In the fourth in a series of articles on Integrative Medicine, Nutritionist Belinda Rennie looks at the interaction between drugs, foods and nutritional supplements.

Integrative medicine is an exciting and emerging field that brings western medicine together with complementary health to maximize the body’s innate potential for self-healing.  The patient stands to benefit the most when a “health care team “ can manage their recovery using a variety of therapies including nutritional programs, osteopathy, exercise, mind-body work and homeopathy alongside the GP.

Does your doctor discuss the side effects of a drug with you? Are they aware of the interaction with food and nutrients? The partnership between the GP and nutritionist becomes paramount whilst on medication as drugs can deplete the body of specific nutrients leading to malnutrition. Nutritional supplementation can work in tandem with medications and in some cases people can gradually reduce and discontinue drugs in consultation with their doctor when diet and lifestyle changes are working. Homeopathic treatment can also combine well with medications and can help offset side effects.

The liver is the main organ under threat when looking at the toxic effects of drugs, covered last month under liver detox. Physicians conduct liver function tests to check the patient can tolerate a specific drug metabolized by the liver. This does not suggest that the patient will have no adverse side effects. Do your own research and ask questions about the medication: how long do I need it for, do I take it with or without food?

The nutrients most depleted by drugs include zinc, magnesium, calcium, potassium, protein and Vitamin B 12. Here are some common drug-nutrient interactions.

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      Cholesterol lowering drugs (bile sequesterants) can decrease the availability of fat soluble vitamins A, D, E, K, essential fatty acids, folic acid, Vitamin B12, calcium, iron and betacarotene. The statin class of drugs (eg Lipitor) deplete the body of CoQ10 an essential antioxidant vitamin.

      Diuretics increase the excretion of calcium, potassium, magnesium, zinc and chloride.

      Aspirin reduces the availability of Vitamin C, D, K B nutrients folic acid, calcium, iron.

      Antacids deplete calcium, magnesium, iron, vitamin A, D, C, B1, B12 folate, digestive enzymes, potassium and phosphate.

      Oral contraceptives deplete B group vitamins including B6, B12, B2, folate, zinc, magnesium and Vitamin C.

      Corticosteroids can contribute to osteoporosis by depleting body stores of calcium and Vitamin D.

When taking a drug, you may not notice nutrient depletion but in the case of antibiotics, thrush is often the reminder that the drugs have killed all your beneficial bacteria. Not only does it predispose you to gut dysfunction such as diarrhea and constipation and ironically lowered immunity, the destruction of the natural flora makes drugs like oral contraceptives and warfarin less effective. Whenever a doctor prescribes antibiotics they must also prescribe probiotics like lactobacillus acidophilus and bulgaricus to restore beneficial bacteria. These are best taken apart from the antibiotics and a four hour period is suggested between medication and food supplements in general.

On the other hand taking food supplements, herbs, vitamins and minerals can interact with drugs both positively and negatively. For example, did you know that taking grapefruit can reduce the rate of elimination of certain drugs by the liver increasing toxicity? It is recommended that you should stop taking grapefruit 1 week before commencing drug therapy. Other problematic interactions include:

      Thyroxine taken for hypothyroidism should not be taken with an iron supplement as the two bind leaving no iron or drug available in the body.

      Fibre such as psyllium, bran or pectin can bind certain drugs (digoxin) making them unavailable (the conditions in which fibre work well are for the cholesterol lowering effect and combine well with the drug colestyramine).

      St John’s Wort, a herb used for depression and SAMe (S-adenosylmethionine) can interact with antidepression medication.

On the positive side, people suffering with the pain of joint problems can use chondroitin and glucosamine in combination with anti-inflammatory drugs. These supplements can reduce the need for NSAID thereby reducing toxicity and side effects. Studies done on the blood-thining drugs aspirin and warfarin showed that fish oils can be used concurrently with no problems. With a cholesterol lowering drug called Pravastatin, fish oils were beneficial in improving cholesterol levels.

These are a few examples highlighting the importance of discussing with your doctor any food, herbs or vitamin supplements that you may be taking. Herbs can have powerful actions and effects that need to be monitored by your complimentary therapist, especially whilst pregnant and breastfeeding. Similarly, megadoses of vitamins and minerals can be dangerous as nutrients are interdependent where large doses of one can create deficiencies in another.  

The doctor, therapist and patient relationship works best when all parties are knowledgeable about the possible drug-nutrient interactions and can make informed decisions.

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