An Introduction to Nutritional Medicine

Late 20^th Century medicine supplied two easy answers to patient’s questions about nutritional supplements – too easy, unfortunately, to be adequate:

1. If it’s a natural substance, it might not do you much good but it can’t do you any harm. Although there is some truth in this when referring to a modest dose of a vitamin, for instance, we now have evidence that higher “pharmacological” doses of vitamins like vitamins E, A and B6 might be harmful in some circumstances, but the evidence is inconclusive. Since herbal remedies are sometimes referred to as supplements, every GP will realise that herbs like St John’s Wort are more like drugs, with side effects and the potential for interaction with other drugs.
2. You don’t need to take extra vitamins and minerals if you eat a well-balanced diet. This is a gross oversimplification. We now know that even the best, most varied, Western diet is not the same as the stone-age diet that we are adapted to as a result of millions of years of evolution. This is especially true of the low vegetable fibre content of modern diets. Added to this, many of our patients have psychological and money problems that prevent them from eating well. Nearly all food surveys show that 20-30% of people in the UK never eat fish, and some will tell you that they find the very thought of it disgusting
3. Another easy answer is to tell patients with normal IgE blood test (immune globulin E) and the related allergy tests that “….food allergy is all in the mind”. We now know that this is not necessarily the case. For instance, some patients with irritable bowel syndrome (IBS) can tell you exactly which foods exacerbate their symptoms although they do not test positive on any standard type of allergy testing. The balance of evidence from dietary studies suggests a rule of halves:

• Half the patients who think they have a “food allergy” but have normal IgE and RAST (radioallergosorbent test) will have a genuine food intolerance and half will be imagining it.
• Half the patients with a genuine food intolerance will have some idea what foods are problematic and, with minimal help and understanding, they will be able to control their symptoms.