Not all grains need be wholegrain

Review suggests a place for refined grain favourites

In Australia, the current dietary guidelines recommend “Eat plenty of cereals (including breads, rice, pasta, and noodles), preferably wholegrain”, however they do not give any recommendations about what proportion of cereal foods can still be consumed as refined grains.

At the Public Health Association of Australia National Food Futures conference in November, Assoc. Professor Peter Williams presented the findings from his scientific literature review of the evidence designed to answer the question: What proportion of refined grains can be consumed in a healthy diet? 

The literature review, commissioned by Go Grains, summarises the findings of 135 studies from the last ten years. The great majority found no associations between the intake of refined grain foods and cardiovascular disease, diabetes, weight gain or overall mortality

Of the 31 prospective cohort studies included in the review, only 5 reported refined grain intake to be associated with adverse health outcomes. Two of these used refined grains high in fat (pizza, cakes and biscuits). There was no association between higher refined grain intake and cardiovascular disease.  

Of the nine intervention studies included in the review, which largely studied the effect of wholegrain or low GI on cardiovascular or metabolic risk, six reported no significant difference

The author concluded that there is inconsistent evidence on the effect of refined grain on cancer. Seven of the 10 recent case control studies found that very high intakes might be associated with some types of cancers (renal, upper-digestive, stomach and colorectal), but at moderate levels of consumption the risks were not significant.

In summary, the evidence from the review indicates that consuming up to 50% of all grain food foods as refined grain core foods is not linked with any increased disease risk. Refined grain core foods were defined in the study as those without high levels of added fat or salt. It is important to remember that grain-based foods with large amounts of added fat, salt or sugar such as cakes, muffins, pastries or pizzas should still only be enjoyed as occasional indulgence foods.

Wholegrain foods have been shown to be associated with reduced risk of heart disease, diabetes, weight gain and some cancers which is why it is recommended Australians eat ‘preferably wholegrain’ grain foods. This study indicates that you can still also enjoy some refined grain foods as part of a healthy diet.

Examples of refined grain core foods included in the review are:

• Breads: white bread, pita and mountain breads, bagels, crumpets, tortillas
• Breakfast cereals: low fibre cereals and those containing < 25% wholegrain
• Refined cereal grains: white rice, polenta, semolina, couscous
• Pasta and noodles: those based on white wheat or rice flour.

‘One a Day is OK’

Putting this in to practice as part of a healthy diet that includes choosing high fibre and wholegrain most of the time, it means one meal each day could be a refined grain meal. For example, a high-fibre wholegrain breakfast cereal, a white bread sandwich at lunch and brown rice for dinner.

So you don’t have to give up your favourite refined grain core food like pasta or a low-fibre cereal, just make sure your other choices in the day are wholegrain.

Reference:

Williams P. Evaluation of the evidence between consumption of refined grains and health outcomes. 2012 Nutrition Reviews (In Press)

Avoid unwanted kilos with wholegrains

20 year study shows how to halt weight gain

Have you ever wondered which foods and beverages, when consumed on a regular basis, are most likely to pack on the kilos? A recent paper published in the New England Journal of Medicine sheds light on this very question.

The researchers looked at the relationship between the intake of 15 key food groups and long-term weight changes. They examined data from three large prospective studies that included over 120,000 non-obese American men and women. The changes in body weight were evaluated in 4-year intervals from 1986 to 2006. Wholegrain foods and refined grain foods were among the 15 key food groups that they examined.

In each 4-year period, participants gained an average of 1.51kg. Weight gain was most strongly associated with intakes of potato chips, potatoes, sugar-sweetened beverages, unprocessed meats, processed meats, and sweets /desserts. Having an increased intake of refined grain foods was also moderately associated with weight gain. However, the effect of refined grains foods in the diet was found to be much less than the impact of other food categories, such as potato crisps and sugar-sweetened beverages, listed above.

On the flipside, weight gain was halted with greater intakes of yoghurt, nuts, fruits, wholegrains and vegetables. Findings were similar in magnitude and direction across the three study populations for men and women.

The researchers concluded the strong link between weight gain with processed foods and refined grains might be because these foods are less satiating, which increases subsequent hunger signals and triggers the desire to eat more at the next meal.

They noted that some foods, including wholegrains, were associated with less weight gain, when intakes were actually increased. This is most probably because an increase in these nutrient dense foods means there is a decrease in the intake of other foods with higher kilojoule content. Also, wholegrain foods, fruits, vegetables and nuts have a higher fibre content and slower digestion rate – two factors which promote satiety (the state of being satisfactorily full).

This very large and well-conducted study provides further evidence to support the role of wholegrains in the prevention of unwanted weight. Most interestingly, when it comes to weight control, this study revealed elevated intakes of wholegrain foods has a larger protective effect than elevated intakes of vegetables.

The study participants had a very similar pattern of grain food intakes to Aussies, with approximately one-third from wholegrain foods and two-thirds from refined grain foods. A move to make at least half of the cereal foods that we eat wholegrain is likely to help combat excess weight in the Australian population.

Go Grains encourages all Aussies to enjoy 4 plus serves of grain foods each day, with at least half of those serves being from wholegrain foods.

Here are a few simple tips to help you swap those weight gaining foods with wholegrain foods, in your diet:

• Swap potato chips with plain popcorn or a wholemeal sandwich
• Include brown rice or wholemeal pasta instead of mashed potato with you main meal
• Choose wholegrain crackers over sweet biscuits.


References:

Changes in diet and lifestyle and long-term weight gain in women and men. Mozaffarian D, Hao T, Rimm ER, Willett WC, Hu FB. New England Journal of Medicine, 2011; 1364:2392-2404.