Currently available functional foods, foods with beneficial effects on consumer health, are targeted towards non-communicable human diseases.
The concept of functional foods will be modified by Nutrigenomics, the study of the interactions between nutrition and gene function.
Control of obesity, counteracting age-related diseases processes, and providing probiotics to improve digestive health are all possible applications for dairy-based functional foods.
Milk takes its place as a functional food
(Compiled by Milkproduction.com staff from presentations at Alltech’s 22nd Annual Symposium, Nutritional Biotechnology in the Feed and Food Industries)
Foods with beneficial effects on consumer health are known as functional foods (Dunshea, 2006). The majority of functional foods on the market today are targeted towards prevention of non-communicable human diseases. Current functional food products have as their main constituents; dietary fiber, probiotic cultures, minerals and vitamins, oligosaccharides, and unsaturated and omega fatty acids.
As the functional food concept matures, one logical extension is in the area of nutrigenomics. Nutrigenomics is the study of nutrition interacting with a human’s genes. Made possible by the human genome project, this area is in its infancy. Even so, evidence is already emerging that changes in nutritional status can lead to changes in gene expression with far reaching impacts on human health.
Milk is best know for its role in meeting calcium requirements; however, milk has great potential as a functional food. Milk contains a mixture of proteins with unique attributes for nutritional and biological applications. Additionally, whey contains glycomacropeptide (GMP) a bioactive peptide formed by the cleavage of kappa-casein with chymotrypsin during curd formation.
A role for dietary proteins in the regulation of food intake and weight maintenance has been proposed. Specific peptides, such as CMP, may have a direct satiating effect. A recent study at the National Center of Excellence in Functional Foods (Werribe, Victoria, Australia) was conducted with obese minipigs, an excellent model for human nutrition studies (Dunshea et al., 2005, Dunshea, 2006). A high protein diet was shown to reduce diet intake, weight gain, fat deposition and insulin resistance. Enriching the high protein diet with CMP containing whey isolates resulted in the greatest effect on voluntary intake and weight gain.
Selenium is a trace mineral with a long history in nutrition. Initially classified as a toxic compound, in 1957 selenium was recognized as an essential trace element. Further research has shown that levels required to avoid deficiencies are not sufficient for optimal health of domestic livestock species (Schrauzer, 2006). In fact, the US Recommended Dietary Allowance is likely to be increased in the near future. Initially supplemented for its anti-oxidant properties, selenium has now been found to dramatically effect the expression of number of genes involved in aging, as well as Alzheimers disease. A wide variety of human disease states are associated with low plasma, serum, or tissue selenium levels. In fact, the US Food and Drug Association (FDA) has recently allowed the following health claim for selenium; “may reduce the risk of certain forms of cancer”.
Selenium incorporated into milk proteins is highly bio-available and may represent a palatable and effective delivery system for supplemental selenium. In fact, milk from selenium supplemented cows is sold commercially in a number of countries. Preliminary research results suggest that selenium incorporated into milk proteins may be more effective in cancer prevention than other organic sources of selenium (McIntosh, et al., 2004). A rat colon-cancer model showed statistically significant reductions in both the number of rats with tumors and number of tumors per rat when rats were supplemented with selenised casein (casein from the milk of cows supplemented with organic casein). Selenised casein was more effective than another organic selenium source, yeast selenium, in preventing formation of both malignant and benign tumors. It is possible that the effectiveness of selenised casein is due to an additive effect of selenium and other dairy protein components that have been shown to be protective against cancer (McIntosh, et al., 1995).
Fermented milk products can also provide beneficial probiotics. Probiotics are defined as “live micro-organisms which when administered in adequate amounts confer a health benefit on the host” (FAO and WHO, 2001). The most common bacteria in this group include Bifidobacteria and Lactobacillus species which are found in fermented dairy products (Shane 2006). Probiotics have been used in recent years for the treatment and prevention of infectious and antibiotic associated diarrhea, inflammatory bowel disease, and necrotizing enterocolitis. Probiotics have also been used in the management and prevention of atopic dermatitis and recurrent urinary tract infections. As probiotics are becoming more accepted in human heath interventions, it is important to note that probiotics are not interchangeable therapies; specific probiotics have specific efficiencies. Efficiency is often dependent on one or more of the following; host factors, dose, and duration/persistence of the probiotic. In some cases, combinations of products are required for efficiency. All of these factors are concerns in dairy products because these are natural products and may vary in concentration, viability, and species of organisms contained in each batch. Standardization will be required for this type of functional food product.
The future is clear. Milk will not be consumed solely to assure “strong bones & healthy teeth”. Control of obesity, counteracting age-related diseases processes, and providing probiotics to improve digestive health are all current uses for dairy products. As our knowledge increases, milk and other dairy products can only become more important to a healthful diet.
Anderson, G.H. and S.E. More. 2004. Dietary proteins in the regulation of food intake and body weight in humans. J. Nutr. 134:974S-979S.
Dunshea, FR. 2006. Validating functional properties of foodstuffs. Alltech 22nd Symposium. TP Lyons, KA Jacques, and JM Hower, ed. Nottingham University Press.
Dunshea, F.R., J.M. Ferrari, C. Ketses, E. Ostrowska, M. Muralitharan, B.G. Tatham, I. McCauley, M.L. Cox, P.J. Esaon, and D.J. Kerton. 2005. Obese minipigs are insulin resistant compared to lean conventional pigs. FASEB 19 (Suppl. S):A99.
Food and Agriculture Organization of the United Nations (FAO) and World Health Organization (WHO). 2001. Health and nutritional properties of probiotics in food including powder milk with live lactic acid bacteria. FAO and WHO Joint and Expert Committee Report.
McIntosh, G.H., G.O. Regester, R.K. Le Leu, P.J. Royle, and G.W. Smithers. 1995. Dairy proteins protect against dimethylhydrazin-induced intestinal cancers in rats. J. Nutr. 135:809-816.
McIntosh, G.H., B. Scherer, and P.J. Royle. 2004. Selenised dairy protein and colon cancer inhibition in AOM induced rats. Asia Pacific J. Clin. Nutr. 13:S93.
Schrauzer, G. N. 2006. Alltech 22nd Symposium. TP Lyons, KA Jacques, and JM Hower, ed. Nottingham University Press.
Shane, A. L. 2006. Probiotics versus antibiotics in maintaining balance in the intestinal flora. Alltech 22nd Symposium. TP Lyons, KA Jacques, and JM Hower, ed. Nottingham University Press.