Whole grain is an important source of dietary fibre, minerals, vitamins, phyto-oestrogens, antioxidants and other components and is low in saturated fatty acids. The nutrients are not uniformly distributed throughout the grain kernel. The highest concentration of nutrients is located in the germ and bran layer. The main nutrients of the three parts are listed below:
Bran : rich in B vitamins, phytonutrients (flavonoids, indoles), fibre, minerals; small amount of protein
Endosperm : predominantly carbohydrate, also proteins, small amounts of B vitamins
Germ : rich in minerals (Fe, Zn), B vitamins, phytonutrients and antioxidant vitamin E
During the milling (or refining) process of grains the bran and germ is removed resulting in a substantial loss of important nutrients.
NOTE : Whole grain products contain the whole package of nutrients from the entire grain kernel !
Dietary Fibre
Dietary fibre is made up of the edible parts of the plant that can not be digested or absorbed in the small intestine. It can be found especially in whole grain products like bran and oat bran cereals, whole and mixed grain breads or wholegrain breakfast cereals for example.
Dietary fibre includes :
- Non-starch polysaccharides : e.g. cellulose, hemicellulose, gums, pectins
- Oligosaccharides : inulin
- Lignin
- Associated plant substances : e.g. lignin and waxes
- Resistant starch : found in pulses, partly-milled seeds and grains as well as in processed cereals. It resists digestion in the small intestine.
Dietary fibre is divided into soluble and insoluble fibre :
- Soluble fibre : in oats, barley, rye, fruits, vegetables and pulses. Soluble fibre may slow digestion and absorption of carbohydrates and therefore help people with diabetes and high blood cholesterol levels improve control their blood glucose and blood lipid levels. Whole grain products provide 20-50 % of their fibre in the soluble (or viscous) form.
- Insoluble fibre : in whole grain cereals and wholemeal bread, is important for bowel function and regularity
What can whole grain do for you ?
Dietary fibre was long considered the most important health protective component of cereal grains. Now more and more evidence evolves that cereals also contain other protective compounds, such as oligosaccharides and phytochemicals (also referred to as bioactive substances; they are commonly found in plant foods and may have beneficial effects on health).
Whole grain foods are "packages" of nutrients, phyto-protective components and fibre. Together these substances probably work far better than one of them alone.
A number of scientific studies indicate significant health benefits of whole grains. The full benefits are not completely known and understood so far but research is on the way to learn more and more about the mechanisms.
Facts
- Epidemiological studies indicate that the risk for type 2 diabetes mellitus can be decreased with a greater consumption of whole grains.
- Whole grain consumption is associated with a reduced risk of coronary heart disease.
- Whole grains reduce the risk of constipation.
- Whole grain foods are digested and absorbed more slowly.
- High fibre foods may promote satiation and satiety resulting in a decreased energy intake.
- Whole grain products help in maintaining a healthy body weight due to being low in fat and high in fibre.
- Whole grain foods tend to have a low GI (glycaemic index) because of the larger particle size and high content of viscous fibre.
Briefly, whole grain may be good for your :
- heart
- blood sugar levels
- insulin levels
- body weight
- overall digestive health
Current consumption of whole grain
A number of surveys show that the consumption of whole grain increases with the age of the consumer and that men consume more whole grain than women, maybe because of a greater overall food intake.
The income and level of education are positively associated with whole grain consumption in the USA and the UK. On the contrary, in Finland the highest intakes of rye bread were found in lower socio-economic groups.
In the USA and UK whole grain consumers were less likely to smoke, tended to be regular exercisers and consumed more fruits and vegetables. These results indicate an association of whole grain consumption with other positive lifestyle traits.
Whole grain consumption in the UK
- People over the age of 65 years consume a weekly average of less than five servings.
- Adults in the age group of 16 to 64 years eat a weekly average of only 2.5 servings.
- Adults between 16 to 24 years have only one serving per week.
- Alarming is that approximately one-third of the British adults and 27% of the children fail to consume any whole grain foods at all.
- In other words 95% of the British adults and 94% of the children do not eat the recommended daily amount of 3 servings.
Whole grain consumption in the USA
- It is estimated that the average whole grain intake in the USA is less than one serving per day.
- Americans consume only an average of 14 to 15 g fibre per day instead of the recommended 25 to 30 grams.
Whole grain consumption of the Scandinavians
- Scandinavians tend to eat more whole grain compared to the USA and UK.
- The consumption of whole grain foods in Norway was reported to be four times that reported for the USA.
- In Finland mainly rye bread is eaten.
Reasons why whole grain consumption may be low
- Sadly, few people are aware of the health benefits of whole grain foods.
- Consumers have difficulties in identifying whole grain foods.
- Consumers express limited knowledge about the preparation and cooking of whole grain foods.
- Whole grain breads are often described as dry and bitter. Whole grain foods in general are sometimes said to be bland and dry in taste.
- Unfortunately whole grain varieties of bread, pasta and rice tend to be more expensive. This deters low-income and vulnerable groups from buying whole grain products.
Increasing variety and availability of acceptable whole grain foods will certainly lead to greater consumption levels.
Which foodstuffs contain whole grain ?
The major sources of whole grain in the UK are bread, breakfast cereals and crackers. Additionally, commonly consumed whole grain foods in Western cultures are dark bread, popcorn, oatmeal and brown rice.
If you find it hard to identify whole grain products look out for the following ingredients :
- wheat flakes
- cereal grains
- whole grain wheat
- whole grain rice
- rolled oats
- oatmeal
- brown rice
- bulgur (cracked wheat)
- whole rye
- pearl barley
- whole grain corn
These ingredients indicate that the product contains whole grain.
Choose whole grain varieties of bread, whole grain breakfast cereals, whole grain pasta and rice or whole grain varieties of biscuits and crackers instead of the white varieties of these products !
How much whole grain is good for you ?
Based on scientific studies an intake of three servings of whole grain per day appears to be beneficial for heart health.
Although benefits are indicated also at relatively low levels (2-3 servings per day), consumption in some Western countries is less than 1 serving per day !
Increased grain consumption is recommended by different international dietary guidelines as a preferred source of carbohydrate, fibre and micronutrients.
Keep in mind
- Choose a wide variety of foods to provide adequate intakes of vitamins, minerals and dietary fibre !
- No single food can provide everything your body needs but the wide variety will do !
- Do not forget enough physical activity to keep your body fit !
