Whole Grains 101: A Guide to Nutritious Choices

Whole grains have existed for centuries, mainly in minimally processed forms directly from their natural plant sources. They are important sources of many nutrients, including fiber, B vitamins, and other minerals. Because whole grains are often less processed, their nutrient density benefits many chronic diseases. 

Despite their well-known nutritional benefits over refined grains, a study from the CDC estimates that only about 16% of the grains consumed by United States adults are whole grains. This article aims to prepare healthcare providers with the education they need about the nutrition of whole grains to best inform their patients.

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What Are Whole Grains?

Whole grains contain all three essential parts of the grain: the bran, germ, and endosperm. 

The bran is the grain's outer layer. It is high in B vitamins, fiber,  antioxidants, and phytonutrients. The germ is also rich in nutrients, including vitamins, minerals, and small amounts of healthy fats. The endosperm is the inner layer. It is higher in starch, complex carbohydrates, and protein.

Here are a few common examples of whole grains:

• Wheat
• Barley
• Millet
• Farro
• Oats
• Brown rice
• Quinoa

Benefits of Whole Grains

Whole grains provide many nutritional benefits, far outpacing their refined, white-grain counterparts.

Fiber

Whole grains are high in fiber, which serves many bodily functions. Fiber is an essential prebiotic, feeding the helpful organisms within the gut microbiome. 

Short-chain fatty acids (like butyrate) are released as the gut microbiota breaks down fiber. They are potent anti-inflammatory compounds that reduce inflammation and support gut lining integrity, reducing the risk of leaky gut syndrome. 

Fiber also promotes fullness, potentially leading to a lower calorie intake overall and helping promote healthy weight maintenance. Lower blood glucose is another benefit of fiber intake, as dietary fiber leads to a slower rise in blood glucoseand a smaller release of insulin following carbohydrate intake.

Vitamins

Whole grains are loaded with B vitamins, which play a wide variety of roles within the body:

• Energy metabolism 
• Anti-oxidation
• Neurological functions
• Neurotransmitter formation
• Cellular health
• DNA replication and repair
• Fatty acid and amino acid synthesis
• Hair and skin health
• Brain and neural tube development in utero
• Nerve and impulse conduction

Whole grains also contain vitamin E, an essential antioxidant that neutralizes free radicals and prevents cellular damage.Vitamin E promotes optimal immune function, helping control inflammation and prevent illnesses.

Minerals

Whole grains contain many minerals, including iron, magnesium, selenium, zinc, and copper, each having specific roles in bodily functions.

Scientific Evidence

Evidence suggests that consuming whole grains has several benefits, including lower cholesterol levels, reduced cardiovascular disease risk, improved digestive health, and a healthier gut microbiome. 

However, some evidence is mixed, with various quality studies and outcomes assessed. This meta-analysis provides a good synopsis of the available peer-reviewed evidence, and the overall consensus is that consuming 2 to 3 servings of whole grains per day is likely beneficial.

Whole Grain Foods

Whole grain foods are available in many varieties, which helps incorporate them into various dishes. Common whole-grain foods include bread, pasta, cereals, brown rice, quinoa, and barley. 

It's important to examine labels closely to identify whole-grain products. Look for terms like "100% whole grain" or "whole wheat," and ensure that whole grains are listed as the first ingredient.

It is essential to understand that increasing numbers of processed foods (like cereals, crackers, cookies, and other snacks) are labeled as whole grains. However, processed foods are less healthful and potentially proinflammatory, often with added sugars, compared to their whole, nutrient-dense, anti-inflammatory counterparts. So, patients should focus on consuming minimally processed whole grains as much as possible.

Incorporating whole grains into daily meals can be healthful and delicious. Begin by swapping refined grains for whole grains, such as whole-grain bread over white bread or brown rice over white rice. Grind oats into a fine flour to make baked goods, and add quinoa to stir-fried vegetables.

Gluten-Free Grains

Gluten is a protein found in wheat, rye, barley, and products containing them. Gluten can cause a severe inflammatory response in some patients, such as those with celiac disease and non-celiac gluten sensitivity. 

While many whole grains contain gluten and are therefore not safe for these patients, there are many gluten-free options, such as quinoa, buckwheat, oats, millet, and brown rice. 

These grains are naturally gluten-free, but some may be processed in a facility with other grains, so patients should check the label to ensure they are gluten-free if necessary. 

Healthy Grains: Making Nutritious Choices

Whole grains have various nutrition profiles to consider when choosing. For example, quinoa is not only a whole grain but also an excellent source of complete protein, containing all nine essential amino acids, which is uncommon among plant-based protein sources. 

Oats are high in soluble fiber, potentially offering additional digestive health benefits and helping reduce cholesterol levels. 

Whole grains contain a significant portion of carbohydrates, so patients following a low-carbohydrate diet may want to focus on quinoa, which is lower in carbohydrates and higher in protein. 

By balancing whole grain intake with other non-starchy vegetables, proteins, and healthy fats, patients can minimize the glycemic load and control their blood glucose well.

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Key Takeaways

• Whole grains are nutrient-rich and healthful foods that have been shown to enhance overall health and lower the risk of various chronic diseases.
• Whole grains are high in B vitamins, fiber, vitamin E, and certain minerals, like iron, selenium, zinc, and magnesium.
• When shopping for whole grains, look for whole grains as the first ingredient, and whenever possible, choose the least processed options for better nutrition.
• Many whole grains contain gluten, though options like quinoa, buckwheat, oats, and brown rice are naturally gluten-free.
• Including whole grains into your diet can be easy and delicious with simple substitutions.