How Vegetable Intake Relates to Epigenetic Aging
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Blood carotenoids provide an objective marker related to fruit and vegetable intake, although absorption, supplements, smoking, body composition, and health status can also affect their levels. In this FoundMyFitness interview, Dr. Steve Horvath describes how an association between higher carotenoid levels and lower epigenetic-age acceleration changed his own eating habits. In 4,173 postmenopausal women from the Women's Health Initiative, higher plasma carotenoids were associated with lower acceleration on an extrinsic epigenetic-aging measure. [1]
Epigenetic clocks use DNA methylation patterns to estimate different aspects of biological aging. Their results can vary by clock, tissue, population, and the behaviors included in each model. Other observational research in women has associated healthier dietary patterns with modestly lower acceleration on PhenoAge and GrimAge, while large prospective studies associate greater fruit and vegetable intake with lower cardiovascular and all-cause mortality. These findings support a plant-rich dietary pattern without requiring one specific vegetable or carotenoid dose. [2] [3]
Dr. Rhonda Patrick highlights lutein and zeaxanthin from green vegetables, while Dr. Horvath emphasizes that vegetables contain a wider mixture of carotenoids, fiber, micronutrients, and phytochemicals. Exercise provides complementary benefits that a blood methylation clock may not fully capture, including cardiorespiratory fitness, function, and disease-risk reduction. Together, regular physical activity and a varied diet rich in colorful plant foods support healthy aging through overlapping pathways.
- ^ 10.18632/aging.101168
- ^ 10.1093/ajcn/nqab307
- ^ Aune, Dagfinn; Giovannucci, Edward; Boffetta, Paolo; Fadnes, Lars Thore; Keum, NaNa; Norat, Teresa, et al. (2017). Fruit And Vegetable Intake And The Risk Of Cardiovascular Disease, Total Cancer And All-Cause Mortality—A Systematic Review And Dose-Response Meta-Analysis Of Prospective Studies International Journal Of Epidemiology 46, 3.
Dr. Rhonda Patrick: Do you want to discuss the DIRECT trial?
Dr. Steve Horvath: I do not know enough about that trial to discuss it in detail, but I can explain some properties of epigenetic clocks.
Food-frequency questionnaires do not always reflect what people eat. Memory and the desire to give a healthy answer can bias self-reports. Blood carotenoids provide a more objective marker of fruit and vegetable intake, although they are also affected by absorption, supplements, smoking, body composition, and health status.
In postmenopausal women from the Women's Health Initiative, higher blood carotenoids were associated with lower epigenetic-age acceleration. I recalled a correlation near r = -0.3 with GrimAge and other clocks. That exact coefficient and clock require source confirmation. The readily traceable published WHI paper found smaller associations and used earlier clocks that predated GrimAge.
The association changed my behavior, and I now eat many vegetables.
Dr. Rhonda Patrick: Can you translate the correlation into months?
Dr. Steve Horvath: No. A correlation coefficient cannot be converted directly into months or years. For context, smoking had a strong positive association with GrimAge, while vegetable intake had an inverse association.
Dr. Rhonda Patrick: That is surprising.
Dr. Steve Horvath: Exercise had a smaller association with the methylation clocks in that dataset. That does not mean vegetables provide greater clinical health benefits than exercise. It compares observational associations with one biomarker, not randomized effects on disease, mortality, or lifespan.
Dr. Rhonda Patrick: Do you think carotenoids, vitamins, minerals, fiber, and other compounds in vegetables contribute to the association?
Dr. Steve Horvath: I have not separated those factors. The association is interesting, but the mechanism, vegetable type, and dose remain unknown.
Dr. Rhonda Patrick: Green vegetables supply lutein and zeaxanthin. These carotenoids accumulate in the eye and brain. Trials support lutein and zeaxanthin in selected people at risk for age-related macular degeneration, while cognition findings are more limited and do not prove that carotenoids caused the epigenetic-clock association.
Vegetables also contain other carotenoids, fiber, micronutrients, and phytochemicals. A short randomized twin study found changes in some epigenetic clocks with a vegan diet, but the vegan group also ate fewer calories and lost more weight. Those differences complicate interpretation.
Dr. Steve Horvath: The vegetable association was larger than the exercise association in this dataset. Exercise still has strong benefits that a blood methylation clock may not capture.
For vegan compared with omnivorous diets, I have not seen convincing evidence from epigenetic clocks that people who eat more red meat age much faster than vegans. In an analysis of about 3,000 women, the red-meat association with epigenetic age was small. That narrow clock result does not establish that red or processed meat is risk-free.
I eat meat and vegetables and limit simple carbohydrates.
Dr. Rhonda Patrick: Vegetables are carbohydrates, but they are complex foods that also provide fiber and micronutrients.
Dr. Steve Horvath: More research should identify which vegetables, components, and doses relate to these epigenetic-age measures.
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