A walk down the ‘health aisle’ of your local supermarket is a powerful demonstration of the popularity of the ‘free-from’ movement, including gluten-free and grain-free. But in the pursuit of health by cutting out grains many people may be missing out on a key source of fibre and actually increasing their risk of chronic disease.
A recent study in the US found a diet higher in whole grain foods is more likely to be higher in fibre. While this may not seem like new news to most health care professionals, it seems many consumers may have forgotten the importance of these foods as a source of fibre.
The study found a strong association between the intake of whole grain foods, such as bread and breakfast cereal, with total dietary fibre intake for both children and adults. Compared to those who ate no whole grain, adults who ate at least 3 serves per day were 76 times more likely to fall into the highest fibre intake group. The major whole grain sources included bread/rolls, oatmeal, breakfast cereals, and popcorn. Among those with the highest whole grain intake, whole grain breakfast cereals were the greatest contributor to total dietary fibre.
To help Australians boost their fibre intake it is important to remind people of the importance of eating whole grain foods and high fibre grain foods in line with the Australian Dietary Guidelines recommendation to enjoy grain foods each day, choosing mostly whole grain and/or higher fibre varieties.
While fruit and veggies are an important part of the diet and key sources of fibre, two recent study highlight the importance of cereal fibre in the diet. These studies add to the significant body of evidence that higher intakes of cereal fibre reduce risk of a range of chronic conditions including obesity, heart disease, diabetes and colorectal cancer.
In the first study, a meta analysis of 17 prospective cohort studies found higher cereal fibre intakes were associated with a 23% reduced risk of type 2 diabetes. The risk reduction from cereal fibre was stronger than both total fibre (19%) and fruit fibre (6%). In comparison, there was no significant reduced risk with higher fibre intakes from vegetables.
Interestingly, this is the first study to determine the dose of fibre associated with reduced risk of type 2 diabetes. A reduced risk was seen with as little as 3 grams of cereal fibre per day and the risk decreased by 6 % for each additional 2 grams per day. In comparison a threshold of 25 grams of total fibre was needed before a significant risk reduction was seen.
The second study, an analysis of two large US cohort studies, found heart attack survivors with higher cereal fibre intake had a 25% lower risk of dying in the nine years following their heart attack. Cereal fibre intake in particular demonstrated the greatest protection compared to other sources of fibre.
The current Nutrient Reference Values for dietary fibre are based on an estimated adequate intake for gastrointestinal function and adequate laxation. However this study adds to the significant body of evidence that higher intakes of cereal fibre reduce risk of a range of chronic conditions including obesity, heart disease, diabetes and colorectal cancer. Encouraging Australians to choose foods high in cereal fibre more often and ensuring whole grain foods are available may assist people to meet and/or exceed the adequate intakes for dietary fibre and achieve health benefits beyond the effects of fibre on gastrointestinal function and laxation.
- Li S, Flint A, Pai J, Forman J, Hu F, Willett W, Rexrode K, Mukamal K, Rimm E. Dietary fiber intake and mortality among survivors of myocardial infarction: prospective cohort study. BMJ 2014; 348 doi: http://dx.doi.org/10.1136/bmj.g2659 (Published 29 April 2014)
- Reicks M, Jonnalagadda S, Albertson AM, Joshi N. Total dietary fibre intakes in the US population are related to whole grain consumption: results from the National Health and Nutrition Examination Survey 2009 to 2010. Nutrition Research. 2014,34(3):226-234.
- Yao B1, Fang H, Xu W, Yan Y, Xu H, Liu Y, Mo M, Zhang H, Zhao Y. Dietary fiber intake and risk of type 2 diabetes: a dose-response analysis of prospective studies. Eur J Epidemiol. 2014,29(2):79-88.