We have heard a lot about the harmful effects of refined grains on our health. Interestingly, recent research seems to point in a different direction, exonerating them from the label they have held for so long. Are refined grains not so bad after all? What are the facts? In this article, we will take a closer look at why refined grains seem to have been unfairly vilified.
- Refined grain consumption and your health
Have you been avoiding refined grains such as white bread and pasta? Do you feel bad when you do eat them? Apparently, there’s no evidence to show that refined grains are “bad” for you. Conversely, there is evidence that shows that whole grains are good for you. Somehow along the way, the message has been mixed up – putting a slice of white bread or a dish of white pasta in the same category as pie and piece of cake.
The dietary recommendation has been to make half of your grains whole grains. This does not mean “avoid all refined grains”. They too can fit into your diet.
Contrary to previous research findings, refined grain consumption is not associated with any of the adverse health effects it has been linked to, such as obesity, heart disease, and diabetes. This is according to a new study from the Healthy Lifestyles Research Center at Arizona State University (ASU) published in Advances in Nutrition. The researchers note that what counts is the number of consumed calories, not so much their source.
Analyses of existing research – including 32 publications with data from 24 distinct cohorts – showed that refined grains are not linked to increased disease risk or premature death. The study highlights that the current dietary recommendation to reduce refined grain consumption conflicts with the substantial body of published scientific evidence.
Professor Glenn Gaesser, Ph.D., Director of the Healthy Lifestyles Research Center at ASU“Simply put, refined grains are not the bad guy,” says study author, Professor Glenn Gaesser, Ph.D., Director of the Healthy Lifestyles Research Center at ASU. “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.”
Gaesser theorizes that refined grains have developed a guilt-by-association reputation. He explains that while refined grains are frequently characterized as unhealthy, this can be attributed to their inclusion in a dietary pattern that contains a range of foods that are the real culprits in the link between an unhealthy dietary pattern and an increased risk of a number of chronic diseases.
What were the results of the study?
- No association was observed between refined grain intake and cardiovascular disease or coronary heart disease.
- No association was found between refined grain intake and stroke risk. In fact, one study demonstrated a 10 percent lower reduction of stroke risk.
- No association was found between refined grain intake and risk of Type 2 diabetes.
- Cancer studies are limited. Nonetheless, one meta-analysis shows an inverse association between refined grain intake and total cancer deaths. A second meta-analysis shows that refined grain intake was not associated with the risk of rectal or colorectal cancer.
- Five out of six studies show no relationship between refined grain intake and death rate. The other study shows a statistically significant inverse association between refined grain intake and all-cause death rate.
- Three systematic reviews show no consistent relationship between refined grain intake and body mass index (BMI).
- Is there a link between refined grains and obesity?
The demonization of refined grains has deterred people from consuming them, opting for whole grains instead. Whole grains are higher in calories but touted as more nutritionally-rich.
In reality, the association between refined grain consumption and obesity is murky, with no clear relationship. Weight gain is essentially a result of consuming more calories than you burn. It’s the number of calories that matters most, not so much the type of calories. In studies that do indicate that refined grains are associated with increased risk of weight gain, the association is “inconsequentially small.” Randomized dietary interventions of whole grains and refined grains compared head-to-head reveal no differences between the two.
Both refined grains and whole grains are important in people’s diets. Whole grains are important for health since they provide fiber and essential vitamins. Enriched/refined grains provide fiber too, and 39 percent of the dietary fiber Americans eat comes from refined grains. “As a population, US consumers still fall far short of reaching their daily goals for fiber.
It is important to note that eliminating enriched grain products will result in nutrient shortfalls. Refined grain foods that have been enriched and/or fortified help to alleviate shortfalls including B-vitamins, folic acid, thiamin, niacin, riboflavin, and iron.
A good example is that enriched grains are the largest contributor of folic acid in the American diet. This is key to preventing neural tube birth defects.
- So, what should you eat?
To reduce disease risk and balanced nutrition, the DGA dietary recommends you eat:
- A variety of vegetables from all of the subgroups—dark green, red and orange, legumes (beans and peas), starchy, and other
- Fruits, especially whole fruits
- Grains, at least half of which are whole grains
- Fat-free or low-fat dairy, including milk, yogurt, cheese, and/or fortified soy beverages
- A variety of protein foods, including seafood, lean meats and poultry, eggs, legumes (beans and peas), and nuts, seeds, and soy products
- What is the future for refined grains?
Future research efforts must distinguish between staple grain foods, such as cereals, bread and pasta and indulgent grain foods, such as cakes, cookies, and donuts, according to Gaesser. Most of the studies included in the current paper did not make such distinctions, so it’s impossible to know whether the results would be different if refined grains were categorized separately as a staple or indulgent grain foods.
It is possible that the risk of chronic diseases would be different for the consumption of staple grain foods as compared to the consumption of indulgent grain foods. Randomized-comparison trials are needed to better differentiate the health effects of whole grain and refined grain foods. Most published studies have been too short and do not include enough outcome measures to draw definitive conclusions.
As currently stands, the results of randomized-comparison trials show no consistent benefits of whole-grain foods over refined grain foods. These findings are at odds with the results of large-scale observational studies, which show a clear superiority of whole grains over refined grains. This is a paradox that needs to be resolved,” Gaesser concludes.
- Nutritioninsight (2019): Let us eat cake? Refined grains “falsely” linked to obesity and chronic disease risk. Retrieved from https://www.nutritioninsight.com/news/let-us-eat-cake-refined-grains-falsely-linked-to-obesity-and-chronic-disease-risk.html
- Rust Nutrition (2019): Refined Grains Redefined. Retrieved from https://rustnutrition.com/blog/2019/07/03/refined-grains-redefined/
- NCBI (2019): Perspective: Refined Grains and Health: Genuine Risk, or Guilt by Association? Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6520038/
- Baking Business.com (2019): Study disputes negative health claims surrounding refined grains. Retrieved from https://www.bakingbusiness.com/articles/48376-study-disputes-negative-health-claims-surrounding-refined-grains