KORN KURATED RESEARCH

Multivitamin Supplements Don’t Extend your Life

Multivitamin use is prevalent among US adults for disease prevention, yet extensive research shows no associated mortality benefit. Can we believe this research?

In this post, I am reviewing a major study on multivitamins and providing a commentary on the study by Barnard. The first research publication below examines the use of multivitamins in nearly half a million individuals and assesses whether the vitamins increased their life span. Multivitamins are defined as any supplement with 3 or more vitamins. The findings were multivitamins did not prolong life span.

In his follow-up commentary on the research (Article 2), Barnard suggests that this study reinforces the need to focus on eating plant foods rather than using supplements, as that approach may offer more significant health advantages and longevity benefits. However, he does not fully analyze this study, which is fraught with holes.  So, let’s review!

What are just a few of the problems with the study? First, they relied on self-reported multivitamin use. This reporting is unreliable (as the authors admit) and only tells us a little, except that people report using vitamins.

I then ask: What about the quality of the vitamins? Which brands? Did they have additives and sugars? We can assume that most of the vitamins people used were like the Centrum brand, which are loaded with sugar, hydrogenated palm oil, and other cheap synthetic vitamins found at the local drugstore.

I also scanned the article for details on the type of vitamins but found none. Did they have cyanocobalamin instead of methylcobalamin or folic acid instead of folate, two synthetic forms of vitamins that should not be used? Or did they include a-tocopherol for vitamin E instead of four tocopherols and four tocotrienols? Did they assess whether the participants needed some vitamins and not others?

Pesticide applicators comprised much of the cohort.

Among the 390,000 participants, a significant portion, upwards of 57,000 (plus 42,000 spouses), were pesticide applicators. This raises a crucial question: could chronic exposure to pesticides affect mortality? Is this a potential health risk that cannot be mitigated by a multivitamin alone? The authors also acknowledge some limitations in the study design, further emphasizing the need for comprehensive research in this area.

Back to Barnard’s commentary on the study: There is no question that using nutrient-rich plant foods is healthy. However, see my critique of Barnard's analysis below.

I agree that a nutrient-dense diet is ideal, but this is not an either-or argument. Nor is it an argument favoring a plant-based diet ONLY, which is Barnard's argument. An avowed vegan, he founded the Physicians Committee for Responsible Medicine. It sounds innocuous enough, except it promotes ONLY plant-based diets, especially veganism. What about people who live around the world, like the Inuit of Alaska and Greenland, whose traditional foods are fat and protein from fish and mammals, and who would have to ship in enough legumes, grains, vegetables, bananas, and all other plant foods in order to be vegans, none of which grow locally? Or the Massai of Kenya and Tasmania, whose traditional diet has nourished them for millennia by drinking and eating almost only raw milk, meat, and blood. 

Indigenous peoples of the western hemisphere did just fine with diverse plant and animal diets before contact with European settlers. As did the Celts, the Irish who thrive on salmon and seaweed, the traditional foods of Ireland. As a clinician and long-time vegetarian (who has also eaten as a carnivore), I embrace all types of diets for people that are geared to what they need personally (except the Standard American Diet, the  SAD one, of course); this is my "beef" with such myopic US-centered ideological analysis.

For diet and nutrition to be truly helpful in preventing and treating disease and decreasing mortality, they must be personalized to the individual's needs and include lifestyle, genetic, and cultural factors. This approach respects each person's unique needs, acknowledging that there is no one-size-fits-all solution in nutrition.

Finally, the overall message of this research isn’t helpful: Don't take vitamins; they won’t help you live longer; in fact, you will die sooner.

I give this a thumbs down for both research and commentary.

Tags: multivitamins, supplements, nutrition, longevity

Interested in Learning More?

• Book(s): Nutrition Essentials For Mental Health
• Book(s): Eat Right, Feel Right
• Book(s): The Good Mood Kitchen

Referenced Research Publications

JAMA network open
2024, June 03
DOI: 10.1001/jamanetworkopen.2024.18729

Multivitamin Use and Mortality Risk in 3 Prospective US Cohorts

Abstract

Importance: One in 3 US adults uses multivitamins (MV), with a primary motivation being disease prevention. In 2022, the US Preventive Services Task Force reviewed data on MV supplementation and mortality from randomized clinical trials and found insufficient evidence for determining benefits or harms owing, in part, to limited follow-up time and external validity.

Objective: To estimate the association of MV use with mortality risk, accounting for confounding by healthy lifestyle and reverse causation whereby individuals in poor health initiate MV use.

Design, setting, and participants: This cohort study used data from 3 prospective cohort studies in the US, each with baseline MV use (assessed from 1993 to 2001), and follow-up MV use (assessed from 1998 to 2004), extended duration of follow-up up to 27 years, and extensive characterization of potential confounders. Participants were adults, without a history of cancer or other chronic diseases, who participated in National Institutes of Health-AARP Diet and Health Study (327 732 participants); Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial (42 732 participants); or Agricultural Health Study (19 660 participants). Data were analyzed from June 2022 to April 2024.

Exposure: Self-reported MV use.

Main outcomes and measures: The main outcome was mortality. Cox proportional hazard models were used to estimate hazard ratios (HRs) and 95% CIs.

Results: Among 390 124 participants (median [IQR] age, 61.5 [56.7-66.0] years; 216 202 [55.4%] male), 164 762 deaths occurred during follow-up; 159 692 participants (40.9%) were never smokers, and 157 319 participants (40.3%) were college educated. Among daily MV users, 49.3% and 42.0% were female and college educated, compared with 39.3% and 37.9% among nonusers, respectively. In contrast, 11.0% of daily users, compared with 13.0% of nonusers, were current smokers. MV use was not associated with lower all-cause mortality risk in the first (multivariable-adjusted HR, 1.04; 95% CI, 1.02-1.07) or second (multivariable-adjusted HR, 1.04; 95% CI, 0.99-1.08) halves of follow-up. HRs were similar for major causes of death and time-varying analyses.

Conclusions and relevance: In this cohort study of US adults, MV use was not associated with a mortality benefit. Still, many US adults report using MV to maintain or improve health.

Reference

Loftfield, E., O'Connell, C. P., Abnet, C. C., Graubard, B. I., Liao, L. M., Beane Freeman, L. E., Hofmann, J. N., Freedman, N. D., & Sinha, R. (2024). Multivitamin Use and Mortality Risk in 3 Prospective US Cohorts. JAMA network open, 7(6), e2418729. https://doi.org/10.1001/jamanetworkopen.2024.18729

JAMA Network Open
2024, June 26
DOI: 10.1001/jamanetworkopen.2024.18965

The Limited Value of Multivitamin Supplements

Read Dr. Barnards Commentary: https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2820375

Reference

Barnard, N. D., Kahleova, H., & Becker, R. (2024). The Limited Value of Multivitamin Supplements. JAMA network open, 7(6), e2418965. https://doi.org/10.1001/jamanetworkopen.2024.18965