Supercharging your supper

Eva Lewis of Devenish discusses advances in animal nutrition that offer the potential to improve both animal and human health by ‘supercharging’ animal source foods with essential nutrients.

Animal nutritionists have traditionally focused on formulating diets to keep animals healthy and well, and producing efficiently. But there is an increasing awareness of the importance of the nutritive value of meat, milk and eggs for human health.  ‘One Health’ is the philosophy that health should be simultaneously optimised for animals, humans and the environment. New developments in this area include the ability of animal nutritionists to influence nutritive value by changing the way animals are fed and managed.

Nutritional deficiencies

There is a general appreciation of the dangers of nutritional excesses – high calories, high salt, high sugar.  There is however less awareness that nutritional deficiencies result in a greater number of deaths and disease burden worldwide. These deficiencies are seen as diets low in whole grains, fruit, nuts, seeds, vegetables, legumes, milk, fibre, iron, calcium, vitamins and omega 3 fatty acids.  Nutritional deficiencies result in 12 million deaths and 320 million disability adjusted life years (DALYS) annually compared to nutritional excesses resulting in 7 million deaths and 190 million DALYs annually (2016 Global Burden of Disease).

The mineral intakes of children are an area of particular concern^[1]. Calcium is essential to bone development and it is especially concerning that females aged 11-18 years have a calcium intake that is almost 30% below the lower reference nutrient intake.  This is associated with a reduction in milk consumption.  Calcium deficiency is compounded by associated sub-optimal magnesium and vitamin D intake. Odin, an EU-funded project, estimated that >40% of the EU population are deficient in vitamin D^[2].  Vitamin D plays a role in the maintenance of normal bones, muscle function and teeth, and also contributes to the normal function of the immune system.  Poor consumption of calcium, magnesium and vitamin D in children is associated with an increase in osteoporotic fractures in later life.  Indeed, the frequency of osteoporotic fracture has already increased in many countries, and it is estimated that the prevalence will double in the EU by 2035^[3](EPA) and docosahexaenoic acid (DHA) are two key long chain omega 3 fatty acids, derived from marine sources. The European Food Safety Authority showed that compared to the target intake of 250mg EPA+DHA per person per day that we should be consuming, 11-15 year olds are consuming just 24mg and the ‘best’ group – the 50-64 year olds – are only consuming 169mg.  Worldwide only a small minority of the population (<20%) exhibits optimal blood omega 3 fatty acid levels (Figure 1).  The reason these low levels are of such concern is because elevated blood levels of EPA and DHA are strongly and consistently associated with protection from heart attacks, strokes, Alzheimer’s disease, depression, cancer, diabetes mellitus, and improved brain health – all leading causes of death and disability in the UK.

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Over the past 10 years, the EPA and DHA content of oily fish has decreased by almost half because the diet of the fish has changed.

Nutrient supplementation

Broadly speaking, some of the foods that are rich in these nutrients do not seem to be on our ‘favourite foods list’ (e.g. oily fish, which is a source of both vitamin D and omega 3 fatty acids) and some are seeing a decrease in intake for other reasons (e.g. meat and milk).  In the case of the omega 3 fatty acids EPA and DHA, these are only available naturally from oily fish.  In fact the 250mg per person per day recommended intake level is specifically identified as coming from oily fish.  For those who do not like to eat oily fish, supplements are available, but research shows that, after a time, medium and long term supplement consumption can wane.  In addition, the bioavailability of the fatty acids contained in supplements is not as good as the bioavailability of fatty acids contained in oily fish^[5].  Furthermore, over the past 10 years, the EPA and DHA content of oily fish has decreased by almost half because the diet of the fish has changed^[6].  So today you must eat twice as much oily fish, as compared with 10 years ago, to get the same amount of EPA and DHA. 

Interestingly, similar trends are seen in some other foods, whereby the nutrient content has decreased over the years.  For example, in wheat the concentration of zinc, iron, magnesium and copper have all decreased significantly since 1968, with levels up to 50% lower compared to pre 1968 levels[7].  Amongst food groups themselves, there are also differences in bioavailability, for example iron, vitamin A and vitamin D are all more bioavailable to humans when they are taken in from animal products compared to plant products.

Animal nutritionists are formulating diets and regimes that use fish oil, and more increasingly algal oil, to increase the levels of omega 3 fatty acids in animal products.

Bioenrichment

While continuing to eat the recommended amount of oily fish and milk is important, ‘bioenrichment’ can help to ‘supercharge’ some of these foods too. Animal nutritionists are formulating diets and regimes that use fish oil, and more increasingly algal oil, to increase the levels of omega 3 fatty acids in animal products. This allows consumers to choose omega 3-enriched chicken, eggs and pork in addition to oily fish  (Figure 2).

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Figure 2 Omega 3-enriched chicken

The agri technology company Devenish has been developing the most efficient diet and management regime to imbue chicken meat with the omega 3 fatty acids EPA and DHA, normally only found in marine sources. Research has confirmed that the omega 3 fatty acids in the chicken meat were bioavailable to those consuming the chicken.  After only 6 months of eating omega 3-enriched chicken and eggs, there was a substantial shift in the ‘omega 3 index’ distribution (Figure 3).  The omega 3 index is a way of expressing whether people are in a high risk category (low circulating levels of EPA and DHA) or in a low risk category (high circulating levels of EPA and DHA).  The number of people in the high risk category halved after just 6 months of eating omega 3-enriched chicken and eggs^[8].  Scaled up to the global level, the effects of moving swathes of people from high risk to low risk represents a potentially huge economic saving.

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Figure 3 The effect of eating chicken and eggs enriched or not with omega 3 fatty acids on the proportion of consumers falling into different omega 3 index risk categories (red indicates high risk [low circulating EPA+DHA] and green indicates low risk [high circulating EPA+DHA]). From Stanton et al. (2017)

This overlapping of animal nutrition and health into human nutrition and health is more generally referred to as One Health - using approaches that simultaneously optimise animal, human and environmental health.  Livestock animals will use some of the omega 3 fatty acids, and some of the vitamin D, and all the other nutrients to promote their own growth and development first, before depositing the excess nutrients into meat, milk and eggs.  For example, scientists have shown that animals fed high omega 3 diets have better fertility, immune function and health and those fed high vitamin D diets have better immune function.  Nutritive value and the health-related functionality of food are being used to recognise the sustainability credentials of meat and milk in the context of their high nutritive value.^[9][10]

One Health

An event at the House of Commons in February 2019 explored the role of the agriculture and agri-food sectors in delivering positive health outcomes in support of the 2017 UK Life Sciences Industrial Strategy (Figure 4). It was suggested that a One Health approach providing nutritious food to promote consumer health would be additive to the proposals already contained in the strategy

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Figure 4, House of Commons Event (February 2019) exploring the role of the agriculture and agri-food sectors in helping to deliver the broad objectives of the Life Sciences Industrial Strategy (2017)

Dr Eva Lewis, Head of Food Innovation, Devenish

Lagan House, 19 Clarendon Road, Belfast, BT1 3BG, Northern Ireland

Web devenishnutrition.com

References

1.Givens, D.I. 2018. Review: Dairy foods, red meat and processed meat in the diet: implications for health at key life stages. Animal 12: 1709-1721

2. Cashman, K.D. et al. 2016. Vitamin D deficiency in Europe: pandemic? American Journal of Clinical Nutrition 103: 1033-1044

3. Hernlund, E., Svedbom, A., Ivergård, M., Compston, J., Cooper, C., Stenmark, J., McCloskey, E.V., Jönsson, B., Kanis, J.A. 2013. Osteoporosis in the European Union: medical management, epidemiology and economic burden. Archives of Osteoporosis 8: 136-251

4. Stark, K.D., van Elswyk, M.E., Higgins, M.R., Weatherford, C.A., Salem Jr, N. 2016. Global survey of the omega 3 fatty acids, docosahexaenoic acid and eicosapentaenoic acid in the bloodstream of healthy adults.  Progress in Lipid Research 63: 132-152

5. Elvevoll, E.O., Barstad, H., Breimo, E.S., Brox, J., Eilertsen, K.-E., Lund, T., Ole Olsen, J., Osterud, B. 2006. Enhanced incorporation of n-3 fatty acids from fish compared with fish oils. Lipids 41: 1109-1114

6. Sprague, M., Dick, J.R., Tocher, D.R. 2016. Impact of sustainable feeds on omega-3 long-chain fatty acid levels in farmed Atlantic salmon, 2006-2015. Scientific Reports 6: 21892 DOI: 10.1038/srep21892​

7. Fan, M.-S., Zhao, F.-J., Fairweather-Tait, S.J., Poulton, P.R., Dunham, S.J., McGrath, S.P. 2008. Evidence of decreasing mineral density in wheat grain over the last 160 years. Journal of Trace Elements in Medicine and Biology 22: 315-324

8. Stanton, A.V., Shortall, K., El-Sayed, T., O’Donovan, F., James, K., Kennedy, J., Hayes, H., Fahey, A., Dolan, E., Williams, D., Moran, N. 2017. Eating omega-3 polyunsaturated fatty acid enriched chicken-meat and eggs results in increased plasma docosahexaenoic and eicosapentaenoic acid levels and an improved omega-3-index. Circulation 136(Supp 1): Abstract 19913

9. Drewnowski, A., Rehm, C.D., Martin, A., Verger, E.O., Voinnesson, M., Imbert, P. 2015. Energy and nutrient density of foods in relation to their carbon footprint. American Journal of Clinical Nutrition 101: 184-191

10. McAuliffe, G.A., Takahashi, T., Lee, M.R.F. 2018. Framework for life cycle assessment of livestock production systems to account for the nutritional quality of final products. Food and Energy Security 7(3): DOI: 10.1002/fes3.143