In this episode of the Nutrition Facts Podcast, Dr. Michael Greger explores the controversial topic of vitamin E supplementation. Although widely marketed for immune and brain health, the science behind its efficacy—and safety—tells a more complex story. Drawing on dozens of clinical trials, Dr. Greger presents a sobering picture of vitamin E’s real-world effects on respiratory health, cancer risk, cognitive function, and overall mortality.

Key Points:

Vitamin E supplements show inconsistent benefits and may increase the risk of cancer and early death. Food sources of vitamin E appear safe, but supplement use should be approached with caution.

• Vitamin E and Immunity: Some studies suggest vitamin E may reduce upper respiratory infections, like the common cold, in elderly populations. However, others show worsened symptoms or no benefit, especially in certain subgroups like heavy smokers.
• Does It Help or Harm? Depends Who You Are: Large studies like the ATBC trial revealed that vitamin E could be beneficial for light smokers but harmful for heavy smokers. Such subgroup analysis highlights the complexity of blanket supplement recommendations.
• Cancer and Mortality Risks: Vitamin E was once hoped to reduce cancer risk, but the SELECT trial found a 17% increase in prostate cancer among supplement users. Meta-analyses also suggest a slight but real increase in overall mortality with vitamin E use.
• Alzheimer’s- A Glimmer of Potential: While vitamin E shows no benefit in preventing dementia, two clinical trials on Alzheimer's patients hinted at slower functional decline, though results remain inconsistent and one trial even showed potential harm.