Longevity: Exploring the Science of a Longer, Healthier Life

Written By Adama Diarra, DO, FACP

Over the next few months, I’ll be diving into the latest research and practical recommendations on longevity from an internal medicine perspective. This field is evolving rapidly, with new studies emerging as you read this, potentially shifting our understanding. That’s why I’ve chosen to share this as a newsletter—it gives me the flexibility to update you with fresh insights as they arise.

We’ll explore key factors that influence longevity, including:

  • Healthy diets

  • Exercise to promote health and prevent injury

  • Maintaining a healthy weight

  • Socio-economic implications of living longer

  • Finding your “why” as you grow older

  • Avoiding harmful substances

  • Steering clear of loneliness

Let’s start with dietary choices—one of the most impactful areas for promoting a long, vibrant, and fulfilling life.

Part I: The Centenarian Way of Eating (and of Not Eating)

1. A Balanced Diet

In medical school, I was fascinated by the digestive system's complexity. At the Arizona College of Osteopathic Medicine, we studied the anatomy, physiology, biochemistry, and pathology of the gastrointestinal system almost simultaneously. This integrated approach revealed the brilliance of the human body's design for digesting every macro and micro nutrient we consume.

Each macronutrient—proteins, carbohydrates, and fats—is meticulously broken down into building blocks for absorption, while the body also processes water, vitamins, and minerals with precision. This understanding has made me cautious about absolutist dietary advice like, “You must eat a vegan diet or else.” Instead, I advocate for balance. While individual needs vary, I often recommend two evidence-backed diets: the Mediterranean diet and a plant-based diet.

The Mediterranean Diet

This diet emphasizes fruits, vegetables, whole grains, nuts, and olive oil, with moderate consumption of fish and poultry. It’s not just delicious—it’s proven to extend life and reduce chronic disease risk.

  • The EPIC Study: This large observational study involving over 500,000 Europeans linked the Mediterranean diet to significantly lower mortality from heart disease and cancer. (Buckland et al., 2008)

  • The PREDIMED Study: This randomized controlled trial found that people following the Mediterranean diet had a 30% reduction in major cardiovascular events. Adding olive oil or nuts made the diet even more powerful. (Estruch et al., 2013)

While these studies have limitations—like issues with causation and randomization—they underscore the Mediterranean diet's role in reducing chronic diseases, enhancing cardiovascular health, and promoting longevity.

Plant-Based Diets

Plant-forward eating has been associated with reduced mortality risk, particularly from heart disease. While I encourage patients to reduce animal protein intake, I’m not a food dictator. For some, we aim for a few vegetarian days per week and track biomarkers to assess progress.

  • Adventist Health Study-2: Over 70,000 participants showed lower mortality rates among vegetarians, particularly from cardiovascular diseases. (Orlich et al., 2013)

  • EPIC-Oxford Study: Vegetarians had lower risks of heart disease and some cancers compared to non-vegetarians. (Appleby et al., 2014)

Despite criticisms like self-reported data and confounding lifestyle factors, evidence supports that plant-based diets reduce cardiovascular risk and promote longevity.

2. Intermittent Fasting and Calorie Restriction

Reducing calorie intake or meal frequency has profound effects on health and aging.

Calorie Restriction

Animal studies show that cutting calorie intake by 20-40% extends lifespan and delays age-related diseases. This is linked to reduced inflammation and improved cellular repair pathways like sirtuins and AMPK. (Mattison et al., 2012; Fontana et al., 2010)

Intermittent Fasting

Popular fasting methods, like the 16:8 (16 hours fasting, 8 hours eating), improve metabolic health, reduce inflammation, and activate autophagy—a cellular cleanup process essential for longevity. Human studies have shown intermittent fasting aids weight loss, reduces insulin resistance, and may enhance brain health. (Lee et al., 2016; Phillips, 2014)

3. The Perils of Processed Foods

Processed and ultra-processed foods—packed with preservatives, sugars, and unhealthy fats—are major contributors to chronic disease and aging.

  • Heart Health: High processed food consumption increases the risk of cardiovascular diseases. (Srour et al., 2019)

  • Brain Health: Processed foods elevate inflammation and oxidative stress in the brain, increasing neurodegenerative disease risk. (Spencer et al., 2015)

  • Metabolic Health: These foods disrupt insulin sensitivity, contributing to obesity and type 2 diabetes. (Micha & Mozaffarian, 2018)

What to Do: Replace processed foods with whole, unprocessed alternatives like fresh fruits, vegetables, and whole grains. Even small changes can yield significant health benefits.

Conclusion

From the Mediterranean and plant-based diets to intermittent fasting and avoiding processed foods, your dietary choices can profoundly influence how long and well you live. Future studies leveraging machine learning and big data will refine our understanding, but the message is clear: eating mindfully and balancing macronutrients can help you thrive well into old age.

 

Quick Summary

  • Mediterranean Diet: Rich in fruits, vegetables, whole grains, nuts, and olive oil, with moderate fish and poultry, it’s linked to reduced heart disease and increased lifespan. (Buckland et al., 2008; Estruch et al., 2013)

  • Plant-Based Diets: Lower in animal protein and rich in plant-based foods, these diets reduce mortality risk, especially from cardiovascular diseases. (Orlich et al., 2013; Appleby et al., 2014)

  • Calorie Restriction: Reduces inflammation and oxidative stress, activating longevity pathways like sirtuins and AMPK, which enhance cellular repair and metabolic health. (Mattison et al., 2012; Fontana et al., 2010)

  • Intermittent Fasting: Mimics calorie restriction benefits by promoting autophagy, reducing chronic disease risk, and improving metabolic health. (Lee et al., 2016; Phillips, 2014)

  • Processed Foods: High consumption of ultra-processed foods is associated with cardiovascular disease, cognitive decline, and metabolic disorders. Replacing them with whole foods can improve health and longevity. (Srour et al., 2019; Spencer et al., 2015)

  • Lifestyle Matters: Physical activity, socioeconomic status, and holistic approaches complement dietary strategies for better health outcomes and longevity.

 

Stay tuned for more as we explore other pillars of longevity.

References

  1. Appleby, P. N., Crowe, F. L., Bradbury, K. E., Travis, R. C., & Key, T. J. (2014). Mortality in vegetarians and comparable nonvegetarians in the United Kingdom. The American Journal of Clinical Nutrition, 100(1), 378S-385S. https://doi.org/10.3945/ajcn.113.071597

  2. Buckland, G., González, C. A., Agudo, A., Vilardell, M., Berenguer, T., Amiano, P., … Riboli, E. (2008). Adherence to the Mediterranean diet reduces mortality in the Spanish cohort of the European Prospective Investigation into Cancer and Nutrition (EPIC-Spain). The British Medical Journal, 336(7657), 1348–1351. https://doi.org/10.1136/bmj.39561.501007.BE

  3. Dinu, M., Abbate, R., Gensini, G. F., Casini, A., & Sofi, F. (2017). Vegetarian, vegan diets and multiple health outcomes: A systematic review with meta-analysis of observational studies. Critical Reviews in Food Science and Nutrition, 57(17), 3640–3649. https://doi.org/10.1080/10408398.2016.1138447

  4. Estruch, R., Ros, E., Salas-Salvadó, J., Covas, M. I., Corella, D., Arós, F., … Martínez-González, M. A. (2013). Primary prevention of cardiovascular disease with a Mediterranean diet. The New England Journal of Medicine, 368(14), 1279–1290. https://doi.org/10.1056/NEJMoa1200303

  5. Fontana, L., Partridge, L., & Longo, V. D. (2010). Extending healthy life span—from yeast to humans. Science, 328(5976), 321–326. https://doi.org/10.1126/science.1172539

  6. Lee, C., Longo, V. D., & Mattson, M. P. (2016). Fasting vs dietary restriction in cellular protection and cancer treatment: From model organisms to patients. Cell Metabolism, 23(6), 1048–1059. https://doi.org/10.1016/j.cmet.2016.05.014

  7. Mattison, J. A., Roth, G. S., Beasley, T. M., Tilmont, E. M., Handy, A. M., Herbert, R. L., … de Cabo, R. (2012). Impact of caloric restriction on health and survival in rhesus monkeys from the NIA study. Nature, 489(7415), 318–321. https://doi.org/10.1038/nature11432

  8. Micha, R., & Mozaffarian, D. (2018). Saturated fat and cardiometabolic risk factors, coronary heart disease, stroke, and diabetes: A fresh look at the evidence. Cell Metabolism, 27(4), 719–720. https://doi.org/10.1016/j.cmet.2018.03.002

  9. Orlich, M. J., Singh, P. N., Sabaté, J., Jaceldo-Siegl, K., Fan, J., Knutsen, S., … Fraser, G. E. (2013). Vegetarian dietary patterns and mortality in Adventist Health Study 2. JAMA Internal Medicine, 173(13), 1230–1238. https://doi.org/10.1001/jamainternmed.2013.6473

  10. Phillips, N. E., Hannon, B. A., & Keane, C. A. (2014). Intermittent fasting and its effects on metabolic health: A critical review of clinical studies. The Lancet Diabetes & Endocrinology, 2(9), 675–684. https://doi.org/10.1016/S2213-8587(14)70162-0

  11. Srour, B., Fezeu, L. K., Kesse-Guyot, E., Alles, B., Méjean, C., Andrianasolo, R., … Hercberg, S. (2019). Ultra-processed food intake and risk of cardiovascular disease: Prospective cohort study (NutriNet-Santé). The British Medical Journal, 365, l1451. https://doi.org/10.1136/bmj.l1451

  12. Spencer, S. J., Korosi, A., Layé, S., Shukitt-Hale, B., & Barrientos, R. M. (2015). Food for thought: How nutrition impacts cognition and emotion. Frontiers in Neuroscience, 9, 357. https://doi.org/10.3389/fnins.2015.00357