Unlike prescribed medicines, supplements aren’t required to provide warnings to consumers of their potential risks. While evidence of the beneficial effects of fruits and vegetables is solid, many of the claims made by supplement companies are unsubstantiated. In fact, some supplements used to lower cholesterol and blood pressure may even raise the chances of a heart attack. The Harvard Medical School has warned of three, in particular, that may do more harm than good.
Red yeast rice:
Red yeast rice supplements are derived from a type of mold which is grown on rice in a controlled setting, to allow for the formation of high levels of active ingredients.
These active ingredients are the same ones used in cholesterol-lowering statins.
Clinical trials of red rice found it contained high amounts of monacolin K, which lowers low-density lipoprotein (LDL) cholesterol.
The supplement therefore shares many of the same side-effects, potential interactions and precautions as statins.
Doctor Pieter Cohen, associate professor of medicine at Harvard School who studies dietary supplements including red yeast rice, said: “Some products have little to none of the active ingredients, and others have the same amount as a low prescription dose.
“That may be fine if you’re not taking a statin, but if you are, you could be getting too much of the medication; that can cause muscle pain or even a life-threatening muscle breakdown that can damage other body systems.”
Garlic supplements Garlic supplements are taken by some hypertensive patients to help lower blood pressure.
While the supplement also promises to lower cholesterol, studies looking at the supplement’s effects on cholesterol are mixed.
The risk with this supplement is down to the way it interacts with other drugs, such as blood thinners, cholesterol-lowering drugs and blood pressure drugs.
Furthermore, several studies have found the supplement is loaded with a compound called allicin, which can cause liver toxicity if taken in large quantities.
L-arginine supplements are typically used by individuals looking to increase blood circulation and lower blood pressure.
Arginine works by synthesising nitric oxide, which helps the blood vessels relax and expand.
According to the Mayo Clinic, the supplement can increase the risk of death for people who have recently suffered a heart attack.
In fact, a study of L-arginine’s effect on heart attack survivors was brought to a halt after six participants exposed to the supplement died.
The supplement may also cause blood pressure to dip too low, if the supplement interacts with other blood pressure-lowering medicines.
People prescribed blood thinners could also increase their risk for bleeding after taking L-arginine supplements.
Experts recently warned against dietary supplements claiming to promote muscle growth or weight loss after a number of patients were admitted to hospital with severe liver injuries.
Previous studies, notably one conducted by the University of Colorado, showed that those who took extra vitamins and minerals were more likely to have health problems.
The findings of the study raised serious questions about the efficacy of the dietary supplement market, which is currently worth nearly £500 million in the UK.
Many supplements claim to have properties that underlie the beneficial effects of eating fruit and vegetables, as they soak up harmful byproducts of metabolism which can damage cells and cause ageing. However experts insist the benefits of a healthy diet outweigh those of supplements.