Whole Grains - Good or Bad?
Grains have been getting a lot of attention in the media of late. The messages have been mixed and this can be terribly confusing and, at times, frustrating for consumers. While it is true that refined grain products have the potential to be damaging to your health, it is the exact opposite when it comes to whole grains. Unfortunately with the resurgence of the various low carb diets some people have skipped all grains entirely in fear they are bad for health or will cause weight gain. This is not something I would recommend doing. Regular whole grain intake is generally associated with lower rates of chronic diseases like Type 2 Diabetes, Cardiovascular Disease and some cancers and they are also consistently linked with a lower body mass index. Whole grains are packed full of fibre, so are great for digestive health and your gut microbiota.
Whole Grain Structure
While each grain will vary in structure there are some similarities they all share. Lets take a look:
In their natural state whole grains contain all three parts of the grain; the bran layer, the endosperm and the germ.
The Bran: This is the outer later and holds the majority of the grain's fibre and is rich in vitamins, minerals and antioxidants.
The Endosperm: This is the starchy component of the grain and contains some protein. The Endosperm acts as the energy reserve for the Germ.
The Germ: The embryo of the grain, this section contains healthy fatty acids, and is full of minerals, antioxidants and Vitamins E and B.
Refined grains are milled, a process which removes the bran and the germ. This process results in a loss of many vitamins and minerals and much of the grain's protein and fibre.
Not all Whole Grain Products are Created Equal
While whole grain products still retain the bran, endosperm and germ, and are therefore better choices than refined grain versions, it doesn't mean these products are never processed. As whole grains are processed the nutritional profile of the product changes. Typically the more a grain is altered the greater the surface area, which can reduce the amount of nutrients available and increase the rate in which carbohydrates are broken down and absorbed. For example whole wheat kernels have a glycaemic index of 45 (low GI), whereas whole wheat bread typically has a GI of around 70 (high GI), meaning the carbohydrates in whole wheat bread will be digested, metabolised and absorbed more quickly and cause a quicker rise in blood sugar levels, and consequently insulin, than the wheat kernels.
'If you are trying to manage blood glucose levels or lose weight it is best to stick with whole grain products that have been minimally processed - intact, cut/broken or rolled'.
The Whole Grain Hierarchy
A list which ranks whole grains products from the intact grains to those that are most processed. As you move down the hierarchy you start to see products that are more processed and often have other ingredients added, which can significantly change the caloric density of your meal/snack. If you are trying to manage blood glucose levels or lose weight it is best to stick with whole grain products that have been minimally processed - intact, cut/broken or rolled.
For more information regarding the wholegrain hierarchy please take a look at Dietitian Brenda Davis's video here
Types of Grains
There are many different grains and pseudo grains available for you to enjoy. For those of you with coeliac disease or gluten intolerance I've indicated the gluten free options with an asterix (*).
- Wheat (including wheat varieties like spelt, kamut, farro and durum)
***Avenin is a gluten-like compound which is found in oats, even if they are certified gluten free. Approximately 1 in 5 people with coeliac disease react to pure uncontaminated oats- that is they react to oat avenin.