September 2019 Issue

Whole Grains: Gluten-Free, Grain-Free, and Wheat-Free Diets
By Densie Webb, PhD, RD
Today’s Dietitian
Vol. 21, No. 9, P. 16

What Clients (and RDs) Need to Know

Gluten-free foods are everywhere, it seems. The market for gluten-free food products has grown from about $464 million in 2011 to a projected $2.4 billion by 2020.1 That’s a lot of people eating a lot of gluten-free foods. Moreover, gluten-free often is translated to grain-free, fueling a growing belief that grains, especially wheat, are inherently bad for you. As a result, grain-free diets also are on the upswing. The grain-free diet is pretty self-explanatory—the elimination of all grains, both refined and whole, from the diet, including wheat, oats, rice, rye, barley, buckwheat, bulgur, corn, teff, and amaranth. The popularity of grain-free eating has even made its way into pet foods.2 However, the reasoning for such a restrictive diet is murky at best, and the potential nutrition cons are clear.

While there are specific reasons why clients may need to seek out gluten-free or wheat-free foods, there’s no clear reason for a grain-free, gluten-free, or wheat-free diet for healthy individuals. In fact, all three of these dietary restrictions go against all recognized healthful eating recommendations from the US Dietary Guidelines Advisory Committee and organizations ranging from the American Heart Association to the American Diabetes Association and the Academy of Nutrition and Dietetics, all of which encourage the consumption of grains (six servings per day), especially whole grains (three servings per day). Refined grains are enriched with vitamins and minerals, such as folic acid and iron, and there’s solid evidence to show that including whole grains in the diet is associated with a lower risk of CVD, metabolic syndrome, type 2 diabetes, cancer, and even early death.3-6 But the average intake of whole grains in the United States already is less than a single serving per day7; adhering to a diet that advocates avoiding grains could lower that intake to zero.

Who Really Needs to Avoid Gluten?
Clients and patients who have been diagnosed with celiac disease (about 0.5% to 1.7% of the population) must avoid all gluten-containing foods.8 Celiac disease is an autoimmune disease in which the ingestion of gluten damages the small intestine. Allesio Fasano, MD, chair of pediatric gastroenterology and nutrition at Massachusetts General Hospital in Boston, author of Gluten Freedom, and an expert on celiac disease, has said that a gluten-free diet is as necessary for people diagnosed with celiac disease as insulin is for individuals with diabetes.

There’s also a little-understood condition called nonceliac gluten sensitivity, which can cause symptoms similar to celiac disease, such as bloating, cramping, and diarrhea, but without the damaging effects in the intestine. Despite four consensus conferences that focused on the condition, no biomarkers for diagnosis have been identified.9 Diagnosis usually is done through process of elimination, making estimates of its prevalence difficult to obtain. However, it has been approximated that between 0.6% and 10.6% of the nonceliac population experiences nonceliac gluten sensitivity, with varying degrees of symptoms.10

For the vast majority of people, however, gluten hasn’t been proven to have negative effects on health. One of the claims regarding gluten is that it increases the risk of heart disease. However, in the Nurses’ Health Study and the Health Professionals Follow-up Study, researchers found no association between gluten intake and development of coronary heart disease.11

Even assuming the highest estimated prevalence of celiac disease and nonceliac gluten sensitivity, it’s virtually impossible that everyone purchasing gluten-free foods has one of these conditions, and when gluten-free is then translated into grain-free, the avoidance of all grains can compromise nutrition status and ultimately health. “I certainly see the gluten-free trend as the springboard for the grain-free trend, and it has only been further catapulted by the Paleo and ketogenic diet trends,” says Alicia Romano, MS, RD, LDN, CNSC, a spokesperson for the Academy of Nutrition and Dietetics and clinical dietitian at Tufts Medical Center in Boston.

Who Really Needs to Avoid Wheat?
Not only do people diagnosed with celiac disease have to avoid wheat, but those with irritable bowel syndrome (IBS) who have a fructan intolerance do, too. The fructans, not the gluten, found in wheat are irritating to the intestinal tract, Romano says. Fructans are polymers of fructose molecules. Some people lack the enzyme necessary to break apart the linkages that connect the fructose polymers during digestion; as a result, they’re not absorbed and arrive in the large bowel, where they’re fermented, causing bloating and diarrhea.

Wheat allergy, on the other hand, involves a reaction of the immune system in response to consuming wheat. According to the American College of Allergy, Asthma & Immunology, wheat allergy is most common in children, who typically outgrow it by adulthood. In fact, about 65% of children with a wheat allergy will outgrow it by age 12.12

Who Really Needs to Avoid All Grains?
Despite the premise of the Paleo diet (the high-protein, grain-free diet our ancestors ate before the development of agriculture and the cultivation of grains) and the keto diet (a low-carb, high-fat diet plan), there’s no clearly established reason for anyone to avoid all grains and, in fact, it could be detrimental to health. While there’s some research suggesting that one of the proteins in gluten (gliadin) may cause a “leaky gut,” in which compounds are “leaked” into the bloodstream, causing an inflammatory response, research suggests that gliadin-triggered inflammation likely occurs only in people with a genetic predisposition, and it’s unclear whether, and to what extent, it might affect disease risk.13

Grain Recommendations for Health
Despite the growing popularity of diets that recommend eliminating some or all grain foods
to improve health, there’s little research to suggest that avoidance of gluten, wheat, or all grains is beneficial for people who haven’t been diagnosed with wheat allergy, celiac disease, IBS, nonceliac gluten sensitivity, or any other intestinal disorder. In fact, avoidance of grains can have the opposite of the desired result—poor health.

Removing all grains (refined and whole) results in the elimination or reduced consumption of several nutrients, including B vitamins, such as thiamine, riboflavin, niacin, and folate, as well as iron, magnesium, zinc, and selenium. Eliminating whole grains removes a rich source of fiber and a collection of phytochemicals thought to be instrumental in providing health benefits. Studies have shown that people who eat three servings of whole grains per day may reduce their risk of heart disease by 25% to 36%, stroke by 37%, type 2 diabetes by 21% to 27%, digestive system cancers by 21% to 43%, and hormone-related cancers by 10% to 40%.14

“Very few gluten-free products are fortified or enriched with the vitamins and minerals found in gluten-containing grain products,” Romano says. The bottom line, she says, is that “gluten-free and wheat-free diets should be reserved for when they’re medically indicated, such as those with celiac disease, nonceliac gluten sensitivity, wheat allergy, or IBS with fructan intolerance. Everyone else should consume a balanced diet rich in plant-based foods, including a variety of whole grains.”

If a patient or client is adamant about avoiding gluten or wheat, let them know there are plenty of other grains that are gluten-free and not derived from wheat and that help meet the dietary recommendation for whole grains, including amaranth, buckwheat, corn, millet, quinoa, rice, sorghum, teff, and wild rice.

— Densie Webb, PhD, RD, is a freelance writer, editor, and industry consultant based in Austin, Texas.

1. Retail dollar sales of gluten-free products in the United States from 2011 to 2020 (in million U.S. dollars. Statista website. Accessed July 10, 2019. Updated November 8, 2016.

2. Mull A. How Americans decided dogs can’t eat grain. The Atlantic website. Published July 2, 2019. Accessed July 9, 2019.

3. Aune D, Keum N, Giovannucci E, et al. Whole grain consumption and risk of cardiovascular disease, cancer, and all cause and cause specific mortality: systematic review and dose-response meta-analysis of prospective studies. BMJ. 2016;353:i2716.

4. Kyrø C, Tjønneland A, Overvad K, Olsen A, Landberg R. Higher whole-grain intake is associated with lower risk of type 2 diabetes among middle-aged men and women: the Danish Diet, Cancer, and Health Cohort. J Nutr. 2018;148(9):1434-1444.

5. Reynolds A, Mann J, Cummings J, Winter N, Mete E, Te Morenga L. Carbohydrate quality and human health: a series of systematic reviews and meta-analysis. Lancet. 2019;393(10170):434-445.

6. GBD 2017 Diet Collaborators. Health effects of dietary risks in 195 countries, 1990-2017: a systematic analysis for the Global Burden of Disease Study 2017. Lancet. 2019;393(10184):1958-1972.

7. US Department of Health and Human Services; US Department of Agriculture. 2015–2020 Dietary Guidelines for Americans: eighth edition. Published January 7, 2016. Accessed July 9, 2019.

8. Roszkowska A, Pawlicka M, Mroczek A, Bałabuszek K, Nieradko-Iwanicka B. Non-celiac gluten sensitivity: a review. Medicina (Kaunas). 2019;55(6):E222.

9. Dr. Fasano: gluten free for all? Really? YouTube website. Published March 20, 2015.

10. Catassi C, Alaedini A, Bojarski C, et al. The overlapping area of non-celiac gluten sensitivity (NCGS) and wheat-sensitive irritable bowel syndrome (IBS): an update. Nutrients. 2017;9(11):E1268.

11. Lebwohl B, Cao Y, Zong G, et al. Long term gluten consumption in adults without celiac disease and risk of coronary heart disease: prospective cohort study. BMJ. 2017;357:j1892.

12. Wheat allergy. American College of Allergy, Asthma & Immunology website. Accessed July 11, 2019.

13. Sturgeon C, Fasano A. Zonulin, a regulator of epithelial and endothelial barrier functions, and its involvement in chronic inflammatory diseases. Tissue Barriers. 2016;4(4):e1251384.

14. Whole grains 101. Oldways Whole Grains Council website. Accessed July 8, 2019.