The study – published in Advances in Nutrition, a peer-reviewed medical journal from the American Society of Nutrition – has demonstrated that current dietary recommendations to reduce refined grain consumption conflict with the substantial body of published scientific evidence.
According to the study’s author Glenn Gaesser, professor of exercise science and health promotion and director of the Healthy Lifestyles Research Center at Arizona State University, refined grains are not responsible for a host of negative health risks usually attributed to them.
“Quite simply, refined grains are not the bad guy,” said Prof Gaesser.
“Contrary to popular belief and current dietary guidance, refined grain intake is not associated with type 2 diabetes, cardiovascular disease, coronary heart disease, stroke, hypertension, cancer or death.”
Guilt by association
He theorizes the grains developed their ‘bad rap’ through a guilt-by-association reputation.
“The Western dietary pattern – which includes red and processed meats, sugar-sweetened foods and beverages, French fries, high-fat dairy products and refined grains – is linked to many chronic diseases,” said Prof Gaesser.
“However, when analyzed as a distinct food group, refined grain consumption is not linked to chronic diseases or death.”
Over a year, Prof Gaesser undertook extensive analyses of existing published studies (encompassing 11 meta-analyses, including 32 publications with data from 24 distinct cohorts) and found the intake of refined grains had:
- No correlation to cardiovascular disease or coronary heart disease.
- No association to stroke risk; one study demonstrated a 10% lower reduction of risk.
- No connection to risk of type 2 diabetes.
- No risk of rectal or colorectal cancer: One meta-analysis showed an inverse association to total cancer deaths.
- No relationship to the all-cause death rate: One study found a statistically significant decrease.
- No consistent relationship to body mass index (BMI), used to define obesity.
Eat your refined grains
The study even suggests the advice by health professionals to replace most refined grains with whole grains could, in fact, cause consumers to overlook critical nutrients, like B-vitamins, folic acid, thiamin, niacin, riboflavin, and the mineral iron.
Refined grains are typically enriched so eliminating them will result in nutrient shortfalls, said Sylvia Klinger, a registered dietitian nutritionist who sits on the Scientific Advisory Board of the Grain Foods Foundation, which provided a grant towards the manuscript.
“For example, enriched grains are the largest contributor of folic acid in the American diet. This is key to preventing neural tube birth defects,” she said.
However, it is important to note the study does not discourage the importance of whole grains. It includes the contribution of both whole and refined are essential, particularly as 90% of Americans fall short of the dietary fiber recommendation.
“The important takeaway of this study is that consumers need to know their stuff before they cut,” added Klinger.
“At the end of the day, you can have your refined grains and eat them, too.”
Listen to the BakeryandSnack Chat Podcast with Prof Gaesser.