Are Grains Really Necessary for a Healthy Diet?

We hear a lot about the value of whole grains.  Could a grain-free diet be a healthy option?

Monica Reinagel, MS, LD/N, CNS,
March 22, 2011
Episode #132

This article is adapted from my new book, Nutrition Diva’s Secrets for a Healthy Diet: What to Eat, What to Avoid, and What to Stop Worrying About.  It’s available wherever you buy or download books. Click here to read another free excerpt.

Are Grains Really Necessary for a Healthy Diet?

One of the reasons that grains have become such a central part of the human diet is that they have a long shelf-life. Unlike meat, dairy, and fresh produce, grains pack a whole lot of food energy (also known as calories) into a small, lightweight package that can be stored indefinitely without refrigeration or other preservation.  If you’ve got some dirt and a water supply, your last handful of grain can be used to create the next season’s food supply. You can see why they caught on.

What Are Whole Grain Foods?

Although grains are portable and non-perishable, they’re not really edible in their raw state.  You can boil, steam, or sprout whole grains and eat them that way. Or you can mill the grains into flour and use it to make bread, tortillas, or pasta.  Either way, it’s considered a whole-grain food if all of the parts of the grain are included—the nutrient-rich germ, the starchy endosperm, and the fibrous bran.  When the bran and germ have been removed, as in white flour, it’s said to be a refined grain. 

The Advantages of Whole-Grain Foods

The more grain-based foods you eat, the more important the quality of those grains becomes.

Keeping the germ makes whole-grain foods somewhat higher in certain vitamins and minerals.  But the primary nutritional advantage of whole grains is that the fiber from the bran slows down the speed at which the starches in the endosperm are converted into blood sugar.   Said another way, whole-grain foods have a lower “glycemic load” and when you’re talking about glycemic load, lower is generally better. 

Foods with a high glycemic load tend to make your blood sugar and insulin spike, which increases your risk of diabetes and heart disease and can potentially lead to weight gain, as well.  In fact, diets high in refined grains (which have a high glycemic load) have been linked to heart disease, type 2 diabetes, cancer, and obesity.  Choosing whole grains instead of refined grains reduces these risks.

What’s an Intact Grain?

The terminology used to describe grains can be a little confusing.  Breads, cereals, pasta, and other foods can be labeled “whole grain” if they’re made with whole grain flour. But obviously, once you’ve ground a kernel of wheat or rice into a pile of dust, it’s not really “whole” any more.  To avoid confusion, I use the term “intact grains” to refer to grains that are still more or less in their original shape—things like whole oats, bulgur wheat, quinoa, and brown rice.  (My book, Secrets for a Healthy Diet includes a guide to all the different types of grains and their nutritional profiles.)

Most of the dietary guidelines you’ll come across emphasize the importance of whole grains, but they rarely distinguish between intact whole grains and milled whole grains, or flour.  In fact, there are some important differences. Intact grains are digested and absorbed more slowly than milled grains, which is generally a plus.  And although whole grain flour contains all the parts of the original grain, some nutrients are lost or degraded in the milling process. For these reasons, I consider intact whole grains a notch above foods made with whole-grain flour. And the more grain-based foods you eat, the more important the quality of those grains becomes.

Do You Really Need to Eat Grains?

So why do so many dietary guidelines emphasize the importance of whole grains? Well, as I mentioned above, research shows that people whose diets are high in whole grains have lower rates of heart disease, diabetes, and tend to be leaner and healthier. But most if not all of these studies are comparing people who eat whole grains with people who eat refined grains, or things made from white flour.  They’re not comparing people who eat whole grains with people who eat little or no grains.

It’s pretty clear that replacing refined grains with whole grains is a step in the right direction. What’s not as clear is whether the benefits that are usually attributed to whole grain consumption really come from eating more whole grains—or whether these benefits are really the result of eating fewer refined grain products.   

Some people argue that you’d be better off without any grains at all—and I’d have to agree that grains are not essential to a healthy diet.   If you prefer to eliminate them, you have my blessing. For most people, however, a diet including whole grains is more convenient, affordable, practical, and familiar—and I think it can also be a perfectly healthy choice.

How Much Grain Should You Eat?

If you do opt to eat grains, current dietary recommendations suggest that average sized adults should have about six servings of grain foods every day and that at least three of them should be whole grains.

I see this a bit differently. First of all, if you didn’t want to eat six servings of grains a day, that would be fine with me.  And secondly, because refined grains offer so little nutritional value and appear to actually do some harm, I think getting half your grains from refined grains is too much.  Something more like 0 to 10% of your grains as refined grains would be more like it.

The Quick and Dirty Secret:   Whole grains are good, whole intact grains are better, and refined grains should be consumed in limited quantities.

I hope you enjoyed this excerpt from Nutrition Diva’s Secrets for a Healthy Diet: What to Eat, What to Avoid, and What to Stop Worrying About.  The book is available in both print and e-book editions on Amazon, Barnes and Noble, iTunes or wherever you buy books.

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Have a great week and remember to eat something good for me!


Dietary Guidelines on Grains (USDA)

A Different Twist on Whole Grains  (Blog post)

Grains image courtesy of Shutterstock

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