Why eat whole grains? Understanding their health benefits
Grains in seem to be having a hard time lately, with gluten being blamed by some for major health problems and new grain-free diets springing up every year. So one can easily wonder why eat whole grains at all, as recommended by health authorities everywhere.
However, according to Dr. Frank Hu, Professor of nutrition at the Harvard T.H. Chan School of Public Health and author of two long-running studies, eating 70g of whole grains per day could reduce your risk of dying by 5%. With each additional 28g serving, the risk of dying of heart disease is reduced by 9%. The study also found that replacing refined grains and red meats by whole grains in equal amounts could potentially increase your lifespan by 8% to 20%.
There is so much to explain about whole grains that I have split this subject in two. Part 1 covers Why eat whole grains, and Part 2 deals with ways to eat more whole grains.
What are whole grains?
Grains, also called cereals, are the seeds of some grasses, which are cultivated for food. The following are all grains you’re likely to come across in the shops, although not all in the form of whole seeds (alternative names in brackets):
- Buckwheat (or kasha)
- Corn (hominy, popcorn, maize)
- Oats (oatmeal)
- Wheat (triticale, semolina, seitan, farro, kamut)
- Wild Rice
Whole grains vs. refined grains
A whole grain will contain the whole kernel, i.e.:
- The bran – the outer layer, which contains vitamins, minerals, and fibers.
- The endosperm – the main part of the grain, which can be ground to make flour. Initially destined to feed the embryo, the germ, when it develops into a new plant. Contains carbohydrates, proteins, vitamins, and minerals.
- The germ – the smallest component of the kernel, which is supposed to germinate if planted. Contains proteins, vitamins, minerals, and fat.
100% whole grains will contain all 3 parts of the kernel (the bran, the endosperm, and the germ). To obtain refined grains, whole grains are milled to remove the bran and the germ. The end result is of finer texture and keeps for longer. The process removes, however, a lot of the nutrients, in particular, fiber.
Whole grains can still be milled, rolled, crushed or cracked. As long as the whole of the kernel is present in the end product, they are still “whole grains”.
Note – when we eat refined grains, our bodies actually use nutrients to digest these nutrient-poor foods, which leaves us poorer in nutrients than before eating them!
Note 2 – This is why you might come across the terms “enriched grains” and “fortified grains”. “Enriched grains” means some of the nutrients lost during the milling stage are replaced, such as vitamins. “Fortified grains” means that some nutrients that were not initially in the kernel have been added.
Whole grains and fibers
As you can see from the Nutritional info above, one of the main nutrient to be removed during the refining process is fiber. It’s the part of a plant food that the body cannot digest. As it moves through our digestive system, it absorbs water and helps the body eliminate food waste quicker.
A higher consumption is linked with a lower risk of heart disease, as it helps lower blood pressure and cholesterol, and stabilizes blood sugar. It also fills you up and is an essential tool for weight loss and weight management.
There are 2 varieties of fiber: insoluble and soluble. Good sources of insoluble fiber in grains are whole wheat and popcorn (minus any added butter or sugar), but also teff, spelt and millet. Barley and oatmeal, as well as amaranth, contain soluble fiber. The body needs both in equal measures for optimal health.
The current recommended intake of fiber ranges from 21 to 25 grams for women and 30 to 38 grams for men. However, the vast majority of us only get to about half of that amount per day, mostly thanks to our highly processed diet of refined grains and our low intake of high-fiber food such as fruits and vegetables.
Check my next post on How to eat more whole grains to figure out how to increase your fiber intake the easy way.
So why eat whole grains?
The higher fiber content of whole grains is linked with lowering your general risk of mortality, but that’s not the only reason why eating whole grains is beneficial to our bodies. The bran and germ of grains also contain a whole range of phytochemicals, vitamins, and minerals, as well as proteins, all playing a beneficial role. Let’s list a few of the main benefits here:
1. They slow down digestion,
…stabilizing your blood sugar and insulin levels. When ingested, refined grains break down immediately into glucose, much the same way as pure sugar. This sends your blood sugar rocketing, then plummeting, later on, causing sugar crash and cravings.
Whole grains are broken down more slowly, keeping you full for longer.
2. They have been found to help with weight management
…by not sending you reaching for the next sugar or starchy fix, three servings per day being associated with less abdominal fat.
3. Whole grains, therefore, help with preventing type 2 diabetes
…through healthy weight control and stabilization of your blood sugar levels. Those benefits kick in from only two servings per day (read my post on How to eat more whole grains to figure out what a serving is). This could be due to their high-fiber and high-magnesium content, both linked with better carbohydrate metabolism and insulin sensitivity.
4. Whole grains can help lower blood cholesterol,
…oats being a real champion in this category. Their higher soluble fiber content helps with eliminating cholesterol, by binding the cholesterol and its precursors together in the digestive tract and eliminating it quickly. The antioxidants found in oats also play a role.
5. They can help decrease your blood pressure,
…in particular, whole grains with a high soluble fiber content, such as barley and oats. Their antioxidants help improve cardiovascular health and reduce inflammation.
6. Numerous studies on more than 20 types of cancer
…have found a link between eating three servings of whole grains per day and a reduced risk of cancer. This is in particular valid for gastrointestinal cancers and cancers of the oral cavity, such as pharynx, esophagus, and larynx.
Whole grains offer protective nutrients, such as fiber, antioxidants (vitamin E and selenium in particular) and phytochemicals which can help suppress the growth of cancer cells, block DNA damage and prevent the formation of carcinogens.
And if the benefits of whole grains start at just two servings per day, research has shown that the health improvements increase with each extra serving, to reach the 3-4 servings of whole grains recommended daily by the Dietary Guidelines for Americans.
The take-home message: load up on whole grains for optimal health
How to do this? There are a lot of easy ways to identify whole grains in your food and increase your intake. Read up on those in my next article on How to eat more whole grains.