The Outspoken Nutritionist

Since the 1960s, life expectancy for people in developed countries has increased by nearly 10 years, leading to a greater incidence of chronic diseases such as arthritis, hypertension, heart disease and adult onset diabetes.

 This has caused the long-term use of many prescription and over-the-counter drugs to escalate, increasing the frequency and severity of drug-nutrient interactions.

 While the short term use of drugs is less likely to have any adverse effects on a person’s nutrition, there is still a worrying potential for it to.

 These interactions fall into one of three classifications:

 1) Physicochemical - the depletion of a nutrient by a drug, leading to loss of the nutrient and lower activity of the drug

2) Physiological - drug-induced changes in appetite, digestion, metabolism and excretion - all of which can affect the body’s nutrient status

3) Pathophysiological - when a drug impairs nutrient absorption or metabolism, or a drug inhibits the metabolic process

 Frequently, drug-nutrient interactions are bi-directional - while the drug may impair the absorption of some vitamins, the drug absorption is also often impaired by vitamins.

For example, drug classes including antimicrobials, hypoglycaemic and hypocholesterolaemic agents can all be affected by the presence of food, with elderly patients particularly at risk.

Aspirin, however, commonly causes gastric irritation and so should be consumed with food.  Aspirin also appears to alter the transport of folate, and 70% of rheumatoid arthritis patients display low folate concentrations.

Antacids, commonly taken to relieve heartburn, neutralise gastric acid by modifying the gastric pH, often leading to reduced absorption of calcium, iron, magnesium and zinc.  Regular use can also lead to reduced absorption of B12, a particular concern for the elderly who are already at risk of B12 deficiency.

Antibiotics can cause Vitamin K deficiency and impair blood clotting.  Tetracycline antibiotics in particular bind to calcium in dairy products, preventing effective absorption of both the calcium and the antibiotic.  Calcium deficiency naturally leads to reliance on bone calcium, subsequently causing osteoporosis, a common problem for the ageing population.

Anticoagulants such as warfarin work by interfering with the metabolism of Vitamin K, and users should be warned about the consumption of foods high in Vitamin K in case this interferes with the effectiveness of the treatment.  Furthermore, elderly anticoagulant patients taking antioxidants such as tocopherol, or doses of Vitamin C greater than 10g, can be at increased risk of of haemorrhages.

Evidently, as more and more people rely on long-term use of drugs, there is a greater need for understanding of drug-nutrient interactions.

If you, or someone you know - particularly anyone who is elderly - are using prescription or over-the-counter drugs, consult a qualified nutritionist to ensure you are minimising the possibility of any adverse drug-nutrient interaction.

To our wellbeing
The Outspoken Nutritionist