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Feeling your oats? They are healthy as well as nutritious

Robert W Welch
BSc PhD FIFST RNutr
Senior Lecturer in Nutrition and Food Science
Northern Ireland Centre for Diet and Health
School of Biomedical Sciences
University of Ulster
Coleraine

Oats are a traditional foodstuff and were a dietary staple in the western and northern parts of the UK until the nineteenth century. Despite the subsequent decline in consumption, advances in nutrition have confirmed that oats are a valuable foodstuff and may be considered as a multifunctional food.(1)

Oatmeal is a wholegrain cereal that provides nutritionally significant amounts of protein, and of vitamins such as folic acid and Vitamin E. Oats are also a good source of fibre. Furthermore, oat fibre, unlike the fibre in other food grains such as wheat, rice or maize, is rich in soluble fibre (b-glucan).(2) It is the b-glucan that is the main cholesterol-lowering component in oats. Following the first report in 1963 that oatmeal could lower plasma cholesterol, this beneficial effect has been confirmed in many studies. Furthermore, oat bran, a coarse milling oat fraction that is enriched in b-glucan, was found to be particularly effective at lowering cholesterol.
 
There is considerable epidemiological and other evidence to show that wholegrain cereals such as oats can help to decrease the incidence not only of heart disease but also of certain cancers. Consequently, in 1999 the FDA permitted the whole grain, heart disease and cancer health claim.(2)
 
The way that whole grains exert these beneficial effects are unclear. Structural factors or fibre components may play a role, as may the diverse range of phytochemicals that are in whole grains. These phytochemicals include a wide range of non-nutrient antioxidants that may decrease pathophysiological oxidant damage to biomolecules such as LDL-cholesterol or DNA.
 
Oats are a very rich source of antioxidants, and these include phenolics, among which are the avenanthramides, unique to oats.(3) Avenanthramides are structurally very similar to the drug tranilast, which has anticancer, antiallergic and other therapeutic effects. This suggests that the potential beneficial effects of these oat phytochemicals may extend beyond their antioxidant activity.
 
In addition to effects on cholesterol, there is also increasing evidence that oats can impact favourably on other factors associated with Metabolic Syndrome X. These include improved postprandial glucose and insulin responses, reduction in blood pressure, and alleviation of obesity attributed to increased postprandial satiety. Furthermore, oat b-glucan may act as prebiotic and thus impact favourably on gut health.(2)
 
Since the characterisation of coeliac disease (CD), oats, along with wheat, barley and rye, have been proscribed for CD patients. However, oats are not closely related to these other cereals, and in recent years there is increasing evidence that oats are safe in moderate amounts for both adults and children with CD.(4) There is still concern that oats may contain coeliac reactive peptides, or that they may be contaminated with wheat. However, 100% pure oats are becoming increasing available, and it appears that oats may provide an inexpensive, nutritious and healthy addition to the diet of CD patients.

Currently oats provide only about 1% of total dietary energy in the UK. This equates to an average consumption of around one 45-gram portion per head per week. Thus there is clearly substantial scope for increasing our consumption of this nutritious and healthy homegrown cereal.

References

  1. Welch RW. Oats - a multifunctional food. In: Sadler MJ, Saltmarsh M, editors. Functional Foods: The Consumer, the Products and the Evidence. Cambridge: Royal Society of Chemistry; 1998. p. 99-105.
  2. Welch RW, McConnell JM. Oats. In: Dendy DAV, Dobraszcyk BJ, editors. Cereals and Cereal Products: Chemistry and Technology. Gaithersburg: Aspen Publishers Inc; 2001. p. 367-90.
  3. Peterson DM. Oat antioxidants. J Cereal Sci 2001;33:115-29.
  4. Oats and Celiac Disease/Gluten Intolerance.
    Available from URL: http://www.celiac.com/
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