We've all heard a lot about the adverse effects that nutritional supplements can have on pharmaceutical drugs, but nobody ever mentions the positive effects that nutritionals can have. There's growing evidence to suggest supplements interfere with the processes of some drugs, but there's also plenty of evidence to suggest that nutritional supplements can actually help the effectiveness, or offset the toxic effects, of many others.
This almost never gets a mention, and so leading nutritionist Dr Leo Galland has decided to redress the balance.
Like us, Dr Galland is intrigued by the number of press headlines that have been warning people off nutritional supplements. But when he started researching the underlying supportive evidence, he was "struck by the high degree of speculation and the low level of documentation". Most of the interactions were pharmacodynamic, which relates to the effects a nutritional might have on a pharmaceutical. "These possible effects are interesting, but they may never occur, or they may be beneficial rather than harmful, depending upon the circumstances of the individual case," says Dr Galland.
Perhaps the best-known example is St John's wort, the natural antidepressant, which has significant adverse reactions with 24 different drugs. Of the drugs, warfarin, the anticoagulant, is the one most likely to be affected by a supplement. Dr Galland identified 49 natural products that might block the pharmacological effects of the drug.
But researchers have ignored the possible positive effects that a nutritional can have on a prescription drug. Sometimes they enhance the effects of the drug, sometimes they compensate for the drug's toxic effects. Fish oil is the supplement that has the greatest positive effect on drugs, and especially with the anti-inflammatories, the anti-arrhythmics, antidepressants, neuroleptics, beta-blockers, anti-lipemic drugs, insulin and lithium. Dr Galland has identified 37 natural products that have a directly beneficial effect when taken with a drug. As he points out, around half of all prescription drugs deplete our nutritional stores, and so it's important that we supplement if we are going to maintain a healthy immune system.