THE POWER OF TELOMERES

Almost everyone has heard of telomeres by now. Their role in longevity is often discussed in the news and on radio programs. But what exactly are they? Our genes are made of twisted, double-stranded molecules of DNA called chromosomes. Chromosomes are present in the nucleus of nearly all the cells of the human body. Both ends of these chromosomes are “capped” with DNA pieces that protect our genetic data. These “caps” are the telomeres. They allow cells to divide but not lose important genes that are part of the blueprint for the production of new healthy cells through cell division (1).

Why is cell division important? The definition of a living thing is the presence of growth and reproduction, activities which are accomplished through cell division. When a living being grows, it does so through cell division. When a living being reproduces, this also happens through cell division. As cells become damaged through injury or die from old age, they need to be replaced. Once again, cell division becomes the process that is called upon. Telomeres ensure that the genetic information that is passed along during division of cells is accurate, making telomeres crucial in any tissue that must be replenished throughout life. It is estimated that the human body undergoes nearly two trillion cell divisions every day (1,2).

Each time a cell divides, the telomeres become shorter. This is due to limitations of the enzymes that regulate the replication of the DNA at the ends of the chromosomes (3). When cells are young, telomeres allow chromosomes to divide successfully by preventing the ends of the chromosomes from being lost through fraying or fusing incorrectly to another cell component. However, with each cell division some of the telomere is lost. It appears that most body cells are able to divide an average of 40 to 60 times before the telomere becomes too short and the cell is no longer able to replicate successfully. This results in the death of the cell (4,5).

There is also another important enzyme involved here. It is called telomerase and it supports the maintenance and even the lengthening of telomeres through the addition of new DNA (2). Telomerase is present in cell types that need to undergo many divisions (for example, stem cells found in rapidly dividing tissues such as the blood, heart and bone marrow) or cells that are involved in reproduction (for example, those in sperm and eggs). Cancer cells also employ telomerase to keep them alive and growing. Telomerase exists at very low levels in most other human cells (1,6).

Though telomeres themselves are not the only factor involved in aging, shortening of telomeres is associated with how quickly we age and how long we live. It is also linked to our risks of chronic diseases such as heart disease, cancer and dementia (7,8,9,10). Telomere length seems to represent our biological age as opposed to our chronological age. As such it is important for us to be aware of ways to encourage long, healthy telomeres.
In 2011 an extensive review of studies examined the relationship between telomere length and lifestyle habits and found that these two factors are very much interconnected. Here are the associations that were found (11);

Associations with shortening telomeres:
Telomere length decreases with age and may predict shortening of lifespan
Faster telomere shortening may increase the pace of aging
Smoking may hasten telomere shortening and the process of aging
Obesity is associated with excessive telomere shortening and accelerated aging
Exposure to harmful agents such as pollution and other gene-toxic substances may be linked to telomere shortening
Stress increases the speed of telomere shortening and of aging
Higher dietary intake of polyunsaturated fatty acids (especially linoleic acid, typically found in isolated oils derived from plants) is associated with shorter telomeres
Older people who have shortened telomeres triple their risk of dying from heart disease and the risk of dying from an infectious disease is increased eight-fold.

Associations with lengthening telomeres:
Longer telomeres and reduced rates of aging are associated with lower protein and higher carbohydrate in the diet
Higher dietary intake of fiber is associated with longer telomeres
Dietary intake of antioxidants reduces the rate of telomere shortening
Eating lower volumes of food reduces the pace of aging
Exercise may preserve telomeres and slow the process of aging

Our lifestyle and environment can indeed have a substantial effect on our telomeres and, as an extension of this, on the way that we age.

The following are some scientific investigations from the last couple of decades that have examined different aspects of lifestyle as it affects telomere health.

STRESS:

Recognizing the huge amount of stress caused by caring for a sick child, a 2004 study compared mothers of healthy children to those of chronically ill children and found that more years of caregiving by the mother translated into shorter telomeres, lower telomerase activity and greater oxidative stress. This holds true even after controlling for the age of the mother. These changes were comparable to those caused by at least a decade of aging (3).

A similar effect happens in those suffering the chronic stress of caring for an Alzheimer’s sufferer (12) or those enduring severe work-related exhaustion (13) or those who have been abused as children (14).

A study from 2013 looked at the effect of meditation on telomere length. The “treatment” group practiced a Buddhist traditional meditation called Loving-Kindness Meditation while the “control” group did not meditate at all. At the end of the study those practicing meditation, especially the women, showed significantly longer telomeres than the controls (15).

SLEEP:

Scientific trials have demonstrated that women younger than 50 years of age who sleep less than 6 hours a night have shorter telomeres on average than women who sleep an average of 9 hours nightly (16).

Other investigations have looked at women who report poor sleep quality and reveal that these women have shorter telomeres (17).

PHYSICAL ACTIVITY:

A study of 2400 men and women compared their telomere lengths with their physical activity and showed that higher amounts of exercise were associated with longer telomeres (18).

Since estrogen is linked to protection of telomere length, a study looked at the amount of exercise postmenopausal women were doing compared to their telomere length. Results showed that those women participating in regular exercise more than three times a week over an average of about 1.5 years had significantly longer telomeres than sedentary women (19).

A 2009 study of track and field athletes found that 20-year-old athletes, like most people of that age, have long, healthy telomeres. But, at age 50, when telomere length has shortened due to aging, athletes maintained longer telomeres than people exercising minimally or not at all (20).

DIET:

A study looking at the influence of micronutrients on telomere length showed that higher consumption of vegetables was related to significantly longer telomere length (21).

A review of telomere research showed that eating foods high in fiber and vitamins is associated with longer telomeres while eating processed meats and foods high in polyunsaturated fats is linked to shorter telomeres (17).

The association between fats, fruits, vegetables and telomere length was studied in a group of almost 2000 men and women. Results showed that both total fat and saturated fat intake were associated with shorter telomeres, while longer telomeres were linked to higher vegetable consumption. Participants consuming the most butter and least fruit had significantly shorter telomeres than those consuming the lowest amounts of butter and highest amounts of fruit (22).

Another study showed that the more short- to medium-chain saturated fatty acids women ate, the shorter were their telomeres on average. When even a small amount of the saturated fatty acids were replaced by any other energy source telomere length increased (23).

A cross-sectional study looked at associations between telomeres and various dietary patterns and showed that eating processed meat or fish were both associated with significantly shortened telomeres (24).

COMPREHENSIVE LIFESTYLE CHANGES:

In 2013, the publication of two separate studies identified the lifestyle changes with the most positive effect on telomeres. The first study recruited men with early stage prostate cancer proven by biopsy who had chosen to delay treatment and simply undergo surveillance (watchful waiting) to see if their disease progressed. These men were placed into two groups, with the “control group” undergoing watchful waiting only and the “treatment group” following a program of comprehensive lifestyle changes. The changes consisted of a plant-based diet high in fruits, vegetables and unrefined grains and low in fat and refined carbohydrates; moderate exercise such as walking 30 minutes a day, six days a week; stress management through gentle yoga-based stretching, breathing exercises and meditation; and weekly social support. After five years, the results were clear. The telomeres of the men in the “treatment group” were on average 10% longer than they had been at the start of the study. In contrast, the men in the “control group” showed an average 3% shortening in their telomeres over the same time period. Additionally, the more closely the men in the “treatment group” adhered to the recommended program, the longer were their telomeres (25).

This study revealed a major beneficial effect on telomeres. But many factors were involved and the next step would be to discover just what lifestyle changes made the most difference. This is where the second study comes in. Its goal was to identify lifestyle factors with the strongest effects on telomeres. About 400 overweight/ obese women were randomized into four groups – group 1 simply reduced the calories in their diet; group 2 made no diet change but added moderate to vigorous intensity exercise; group 3 combined the diet and exercise of groups 1 and 2; group 4 was the control and did not change anything. After twelve months none of these lifestyle changes resulted in meaningful effects on either telomere length or weight loss in most of the women (26).

This tells us that simply reducing calories or increasing exercise has no perceptible effect on telomere length. It takes a major change in diet composition to create the astounding result achieved by the men with prostate cancer.

 

IN SUMMARY: WHAT CAN WE DO IN OUR OWN LIVES TO PROMOTE GRACEFUL AGING AND A LONGER HEALTHIER LIFE?

Firstly and most importantly, look at your diet. Make it your goal to eat lots of healthy, whole carbohydrates and to decrease intake of fat and protein. Fill your plate with plant-sourced foods including fruits and vegetables with their healthy antioxidant and fiber components. Avoid eating foods containing saturated fats (animal-based foods and plant oils such as coconut oil and palm oil), polyunsaturated fats (isolated plant oils and processed foods), processed meats and fish. Eat until satisfied but try not to overeat.

Other helpful changes include the following;
Reduce stress as much as possible. Practicing meditation may help.
Sleep for 8 to 9 hours each night.
Exercise regularly.
Maintain a healthy weight.
Cultivate a supporting circle of friends and family.
Do not smoke.
Avoid chemicals as much as possible by using natural methods in activities such as cleaning and pest control

Telomeres are an important factor in longevity but they can be damaged by many forces both inside and outside of the body. Smart lifestyle choices have great potential to not only slow the rate of telomere shortening but also to lengthen telomeres thus delaying onset of age-associated diseases, slowing aging and increasing lifespan.

 

SOURCES:

1 https://learn.genetics.utah.edu/content/basics/telomeres/

2 https://www.utsouthwestern.edu/labs/shay-wright/research/facts-about-telomeres-telomerase.html

3 Epel, E.S., Blackburn, E.H., Lin, J., Dhabhar, F.S., Adler, N.E., Morrow, J.D., Cawthon, R.M. Accelerated telomere shortening in response to life stress. Proc Natl Acad Sci U S A. 2004 Dec 7;101(49):17312-17315.

4 https://www.nature.com/scitable/topicpage/telomeres-of-human-chromosomes-21041

5 Hayflick, L. The limited in vitro lifetime of human diploid cell strains. Exp. Cell Res. 1965; 37 (3) : 614–636.

6 Cong, Y.-S., Wright, W.E, Shay, J.W. Human Telomerase and Its Regulation. Microbiol Mol Biol Rev. 2002 Sep; 66(3): 407–425.

7 D’Mello, M.J., Ross, S.A., Anand, S.S., Gerstein, H., McQueen, M., Yusuf, S., Paré, G. Telomere Length and Risk of Myocardial Infarction in a MultiEthnic Population – The INTERHEART Study. J Am Coll Card April 2016; 67(15): DOI:10.1016/j.jacc.2016.01.061.

8 Panossian, L.A., Porter, V.R., Valenzuela, H.F., Zhu, X., Reback, E., Masterman, D., Cummings, J.L., Effros, R.B. Telomere shortening in T cells correlates with Alzheimer’s disease status. Neurobiol Aging. 2003 Jan-Feb;24(1):77-84.

9 Haycock, P.C., Heydon, E.E., Kaptoge, S., Butterworth, A.S., Thompson, A., Willeit, P. Leucocyte telomere length and risk of cardiovascular disease: systematic review and meta-analysis. BMJ 2014; 349:g4227.

10 Needham, B., Mezuk, B., Bareis, N., Lin, J., Blackburn, E., Epel, E. Depression, anxiety, and telomere length in young adults: Evidence from the National Health and Nutrition Examination Survey. Mol Psychiatry. 2015 Apr; 20(4): 520–528.

11 Masood A. Shammas. Telomeres, lifestyle, cancer, and aging. Curr Opin Clin Nutr Metab Care. 2011 Jan; 14(1): 28–34.

12 Damjanovic, A.K., Yang, Y., Glaser, R., Kiecolt-Glaser, J.K., Nguyen, H., Laskowski, B., Zou, Y., Beversdorf, D.Q., Weng, N.P. Accelerated telomere erosion is associated with a declining immune function of caregivers of Alzheimer’s disease patients. J Immunol. 2007 Sep 15;179(6):4249-4254.

13 Ahola, K., Sirén, I., Kivimäki, M., Ripatti, S., Aromaa, A., Lönnqvist, J., Hovatta, I. Work-related exhaustion and telomere length: a population-based study. PLoS One. 2012;7(7):e40186.

14 Shalev, I., Moffitt, T.E., Sugden, K., Williams, B., Houts, R.M., Danese, A., Mill, J., Arseneault, L., Caspi, A. Exposure to violence during childhood is associated with telomere erosion from 5 to 10 years of age: a longitudinal study. Mol Psychiatry. 2013 May;18(5):576-581.

15 Hoge, E.A., Chen, M.M., Orr, E., Metcalf, C.A., Fischer, L.E., Pollack, M.H., De Vivo, I., Simon, N.M. Loving-Kindness Meditation practice associated with longer telomeres in women. Brain Behav Immun. 2013 Aug; 32:159-163.

16 Liang, G.Y., Schernhammer, E., Qi, L., Gao, X., De Vivo, I., Han, J.L. Associations between Rotating Night Shifts, Sleep Duration, and Telomere Length in Women. PLoS ONE. 2011;6:e23462.

17 Shalev, I., Entringer, S., Wadhwa, P.D., Wolkowitz, O.M., Puterman, E., Lin, J., Epel, E.S. Stress and Telomere Biology: A Lifespan Perspective. Psychoneuroendocrinology. 2013 Sep; 38(9):1835-1842.

18 Cherkas, L.F., Hunkin, J.L., Kato, B.S., Richards, J.B., Gardner, J.P., Surdulescu, G.L., Kimura, M., Lu, X., Spector, T.D., Aviv, A. The association between physical activity in leisure time and leukocyte telomere length. Arch Intern Med. 2008 Jan 28;168(2):154-158.

19 Kim, J.H., Ko, J.H., Lee, D.C., Lim, I., Bang, H. Habitual physical exercise has beneficial effects on telomere length in postmenopausal women. Menopause. 2012 Oct;19(10):1109-1115.

20 Werner, C., Fürster, T., Widmann, T., Pöss, J., Roggia, C., Hanhoun, M., Scharhag, J., Büchner, N., Meyer, T., Kindermann, W., Haendeler, J., Böhm, M., Laufs, U. Physical exercise prevents cellular senescence in circulating leukocytes and in the vessel wall. Circulation. 2009 Dec 15;120(24):2438-2447.

21 Marcon, F., Siniscalchi, E., Crebelli, R., Saieva, C., Sera, F., Fortini, P., Simonelli, V., Palli, D. Diet-related telomere shortening and chromosome stability. Mutagenesis. 2012 Jan;27(1):49-57.

22 Tiainen, A.M., Männistö, S., Blomstedt, P.A., Moltchanova, E., Perälä, M.M., Kaartinen, N.E., Kajantie, E., Kananen, L., Hovatta, I., Eriksson, J.G. Leukocyte telomere length and its relation to food and nutrient intake in an elderly population. Eur J Clin Nutr. 2012 Dec;66(12):1290-1294.

23 Song, Y., You, N.C., Song, Y., Kang, M.K., Hou, L., Wallace, R., Eaton, C.B., Tinker, L.F., Liu, S. Intake of small-to-medium-chain saturated fatty acids is associated with peripheral leukocyte telomere length in postmenopausal women. J Nutr. 2013 Jun;143(6):907-914.

24 Nettleton, J.A., Diez-Roux, A., Jenny, N.S., Fitzpatrick, A.L., Jacobs, D.R. Jr. Dietary patterns, food groups, and telomere length in the Multi-Ethnic Study of Atherosclerosis (MESA). Am J Clin Nutr. 2008 Nov; 88(5):1405-1412.

25 Ornish, D., Lin, J., Chan, J.M., Epel, E., Kemp, C., Weidner, G. et al. Effect of comprehensive lifestyle changes on telomerase activity and telomere length in men with biopsy-proven low-risk prostate cancer: 5-year follow-up of a descriptive pilot study. Lancet Oct 1, 2013; 14(11): P1112-1120.

26 Mason, C., Risques, R., Xiao, L., Duggan, C.R., Imayama, I., Campbell, K.L et al. Independent and combined effects of dietary weight loss and exercise on leukoctye telomere length in postmenopausal women. Obesity (Silver Spring). 2013 Dec;21(12): E549-554.