Surprising Side Effects of Giving Up Grains, Say Dietitians

The label ‘whole grain’ is like a nutritional Golden Ticket when it comes to healthy foods.

“A whole grain is the entire seed—the bran, the endosperm, and the germ. Whole grains contain key nutrients that contribute to satiety and fullness, in addition to extensive health benefits,” says registered dietitian Bonnie Taub-Dix, RDN, creator of BetterThanDieting.com, author of Read It Before You Eat It – Taking You from Label to Table. “Many foods contain whole grains, like oatmeal, whole-wheat pasta, and even popcorn.”

But going grain-free has become more popular in recent years, and there may be many reasons someone may give up grains. For example, popular diets like the Paleo Diet and the Whole30 Diet require dieters to go grain-free.

“When grains are given up, that practice generally arises more from a desire to ditch carbs rather than a medical need to avoid them,” says Taub-Dix.

And people with certain health conditions may need to go grain-free.

“People with food allergies and/or intolerances or inborn metabolic errors, such as phenylketonuria or celiac disease,” says Sandra J. Arevalo, MPH, RDN, CDN, registered dietitian nutritionist and National Spokesperson for the Academy of Nutrition and Dietetics.

Overall, there can be many positives and negatives related to going grain-free. Here are 10 side effects of not eating grains, according to dietitians. Read on, and if you’re reading this because you’re doing Whole30, don’t miss The Ultimate Guide to Exactly What Foods You Can and Can’t Eat on Whole30.

A 2016 BMJ study found that cutting out grains may increase your risk for cardiovascular disease.

“This is due to the lack of dietary fiber that provides important nutrients that help clean antioxidants,” says Arevalo. To see more about what can happen when you don’t get enough fiber, check out these 5 Major Side Effects Of Not Getting Enough Fiber, Says Science.

“Whole grains multitask by providing a powerhouse of nutrients like fiber, B vitamins, folate, protein, iron, antioxidants, and much more,” says Taub-Dix. “Grains that are enriched can make up for nutrients we may not get in our diets from other foods, like iron. Iron-fortified foods are particularly important for menstruating women.”

RELATED: Sign up for our newsletter to get daily recipes and food news in your inbox!

A May 2017 study found that giving up grains may also increase your risk for diabetes.

“The more whole grains you eat, the lower your risk to develop diabetes,” says Arevalo.

“Giving up grains, particularly whole grains, can lead to constipation, bloat, and gastrointestinal distress,” says Taub-Dix. “If you barely eat any grains now, add those that are high in fiber back to your diet slowly, and be sure to pair with fluids, like water or tea, to minimize any side effects. Adding a variety of whole grains will really move you (in a good way)!”

An August 2015 study in the Journal of the Academy of Nutrition and Dietetics found that 92% of participants who ate the Specific Carbohydrate Diet (a grain-free diet) reported it helped them stay healthy and in remission from IBS.

A March 2017 study found that giving up grains could actually lead to weight gain.

“Not eating enough whole grains can help decrease the resting metabolic rate, and thus lower the amount of calories we burn,” says Arevalo. (Read more: 26 Worst Habits Slowing Your Metabolism, Says Science.)

An October 2018 meta-analysis of 9 studies found that increasing your intake of whole grains can actually help reduce inflammation. While the study didn’t look at the mechanism behind how whole grains can decrease inflammation, the researchers pointed out a few hypotheses: One is that whole grain products contain phytochemicals that can exert anti-inflammatory. And another is that whole grain foods contain compounds that are metabolized by the beneficial bacteria in our gut microbiota, which produce short-chain fatty acids (SCFA) that have been linked to decreased levels of low-grade systematic inflammation.

Skipping whole grains may actually cause your immune system to take a hit.

“Whole grains make your gut bacteria (the good ones) smile! Science has shown that fiber helps to fuel the microbiome to help us support a healthy immune system,” says Taub-Dix.

An August 2019 study found that eating whole grains may help prevent breast cancer.

“When your diet lacks whole grains, you are missing out on an important source of bioactive phytochemicals, helpful in the management of each stage of breast carcinogenesis,” says Arevalo.

Some grains, like whole wheat, are sources of gluten: a protein that can cause digestive discomfort in sensitive individuals. A February 2018 study found that those with gluten-related disease (like celiac disease) and gluten sensitivities who stayed on a gluten-free diet (which excludes some grain foods) reported decreased symptoms. If you’re thinking about removing grains from your diet because you think you have a gluten sensitivity, consider these Side Effects of Giving up Gluten, According to Science first.