Healthy dietary patterns are known to reduce the risk of cardiovascular disease, and the gut microbiota has been identified as a potential mediator in the impact of diet on cardiovascular disease. Results from studies exploring the impact of red meat on cardiovascular disease risk in older adults have been inconsistent, and the existing literature does not indicate the impact of including red meat in a healthy diet among young adults without disease. To fill this void in our understanding Wang and colleagues conducted a study using young adults consuming prescribed diets and report their results in the May 2023 issue of The Journal of Nutrition.
Participants (8 females) were randomized within a controlled, crossover trial that included 3, 3-week dietary periods separated by 5 week washout periods. The diets were a healthy lacto-ovo vegetarian diet (LOV), a LOV diet that included 3 ounces/day of unprocessed lean red meat, and a LOV diet with 3 ounces/day of processed lean red meat. Fasting blood samples, along with fecal samples were collected before starting each dietary intervention and during the last 2 weeks of each diet period.
The LOV diet induced changes in some bacteria, reductions in serum total cholesterol and LDL-cholesterol concentrations, but did not affect fecal short chain fatty acids, serum triglycerides, HDL-cholesterol, total cholesterol/HDL-cholesterol ratio, or blood pressure. Adding unprocessed or processed lean red meats to the LOV diet did not influence the short-term changes in gut microbiota. When observations from all three experimental diet periods were combined, changes in some bacteria were associated with improvements in total cholesterol, LDL-cholesterol, triglycerides, HDL-cholesterol, and the total cholesterol/HDL-cholesterol ratio. These observations led the authors to suggest that healthy young adults that consume a healthy dietary pattern that may include lean red meat will experience short-term changes in gut microbiota and those changes are associated with improvements in lipid-related cardiovascular disease risk factors.
Wang Y, Lindemann SR, Cross T-WL, Tang M, Clark CM, Campbell WW. Effects of adding lean red meat to a U.S.-style healthy vegetarian dietary pattern on gut microbiota and cardiovascular risk factors in young adults: a crossover randomized controlled trial. Journal of Nutrition, Volume 153, Issue 5, May 2023, Pages 1439-1452, doi.org/10.1016/j.tjnut.2023.03.013.
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