J. Baqai Med. Univ. Vol. 3, No. 1 & 2, Jan - Jun; July - Dec 2000 : 35-37

IMPACT OF CEREALS ON HEALING COMMON DISEASES

Rashida AlY

Abstract

The Cereals, major part of the diet have demonstrated their effective contribution in controlling the nutritional deficiency diseases. Cereal products also play the key role in decreasing ailments due to the over consumption of the calories and the ill impacts of the intake of the unbalanced diet. Thus fortification, enrichment, modification and nutrification has further upgraded the status of cereal products in healing the diet-borne-diseases. The role of the insoluble fibers of the rice bran has been found significant in decreasing blood cholesterol with reference to LDL (Low Density Lipoprotein) to reduce the risk of the cardiovascular disease. The cereal fibers from different grains are known to heal gall stone, gastro-intestinal ailments, cancers, allergies, diabetes, coronary heart diseases (CHD) obesity and other disorders due to over weight. The 8-glucan or the soluble fiber of the oats has shown multiple positive physiological responses in overcoming chronic and simple ailments. The specific components of the rye, barley, wheat and corn have been identified in extending the beneficial effects to cure certain diseases. The present review deals with the machnism of the active components of the cereals in the treatment of the common diseases of the modern age.

Introduction

The bran of the cereals is full of nutrients and comprises approximately 8- 14% of the kernel. A modern serving of the rice bran provides half of the RDA for magnesium. The whole grain or the bran consists of numerous such active components which take part either in curing the diseases directly or reduce the risk of many ailments indirectly. Some of these biologically active primary or secondary metabolites such as the dietary fibers, bran oil, flavonoids, carotenes, bran proteins, minerals, vitamins and other natural antioxidents responsible for prevention and control of the diseases are briefly discussed here.

The bran is composed of 12-30% fat, 6-32% fiber, 8-18% ash, 11-17% protein and 1-10% of the available carbohydrates1. The micro ingredients include non saponifiable matter as sterols, terpenes, vitamins (fat soluble) and other antioxidents. Althrough endosperm is the larger portion of the cereals, the present discussion is limitted to the bran only because of the high concentration of the nutrients localized in the outer skin and to emphasize the ignorance about the medicinal value of the bran. Unfortunately the cereals in Pakistan are generally consumed free of bran due to the unawareness about the high nutritive value of the cereal components.

Fiber

The fiber consisting of both soluble and insoluble portion is the major component of the bran ranging fiom 6-32%l. The soluble (SF) and insoluble fibers (IF) consisting mostly hemicelluloses and celluloses respectively play significant part in controlling variety of the diseases. The SF of the bran are D-D-glucan composed of glucose units linked at 1-3, 1-4 carbons shows high water absorption capicity (WAC). The increased fluid viscosity facilitate reducation in serum cholesterol level. The IF are found efficient in catching the bile acids in the GI which emulsifL the fat for further metabolism. As the cholesterol is synthesised from fat, its concentration in blood is lowered. The cholesterol also gets converted into bile acids in hypobileacid condition. Thus hypocholesterolemic activity of the both kinds of the fibers involves complex mechnism2". In the absence of the lipids the process of the formation of the LDL (Low Density Lipoprotein) and HDL (High Density Lipoprotein) also slows down the synthesis of LDL which is more adversely affected'l~~~. The wheat, rice, barley and oat brans have similar effects in controlling the blood cholesterol fat and LDL levels6,' in th serum.

* Professor of Nutrition and ~ o o d Technology, Faculty of Health Sciences, Baqai Medical University, Karachi.

Vol. 3, No. 1 & 2, Jan - Jun; July - Dec 2000 Rashida Ali J. Baqai Med. Univ.

Anticarcenogenic behavior

The research in the last few decades has shown that the fiber rich diet has reduced the risk of breast ~ance r '~ ,~" while butyrates produced in the fiber degration in the large intestine by colonic becteria have recently been recognised as cancer inhibiting corn pound^'^.'^. The appropriate ratio between soluble and insoluble fiber is essential to absorb the carcinogens otherwise the protective effect of the fiber may not be effective. The GI disorders as consitipation, diarrhea, reduction in the bowel transit time; rapid fecal expell, diverticulitis etc. are gradually healed with the constant intake of the htgh fiber dietla.

Bran Oil

Rice bran oil is an excellent supplement food in the quality where palmitic, oleic and linoleic acid represent 95% of the fatty acid8. Rice bran wax with logn chain fatty acid and high melting point is a good coating agent for nuts, fruits and vegetables9. Although rice bran oil is rich in oleic (monounsaturated fatty acid) and lenoleic acids (the essential polyunsaturated fatty acid) the hypocholesterolemic property is beleieved to be realted to the unsaponifiable matter (UM) of the lipids'". The UM consists of several phytosterols and triterpene alcohols which decreases cholesterol absorption and enhances the excretion of the bile acids in the stools, as both of the activities are against CHD",'2 the rice bran oil is now thought as a superior thereupeatic food. The oryzanols particullarly Gama oryzanols and tocotrienols promote transfer of LDL cholesterol from blood to liver for further out let1'J4.

The qualititative and quaititative status of the rice bran proteins has been widely accepted recently and they are included in the diet for f~rtification~~.

Antidiabetic Activity

The B-glucan fractions of the oat and other bran have the unique property of increasing the viscosity of the gut fluid or the luminal viscosity which directly effects the nutrient's absorbtion and the glucose entery in the blood also slows down. The soluble fibers thus keeps the blood glucose and insulin level at the lower ~ide'~.~'?.

The bran being rich in minerals is a good natural resource of the magnesium - a blood pressure - modulator which also promotes the synthesis of vitamin D. The bran also

supplies phosphorus, iodine and selenium in the reasonable quantity.

Conclusion

The rapid developments in focussing the hnctional and nutraceutical properties of the biologically active components of the common cereals as the potent health promoters appear as the most dynamic tool for natural h e a l h ~ g ~ ~ , ~ ~ . The research interests of the nutritionists, food scientists, and processers in recognizing the cereals as the medicinal food is justified inview of the fact that about 60% of the daily calories requirement are supposed to be provided by the cereals according to the concept of the balance diet. The elaboration and elucidation of the benefical impact of multigrain has also enhanced the consumption of variety of cereals in the developed part of the world. However more research input is needed to pronounce the effects of interaction of nutrients at molecular level. Never the less at this stage it can be easily concluded that advanced cereal reseach shoud exaccrbate the beneficial impact on human health.

References

1. Wells, JH, Utilization of rice bran and oil in human diets, Louisiana Agriculture 1993, 36(3); 5-8.

2. Hegsted M, and MM Windhauser, Reducing human heart disease risk with rice bran, Louisiana Agriculture, 1993, 36(3); 22-24.

3. Normand FL, RL Ory and RR Mod, Binding of bile acids and trace minerals by soluble hemicelluloses of rice, Food Technol, 1987,41; 86-99.

4. Kahlon TS, FI Chow and RN Sayre, Cholestrol- lowering properties of rice bran, Cereal Foods World, 1994,39(2); 99- 103.

5. Jansen GR. A consideration of allowable fiber level in weaning foods, Food Nutrition Bull, 1980, 2(4) 38-48.

6 . Mclntosh GH, J Whyte, R McArthur and PI Nestle, Barley and wheat foods, influence on plasma cholesterol concentrations in hypercholesterolemic men, Am J Clin Nutr, 1991, 53; 205-1209.

7. Pasquier B, M Armand, F Guyon, C Castellain and D Lairon, Soluble fibres their alter emulsification of

Vol. 3, No. 1 & 2, Jan - Jun; July - Dec 2000 Rashida Ali J. Baqai Med. Univ.

dietary fat in vitor, Proceedings of the European workshop on Mechanisms of Action of Dietary Fibre on Lipid and Cholesterol Metabolism, D Lairon, Luxembourg, Commission of the European Communities, 1994, 45-47.

8. Sayre Rn, Rice bran as a source of edible oil and higher value chemicals, presented at the American Association of Cereal Chemists 73rd. Annual Meeting, October 12, 1988, San Diego, California, 1988, 1-11.

9. Sayre RN and RM Saunders, Rice bran and rice bran oil, Lipid Technology, 1990,2(3) 72-76.

10. Nicolosi RJ, LM Ausman and DM Hegsted, Rice bran oil lowers serum total and low density lipoprotin cholesterol and apoB levels in nonhuman primates, Atherosclerosis, 1991, 88 133-142.

1 1. Hegsted M and CS Kousik, Rice bran and rice bran oil may lower heart disease risk by decreasing cholesterol synthesis in the body, Louisiana Agriculture, 1994, 37(2) 16-1 7.

2. Rogers EJ, SM Rice, RJ Nicolosi, DR Carpenter, CA Mc Clelland and LJ Romanczyk, Identification and pointitation of Gamaoryzanol components and simultaneous assessment of tocols in rice bran oil, JAOCS, 1993 70,301-307.

13. Rukmini C and CT Raghuram, Nutritional and biochemical aspects of the hypolipidemic action of rice bran oil, A review, J AM College Nutr. 1991, 10, 3661-3669.

14. Qureshi N and A A Qureshi, Tocotrienols, Novel hypochoesterolemic agents with antioxidant properties, Vitamin E in Health and Disease, L Packer and J Fuchs, New Your, NY, Marcel Decker Inc, 1993, 247-267.

15. Baghurst PA, TE Rohan, High-fiber diet and reduced risk of breast cancer, Int J cancer, 1994, 56, 173- 176.

16. Harris PJ, AM Robertson, ME Watson, CM Triggs and LR Ferguson, The effects of soluble-fibre polysaccharides on the adsorption of a hydrophobc carcinogen to an insoluble fibre, Nutr. Cancer, 1993, 19 43-45.

17. Mclntyre APR, Gibson and G P Young, ~utyrate

production from dietary fibre and protection against large bowel cancer in a rat model, Gut, 1993,34 386- 391.

18. Firshein R, Nutraceutical Revolution, The Berkley Publishing group, 1999, 132- 140.

19. Edwards CA, N A Blackburn, L Craigen, P Davison, J Tomlin, K Sugden, IT Johson and NW Rad, Viscosity of food gums determined in vitro related to their hypoglycemic actions, Am J clin, Nutr., 1987, 46; 72-77.

20. Jenkins DJA, AL Jenkins, T MS Wolever, V Vuksan, A V Rao, L U Thompson and RG Josse, Dietary fibre, carbohydrate metabolism and diabetes, Dietary Fibre in Health and Diseases, D Kritchersky and C Bonfield, ST Paul, MN, Eagan Press, 1995, 137- 145.

21. Blake DE, CJ Hambleu, PG Frost, PA Judd and PR Ellis, Wheat bread supplemented with depolymerized guar gum reduces the plasma cholesterol concentration in hypercholesterolemic human subjects, AM J Clin, Nutr. 1997, 65 107- 1 13.

22. Dubosis C, M Armand, M Senft, H Portugal, A M Pauli, PM Renard, H Lafont and D Latron, Chronic oat bran intake alters postprandid lipermia and liproteins in healthy adults, AM J Clin, Nutr., 1995, 61 325-333.

23. Mazza G, (ed) Functional Foods, Biochemical and Processing aspect, Technical Publishing Co, 1998,71- 89.

24. Goldberg I, ed, Functional Foods, ~ e s i ~ n e r Foods. Pharma Foods, Nutraceuticals, NY, Chapman & Hall, 1994.

25. Slavin J, Jacobs D, Marquat L, Whole-grain consumption and chronic disease: protective mechanisms, Nutr. Cancer, 1997, 27 14-2 1.

26. Hettiarachchy N, PS Landers, K Griffin and U Kalapathy, Utilization of rice bran proteins in food, Arkanas Rice Research Studies 1993, Wells, BR, ed, Fayetteville, AR, Arkansas Agricultural Experiment Station Research Series 439, 1994, 205-21 1.

27. Wyn EL, Gori GB, Contrbutions of the environment to cancer incidence, an epidemiological exercise. J Natl Cancer Inst, 1977, 58 825-832.