More and more of us are taking food supplements to 'balance' our diets. But are they doing us more harm than good?
They are exculpation, insurance and saintliness in handy pill form. They supposedly guard against anything from wrinkles to cancer. But are dietary supplements - from the humble multi-vitamin to the mega-dose antioxidant - really as benign as they seem?
A study published last week in the Journal of the National Cancer Institute found that men with prostate cancer who took more than seven multivitamins a week were 30% more likely to get an advanced and fatal form of the disease. This comes after a large - though hotly contested - review published in the Journal of the American Medical Association in February found that people who took antioxidant vitamin tablets (particularly vitamins A and E and beta-carotene) were more likely to die earlier than those who did not.
Such research seems to fly in the face of common sense. We all know vitamins are "good" for us. Indeed, thanks to a national obsession with TV diet "gurus", many people believe they are de facto deficient in key nutrients and can only be healthy if they supplement their food with pills or potions. Even those not downing spirulina algae with breakfast probably own at least one pack of multi-vitamins.
However, says Catherine Collins, chief dietician at St George's hospital, London, "The whole idea that you must meet some vitamin and mineral target every day of your life is a marketing myth: you can eat lots of fruit and veg one day and not much the next, but over a week you will still get the right amount of nutrients." What's more, she says, "There is very little scientific evidence of any benefit whatsoever in taking a daily multi-vitamin, even in old people." Indeed, taking daily vitamins could be positively harmful if you eat a poor or highly restricted diet, then assume you are nutritionally covered by popping a pill.
"You cannot exist on a poor diet and then shore yourself up with a multi-vitamin," says Collins.
Source - Guardian