It probably seems confusing that I am writing about the health benefits of whole grains when there has been so much coverage promoting grain-free and carb-free diets. Whole grains have been on the menu for at least ten thousand years, so why would we want to stop eating them?
As mentioned in part 1 of this series, I think the real confusion has come about due to our misunderstanding of the differences between whole and refined grains. In this article, I outline the health benefits of whole grains.
Health benefits of whole grains
The health benefits of whole grains are thought to arise from the complex mixture of fibre, nutrients, and phytochemicals that work together to prevent chronic disease.
The phytochemicals in whole grains complement those found in fruits and vegetables when they are eaten together. This highlights the importance of basing our meals on plant foods—think plant foods before animal foods when you are planning your meals.
No single component in whole grains has been found to be responsible for their health benefits, thus emphasizing the need to eat whole grain foods rather than taking supplements.
Scientific research indicates that eating two to three serves of whole grain foods daily contributes to health benefits.
#1 High in nutrients and fibre
Nutrients, phytochemicals, and fibre are found in different parts of the grain:
- The bran layer provides fibre, B group vitamins, copper, iron, magnesium, zinc, antioxidants, and phytochemicals.
- The germ is rich in healthy fats, B group vitamins, vitamin E, antioxidants, and phytochemicals.
- The endosperm provides carbohydrate, protein and small amounts of some B group vitamins and minerals.
These components potentially support our health in a number of different ways:
- Bran, fibre and other compounds contribute to the lower glycemic index (GI) of whole grain foods, assisting in the regulation of insulin levels and other metabolic processes.
- Fibre, phytochemicals and other compounds that have disease prevention effects.
- Fibre helps lower blood cholesterol levels and may assist in the prevention of blood clots forming, therefore preventing heart attacks and stroke.
- Essential minerals and phytochemicals may play a role in preventing some cancers.
- Fibre helps move waste through the digestive tract, reducing transit time which is beneficial to gut health.
- Prebiotic effects of whole grains result in positive alterations to the gut microbiome. Prebiotics feed healthy bacteria in the gut.
- Contribute to beneficial pH changes in the colon.
#2 Reduced risk for cardiovascular disease
Eating whole grains, rather than refined grains, lowers risk factors for heart disease such as LDL cholesterol, triglyceride, and insulin levels.
Research studies suggest that eating 2 to 3 serves of whole grains daily reduces the chance of heart attack or death from heart disease by 21–30%.
#3 Reduced possibility of hypertension
Hypertension (high blood pressure) is a major risk factor for cardiovascular disease. Results of the Women’s Health Study showed that women who ate 4 serves of whole grains daily, had a 23% reduction in risk for hypertension, compared to women who ate less than 1/2 a serving a day.
#4 Lowered risk of developing type 2 diabetes
Swapping refined grains with whole grains may reduce the risk of developing type 2 diabetes by as high as 43%. A review of 66 studies indicated a risk reduction of 26% when 3 to 5 serves of whole grains were consumed per day.
The fibre, nutrients, and phytochemicals in whole grains potentially improve the actions of insulin and glucose metabolism and reduce the rate of absorption of food—resulting in well-controlled blood sugar levels.
#5 Protect against cancer
The scientific studies are not clear when it comes to the relationship between eating whole grains and cancer prevention.
Whole grains offer some protection against developing colorectal cancer. Eating whole grains may reduce the risk of colorectal cancer by 20%.
#6 Improved digestive health
Dietary fibre, and adequate fluid help to keep the stool soft and bulky, making it easier to pass. This helps to prevent constipation and diverticular disease.
Digestive health is also supported by a healthy balance gut microbiome. You might like to read my earlier post on healthy digestion here.
#7 Healthy body weight
Results have varied when reviewing the link between whole grains and body weight.
Whole grains potentially assist healthy body weight regulation due to their lower energy density, lower GI, high satiation value (make you feel full) and by providing fuel for health-promoting gut bacteria.
If you have been avoiding grains because you thought they were bad for your health, then please reconsider whole grains. As you can see, unless you have coeliac disease or wheat allergy, the health benefits of whole grains are difficult to ignore.