Of the dozens of vitamins and minerals that are essential to life, only a few have managed to gain widespread renown and acceptance. When a nutrient makes the transition from chemical obscurity to trusted remedy, it usually does so on the basis of some specific action or effect. Vitamin A, for instance, is famous for its ability to help us see in the dark, while iron is well known for its role as blood builder. Yet science shows that individual vitamins and minerals have a varied assortment of effects in the body. This means that while a nutrient may make its name through some biological party piece, the fact is it often has numerous other talents that may go quite unnoticed.
One nutrient that appears to have become somewhat typecast is folic acid. This vitamin has for more than a decade been lauded for its ability to prevent birth defects, such as spina bifida. However, more and more research suggests that it has other important but unrecognised roles in the body. In the past few weeks alone, studies have been published that link this nutrient with protection from a range of conditions, including colon cancer, heart disease and dementia. To my mind, the time has come to take a closer look at folic acid's hidden talents.
One of folic acid's chief roles is to ensure the normal functioning of DNA: the stuff in the body's cells that carries our genetic code. DNA is key to many body processes, and glitches in its function have the potential for diverse effects. Normal function of DNA is especially important during pregnancy. If DNA goes awry at this time, problems with the development of the foetus are more likely. By helping to ensure DNA does its job without mishap, folic acid helps reduce the risk of genetic problems, such as spina bifida (failure of the spinal column to close during development).
Malfunctioning DNA is also thought to be a key issue in the development of cancer in the body. And it appears that folic acid may offer considerable protection here. Recent research published in the International Journal of Cancer found that women consuming the most folic acid had a substantially lower risk of colon cancer. Folic acid also seems to protect against the increased risk of breast cancer associated with the consumption of alcohol. Interestingly, Australian researchers have also found that children born to mothers who supplemented with folic acid during pregnancy have a significantly reduced risk of leukaemia. The little work that has been done looking at the effect of folic acid on cancer has been encouraging to say the least.
Still more benefits may be had from folic acid through its relationship with a substance called homocysteine. High levels of this amino acid are associated with an increased risk of heart disease and stroke. Folic acid helps in the conversion of homocysteine into a harmless substance called cystanthionine. Just a few weeks ago, British research was published which found that supplementing with folic acid brought about a significant drop in homocysteine levels. Eyes are now turning to folic acid as a potential big gun in the fight against circulatory conditions, such as heart disease and stroke.
Folic acid's ability to lower homocysteine levels may be good news for the brain, too. Research has found that individuals with the highest levels of homocysteine have about twice the risk of developing Alzheimer's disease compared to those with the lowest levels. Very recently, a team of American researchers published a study examining the effect of a low folic-acid diet on mice known to be prone to Alzheimer's disease. A lack of folic acid in their diet led to substantial increases in homocysteine levels, and a tendency for brain cells to be knocked off in vast numbers. While it is not always appropriate to extrapolate the results of animal experiments to humans, the lead author of this study did suggest that increasing folic-acid intake, through diet and supplements, makes good sense for the population at large.
Some of the richest natural sources of folate (the term used to describe the version of folic acid found in food) include green vegetables, such as asparagus, spinach, Brussels sprouts, broccoli, beans and pulses, liver and orange juice. In the UK, the recommended daily allowance for folate is 200mcg per day. However, women planning pregnancy are generally advised to take 400mcg per day in supplement form, and between 400-600mcg of folic acid per day is required to lower levels of homocysteine. Folic acid is generally an extremely safe nutrient to take at these doses. However, one potential hazard of supplementing with it is that it can mask deficiency in another nutrient - vitamin B12. For this reason, it is generally advised that folic acid and vitamin B12 are taken in combination. B-vitamin supplements that contain both these nutrients are freely available in health-food stores.
Dear John
I suffer from hepatitis C. Can you give me any advice about what I can do to help myself through diet or other natural means?
Clare Pickering, by email
Hepatitis C is caused by a virus spread through blood. About 80 per cent of sufferers are symptom-free, though the condition can cause fatigue, nausea, loss of appetite, jaundice and general malaise. Cirrhosis of the liver is a potential long-term complication.
From a dietary perspective, it makes sense for you to avoid any foods that tend to stress the liver. You would do well to limit your intake of alcohol, caffeine and food high in unhealthy fats, such as fried food, fast food and most processed food and concentrate on eating plenty of fresh fruit, vegetables, beans, pulses, wholegrains and some fish. I would also suggest you drink about 1-2 litres of filtered or mineral water each day. Herb and fruit teas are another option.
Certain natural substances may help your liver and control your symptoms. Vitamin C is known to help protect the liver from damage, and also has anti-viral properties. I recommend that you take 1g of vitamin C three times a day. I also recommend that you take a supplement of milk thistle ( Silybum marianum ). This herb has been shown to have beneficial effects on liver function, and may help restore health to your liver in time. Take 200mg of milk thistle extract twice a day for a month, reducing the dose to 100-150mg twice a day in the longer term.
Nutrition news: Rhythm in a heartbeat
A healthy heart generally gives between 60 and 90 regular beats each minute. Sometimes, the electrical circuitry of the heart can misfire causing problems with the rate and/or rhythm of the heartbeat. Severe problems here can mean that the heart simply fails to get blood around the system and may lead to something known as sudden cardiac death. A recent study in men suggests that eating more fish may help protect against this condition. One study showed that, compared to individuals eating practically no fish, men consuming just one serving of fish each week had half the risk of dying from sudden cardiac death. The theory is that healthy fats found in many types of fish help to maintain a normal heart rhythm.
· If you have any issues you would like Dr John Briffa to address in this column, please contact him by email on life@observer.co.uk. Please note that Dr Briffa cannot enter into any personal correspondence.
