The debate about the health benefits of whole grains continues. On one hand, you have research, like a Harvard study, showing whole grain consumption is linked with a lower risk of premature mortality. On the other side are people in the low carb and Paleo camp who believe that all grains, whole or refined, are harmful. They argue that grains are a rather recent addition to the human diet and humans haven’t had a chance to adapt to them. The low-carbers point out that grains are high in carbs, and carbohydrates may be fueling the rise in type 2 diabetes.
Who should you believe in this seemingly never-ending argument?
First, let’s distinguish between whole grains and refined grains. Whole grains are the whole seed or grass in its unaltered state and consist of three layers – the endosperm, germ, and bran. Whole grains become refined grains when manufacturers strip them of their bran and germ. Unfortunately, these portions of the grain are high in fiber and contain most of the nutrients. Therefore, you lose fiber and nutrients, like B-vitamins and magnesium, when whole grains are processed into refined grains.
To make up for the nutritional shortfall, manufacturers add synthetic nutrients, like B-vitamins, to refined grains through a process called fortification. But, you can’t make up for the loss of fiber and that’s one of the features that distinguish whole grains and refined grains – whole grains typically have double the fiber that refined grains have.
Types of Whole Grains
You’re probably familiar with some of the more popular whole grains, such as oats, barley, rye, buckwheat, corn, and rice, but there are lesser known grains as well, such as quinoa. Spelt, kamut, amaranth, and teff. Some of these are called ancient grains because they still exist in their unaltered state after thousands of years, in contrast to modern grains that scientists have selectively bred to change their characteristics.
One reason the Paleo community avoids, even ancient grains, is because they believe they trigger inflammation. Much of this fear comes from the fact that people with a condition called celiac disease experience intestinal inflammation when they consume any form of wheat, rye, or barley. Celiac sufferers react to one of the proteins in these grains, mainly gluten.
Celiac is a condition that affects around 1% of the population, although some experts believe the number is higher and many people are undiagnosed. In addition, around 10% of the population appears to have some degree of gluten intolerance. These folks experience symptoms when they consume grains that contain gluten, although they test negative for celiac and have no detectable intestinal inflammation suggestive of celiac disease.
Yet, the majority of the population has no evidence of celiac disease OR gluten intolerance and feel fine when they consume whole grain foods. Yet, there are still those who believe any type of grain is harmful and consuming them causes problems like a leaky gut that fuels inflammation.
Whole Grains and Gut Health
Are all grains bad for your gut, including whole grains? Just as importantly, are they linked with intestinal inflammation? A study published in the American Journal of Clinic Nutrition finds that this is not the case. This study found that when healthy adults substituted whole grains for refined grains, they ended up with a more diverse gut microbiome (as documented by stool analysis).
What’s more, the bacteria that increased on the whole grain diet were species that produce short-chain fatty acids. Short-chain fatty acids are anti-inflammatory and help keep the lining of the gut healthy. In addition, the participants who ate the whole grains showed improvements in markers associated with a healthy immune response. If you review the literature, you’ll find that most studies show that whole grains either have no impact on inflammation or are anti-inflammatory.
It’s not surprising that participants who ate whole grains enjoyed greater microbiome diversity. Whole grains are rich in fiber and support the health of gut-friendly bacteria. Low-carb proponents avoid them because of their high carbohydrate content, but the fiber in whole grains helps reduce the blood sugar response that occurs when we eat carbohydrates. In contrast, refined grains that lack fiber DO cause a rapid rise in blood sugar.
People who avoid whole grains also point out that they contain anti-nutrients called phytates that reduce mineral absorption. However, other non-grain plant-based foods contain phytates as well, and when you cook, sprout, or ferment plant-based foods and whole grains it reduces the level of phytates. Likewise, grains contain lectins that bind to cell membranes, including intestinal cells. But, lectins are also destroyed by heat. So, if you’re cooking your grains, they’re probably not an issue.
Who Shouldn’t Consume Grains
We know that whole grains are rich in fiber, vitamins, minerals. Plus, they contain phytonutrients, compounds with antioxidant activity. Still, we’re all a bit different. If you have celiac disease, gluten sensitivity, or a wheat allergy, gluten-containing grains shouldn’t be a part of your diet.
In addition, some people who have irritable bowel syndrome do best when they eliminate certain carbohydrates known as FODMAPs, as they can cause gas and bloating. Some grains contain FODMAPs while others are relatively low in these carbs. You can find lists of low and high FODMAP foods. If you have irritable bowel syndrome, try eliminating foods, including grains, that are high in FODMAPs. If you suspect grains are a problem for you, take them out of your diet for a few weeks and see how you feel. But, if you have symptoms consistent with celiac disease, see your physician/
If you don’t have any of the above health issues, whole grains can be a healthy addition to your diet and you should definitely choose whole grains over refined ones. However, you can also get many of the benefits that whole grains offer by eating more fruits and vegetables. Vegetables and fruits are high in fiber and contain many of the minerals and vitamins that whole grains offer. So, a completely grain-free diet can be healthy if you include lots of high-fiber, whole foods.
The Bottom Line
Whole grains aren’t necessary for a healthy, balanced diet, but they are nutrient rich and blood sugar friendly in moderation. Thanks to their high-fiber content, they’re also satiating. Plus, some studies suggest that diets that contain whole grain foods lower the risk of heart disease, stroke, and type 2 diabetes.
The most important thing, from a dietary standpoint, is to avoid refined grains since they lack the health benefits of whole grains and DO cause a rapid rise in blood sugar and potential weight gain. The preponderance of evidence suggests that whole grains are not pro-inflammatory and may have anti-inflammatory benefits based on how they impact the gut microbiome. So, if you’re otherwise healthy, enjoy whole grain foods as part of a balanced diet.
References:
Am J Clin Nutr. 2015 Feb;101(2):251-61. doi: 10.3945/ajcn.114.088120. Epub 2014 Dec 3.
HealthLine.com. “9 Legitimate Health Benefits of Eating Whole Grains”
Eur J Clin Nutr. 2012 Jan;66(1):18-24.
Eur J Clin Nutr. 2006;60(10):1145-1149.
Nutr Rev. 2013 Aug;71(8):511-27.
Precision Nutrition. “Settling the Great Grain Debate”
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