People pop dietary supplements under the pretense that they should improve health, right? While that may be the widely held belief among many, there is an increasing amount of evidence to suggest that they don’t really do anything positive in individuals who don’t need them, and could actually be detrimental to our health. And worryingly, a new analysis of years of research into the subject has found that, rather than reducing our risk of developing cancer, many supplements could actually be raising it.
“We are not sure why this is happening at the molecular level,” explains researcher Tim Byers, “but evidence shows that people who take more dietary supplements than needed tend to have a higher risk of developing cancer.”
Research into this subject was sparked some 20 years ago when scientists began observing that those who consumed more fruit and veg tended to have a lower incidence of cancer. Since dietary supplements are packed full of the beneficial vitamins and compounds found in these foods, scientists wondered whether taking them could further reduce the risk of developing cancer, so they began designing experiments to investigate this.
Initially, and encouragingly, results from tissue and animal research seemed to support this idea, so scientists began population-based studies expecting to observe a similar cancer-reducing trend in humans. But after following thousands of people, much to the surprise of scientists, they actually began to observe the opposite. Not only did supplements bestow no obvious health benefits, but some actually raised the risk of developing cancer when taken in excess of the recommended dietary amount.
For example, back in 2006, folic acid supplements were found to increase the risk of developing breast cancer by 20%. Furthermore, women with the highest levels of folic acid intake, which was mainly from supplements, had a 32% higher risk of breast cancer than those with the lowest levels. But folic acid’s disappointing story didn’t end there as another trial found that it increased the number of growths, called polyps, in the colon. Although many of these are harmless, some can become cancerous.
Several studies in men have also found that vitamin E supplements are associated with an increased risk of developing cancer, and one even found that it could double the risk of prostate cancer. And in women, those taking multivitamins were almost 20% more likely to develop a breast tumor than those not taking supplements.
“This is not to say that people need to be afraid of taking vitamins and minerals,” Byers said. “If taken at the correct dosage, multivitamins can be good for you.”
That being said, most people should be able to achieve their recommended daily doses of vitamins and minerals by eating healthy, nutritional meals. Most people therefore don’t need to pop pills every day, and should probably stop wasting their money.
“At the end of the day,” says Byers, “we have discovered that taking extra vitamins and minerals do more harm than good.”