Supplements and Cancer Survivorship
For lower risk of primary cancer, studies of supplements have been conducted for numerous compounds found in foods. AICR research concludes that there is not enough clear evidence to recommend that individuals rely on supplements to protect against cancer. There are other reasons individuals may need to take supplements to help fill gaps in nutrient needs that cannot be met by diet, but it's important to remember that more is not necessarily better. If you have been diagnosed with cancer, it is important that you speak to your physician about vitamin, mineral or any other supplements you are taking.
What Research Shows - During Treatment
If you are still undergoing cancer treatment, discuss supplementation with your physician. Several recent population studies suggest that antioxidant supplements may interfere with cancer treatment, yet the research is not conclusive. Theoretically, the same mechanisms that antioxidant supplements use to protect healthy cells from cancer may also protect the cancer cells during treatment.
What Research Shows - After Treatment
If you have concluded treatment, it's possible you may need to take certain supplements. Again, speak with your health care team on any supplements you are taking and your needs.
Every individual is different yet overall, research shows that supplements do not offer cancer protection or benefits for survivors related to recurrence. In general, the research is conducted among adults without known nutritional deficiencies. Some supplements may even increase cancer risk among some populations. There is not yet enough research to weigh the benefits against the harms.
The U.S. Preventive Services Task Force (USPSTF), a government-appointed group of experts tasked to give recommendations on issues of public health also made no recommendation on almost all single dose supplements and multivitamins for the prevention of cancer and cardiovascular disease.
The only two vitamin supplements they found with enough research were beta-carotene and vitamin E. For these, the task force recommended against taking either supplement for cancer and cardiovascular prevention. B-carotene supplements increase the risk for lung cancer in smokers, who are at increased risk for this cancer, they concluded. And the evidence showed that vitamin E supplements provide no overall protection.
Research suggests you cannot obtain the protective benefits linked to eating a wide variety of plant-based foods such as vegetables and fruits by isolating specific substances into pills. Scientists have not yet identified all the protective phytochemicals in fruits and vegetables, and studies suggest that phytochemicals in foods work together to provide cancer protection and other health benefits. In addition, a balanced diet provides fiber, protein and essential fatty acids necessary for health.
To reduce your risk of cancer, AICR recommends choosing a balanced diet with a variety of foods rather than taking supplements.