02.What is a whole grain?
Wholegrains are cereals in which all the natural grain, including the outer bran layer, germ and endosperm layers (see Anatomy of a wholegrain), are retained. The most commonly eaten grains, white flour and white rice, have had these healthy components removed in the refining process.
Common wholegrains are:
- Whole wheat, including wholemeal.
- Brown rice. Corn (even popcorn).
- Oats, which mean porridge and muesli to most of us.
In a consumer survey, most people knew wholegrains were good for them and many said bread and breakfast cereals were good sources of wholegrain. However, many people also thought rice, muesli bars and pasta were common sources of wholegrains, whereas in fact many are not. Only brown rice and wholegrain pasta would fit the bill, plus muesli-type snack bars that contain a majority of refined grains
What do they do
Wholegrains are high in many phytochemicals (plant substances), which have been shown to protect us from a wide range of health problems. They contain not just antioxidants, but such things as: Sterols, saponins, squalene, oryzanol and tocotrienols, which can reduce cholesterol levels.
Lignans, which lower the risk of heart disease, and may have anti-cancer effects. Phytates, which may affect how quickly starch is digested and reduce the GI of food. Vitamins and minerals such as magnesium and potassium.
Soluble fibre Numerous studies support the idea that foods rich in soluble fibre — such as the wholegrains oats and barley — can lower cholesterol. Wholegrains can also improve insulin levels and blood sugar control, which not only helps with diabetes but also heart disease.
How much is plenty?
The Australian dietary guidelines say we should eat ‘plenty’ of bread and cereals, preferably wholegrain. Aim for at least four serves of grain-based foods a day — even as many as nine or 12, depending on your age, sex and activity. A serve is two slices of bread, or a cup of cooked rice/pasta/porridge, or 1¹⁄³ cups of breakfast cereal, for example.
Health proponents say you should aim to eat half your intake of bread and cereals as wholegrain, which means at least two serves each day. Experts from the cereal-industry-based group Go Grains Health and Nutrition have developed a program to help us eat enough cereal foods and enough wholegrains. The group has members right through the food chain, from growers to cereal food manufacturers.
The 4+ serves a day program educates us how to include four or more serves of grain-based foods each day. It’s also set a target of at least 48 g of wholegrains a day, based on the scientific evidence. Manufacturers are encouraged to label their foods with statements such as, "Aim for 48 g or more of wholegrains each day. One serving (x g) of this product contains y g of wholegrains."