The role of animal nutrition in improving the nutritive value of animal-derived foods in relation to chronic disease
D. I. Givens
Nutritional Sciences Research Unit, School of Agriculture, Policy and Development, University of Reading, Reading R6 6AR, UK
Foods derived from animals are animportant source of nutrients in the diet; for example, milk and meat together provide about 60 and 55 % of the dietary intake of Ca and protein respectively in the UK. However, certain aspects of some animal-derived foods, particularly their fat and saturated fatty acid (SFA) contents, have led to concerns that these foods substantially contribute to the risk of CVD, the metabolic syndrome andother chronic diseases. In most parts of Europe dairy products are the greatest single dietary source of SFA. The fatty acid composition of various animal-derived foods is, however, not constant and can, in many cases, be enhanced by animal nutrition. In particular, milk fat with reduced concentrations of the C12–16 SFA and an increased concentration of 18 : 1 MUFA is achievable, although enrichmentwith very-long-chain n-3 PUFA is much less efﬁcient. However, there is now evidence that some animal-derived foods (notably milk products) contain compounds that may actively promote long-term health, and research is urgently required to fully characterise the beneﬁts associated with the consumption of these compounds and to understand how the levels in natural foods can be enhanced. It is alsovital that the beneﬁcial effects are not inadvertently destroyed in the process of reducing the concentrations of SFA. In the future the role of animal nutrition in creating foods closer to the optimum composition for long-term human health is likely to become increasingly important, but production of such foods on a scale that will substantially affect national diets will require political andﬁnancial incentives and great changes in the animal production industry. Chronic disease: Foods from animals: Animal nutrition
The burden of chronic disease is rapidly increasing worldwide. Recent data (World Health Organization/Food and Agriculture Organization, 2003) suggest that in 2001 chronic diseases were responsible for about 60 % of the 56.5 million deaths reported worldwide and about 46 % ofthe global burden of disease. It has been projected that by 2020 chronic diseases will account for approximately 75% of all deaths worldwide. Approximately half the total deaths from chronic disease are attributable to CVD, but the rapid increase in the obesity–type 2 diabetes syndrome is particularly worrying, not only because it already affects a large proportion of the population worldwide,but also because it is now starting to affect individuals earlier in life. Also, contrary to popular belief, developing countries are increasingly being affected by chronic disease (World Health Organization, 2002).
It has been known for many years that diet plays a key role as a risk factor for chronic disease. At a global level it is clear that in the second half of the twentieth century therewere very major changes to diet in the developed world and, more recently, in developing areas. Often largely plant-based diets have been replaced by an increased consumption of animal products, with a consequent increase in fat content and hence energy density. It is mainly because of the composition of many animal fats that their increased consumption has been associated with increased chronicdisease. The present paper will examine the opportunities to improve the composition of animal fats through animal nutrition and will also discuss how these improvements need to be rationalised against other evidence that points to beneﬁts from the consumption of animal-derived foods.
Abbreviations: CLA, conjugated linoleic acid; SFA, saturated fatty acids. Corresponding author: Professor D....