People sometimes think that medications, prescribed or over-the-counter (OTC), do only good and no harm. In reality, there is always the potential for harm with unintended consequences among which are significant interactions with nutrition.
Drugs can interact with foods, nutrients, and herbs in a number of ways. Each may affect the absorption, actions, metabolism, or excretion of the others.
Some medications are known to interact with specific nutrients. In addition, alcohol is infamous for its interactions with nutrients, and the more alcohol ingested, the more likely that a significant nutrient interaction will occur.
Here are some ways foods, drugs, and herbs can interact:
· Both food, nutrients, and herbs along with medications (both prescription and OTC), can enhance/delay/prevent absorption of one another.
· Nutrients in food can increase or decrease a drugs action, metabolism, and excretion.
· Drugs can increase or decrease nutrient action or excretion.
· Drugs can modify our appetite and taste.
· Herbs are known to modify the actions of medications.
Selected nutrient-drug interactions
· Antacids – Can reduce iron absorption while increasing calcium and phosphorus excretion. Antacids may also accelerate destruction of thiamin.
· Antibiotics – Can reduce absorption of fats, amino acids, folate, fat-soluble vitamins, vitamin B12, calcium, copper, iron, and other minerals. They can also increase excretion of folate, niacin, potassium, riboflavin, and vitamin C. Plus prolonged use of antibiotics are known to destroy vitamin K-producing bacteria which reduces vitamin K production.
· Antidepressants – Are known to slow breakdown of tyramine, with dangerous blood pressure spike and other symptoms on consuming tyramine-rich foods (aged cheese, aged meats, alcoholic beverages, feta cheese, lima beans, mushrooms, and fermented foods such as sauerkraut or sausage).
· Aspirin – Can lower blood concentration of folate. It can increase excretion of thiamin, vitamin C, and vitamin K and can cause iron and potassium losses through gastric blood loss.
· Caffeine – Can increase excretion of small amounts of calcium and magnesium. It also stimulates release of fatty acids into the blood.
· Cholesterol-lowering “statin” drugs – Grapefruit juice slows drug metabolism causing a buildup of high drug levels with potentially life-threatening muscle toxicity resulting.
· Diuretics – Can raise blood calcium and zinc while lowering blood folate, phosphorus, electrolytes, vitamin B12. They can increase excretion of calcium and water-soluble vitamins while increasing storage of zinc.
· Estrogen replacement therapy – May reduce absorption of folate. Can cause sodium retention and may raise blood glucose, triglycerides, vitamin A, vitamin E, copper, and iron.
· Laxatives – May reduce absorption of many nutrients and increase excretion of all unabsorbed nutrients.
· Oral contraceptives – May reduce absorption of folate but may improve absorption of calcium. Can cause sodium retention and raise blood vitamin A, D, copper and iron. They can also lower blood beta-carotene, riboflavin, vitamin B12, and vitamin C.
Significant drug-nutrient interactions do not occur every time a person takes a medication. The potential for interactions are greatest for those who:
· Take a medicine for a long time
· Anyone who take multiple medications
· Anyone who drinks daily
· Anyone poorly nourished to begin with
Any medication you take, whether prescribed or OTC, do so wisely. Ask your pharmacist, physician or other healthcare provider for specific instructions about the doses, times, and how to take the medication – for example, with meals or on an empty stomach.
If there are any symptoms that arise or if the drug does not seem to be working well, consult your physician.