Insufficient Evidence on Role for Multivitamins in Cancer Prevention

25 Feb 2014 --- The U.S. Preventive Services Task Force (Task Force) has posted its final recommendation statement on vitamin, mineral, and multivitamin supplements for the prevention of cardiovascular disease and cancer. However, the Task Force concluded there is not enough evidence to determine the effectiveness of taking vitamins and minerals to prevent cardiovascular disease or cancer.

“Cardiovascular disease and cancer have a significant health impact in America, and we all want to find ways to prevent these diseases,” says Task Force chair Virginia Moyer, M.D., M.P.H. “However, we found that there is not enough evidence to determine whether taking single or paired nutrients or a multivitamin helps to prevent cardiovascular disease or cancer.”

Additionally, there are two vitamins that the Task Force recommends against using: beta-carotene and vitamin E. This is a D grade recommendation. “The evidence shows that there is no benefit to taking vitamin E and that beta-carotene can be harmful because it increases the risk of lung cancer in people who are already at increased risk for the disease,” says Task Force co-chair Michael LeFevre, M.D., M.S.P.H. “Due to the uncertain benefit of vitamin supplements to prevent cardiovascular disease and cancer, health care professionals should use their best judgment and consider their patient’s health history, values, and preferences when having conversations about nutritional supplements.”

For most people the best way to get important nutrients essential for health is through a balanced diet. Adequate nutrition by eating a diet rich in fruits, vegetables, whole grains, fat-free and low-fat dairy products, and seafood have been associated with a reduced risk of cardiovascular disease and cancer.

In response to the final report, “Vitamin, Mineral and Multivitamin Supplements for the Primary Prevention of Cardiovascular Disease and Cancer,” from the U.S. Preventive Services Task Force (USPSTF), the Council for Responsible Nutrition (CRN), the leading trade association representing the dietary supplement industry, issued the following statement:

Statement by Duffy MacKay, N.D., senior vice president, scientific and regulatory affairs, CRN: “CRN appreciates the effort that the USPSTF has taken in releasing this final report to clarify its conclusion—that the evidence is insufficient to make a recommendation for the use of vitamin supplements for the primary prevention of cardiovascular disease and cancer—should not be more broadly interpreted.”

“We were pleased to see that in the USPSTF’s press release, the Task Force reminds everyone that ‘…this recommendation is limited to use of these vitamins and supplements specifically for the prevention of cardiovascular disease and cancer.’ Despite the misleading headlines that resulted from the earlier draft report from the USPSTF published in December, both the draft and this final report make no recommendations on the value of vitamins and minerals for overall health and wellness or for filling nutrient gaps, the areas for which research tells us consumers are most likely to take them.”

“The report’s conclusion that there is ‘…not enough evidence…’ for recommendations in the areas of cancer and cardiovascular disease should not be considered as a lack of benefit as there is a big difference between lack of research and lack of positive results. Even with a current gap in the research, what few studies there were that met the USPSTF criteria pointed to a potential promise for cancer protection.”

“We commend the Task Force for wisely recognizing that nutrients are not drugs, acknowledging that there are significant challenges to studying vitamins using methods similar to those used for studying pharmaceutical interventions. Importantly, the final report calls for new and innovative research methodologies—which is in contrast to the suggestion by a medical journal that called for the end of vitamin research when the draft report was published. We strongly support both the need for more research and the need for the scientific community to come to terms with a rigorous approach to studying nutrition that may not reflect the current model of studying drugs.”

“In the meantime, there are real life reasons why people should take vitamins and why so many doctors recommend them.”