In this episode of The School of Greatness, Dr. Michael Greger discusses how diet and lifestyle choices can influence the aging process. He explains that while genetics play a role in longevity, daily habits like maintaining a healthy weight, exercising, and eating specific foods can add up to a decade of life. The discussion covers how certain dietary choices activate anti-aging pathways in the body and potentially reverse aspects of aging.
Dr. Greger delves into practical dietary recommendations, including the benefits of whole-food plant-based nutrition, the importance of meal timing, and the role of fasting in cellular health. He also addresses gaps in medical education regarding nutrition and explains how the current healthcare system often overlooks evidence-based nutrition information due to profit-driven motivations.

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Dr. Michael Greger explains that while genetics accounts for only about 25% of lifespan differences, lifestyle choices can significantly impact longevity. He notes that basic behaviors like maintaining a healthy weight, exercising, and eating fruits and vegetables can add up to a decade of life. According to Greger, slowing the aging process through lifestyle interventions can reduce the risk of age-related diseases like stroke, dementia, and cancer. He discusses how the "anti-aging pathway," activated by vinegar, exercise, and calorie restriction, can potentially reverse aspects of aging.
Greger emphasizes the importance of a whole-food, plant-based diet for longevity. He identifies legumes as particularly beneficial, noting they provide prebiotics that support gut health and improve immunity. Walnuts receive special attention, as Greger explains they contain more omega-3 fatty acids and antioxidants than other nuts, with studies showing they can improve artery function within hours of consumption. On sodium intake, Greger advocates for reducing processed foods and suggests switching to potassium salt (with medical approval) to effectively reduce cardiovascular disease risk.
The discussion turns to meal timing and fasting. Greger explains that while autophagy (cellular cleaning) requires 36-48 hours of fasting under medical supervision, benefits can be achieved through shorter fasting windows. He recommends limiting daily eating to a 12-hour window earlier in the day, noting that people in longevity hotspots typically eat light, early dinners. According to Greger, aligning meals with circadian rhythms enhances metabolic health and the body's ability to process nutrients.
Greger highlights significant gaps in medical education regarding nutrition, revealing that even at top medical schools, doctors receive minimal training in clinical nutrition. He points out that this deficiency is particularly problematic given that 80% of primary care visits involve lifestyle-related chronic diseases. Through his work with the American College of Lifestyle Medicine and NutritionFacts.org, Greger aims to address this knowledge gap by disseminating evidence-based nutrition information that the current healthcare system often overlooks due to profit-driven motivations.
1-Page Summary
Dr. Michael Greger provides insight into how a healthy diet, lifestyle changes, and understanding of cellular processes can contribute to longevity and potentially slow down the aging process.
Greger emphasizes that the vast majority of premature deaths and disabilities are preventable, with only about 25% of the differences in lifespan between people due to genetics. This highlights the significant impact of lifestyle on longevity. He argues that basic behaviors, including not smoking, maintaining a healthy weight, exercising, and consuming fruits and vegetables, can add up to a decade of life. Greger also discusses cellular senescence, one of the aging pathways he covers in his book, suggesting that lifestyle interventions can influence this process.
According to Greger, slowing down the aging process can reduce the risk of various diseases, which rise exponentially with age. He specifically mentions stroke, dementia, cancer, and heart disease. Premature senescence of cells, which can be prevented by consuming antioxidant-rich foods like berries and greens, relates directly to the prevention of these diseases through diet and lifestyle, rather than genetics alone.
Greger introduces the "anti-aging pathway," which can be activated by acetic acid found in vinegar and is further stimulated by exercise and calorie restriction. This pathway has the potential to reverse aspects of aging, thus enhancing both lifespan and quality of life. Greger also highlights the Ha ...
The Science of Longevity and Anti-Aging
Michael Greger emphasizes the importance of a whole-food, plant-based diet for health and longevity, supported by research pointing to blue zones, where people live longer and healthier lives.
Legumes, such as beans, split peas, chickpeas, and lentils, are noted by Greger to be associated with the largest expected life expectancy gains according to a study. He suggests including more legumes in your diet because they are the most concentrated sources of prebiotics, such as resistant starch and dietary fiber, that feed the good bacteria in our gut. Legumes are also linked to benefits like decreased inflammation, improved immunity, and muscle strength in frail individuals.
Greger asserts that nuts, especially walnuts, are associated with the longest lifespan. Walnuts contain more omega-3 fatty acids and antioxidants than other nuts and are the only nuts that have been shown to improve artery function within hours of consumption. They also played a critical role in the PRET-D-Med study in reducing cardiovascular disease rates. Consuming a palmful of walnuts daily is recommended, with health benefits plateauing at one ounce, potentially adding up to two years to lifespan.
Michael Greger discusses the benefits of eating walnuts, including their impact on heart health. Interventional trials showed that walnuts might improve heart health and cholesterol levels. This could be a contributing factor to their ability to prolong life, as demonstrated by observational studies that found decreased heart disease risk among nut eaters.
Greger advocates for the consumption of unsalted nuts and a reduction in sodium intake, as it's the number one dietary risk factor for death globally. Most of the sodium in our diet comes from processed foods. Greger expl ...
Optimizing Diet and Nutrition For Health and Longevity
Michael Greger and Lewis Howes discuss how factors beyond what you eat can impact aging, focusing on meal timing and its relation to the body's natural processes.
The conversation explores the benefits of narrowing the eating window and timing meals to align with the body's circadian rhythms.
Greger explains that while autophagy, a cellular cleaning process, has benefits and contributes to the aging process, it generally doesn't ramp up until 36 to 48 hours into fasting. He stresses that prolonged fasting should be done under medical supervision to avoid serious health risks such as electrolyte abnormalities.
The discussion looks at the intermittent fasting literature, which Greger admits can be confusing. He highlights that fasting with an eating window earlier in the day has remarkable benefits, but when the eating window is late in the day, it could be harmful, potentially causing metabolic issues. Greger emphasizes skipping supper rather than breakfast and suggests that eating the same food in the morning rather than the evening leads to less of a blood sugar spike, due to the circadian rhythms.
Greger suggests that one should ideally collapse their daily feeding window to 12 hours or less, stressing that this eating schedule should be earlier in the day to align with circadian rhythms. He mentions that people in regions known for longevity tend not to eat a lot of dinners, or if they do, their dinners are light or early, typically before 7 PM or even before 4 PM.
He also highlights the importance of chronobiology and how our circadian rhythms have a significant impact on our biol ...
Other Lifestyle Factors Beyond Diet That Impact Aging
Michael Greger outlines serious deficiencies in the medical system's approach to chronic disease prevention and treatment, highlighting a need for greater focus on nutrition education within the medical field and confronting the consequences of profit-driven health care.
Lewis Howes brings up that medical education largely neglects nutrition, often offering at most an hour-long class on the subject. Greger agrees, pointing out that even in medical schools known for their nutrition training, such as the one he attended, he received only 19 hours of instruction, much of which focused on basic biochemistry rather than clinical nutrition or using diet to prevent or reverse diseases. Greger states that graduating doctors, as a result, lack the tools to fully heal patients despite lifestyle-related chronic diseases making up 80% of primary care visits.
Greger comments on how hospitals and the pharmaceutical industry profit from treatments and lifestyle drugs for chronic conditions, suggesting a financial incentive to treat symptoms rather than prevent disease through lifestyle changes. He also discusses how businesses maximize profit at the expense of public health, noting that unhealthy, processed foods offer higher profits due to lower production costs and longer shelf lives.
Greger emphasizes that peer-reviewed medical literature establishes the foundations of what we know in medicine, but this knowledge has not been assimilated into clinical practice or public awareness due to a lack of direct profit motives. He also points out that beneficial studies on natural foods are not widely promoted because there isn't a lot of money to be made, and the profitability of foods is inversely related to their health benefits.
Greger highlights the absence of advertisements and promotional campaigns for healthy foods, due to their lack of brand identity, which precludes individual growers from profiting sufficiently to justify significant advertising ...
Medical System Critiques and Change Recommendations
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