The United States Preventive Services Task Force (USPSTF) and several distinguished professors from The Johns Hopkins University have spoken—and what they’re saying about vitamins may surprise you.
Estimates are that more than half of American adults currently take at least one dietary supplement. About 28 billion dollars are spent on multivitamins each year. While dietary supplements are clearly helpful for patients with certain digestive diseases, or for pregnant women, the question we will tackle here: are they helpful for everyone?
The majority of people taking supplements are already adequately meeting their nutrient demands, and are thus experimenting with the effects of increased levels of minerals and vitamins.
What is troubling is that many studies over the last couple of decades suggest that very high levels of certain vitamins put some individuals at increased risk of disease and mortality.
In 1994, an article in the New England Journal of Medicine showed that people who are already at risk for lung cancer had a much greater likelihood of suffering from lung cancer or heart disease when taking daily beta-carotene supplements.
Two years later, in the same prestigious journal, researchers hoped to delve a little deeper. But their work was cut short when they found the risk of death from lung cancer in susceptible patients was 46 percent higher for those taking both vitamin A and beta-carotene. Upon this discovery, the research trial was stopped.
In 2004, a study that sought to show that individuals treated with Vitamins A, C, E, and beta-carotene have less intestinal cancers actually showed something much worse – increased rates of mortality!
Almost 20 years later, the USPSTF is reaffirming these messages to ensure the safety of individuals who believe indiscriminate vitamin supplementation will help prevent cancer or chronic disease.
Recently, Dr. Larry Appel and Dr. Edgar Miller published an editorial in Annals of Internal Medicine thoroughly denouncing the widespread use of a daily multivitamin. “There used to be this belief that they might not be beneficial, but they’re certainly not harmful. Well, that idea has been dispelled,” commented Dr. Appel in Inside Hopkins. "Most supplements do not prevent chronic disease or death, their use is not justified, and they should be avoided."
“There’s really no evidence of benefit, and there is evidence of harm. Our recommendation is don’t waste your money,” commented Dr. Miller.
These Johns Hopkins experts want to stress to consumers that the ongoing clinical trials, which are being done to solidify the “small benefits” many claim are associated with supplementation, are not truly capable of identifying the so-called “small effects.”
So don’t hold your breath waiting for more data to prove this point. Dr. Appel and Dr. Miller are confident that the current case on vitamin supplementation is “closed.”
Take this example to heart. Vitamin E, known for its antioxidant functions, has proven harmful as a supplement in many studies during the past decade. In 2005, a summary of 19 different clinical research trials showed that taking vitamin E supplements actually increased the risk of dying. Also, in a similar study of patients with vascular disease and diabetes, Vitamin E increased the risk of heart failure. Most recently, a study linked vitamin E supplementation to increased risk of prostate cancer.
The key message here is that we need to choose our diets wisely to ensure that our bodies are already receiving necessary nutrients. Many people want to believe that a multi-vitamin can “make up” for poor diet choices. But we now know that for the vast majority of people this is not the case!
And while it’s probably true that not all vitamins are harmful, they are definitely not meaningfully helpful to most people.
The USPSTF does not have enough data to comment on all individual vitamins. However, they can claim with moderate certainty that vitamin E and beta-carotene are not helpful, and that beta-carotene likely increases the risk of lung cancer in at risk individuals. Do you want to take the risk with large doses of the other less tested vitamins?
In my view, the main problem is that people want the easy fix. It is hard to exercise and to eat right – but at least we know that these work!
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