There is little evidence that vitamin and mineral supplements protect people from cancer and heart problems, according to a new analysis.

Based on those findings, a U.S. government-back panel issued draft recommendations that echo its previous conclusion: it cannot recommend for or against taking vitamins and minerals to prevent those conditions.

"At this point in time the science is not sufficient for us to estimate how much benefit or harm there is from taking vitamin or multivitamin supplements to prevent cancer or heart disease," Dr. Michael LeFevre said.

LeFevre is co-vice chair of the U.S. Preventive Services Task Force (USPSTF), which issues recommendations to help guide doctors and health systems. The USPSTF sponsored the new analysis.

The panel's draft statement also says neither beta-carotene nor vitamin E should be taken to prevent heart disease or cancer.

Previously, beta-carotene was found to further increase the risk of lung cancer among people who are already at an increased risk.

About 600,000 people die of heart disease in the U.S. every year, according to the Centers for Disease Control and Prevention. Another 580,000 die of cancer, the American Cancer Society says.

Cancer and heart disease share a number of risk factors including inflammation, researchers wrote in the Annals of Internal Medicine. Animal and lab studies have suggested supplements may guard against some of those risk factors.

It's estimated that Americans spend about $12 billion each year on supplements.

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