secreted into bile. The ability of the bile acids to solubilize cholesterol in bile is a primary mechanism by which to ensure optimal cholesterol metabolism and elimination from the body.

It is well known that the use of bile acid sequestrants, such as cholestyramine, result in a decline in plasma cholesterol. Bertolotti et al., Hepatology 14: 830-837, 1991. It is documented that the interruption of the enterohepatic circulation of bile acids by cholestyramine influences the hepatic metabolism of cholesterol. It was observed that removal of bile acids enterically results in a decline in plasma cholesterol. Moreover, the synthesis of bile acids is increased with the administration of cholestyramine, as seen by the increase in 7α hydroxylase, a rate limiting enzyme for bile acid synthesis. The increased metabolism of cholesterol to bile acids causes an enhanced demand for cholesterol in the liver cells. In response to the demand for cholesterol in the liver, cholesterol synthesis and the expression of LDL receptors is increased. As a result, the plasma level of LDL cholesterol is lowered. Einarsson et al., Eur. J. Clin Pharmacol. (1991) 40(Suppl 1): S 53 - S 58.

Therefore an agent which could increase bile acid removal was envisioned as a potential means of decreasing LDL cholesterol. Hardison et al., Gastroenterology, Vol. 84, p.617-620 (1983). It is known that taurine-supplemented diets increase bile acid conjugation in humans. It is also known that taurine can stimulate bile acid synthesis in guinea-pigs, Kibe et al., Lipids, Vol. 15, No. 4, p.224-229 (1979) and in hamsters, Bellentini et al., J. Lipid Res., Vol. 28, p.1021-1027 (1987).

It is also well known that psyllium, a mucillaginous material isolated from plant seeds of the Plantago genus, decreases plasma triglycerides and LDL cholesterol, especially in humans and hamsters. The specific use of a psyllium hydrophilic mucilloid to lower cholesterol in serum was documented by Anderson et al., Arch. Intern. Med. Vol. 148, Feb 1988, 292-296 (1988), Anderson et al., Am J. Clin Nutr. Vol.56, p. 93-98, July 1992. It has been theorized that psyllium, which belongs to a class of gel forming soluble fibers, disrupts the absorption or metabolism of cholesterol by binding, entrapping, absorbing, or otherwise interfering with the reabsorption of bile acids across the intestinal lumen. It is also theorized that the soluble fiber interferes with the intraluminal formation of micelles, resulting in decreased cholesterol and bile acid reabsorption. The end result is that more bile acids and dietary cholesterol are ultimately excreted in the feces, resulting in a decreased level of serum cholesterol.

Psyllium was also found to remove primarily taurine- conjugated bile acids relative to glycine-conjugated bile acids, thus disrupting the balance of taurine-conjugated and glycine-conjugated bile aids. See Table 1. To restore the balance, the liver increases total bile acid synthesis. The preference of psyllium for taurine conjugates reveals that a means for increasing taurine-conjugated bile acids would enhance the total removal of bile acids during psyllium consumption. Although humans primarily produce glycineconjugated bile acids, it was observed that with taurine supplemented diets, bile acid conjugation with taurine in humans and other animals can be enhanced. Truswell et al., J. Atheroscler. Res., 5, p. 526-532 (1965). Taurine becomes preferentially conjugated to bile acids causing a partial depletion of hepatic cholesterol, enhancement of hepatic LDL receptor activity, and consequently a decrease in serum cholesterol. The increase in taurine-conjugated bile acids facilitates the action of psyllium in removing bile acids from the body.

Therefore, it has been found that the therapeutic use of the combination of taurine and a soluble fiber, such as psyllium, in a dietary composition or supplement results in an enhanced hypocholesterolemic effect which is advantageous in preventing cardiovascular disease.

It is therefore a principal object of this invention to provide for an effective and economically produced food composition comprising taurine and a soluble fiber which, when consumed in effective amounts, lowers serum cholesterol.

It is also an object of this invention to provide a method to increase bile acid removal allowing for a method of decreasing serum LDL. With the ability to remove LDL in the plasma, the risk of coronary heart disease and atherosclerosis may be decreased and potentially reversed.

It is a further object of this invention to provide for a food composition containing taurine and a soluble fiber which is palatable and suitable for human consumption in a food product while providing the benefits of lowered serum cholesterol levels.

SUMMARY OF THE INVENTION

This invention provides for a food product enriched with a composition of taurine and a soluble fiber, wherein the soluble fiber is present in an amount ranging from about 2 wt.% to about 30 wt.%, based on the dry weight of the composition.

Taurine may be incorporated into the food product in a number of ways. Ready-to-eat cereals and other grain-based foods and beverages can be produced with taurine and psyllium components. The concentration of taurine to be administered should be approximately 100 to 1000 mg/day or alternatively at least 0.003% of the food product.

The concentration of soluble fiber in the finished product should be at least 2% by dry weight basis and preferably no more than 25 - 30% by dry weight basis. Soluble fibers useful for this invention include psyllium, pectin, galactomannan, carrageenan, alginate, xanthan, guar, gum arabic, tragacanth and soluble cellulose.

Preferably, the soluble fiber concentration should be about 2 to about 30%, and more preferably about 5 to about 19% and most preferably from 11 to about 14%. It has been found that a ready-to-eat cereal, high fiber bars, high fiber puffs, cookies, and high fiber beverages containing soluble fiber, such as psyllium within the above ranges have good flavor and textural characteristics and are acceptable to the human palate. Concentrations above 30% typically exhibit a slimy mouthfeel and would not be appropriate for human consumption. DETAILED DESCRIPTION OF THE INVENTION

Food products supplemented with taurine and soluble fiber are particularly suited for incorporation into grain-based products, such as ready-to-eat dry cereals. In ready-to-eat dry cereals, the soluble fiber should be incorporated so that the product has a fiber content ranging from about 2 to about 30%, more preferably from about 5 to about 19%, and most preferably from 11 to about 14%, based on the dry weight of the food product.

Due to the mucillaginous nature of psyllium, it acquires a slimy or adhesive texture and mouthfeel upon hydration. In addition, psyllium develops a distinctive, undesirable flavor in the presence of heat and moisture which further limits its use in food products. However, various psyllium-containing food products have been proposed which promote natural bowel function, or the satiating or fullness-feeling effect. See, e.g. U.S. Patent Nos. 3,574,634 and 4,348,379, the disclosures of which are incorporated by reference.

In addition to use of soluble fiber as a hypocholesterolemic agent, the food industry has often used as little as 1%, as a thickener in products such as ice cream, puddings, yogurt and the like.

The taurine should be incorporated into the food product so that the taurine is present in an amount ranging from approximately 100 to 1000 mg per ingestion.

In general, the taurine and soluble fiber can be added to grain-based foods. A wide variety of ingredients used in grain-based food production can be combined with the taurine in accordance with the present invention. These ingredients include, but are not limited to: whole grains such as whole wheat, rice, oats, barley, corn and rye etc.; grain components such as germs and brans including oat bran, wheat bran, etc.; flour such as wheat flour, corn flour, etc.; legumes such as soybeans, peas, beans and the like; and non-bran fiber sources such as prune fiber, guar, beet fiber and citrus pulp and other raw material ingredients which can conventionally be included in grain-based food products, such as ready-to-eat cereals, high fiber bars, high fiber puffs, cookies and high fiber beverages.

The process of the invention also includes lowering serum cholesterol levels by increasing the bile acid excretion by consuming a dietary composition of the invention, where the taurine is preferentially conjugated with bile acids and excreted with psyllium leading to a partial depletion of hepatic cholesterol and therefore a decrease in serum cholesterol.

While humans can produce either taurine or glycine- conjugated bile acids, humans primarily produce glycine- conjugated bile acids. However, this phenomenon may result from the fact that taurine is not readily synthesized by humans and is not currently considered an essential amino acid in humans; thus taurine is not present in the body at high levels. With the addition of taurine and psyllium to the daily diet, the bile acids become preferentially conjugated to taurine and can then be excreted with psyllium.

Although psyllium is known to have a hypocholesterolemic effect, it was surprisingly found that the use of taurine in combination with psyllium resulted in an accentuated decrease in serum LDL cholesterol.

This invention will be better understood by reference to the following examples, which are included here for purposes of exemplification and are not to be construed as limitations.

Example 1

The following ingredients are incorporated into a ready-to-eat cereal:

Bulk ingredients %Dry basis wt.

heavy wheat bran 50.23 oat bran 12.20 sugar 8.13 beet fiber 2.44 prune powder 2.42 rice flour 2.11

42% HFCS (high fructose corn syrup) 1.63 salt 0.89 barley malt syrup 0.81 guar gum 0.09 calcium carbonate 0.08 trisodium phosphate 0.05 caramel color 0.04

Psyllium-containing additive

75% Psyllium husks 11.63

15% oat bran 2.33

5% sucrose 0.78

5% rice flour 0.78

Coating

sucrose 2.00 honey 1.00 salt 0.20

Taurine*

500 mg per serving 0.18

* Taurine , a water-soluble , tasteless , free amino acid , can readily be incorporated into any food product.

The bran flake ready-to-eat cereal in the above table is prepared in the following manner. The bulk dry ingredients are first mixed and then the flavoring ingredients sugar, salt, color HFCS, and malt syrup, which had previously been diluted with warm water, are added in a rotating cooker. The bulk ingredients are then cooked for 65 minutes at 17 psi at standard cooking temperatures. Thereafter, the psylliumcontaining intermediate nuggets having the composition set forth in the table and the taurine component, are blended with the bran in a mixer. The blended mixture is then milled with a Fitz mill and pelleted, and the pellets are dried to a moisture content of 20%. The product is then tempered hot for 30 minutes, flaked and toasted at 370°F. The finished flakes have a food moisture content of 3%. The product has a crispy texture, desirable appearance and acceptable flavor.

Example 2

Test subjects with moderate hypercholesterolemia are recruited for the study. The following amounts are administered orally on a daily basis from a variety of food formulations:

1) taurine at doses of 100, 400, or 1000 mg/day

2) psyllium at doses of 10, 15, 25 gms/day

3) combinations of taurine and psyllium within the ranges set forth in 1) and 2).

The following measurements are taken from the subjects on a weekly basis: levels of plasma LDL/HDL cholesterol, total cholesterol and triglycerides and plasma bile acid profiles are measured. Each individual is randomly rotated through all three treatments at six week intervals to determine the significance of the combined taurine and psyllium effect as compared to the individual supplements.

The results of the experiment show that the ingestion of taurine alone has no effect on plasma lipids. Psyllium treatment alone lowers plasma cholesterol in a dose- response manner and by about 10% to 15% at 25 gms/day treatment and will improve the HDL/LDL ratio.

However, treatment with the combination of taurine in amounts greater than or equal to 400 mg/day and psyllium at amounts greater than or equal to 15 gms/day decreases plasma cholesterol in amounts greater than psyllium alone, generally about 20% to 25%, and has a greater positive impact on the HDL/LDL ratio.

It is also possible that the hypocholesterolemic effect of combined treatment of taurine and psyllium may be present at lower concentrations. Therefore, the concentrations set forth in this example should not be construed as limitations.

Further, it is believed that other ingredients, such as fruit compositions, nuts, to add flavor, and/or texture can be added to the food product of the present invention without departing from the spirit and scope of the invention. Further, it is not intended that the present invention be limited to only the described embodiments. Modification of these embodiments will be recognized by those skilled in the art. Rather, the invention should be circumscribed by the scope of the appended claims.

Table 1

Individual bile acid profile in gallbladder bile from hamsters fed a gallstone diet or that diet supplemented with 5% psyllium or 1% cholestyramine.

Diet

Basal Gallstone Psyllium Cholestyramine a per group 6 8^† 11 12

mM

Taurocholste 38.2± 13.4 13.1±8.0^a 19.6±16.4^b 42.4±20.6^a,b

Clycocholate 27.1±9.0 7.5±5.4^a,b 34.1±24.1^a 41.4±17.5^b

Taurochenodeoxycholate 27.0±10.2 29.7±1618^a 20.0±22.1 4.8±3.2^a

Clycochenode oxycholate 19.2±3.6 13.6±16.0 17.9±11.5^a 3.0±1.7^a

Taurodeoxycholate 5.0±2.4 1.4±1.0^a 5.8±1.2 9.1±5.3^a

Glycodeoxycholate 1.3±1.9 2.6±2.1 5.6±2.8 6.4±4.1 percent distribution

Taurocholate 32±6 20±6^a 17±7^b 41±1 1^a,b

Clycocholate 24±8 12±5^a,b 33±6^a 38±8^b

Taurochenodeoxycholate 23±7 46±8^a,b 15±10^a,c 4±1_b,c

Glycochenodeoxycholate 17±4 15± 10^a 21±14^b 3±1^a,b

Taurodeoxycholate 4±2 1±1^a,b 5±3^a,c 8±3^{b, c}

Glycodeoxycholate 1±2 5±4 9±8 6±4

ratios

Cholate:Cheno 1.4±0.2 0.5+0.2^a 1.6±0.7^b 12.3±3.3^a,b

Glycine:Taurine 0.8±0.4 0.5±0.3^a 2.4±2.0^a,b 1.0±0.4^b

1°;2° bile acids 21.6±10.7 18.3±11.8^a,b 8.0±4.9^a 6.8±2.6^b

Hydrophobldry index +0.2410.02 +0.3410.04^a,b +0.28±0.05^a,c +0.14±0.03^b,c

Values are mean ±SD.

a,b Means tharing a common superscript are significantly difTertnt (ρ<0.05) using one-way ANOVA and Scheffe's F-test.

† Due to the presence of gallstones gallbladder bile samples could not be obtained from 4 hamsters.

Claims

1. A food composition for human or animal consumption which lowers serum cholesterol comprising a pharmaceutically effective amount of taurine in combination with a soluble fiber material.

2. The composition of claim 1, wherein the serum cholesterol is VLDL cholesterol.

3. The composition of claim 1, wherein the serum cholesterol is LDL cholesterol.

4. A composition of claim 1, wherein the soluble fiber is selected from the group consisting of psyllium, pectin, galactomannan, carrageenan, alginate, xanthan, guar, gum arabic, tragacanth and a soluble form of cellulose.

5. A composition of claim 1, wherein taurine is present in about 100 to about 1000 milligrams per serving.

6. A composition of claim 1, wherein the soluble fiber is present from about 2 to about 30% by weight of food product.

7. A food composition of claim 1, wherein the soluble fiber and taurine are combined in a food product selected from the group consisting of a grain-based product and a high fiber beverage.

8. A composition of claim 7, wherein the grain-based product is selected from the group consisting of a breakfast cereal, a high fiber bar, a high fiber puff, and a cookie.

9. A method for lowering serum cholesterol levels comprising orally administering to a human or animal susceptible to or afflicted with hypercholesterolemia, the food composition of claim 1.

10. The method of claim 10, wherein the serum cholesterol is VLDL cholesterol.

11. The method of claim 10, wherein the serum cholesterol is LDL cholesterol.

12. A method of claim 10, wherein the food composition contains a soluble fiber selected from the group consisting of psyllium, pectin, galactomannan, carrageenan, alginate, xanthan, gum arabic, guar, tragacanth and a soluble cellulose.

13. A method of claim 10, wherein said food composition contains taurine in an amount from about 100 to about 1000 milligrams per serving.

14. A method of claim 10, wherein the food composition contains soluble fiber in an amount from about 2 to about 30% by weight thereof.

15. A process of lowering serum cholesterol levels and reducing the incidence of associated cardiovascular disease comprising increased bile acid excretion of a subject in need thereof by administering the food composition of claim 1, in an amount sufficient to preferentially conjugate bile acids with taurine and provoke excretion thereof with psyllium contained in said food composition.

16. A process of lowering serum cholesterol levels in a subject comprising removing taurine-conjugated bile acids of said subject by administering an amount of psyllium sufficient to remove said taurine-conjugated bile acids.

17. A ready-to-eat cereal product comprising at least one cereal ingredient as a major component, at least 2% by dry weight soluble fiber and at least 0.003% by weight taurine.

18. The ready-to-eat cereal of claim 18, wherein the cereal ingredient is selected from the group consisting of whole wheat, rice, oats, barley, corn, rye, wheat germ, oat bran, wheat bran, wheat flour, corn flour, legumes, prune fiber, guar, beet fiber and citrus pulp.

19. The ready-to-eat cereal of claim 18, wherein the soluble fiber is selected from the group consisting of psyllium, pectin, galactomannan, carrageenan, alginate, xanthan, gum arabic, tragacanth and a soluble form of cellulose.