Telomeres - Cap It All Off with Diet.001

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How to Protect Our Telomeres with Diet

In my video, Does Meditation Affect Cellular Aging?, I discussed how stress reduction through meditation might be able to lengthen telomeres, the protective caps at the tips of our chromosomes that tend to deplete as we age.

What about exercise? We can’t always change our situation in life, but we can always go out for a walk. London researchers studied 2,400 twins, and those who exercised more may have pumped up their telomeres along with their muscles. Apparently it doesn’t take much either. The “heavy” exercise group was only averaging about a half-hour a day.

These were mostly folks in their 40’s, but does it still work in your 50’s? Yes. A study out of South Korea found that people in their 50’s who work out three hours a week had longer telomeres.

In my video, Telomeres: Cap It All Off with Diet, you can see the telomere lengths of young healthy regular folk controls at around age 20, and then at age 50. As we’d expect, the older subjects’ telomeres were significantly shorter. What about athletes? The young athletes started out in the same boat, with nice, long, young, healthy telomeres capping all their chromosomes. The older athletes, in contrast to the controls, appeared to still have the chromosomes of 20-year-olds. But these were marathon runners, triathletes running 50 miles a week for 35 years.

What was it about the Ornish intervention that so powerfully protected telomeres after just three months? We saw that stress management seems to help, but what about diet and exercise? Was it the plant-based diet, was it the walking 30 minutes a day, or was it just because of the weight loss? In 2013, a study was published that can help us answer just that question.

The researchers took about 400 women and randomized them into four groups: a portion-controlled diet group, an exercise group, a portion controlled diet and exercise group, and a control group for a full year. In the video, you can see a comparison of the length of each group’s telomeres. After a year of doing nothing, there was essentially no change in the control group, which is what we’d expect. The exercise group was 45 minutes of moderate-to-vigorous exercise like jogging. After a year of that, they did no better. What about just weight loss? Nothing. The same thing for exercise and weight loss, no significant change either.

So, as long as we’re eating the same diet, it doesn’t appear to matter how small our portions are, or how much weight we lose, or how hard we exercise. After a year, the subjects saw no benefit. On the other hand, the Ornish group on the plant-based diet, who lost the same amount of weight after just three months and exercised less than half as hard, saw significant telomere protection.

It wasn’t the weight loss or the exercise: it was the food.

What aspects of a plant-based diet make it so protective? Studies have associated more vegetables and fruit, and less butter, with longer telomeres. From the latest review, foods high in fiber and vitamins are strongly related to longer telomeres. However, the key may be avoiding saturated fat. Swapping just 1%  of saturated fat calories in our diet for anything else can add nearly a whole year of aging’s worth of length onto our telomeres.

Saturated fats like palmitic acid, the primary saturated fat in salmon, and found in meat, eggs, and dairy in general, can be toxic to cells. This has been demonstrated in heart cells, bone marrow cells, pancreatic cells, and brain cells. The toxic effects on cell death rates happen right around what you’d see in the blood stream of people who eat a lot of animal products. It may not be the saturated fat itself, however, as saturated fat may just be a marker for the increased oxidative stress and inflammation associated with those foods.

With this link to saturated fat, it’s no wonder that lifelong low cholesterol levels have been related to longer telomeres and a smaller proportion of short telomeres—in other words, markers of slower biological aging. In fact, there’s a rare congenital birth defect called progeria syndrome, where children age 8-10 times faster than normal. It seems associated with a particular inability to handle animal fats.

The good news is that “despite past accumulated injury leading to shorter telomere lengths, current healthy behaviors might help to decrease a person’s risk of some of the potential consequences like heart disease.” Eating more fruit and vegetables and less meat and having more support from friends and family attenuate the association between shorter telomeres and the ravages of aging.

To summarize: inflammation, oxidation, damage and dysfunction are constantly hacking away at our telomeres. At the same time, our antioxidant defenses, healthy diet, exercise and stress reduction are constantly rebuilding them.


I’ve asked this diet versus exercise question in a few other contexts. See:

Though dietary change appears more impactful, I’m a big fan of walking. See Longer Life Within Walking Distance and for my personal favorite exercise, Standing Up for Your Health.

For more on the role saturated fat may play in disease, see, for example, my videos Heart Disease Starts in Childhood and Treating Multiple Sclerosis with the Swank MS Diet.

In health,
Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live year-in-review presentations Uprooting the Leading Causes of Death, More Than an Apple a Day, From Table to Able, and Food as Medicine.


Michael Greger M.D., FACLM

Michael Greger, M.D. FACLM, is a physician, New York Times bestselling author, and internationally recognized professional speaker on a number of important public health issues. Dr. Greger has lectured at the Conference on World Affairs, the National Institutes of Health, and the International Bird Flu Summit, testified before Congress, appeared on The Dr. Oz Show and The Colbert Report, and was invited as an expert witness in defense of Oprah Winfrey at the infamous "meat defamation" trial.

38 responses to “How to Protect Our Telomeres with Diet

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    1. Hi Kevin –

      Good for you!

      I liked this overview on research relevant to how to protect one’s telomeres through diet and lifestyle. As usual, Dr. Greger provides easy links to the research studies that he refers to, so you can judge their value for yourself.

      A correction though. For some reason Dr. Greger greatly underestimated the effect of the Ornish program on telomeres by not mentioning the longer term effect seen after 5 years. The Ornish program did not just “powerfully protect” telomeres, it actually lengthened and rejuvenated them.

      The 129% increase in TA the Ornish’s group saw after three months of a vegan very low fat diet after 5 years translated into a statistically significant increase in telomere length – by this measure, the participants in the study actually grew younger. ( )

      How much younger? Well, telomeres in the control group after 5 years decreased by 0·03 T/S units, while the telomeres in the Ornish group increased from baseline by a median of 0·06 telomere to single-copy gene ratio (T/S)units, in effect becoming 10 years younger than from where they started out at baseline, five years earlier. Or to put it another way, for every day his subjects stayed on the program, their telomere length increased, becoming in effect one two days younger.

  1. There is evidence that obese adults have shorter telomeres than normal weight people.

    There is also evidence that, at a population level, meat consumption is strongly linked with obesity:

    “Spearman analyses of the different major food groups shows that meat availability is most highly correlated with prevalence of obesity (r = 0.666, p < 0.001) and overweight (r = 0.800, p < 0.001) and mean BMI (r = 0.656, p < 0.001) and that these relationships remain when total caloric availability, prevalence of physical inactivity and GDP are controlled in partial correlation analysis. Stepwise multiple linear regression analysis indicates that meat availability is the most significant predictors of prevalence of obesity and overweight and mean BMI among the food groups. Scatter plot diagrams show meat and GDP adjusted meat are strongly correlated to obesity prevalence."

    This does not prove cause and effect, of course, but it may be one part of the puzzle.

  2. Just as an aside, has anyone else heard about the CEO of BioViva (Elizabeth Parrish) who is being a “human guinea pig” and received the first telomere-lengthening gene therapy? It actually appears that she now has longer telomeres in her white blood cells. Of course, this is unpublished data and needs closer scrutiny, but it’s interesting nonetheless. Personally I’d rather achieve the same results through diet. :)

  3. A lot of contradictory information out there it is confusing. I always heard about the health benefits of ghee and how the Indian Rishi’s would often just eat ghee and rice and live very long. Doesn’t ghee have a lot of saturated fat? However, I also read that ghee is special in that it doesn’t increase body cholesterol.

    1. You make your own cholesterol. You do not need to eat it. Science is a wonderful thing and it gives us a chance to actually test many ideas that have been out there for a long time. While you may be conflicted about the use of animal products, remember that many of the plants and spices of India are beyond compare. What probably kept those Indian Rishi’s alive an well was turmeric, cardamon, ginger, and amla..
      Milk fat and polished rice – not so much.

    2. I wouldn’t put much faith in stories. And the supposed health benefits have to be considered in the context of “compared to what?”. Most of the studies I have seen that suggest benefits only show that ghee is less unhealthy than hydrogenated vegetable oils, margarine or ordinary butter eg.

      However, other studies show that replacing some ghee with vegetable oil is associated with lower heart disease rates, eg “subjects consuming moderate to high fat diets ….. eating ……. clarified butter as total visible fat had a significantly higher prevalence of coronary artery disease compared to those consuming clarified butter plus vegetable oils in both rural (9.8, 7.1 vs. 3.0%) and urban (16.2, 13.5 vs. 11.0%) men as well as in rural (9.2, 4.5 vs. 1.5%) and urban (10.7, 8.8 vs. 6.4%) women.”

      Of course, none of this shows that ghee or oils or margarine etc are positively healthy – merely that some are less unhealthy than others. Unless you can find a study that shows benefits compared to a whole food plant based diet, I would give all butters, oils etc a miss. There is no evidence of actual benefits while there is evidence of harm

    3. Traditional Indian medicine seems to be a strange mix of quite profound wisdom on one hand and worthless superstition on the other. I have heard that ghee aged a certain length of time can cure any ailment. I doubt if there are many scientists that would take this seriously enough to even want to test it.

    1. Hi Carol. In simple terms, telomeres are the “end caps” on your chromosomes which protect the DNA that you need in the remainder of your chromosome. Each time your cells divide (and therefore your chromosomes in the cell divide), you lose a tiny portion off the end of the telomeres. Therefore, aging is associated with shorter telomeres. An analogy that helps me think about this is a shoelace. A brand new shoelace has the little plastic piece over the end which helps you put it through the holes in your shoes. After lots of wear (think aging), those plastic pieces get worn out and the ends of the shoelace begin to fray. Dr. Greger’s above article describes how to slow or reverse that aging process. If you need a visual, look at the picture at the top of this page. The main part of the X shaped chromosome is blue and the telomeres at the end are in pink. I hope that helps you.

  4. In the second paragraph you wrote: “those who exercised more may have pumped up their telomeres along with their muscles.” but toward the end of this article, it says,” it doesn’t appear to matter how small our portions are, or how much weight we lose, or how hard we exercise.” So which is correct? Does exercise help restore or retain telomere length or not?

    1. Well, these are two different studies and did not look at exactly the same thing. So the results are not identical. The twins study (second paragraph), for example, did not look at how the diets of the exercising and non-exercising twins differed. The Ornish study did.
      Therefore, the explanation may lie in the full quote from the end of the article …. “So as long as we’re eating the same diet, it doesn’t appear to matter how small our portions are, or how much weight we lose, or how hard we exercise.”

      Some of the other videos Dr Greger mentions at the bottom of his article may also throw more light on this point.

  5. If you’re already eating according to the recommendations you suggest and therefore growing your telomeres, will meditating add any to this effect or is the additional effort of doing the meditation a waste of time?

    1. Good question! You want to eat a healthy diet to lengthen your telomeres in addition to stress reduction through meditation. In this previous video and previous blog post, you can see that stress alone can shorten telomeres. A plant based diet plus stress reduction will benefit you the most.

  6. Super confused by the implication of saturated fat as unhealthy here. When plant fiber ferments in the large intestine, the by-product of that fermentation is: saturated fat (butyrate and other short chain saturated fatty acids). Eating a plant based diet means eating a diet that causes bacteria to create tons of sat fat in your gut, which is absorbed by your intestines. Seems like a biased omission to leave out this detail of metabolism when saying we should eat less sat fat and more vegetables, when in fact eating plants can increase the amount of sat fat absorbed by your body ESPECIALLY when much of the research indicates that the saturated fat created by the bacteria has positive health effects.

    Example reference to sat-fat production by fiber and bacteria, and that it’s healthy:

    1. .Really? Fermentation creates saturated fat? No, that is not true. You eat saturated fat when you eat animal products. You can get fat from plants primarily from nuts and a few veggies and fruits, but those fats can be a healthy part of your diet. There are a few saturated fats from plants, like coconut oil that are also best avoided.

      It is primarily fat from animal products that cause problems in your liver, heart, and arteries. Please watch Dr. Greger’s video, “From Table to Able.” There are other sites like and that can give you diet plan for a Whole Food Plant Based Diet.

      A thorough discussion of the different types of bacteria created by plant based diets verses animal based diets is in the video: but there are many others if you search this site.

    2. You are quite correct. Saturated fat in and of itself isn’t unhealthy. However, the consumption of large amounts of isolated and/or concentrated saturated fat is a serious problem. And that is what people mean when they refer to saturated fat being unhealthy.

      The point is that the body makes all the saturated fat it needs from healthy foodstuffs and has no requirement for direct consumption of large amounts of concentrated saturated fats as found in eg cheese, butter, lard and fatty meats. Of course, you will still consume some saturated fat as part of a healthy diet. For example my morning oatmeal contains saturated fat ……

      It is like so many other things. It is the dose that makes the poison. For example, we need iron, copper, selenium from the diet but in large amounts they are toxic. Major health problems emerge when saturated fat is consumed in significant amounts. The US National Evidence Library summarises the evidence of this and, of course, there are many videos on this site which provide useful discussions of aspects of these problems.

    1. SeedyCharacter: It took me a little time, but I finally got around to reading that article you linked to. You are right, great read! Thanks!

  7. Help me please!! I’m a medical student, first year, eastern Europe schooling (Romania)…. It is mostly challenging beacause of the amount of information I seem not to be able to ingest, cellulose, you know…. I was wondering if there is any active substance or natural compound of some sort you could recommend me to enhance my capacities and or concentration even just by a bit… Sincere thanks.

  8. Which cell telomeres get protected? Do cells concerned with the outward visible signs of aging like wrinkles etc also get protection?

  9. Besides the diet that the doctor suggests telomeres should have their own “diet” too and this is no other that the enzyme telomerase! This is exactly what product FINITI does to those who consume it! Get all the facts about FINITI and the company that produces it at

  10. Besides the diet that the doctor suggests telomeres should have their own “diet” too and this is no other that the enzyme telomerase! This is exactly what product FINITI does to those who consume it! Get all the facts about FINITI and the company that produces it at

  11. I have an important question that I can’t find the answer to anywhere:

    Do the pesticides, herbicides and whatever else goes into our conventionally grown fruits and vegetables outweigh their nutritional benefits?

    Organic is not always available (or affordable) and with warnings about pesticides attached to online lists like “The Clean 15” and “The Dirty Dozen” I’m confused.

    Should I still buy those apples even though they’re not organic? Or are no apples better? What’s the definitive answer?

  12. I read the full text of 3 of the references cited.
    Not one of them supported the text’s claims about eating “saturated fat” shorting telomere length.
    In fact a perusal of PubMed found large global scale studies showing inverse correlation between consumption of full fat dairy and mortality, in direct contradiction to the claims of the author.

  13. Hi Jack LaBear , thanks for your question. I noticed that alef1 gave a good comment regarding Dr Ornish work and I am sharing the summary of the research with you regarding a study that Dr Ornish did and found results with reduction in fat and lengthening telomeres. “DR Ornish program on telomeres the longer term effect seen after 5 years”.
    Telomere shortness in human beings is a prognostic marker of ageing, disease, and premature morbidity. We previously found an association between 3 months of comprehensive lifestyle changes and increased telomerase activity in human immune-system cells. We followed up participants to investigate long-term effects.

    This follow-up study compared ten men and 25 external controls who had biopsy-proven low-risk prostate cancer and had chosen to undergo active surveillance. Eligible participants were enrolled between 2003 and 2007 from previous studies and selected according to the same criteria. Men in the intervention group followed a programme of comprehensive lifestyle changes (diet, activity, stress management, and social support), and the men in the control group underwent active surveillance alone. We took blood samples at 5 years and compared relative telomere length and telomerase enzymatic activity per viable cell with those at baseline, and assessed their relation to the degree of lifestyle changes.

    Relative telomere length increased from baseline by a median of 0·06 telomere to single-copy gene ratio (T/S)units (IQR–0·05 to 0·11) in the lifestyle intervention group, but decreased in the control group (−0·03 T/S units, −0·05 to 0·03, difference p=0·03). When data from the two groups were combined, adherence to lifestyle changes was significantly associated with relative telomere length after adjustment for age and the length of follow-up (for each percentage point increase in lifestyle adherence score, T/S units increased by 0·07, 95% CI 0·02–0·12, p=0·005). At 5 years, telomerase activity had decreased from baseline by 0·25 (–2·25 to 2·23) units in the lifestyle intervention group, and by 1·08 (–3·25 to 1·86) units in the control group (p=0·64), and was not associated with adherence to lifestyle changes (relative risk 0·93, 95% CI 0·72–1·20, p=0·57).

    Our comprehensive lifestyle intervention was associated with increases in relative telomere length after 5 years of follow-up, compared with controls, in this small pilot study.

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