Folate (folic acid) is an essential B group vitamin that is needed for the growth and development of body cells (including red blood cells), and the metabolism of proteins and fats in food.
Recently, there have been several studies linking folate intake to a decrease in mortality from coronary artery disease. How is this so?
High levels of homocysteine (an amino acid or ‘building block’ of proteins) in the blood have been suggested as a risk factor for heart and blood vessel disease. Many studies have shown that elevated blood homocysteine levels are found in people with coronary artery disease.
Folate is needed for the metabolism (or breakdown) of homocysteine. When the level of folate in the blood is low, homocysteine levels can build up. In fact, low blood levels of folate are often found in people with high levels of homocysteine. While folate seems to be the most important B vitamin for the metabolism of homocysteine, vitamins B12 and B6 may also be important.
Studies have shown that supplementing the diet with folate can reduce blood homocysteine levels. This effect however, is greatest in people who already have elevated homocysteine levels.
So, can getting enough folate prevent heart disease? At this stage, more studies are needed. While we know that high homocysteine levels are associated with an increased risk of coronary artery disease, and that folate can reduce homocysteine levels, we cannot yet conclude that adequate folate intakes will definitely reduce the risk of heart disease.
However, the evidence appears very promising, and increasing your intake of folate rich foods will not only increase your folate intake, but provide other nutrients essential for a healthy heart, such as dietary fibre and potassium. These foods also tend to be lower in salt, total fat and saturated fat.
How much folate?
Folate intakes of over 400g per day have been associated with desirable homocysteine levels. This is twice the amount recommended for the general population in Australia at present. Good sources of folate include:
enriched breakfast cereals, such as Bush Foods breakfast cereal, wholegrain breads and yeast extracts (which can contain approx. 100g per serve);
fruits, such as oranges, bananas, strawberries and rockmelon;
vegetables, including spinach, broccoli, cauliflower, endive lettuce and asparagus;
nuts, such as peanuts and cashews;
legumes, including lentils, chick peas and soya beans.
Try to eat at least 2 serves of fruit, 5 serves of vegetables and 7 serves of breads and cereals (preferably wholegrain) each day, to ensure you get enough folate, as well as fibre and potassium (but not too much salt, fat or saturated fat).
Remember also that not smoking and including regular exercise are important lifestyle factors for reducing the risk of developing heart disease.
This article was prepared by the nutritionists at Sanitarium Nutrition Service.