The first question a cancer patient often asks is, ‘Will this supplement help?’ but an equally important (and often overlooked) question is, ‘What’s in this supplement?’
While many scientific studies have questioned the benefit of nutritional supplements in cancer prevention, others have questioned the integrity of the supplements themselves. They have raised serious questions about the quality and consistency of the contents inside the bottle and how these may differ from what the label says.
It’s important to know that dietary supplements are exempt from the Federal Drug Administration (FDA) enforced safety and efficacy laws that regulate prescription and over-the-counter medications. This means that a manufacturer does not have to prove the safety and effectiveness of a supplement before it is put on the market! If a supplement on the market is suspected of being unsafe, then the burden is on the FDA to prove that the supplement is unsafe before it can be taken off the shelves.
There is also little assurance that the labels of the supplements provide accurate information. In 2013, an unpublished abstract looked at the best practices of 12 different supplement manufacturers with reasonable reputation’s as quality providers of supplements. While all 12 companies claimed to be operating in full compliance with FDA regulations, three had received warning letters from the FDA for manufacturing violations, two had a product recalled within the last five years, four reported that their products failed Consumerlab.com’s standards for potency or purity, one did not have any product specifications, one was found by the FDA to have inadequate testing, one was found to have a lack of sufficient controls throughout the supply chain to guard against microbiological contamination (a potentially fatal oversight for any patients with compromised immune systems), and two had melamine contamination or lacked melamine testing.
Another reason to steer clear of supplements is the lack of data to support expiration dates, material discrepancies between claims and actual practice, and failure to change the Universal Product Code numbers when active ingredient formulas change. Unknown formula changes are especially concerning for allergy sufferers. The study concluded there was considerable variation in the quality of dietary supplements, raising concerns for patient safety. These concerns were reinforced by a report from the New York State Attorney General in 2015, which found that supplements sold across the state at major retailers were routinely mislabeled and did not contain their purported ingredients.
So, as an oncology dietitian, I encourage my patients to be weary of supplements and instead to eat a balanced diet of whole, unprocessed foods.
Shayne Robinson RD CSO CDN is an oncology dietitian at NewYork Presbyterian Weill Cornell’s Ambulatory Care Network’s Outpatient Practice. To see a dietitian at our outpatient nutrition practice call (212) 746-0838 (physician referral required).
Previous Post: Supplements