Why is nutrition advice so controversial? Often, it seems as if food fights are the fiercest disagreements in medicine. Have you had trouble making sense of changing nutritional guidelines?

For years, nutrition scientists have been telling us that people who eat red meat are putting their health in danger. Then a few months ago, researchers published a handful of articles reviewing the literature on red meat and concluding that meat-eaters are not running much risk, if any at all. (Processed meats such as bacon or hot dogs do appear to be linked to some risk.) What is the bottom line? How do smart people use the same data to come to different conclusions? The papers were published in the Annals of Internal Medicine.

When we discuss studies that are supposed to show whether or not eating red meat will put you in danger, we need to understand the difference between relative risk and absolute risk. Dr. Aaron Carroll explains this and discusses how nutritional guidelines might change with new data.

Numerous studies have shown that people who have low levels of vitamin D are more vulnerable to a range of health problems. It makes sense that vitamin D supplements would reverse that, but many clinical trials have produced disappointing results. We talk with Dr. JoAnn Manson about the VITAL study she led and what we should conclude from the results.

VITAL tested fish oil as well as vitamin D supplements. The findings on fish oil suggest that, at the appropriate dose, omega-3 fatty acids in fish oil can help protect the heart.

Dr. Manson has served on panels that offered nutritional guidelines. She shares how they may change as new data from studies become available.

Aaron Carroll, MD, is Regenstrief Foundation Professor of Pediatrics and Associate Dean for Research Mentoring at Indiana University’s School of Medicine. He is also Director of the Center for Pediatric and Adolescent Comparative Effectiveness Research. His research focuses on the study of information technology to improve pediatric care, health care policy, and health care reform.

In addition to his scholarly activities, he has written about health, research, and policy for CNN, Bloomberg News, the JAMA Forum, and the Wall Street Journal.

He has co-authored three popular books debunking medical myths, has a popular YouTube show called Healthcare Triage, and is a regular contributor to the New York Times’ The Upshot.

Dr. Carroll’s most recent book is The Bad Food Bible: How and Why to Eat Sinfully.

The photo of Dr. Carroll is by Marina Waters.

JoAnn Manson, MD, DrPH, is Chief of the Division of Preventive Medicine at Brigham and Women’s Hospital. She is also Professor of Medicine and the Michael and Lee Bell Professor of Women’s Health at Harvard Medical School. Dr. Manson is the c0-principal investigator of the VITAL trial. Here is a description of the VITAL trial. Results were recently published in JAMA Oncology (Nov. 21, 2019) and Circulation Research (Jan. 3, 2020). 

The podcast of this program will be available the Monday after the broadcast date. The show can be streamed online from this site and podcasts can be downloaded for free. CDs may be purchased at any time after broadcast for $9.99.

Buy the CD

Download the mp3

Both Dr. Carroll and Dr. Manson have been interviewed on The People’s Pharmacy before. Look for Show 1112, Show 1153, Show 1160  and Show 1124.