Interest among patients with cancer in using adjuncts to manage treatment-related symptoms like pain, nausea and inflammation has increased as dietary supplements such as alpha-lipoic acid, turmeric and omega-3s have become widely available. But health care professionals caution that using such supplements during cancer treatment may carry significant risks.
Consulting with health care providers before incorporating supplements into a cancer-care regimen is essential. “It’s important to note that many supplements are not FDA regulated for safety and efficacy, so patients should always let their oncologists and medical teams know if they are taking them,” said Sandra Sacks, MD, a UCLA Health pain-management physician specializing in cancer pain. “These supplements can sometimes interact with cancer therapy, especially for patients on clinical trials or specific types of immunotherapy or chemotherapy.”
This lack of regulation means that supplements can sometimes interfere with the metabolization of cancer drugs, potentially diminishing their effectiveness or leading to harmful side effects. Dr. Sacks highlights the importance of individualized care and careful coordination among oncologists, dietitians and other members of the health care team. This collaboration is key to ensuring that supplements do not compromise cancer treatment.
The Safety of Supplements: Conflicting Information
One of the major challenges patients with cancer face is navigating conflicting information available online regarding the safety of supplements. Reputable organizations can sometimes offer mixed guidance on whether or not supplements should be used alongside cancer therapies.
“You’ll see some cancer centers saying you should never take supplements during cancer therapy because it can interact with the drugs. Then, on another page, they’ll recommend supplements,” Dr. Sacks notes. “There’s a lot of mixed information out there, even from what are otherwise reliable sources.”
This inconsistency underscores the need for open communication between patients and their health care providers. By discussing potential supplement use with their medical teams, patients can ensure they are making informed decisions based on their unique circumstances. Dr. Sacks also advises patients to be particularly cautious when using supplements like omega-3s, which may increase the risk of bleeding in patients who are on blood thinners or with low platelet counts from chemotherapy.
Addressing Nutritional Deficiencies: A Targeted Approach
From a dietary perspective, Emma Veilleux, RDN, a registered dietitian with the Simms/Mann UCLA Center for Integrative Oncology, emphasizes that supplements should not be used in the absence of a confirmed nutritional deficiency, ideally supported by blood tests. Many patients believe that taking supplements will inherently improve their health, but Veilleux points out that the benefits are often overstated.
“We don’t have good evidence to support the idea that taking supplements is always beneficial to health, especially during cancer treatment,” she says. “Using nutritional supplements is typically not something I recommend unless someone has a known nutritional deficiency.”
For patients with cancer, maintaining a balanced diet is often a challenge due to changes in appetite and the side effects of treatment. In cases where dietary intake is compromised, Veilleux may recommend certain supplements, such as vitamin D or B12, particularly for individuals following a vegan diet. However, she stresses that these recommendations should always be guided by lab results confirming a deficiency.
“The discussion around multivitamins often revolves around whether or not the patient is able to eat a balanced diet,” Veilleux explains. “If their nutrition has been impacted by poor appetite or other side effects over a long period of time, then considering a multivitamin might be appropriate. Generally, however, I don’t encourage patients with cancer to take multivitamins unless I suspect they are chronically not getting enough nutrients from their food.”
Potential Interactions with Cancer Therapies
One of the greatest concerns surrounding use of supplements during cancer treatment is the potential for harmful interactions with cancer therapies. Veilleux warns that antioxidant and herbal supplements, in particular, can interfere with the efficacy of cancer drugs. High-doses of some antioxidant supplements have been shown to reduce the effectiveness of some chemotherapy and radiation treatments, while herbal supplements like St. John’s wort may alter drug metabolism, leading to reduced efficacy or increased toxicity.
“Potential interactions between many supplements and cancer drugs are largely unknown,” Veilleux cautions. “I tend to err on the side of caution and recommend that patients avoid these supplements unless there is a clear medical need.”
A Collaborative Approach to Cancer Care
Both Dr. Sacks and Veilleux emphasize the importance of a collaborative approach to the use of supplements in cancer care. Patients should always inform their health care providers about any supplements they are considering, and oncologists, dietitians and pain management specialists should work together to develop an individualized care plan.
By taking a cautious and informed approach to supplement use, patients with cancer can avoid potential risks and ensure that their treatment remains effective. As Veilleux notes, “There are thousands of supplements on the market, but many of them haven’t been studied extensively in the context of cancer treatment. We need more data before we can recommend their widespread use.”
