For cancer prevention, the evidence is pretty clear: vitamins, minerals and other supplements alone don’t work. Not relying on supplements is one of AICR’s recommendations for cancer prevention — a recommendation made after analyzing the global research.
Now a review of the research supports this conclusion, finding that many popular supplements do not protect against both cancer and heart disease, the two leading causes of death in America. At least among healthy individuals. And some supplements may possibly cause harm among certain groups of people. The report was published by the US Preventive Task Force, an update to their 2003 report with similar findings.
The analysis reviewed all the new evidence since the last report, collecting only “good quality” studies. At the end of it, there were 26 new studies.
The studies included many of the most commonly used supplements, including vitamins B, C, D and E; zinc; magnesium; folic acid; beta-carotene; and selenium. All the studies included adults who were not nutrient deficient. Most were over 50 years old and participated in the study for under ten years.
Whether taking one supplement or a multivitamin, the analysis found no evidence that the supplement(s) affects risk of heart disease, cancer or overall mortality. This does not necessarily mean that certain supplements do not offer protection for certain populations.
As the authors note, except for vitamin E and beta-carotene there are few quality-studies.
Overall, the study found little evidence that supplements cause harm except for a few notable exceptions. Smokers who took beta-carotene supplements had an increased risk of lung cancer, for example. And a large trial found that the group taking vitamin D and calcium supplements had a small increase in kidney stones.
About half of US adults report taking supplements, and there are plenty of health reasons people do. For the healthy adult though who wants to protect against cancer, AICR recommends getting your vitamins, minerals and all the stuff of supplements through your food for a variety of reasons.
Vegetables, fruits and other plant foods contain numerous health-protective compounds, some identified only in recent years. Many also contain fiber, which protects against colorectal cancer and may help with weight control. Studies also increasingly suggest that the thousands of compounds in our foods work together to help our health.
Who should take supplements? We have more about that here.