Claims that wheat is making people fat and sick have been propelled into the public’s view in recent years via books such as Wheat Belly and Grain Brain as well as wheat deprived diet plans such as Paleolithic diets and the gluten free phenomenon. In response to this increasing anti-wheat sentiment, independent researchers from the UK and the Netherlands have teamed up to review the accusations which underpin the claims that wheat has adverse health effects.
In this recent review, to obtain ensure the quality of the research the authors used set guidelines to search the scientific literature and critically evaluated the controlled scientific articles they included in this review. Based on their review the authors have discredited claims that wheat is harmful to health and causes weight gain. Their overriding conclusion was the claims which underpin the argument for the general population to eliminate wheat are not substantiated by scientific evidence.
In contrast to the unsubstantiated claims wheat is harmful to health, the authors highlight the body of evidence from scientific studies linking whole grain and high fibre wheat consumption with significant reductions in risks for type 2 diabetes, heart disease, and improved long term weight management.(1)
The following conclusions from the review address the key arguments supporting anti-wheat claims.
1. “Increasing wheat consumption parallels the increase in waist size”
- While it is true wheat consumption parallels increase in waist size, it is not valid to consider them as the cause of each other as this statement implies. For example increases in wheat consumption also parallels sales of cars, mobile phones and sports shoes – but to imply that they cause each other is ridiculous.
- In addition, the increases in wheat consumption has a much longer history than the more recent drastic increases of obesity, which has also occurred in populations that eat little wheat, such as several Asian countries. For centuries, there have been populations who consume wheat-based breads and other wheat products as the main source of their energy intake, such as in Turkey, without increases in weight gain of the population.
2. “Wheat free diets induce weight loss”
- The limited availability of wheat-free foods may itself lead to a reduced overall intake of food and energy. Weight loss is not induced by the absence of wheat but rather a decrease in total energy intake, a dieting-related phenomenon which occurs during virtually all energy restricted diets.
3. “Wheat opioids are so addictive that they cause people to be unable to control their eating, and removal of wheat from the diet causes withdrawal”
- The gluten proteins of wheat and other grains can be divided into two fractions, the gliadins and the glutenins. Incomplete digestion of gliadin has been shown to release a peptide, called gliadorphin which when injected into laboratory tests in rats was shown to induce opiate like effects. However, gliadorphin cannot be absorbed by the intestine and therefore cannot enter the blood stream nor have an effect on the cells of the central nervous system.
- There are no studies in which gliadorphin has been shown to be absorbed in intact form by the intestine and no evidence that gliadin either stimulates appetite or induces addiction like withdrawal effects.
4. Whole-wheat bread has a Glycaemic Index (GI) of 72, which is higher than that of sugar (GI = 59)
- In the first instance the GI Values which support this claim are inaccurate with the internationally accepted average GI of sucrose being 67, white wheat bread being 70 and wholemeal wheat bread being 65.9.
- This statement implies that, based on GI, consuming sugar is better for your health than eating wheat which is a misinterpretation of the use of GI. The GI of carbohydrate food is one measure of carbohydrate quality and should be taken into account with other feature including nutrient density, fibre content, phytonutrient content and whole grain content.
The Australian Context
As wheat is the most consumed grain food in Australia, it makes a significant contribution to the Australian diet. Grain foods contribute a range of essential nutrients to the Australian diet including fibre, folate, niacin, thiamine, iron, zinc, magnesium, protein and carbohydrates. (2)
Australian and international dietary guidelines recommend people eat grain foods (including wheat foods), choosing mostly whole grain and high fibre options.(3) Unlike recommendation to eliminate wheat these dietary recommendations are substantiated to provide adequate nutrition, reduce risk of disease and promote a healthy weight.
What about people with coeliac disease, wheat allergy, gluten intolerance?
While dietary guidelines recommend a variety of grain foods within a balanced diet, it is important to note that there are individuals who cannot tolerate wheat or gluten in their diet. For people with diagnosed coeliac disease, wheat allergy or gluten sensitivity the avoidance of wheat is essential in order to treat or manage these conditions.
It is equally important to note that these conditions affect a small percentage of the population.
Where coeliac disease, a food allergy or sensitivity is suspected the Grains & Legumes Nutrition Council (GLNC) encourages individuals to seek a qualified medical practitioner to obtain a medical diagnosis. In the case of coeliac disease, a food allergy or sensitivity GLNC recommends individuals seek guidance from an Accredited Practising Dietitian to provide individualised dietary advice to ensure a balanced diet.
A final word...
Despite the lack of scientific evidence, it is likely the claims wheat is harming the health of the general population are likely to continue to make headlines, confuse consumers and influence food choices around the world in 2014. This was highlighted in a recent survey from the US in which over 500 dietitians identified an anti-wheat sentiment as the top nutrition and food trend in 2014.(4)
With demand for nutrition information at an all-time high, Australians need evidenced based advice and guidance now, more than ever, to cut through the clutter. It is good to see robust reviews such as this review and Julie Jones’ review on this topic (5) breaking through the noise to provide evidence-based information rather than anecdotal musings.