(CNN) Want to prolong your life expectancy by more than a decade? A new study suggests that you can do just that by following these five healthy habits: never smoke, maintain a healthy body-mass index, keep up moderate to vigorous exercise, don't drink too much alcohol, and eat a healthy diet. 
 
 Adhering to those five lifestyle factors at age 50, compared with not adhering to any of them, was associated with 14 additional years of life expectancy among women and 12.2 additional years among men in the study, published in the journal Circulation on Monday. 
 
 Each of those factors is significantly associated with a reduced risk of dying from the top two killers in the United States, cardiovascular disease and cancer , according to the study. 
 
 About 610,000 people die of heart disease in the US each year, which is about one in every four deaths, according to the US Centers for Disease Control and Prevention 
 
 About 609,640 Americans are expected to die of cancer this year, according to the American Cancer Society 
 
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 "These are some of the leading causes of premature death, so by preventing or reducing the incidence of those diseases, it promotes longevity, and it also improves survival after diagnosis of those diseases," said Dr. Meir Stampfer, a professor of medicine at Harvard Medical School and professor of epidemiology and nutrition at the Harvard T.H. Chan School of Public Health , who was a co-author of the study. 
 
 "We can do so much better for having a long healthy life by pretty simple minimal changes in our behavior, and only 8% of adults in our country are adhering to these," he said. "The main take-home message is that there's huge gains in health and longevity to be had just by simple changes in our behavior pattern, and as a country, I think we need to make it easier for ourselves to do this by promoting tobacco cessation, by providing better environments for physical activity and so on." 
 
 Photos: The countries where people live longest Photos: The countries where people live longest Italy – The Italian diet, combined with a climate that promotes outdoor activity, is thought to play an important role in healthy aging among Italians. Hide Caption 1 of 11 Photos: The countries where people live longest Japan – Japan has the longest-living population in the world, with the average 60-year-old going on to live until age 86. Experts say this is due to good diets, active lifestyles and supportive family structure. Hide Caption 2 of 11 Photos: The countries where people live longest Spain – Spain's version of the Mediterranean diet combined with strong family networks is believed to enhance life expectancy among its population. In Spain, average life expectancy at age 60 is 85. Hide Caption 3 of 11 Photos: The countries where people live longest France – France also tied second with the other countries in southern Europe with, those over 60 living to the age of 85, on average. Pictured, a couple sit on a bench in Cannes. Hide Caption 4 of 11 Photos: The countries where people live longest Andorra – Diet and outdoor lifestyle in Andorra help to keep the country's elderly population healthy. Hide Caption 5 of 11 Photos: The countries where people live longest Australia – The universal health care system in Australia, combined with Australians' outdoor lifestyle, help people live longer, according to experts. Pictured, a war veteran during ANZAC Day. Hide Caption 6 of 11 Photos: The countries where people live longest New Zealand – The outdoor lifestyle and health infrastructure are credited with keeping New Zealanders healthy and living longer. Hide Caption 7 of 11 Photos: The countries where people live longest Switzerland – Switzerland's wealth and health care system are credited with boosting the nation's longevity. Hide Caption 8 of 11 Photos: The countries where people live longest Singapore – After Japan, Singapore has Asia's highest life expectancy at age 60. Hide Caption 9 of 11 Photos: The countries where people live longest Monaco – The extensive wealth of the residents of Monaco is likely to be the main factor supporting health in the elderly. Hide Caption 10 of 11 Photos: The countries where people live longest San Marino – Like many of the other long-lived countries, San Marino's strong economy and infrastructure are thought to be the reason for its long-lived residents. Hide Caption 11 of 11 
 
 Globally, the US ranks 43rd when it comes to life expectancy at birth, with an average life expectancy of 80, according to 2017 data from the Central Intelligence Agency's World Factbook 
 
 The three countries ranked highest for life expectancy at birth are Monaco , with 89.4 years; Japan , with 85.3 years; and Singapore , with 85.2 years, according to those data. 
 
 The countries with the lowest life expectancy at birth, based on that data, are Chad , with 50.6 years; Guinea-Bissau , with 51 years; and Afghanistan , with 51.7 years. 
 
 The 'surprising' impact of behaviors on longevity 
 
 For the new study, researchers measured the association between those five lifestyle factors and premature death using data from the national Nurses' Health Study and the Health Professionals Follow-Up Study . The data came from 1980 to 2014 and included more than 122,000 people combined. 
 
 Then, the researchers used data from the National Health and Nutrition Examination Surveys to estimate the distribution of those modifiable lifestyle factors among adults in the United States. Those data, from 2013 to 2014, consisted of 2,128 adults, 50 to 80 years old. 
 
 The researchers also derived death rates of US adults using the CDC's Wide-Ranging Online Data for Epidemiologic Research database. 
 
 After analyzing the data, the researchers found that, in 2014, the overall projected life expectancy at age 50 was to live 33.3 more years for women and 29.8 more years for men. 
 
 Yet among the adults who reported that they adopted all five healthy lifestyle factors, the researchers found, they lived 43.1 more years among women and 37.6 more years among men. 
 
 Among those adults who reported that they adhered to none of the five healthy lifestyle factors, the researchers found that they lived only 29 additional years among women and 25.5 additional years among men. 
 
 "To me, the surprising outcome was how strong it was: what a big impact these simple behaviors could have on life expectancy," Stampfer said. "I was surprised that it was that pronounced." 
 
 Among the women, on average, about 30.8% of the life expectancy at age 50 that they gained from adopting five, versus zero, of those lifestyle factors was attributed to a reduced risk of cardiovascular disease death; 21.2% was attributed to a reduced risk of cancer and 48% to other causes of death. 
 
 Among the men, those percentages were 34.1% attributed to a reduced risk of cardiovascular disease death, 22.8% attributed to a reduced risk of cancer and 43.1% to other causes. 
 
 The study had some limitations, including that the data on adherence to the five lifestyle factors were all self-reported, making outcome vulnerable to measurement errors. 
 
 Also, the data analysis did not include measures of certain health conditions that are risk factors for a shorter life expectancy, such as diabetes or high blood pressure. 
 
 That limitation, however, "is both a strength and a limitation, in a way ... because what we're estimating here is the prolongation of life expectancy just based on behaviors," Stampfer said. 
 
 "Obviously, it's much better to do these healthy behaviors from childhood, really, but if you're beyond age 50, beyond age 60, beyond age 70, it's not too late," he added. 
 
 The factor that was seen as more 'powerful' 
 
 The findings should encourage and motivate people to adopt a healthier lifestyle, said Dr. Douglas Vaughan, chairman of the department of medicine in Northwestern University's Feinberg School of Medicine , who was not involved in the study. 
 
 Though the study highlighted how the combination of all five lifestyle factors could help prolong life expectancy, Vaughan pointed out how each individual factor also was tied to a reduced risk of premature death. 
 
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 "It looks like cigarette smoking has a more powerful effect than the other lifestyle changes or behaviors. Certainly, maintaining a reasonable body-mass index is a great way to protect oneself against the development of diabetes," Vaughan said. 
 
 Body-mass index, a calculation derived from a person's weight and height, is used as a screening tool for body fatness. A normal or healthy body-mass index is typically said to be between 18.5 and 24.9. 
 
 "So, in aggregate, we see the effect on longevity, but you can imagine it's largely through effects on cardiovascular risk and metabolic risk," Vaughan said. "It suggests potentially at a defined point in life, say age 50, if you adhere to a healthy paradigm like this, you can have an impact on your longevity and on your health span." 
 
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 Dr. Jack Der-Sarkissian, a family medicine physician and assistant area medical director of Kaiser Permanente Los Angeles Medical Center , called smoking "the least-debated health risk factor." 
 
 "Beyond cancer risk, smoking contributes to lung disease, heart disease and diabetes. The study shows that even minimal smoking -- from one to 14 cigarettes a day -- is associated with increased death due to cancer and heart disease," said Der-Sarkissian, who was not involved in the new study. 
 
 As for some of the other lifestyle factors, "getting weight below a BMI of 30 appears to help considerably, according to the study. A higher body weight is linked to increased risk of diabetes and cancer, among other obesity-related conditions," he said. "The study suggests physical activity of at least 30 minutes a day of moderate or vigorous activities, including brisk walking." ||||| Abstract 
 
 Background—Americans have a shorter life expectancy compared with residents of almost all other high-income countries. We aim to estimate the impact of lifestyle factors on premature mortality and life expectancy in the US population. 
 
 Methods—Using data from the Nurses' Health Study (1980-2014; n=78 865) and the Health Professionals Follow-up Study (1986-2014, n=44 354), we defined 5 low-risk lifestyle factors as never smoking, body mass index of 18.5 to 24.9 kg/m2, ≥30 min/d of moderate to vigorous physical activity, moderate alcohol intake, and a high diet quality score (upper 40%), and estimated hazard ratios for the association of total lifestyle score (0-5 scale) with mortality. We used data from the NHANES (National Health and Nutrition Examination Surveys; 2013-2014) to estimate the distribution of the lifestyle score and the US Centers for Disease Control and Prevention WONDER database to derive the agespecific death rates of Americans. We applied the life table method to estimate life expectancy by levels of the lifestyle score. 
 
 Results—During up to 34 years of follow-up, we documented 42 167 deaths. The multivariable-adjusted hazard ratios for mortality in adults with 5 compared with zero low-risk factors were 0.26 (95% confidence interval [CI], 0.22-0.31) for all-cause mortality, 0.35 (95% CI, 0.27-0.45) for cancer mortality, and 0.18 (95% CI, 0.12-0.26) for cardiovascular disease mortality. The population-attributable risk of nonadherence to 5 low-risk factors was 60.7% (95% CI, 53.6-66.7) for all-cause mortality, 51.7% (95% CI, 37.1-62.9) for cancer mortality, and 71.7% (95% CI, 58.1-81.0) for cardiovascular disease mortality. We estimated that the life expectancy at age 50 years was 29.0 years (95% CI, 28.3-29.8) for women and 25.5 years (95% CI, 24.7-26.2) for men who adopted zero low-risk lifestyle factors. In contrast, for those who adopted all 5 low-risk factors, we projected a life expectancy at age 50 years of 43.1 years (95% CI, 41.3-44.9) for women and 37.6 years (95% CI, 35.8-39.4) for men. The projected life expectancy at age 50 years was on average 14.0 years (95% CI, 11.8-16.2) longer among female Americans with 5 lowrisk factors compared with those with zero low-risk factors; for men, the difference was 12.2 years (95% CI, 10.1-14.2). 
 
 Conclusions—Adopting a healthy lifestyle could substantially reduce premature mortality and prolong life expectancy in US adults. ||||| Conclusion In this large study, greater adherence to the Mediterranean diet was associated with longer telomeres. These results further support the benefits of adherence to the Mediterranean diet for promoting health and longevity. 
 
 Results Greater adherence to the Mediterranean diet was associated with longer telomeres after adjustment for potential confounders. Least squares mean telomere length z scores were −0.038 (SE 0.035) for the lowest Mediterranean diet score groups and 0.072 (0.030) for the highest group (P for trend=0.004). 
 
 Given that fruits, vegetables, and nuts, key components of the Mediterranean diet, have well known antioxidant and anti-inflammatory effects, and that telomere length is affected by both of these processes, we hypothesized that greater adherence to the Mediterranean diet would be associated with longer telomere length. Therefore, the main objective of this study was to examine the association between greater adherence to the Mediterranean diet and leukocyte telomere length in US women within the Nurses’ Health Study cohort. For comparison, we also evaluated the association between other existing dietary patters (prudent pattern, Western pattern, and Alternative Healthy Eating Index) and leukocyte telomere length. 
 
 Telomeres are repetitive DNA sequences at the ends of eukaryotic chromosomes that undergo attrition each time a somatic cell divides. 7 Telomeres prevent the loss of genomic DNA at the ends of linear chromosomes and in turn protect their physical integrity. 8 9 Telomere attrition has been shown to be accelerated by oxidative stress and inflammation. 10 11 Telomere length is considered to be a biomarker of aging; shorter telomeres are associated with a decreased life expectancy and increased rates of developing age related chronic diseases. 12 13 14 Telomere length decreases with age and varies considerably among individuals. 15 Studies suggest that telomere attrition is modifiable, as substantial variability exists in the rate of telomere shortening that is independent of chronological age. 16 17 18 Therefore, variability of telomere length may be partially explained by lifestyle practices, including dietary patterns. 19 As accelerated telomere attrition may underlie many chronic diseases, identifying modifiable factors that affect telomere dynamics is important. 
 
 The traditional Mediterranean diet is characterized by a high intake of vegetables, fruits, nuts, legumes, and grains (mainly unrefined); a high intake of olive oil but a low intake of saturated lipids; a moderately high intake of fish; a low intake of dairy products, meat, and poultry; and a regular but moderate intake of alcohol (specifically wine with meals). 1 Observational studies and intervention trials have consistently shown the health benefits of a high degree of adherence to the Mediterranean diet, including reduction of overall mortality 2 3 4 ; reduced incidence of chronic diseases, especially major cardiovascular diseases 5 ; and increased likelihood of healthy aging. 6 
 
 We used multivariable linear regression models to determine the cross sectional association between leukocyte telomere length and adherence to the Mediterranean diet. We calculated multivariable adjusted least squares mean leukocyte telomere length z scores (and their corresponding 95% confidence intervals) across all dietary patterns score groups by using generalized linear models. Firstly, only age at blood draw was included in the models. Models were then additionally adjusted for other potential confounders (body mass index, smoking, physical activity, energy intake, and batch). Finally, other variables were included as potential covariates (for example, postmenopausal hormone therapy, history of hypertension, and socioeconomic status), but these were removed from the final models as estimates remained the same. All P values are two sided, and an α level of 0.05 was used. We used SAS version 9.2 for all statistical analyses. Reported STROBE guidelines have been the basis for reporting our results. 39 
 
 Telomere length was assayed in various batches corresponding to each study. To minimize the impact of potential batch effect on leukocyte telomere length measurements across different studies, we calculated z scores of log transformed leukocyte telomere length by standardizing the leukocyte telomere length in comparison with the mean within each individual study. 18 19 38 
 
 The average relative leukocyte telomere length was calculated as the ratio of telomere repeat copy number to a single gene (36B4) copy number. Leukocyte telomere length is reported as the exponentiated ratio of telomere repeat copy number to a single gene copy number corrected for a reference sample. In all nested case-control studies, the telomere and single gene assay coefficients of variation for triplicates were less than 4%. Coefficients of variation for the exponential ratio of telomere repeat copy number to a single gene copy number were under 18%. In the Nurses’ Health Study, the three year and 10 year interclass correlations for reliability were determined to be 0.80 and 0.60. Although this assay provides a relative measurement of telomere length, ratios of telomere repeat copy number to a single gene copy number highly correlate with absolute telomere lengths determined by Southern blot (r=0.677; P<0.001). 36 
 
 Relative telomere length was determined using a modified, high throughput version of the quantitative real time polymerase chain reaction based telomere assay. 36 37 The quantitative real time polymerase chain reaction telomere assay was run on the Applied Biosystems 7900HT Sequence Detection System (Foster City, CA, USA). Laboratory personnel were blinded to participants’ characteristics, and all assays were processed in triplicate by the same technician and under identical conditions. 
 
 In addition to age at blood draw, we collected information on factors potentially associated with Mediterranean diet and telomere length. Using the biennial questionnaires completed proximal to blood collection and a supplemental questionnaire administered at blood collection, we assessed various anthropometric, reproductive, and lifestyle factors, as well as factors that have been related to telomere length in the Nurses’ Health Study elsewhere: body mass index (kg/m 2 ), cigarette smoking (pack years), 33 34 35 physical activity (total metabolic equivalent hours of activity per week). 16 We calculated dietary factors, including energy intake (total calories), from the 1990 food frequency questionnaire. 
 
 The Alternative Healthy Eating Index measures adherence to a dietary pattern based on foods and nutrients most predictive of risk for chronic disease in the literature. 32 The Alternative Healthy Eating Index ranges from 0 to 110 points. Each of the 11 components of the score (vegetables, fruits, whole grains, sugar sweetened drinks, nuts and legumes, red and processed meat, trans fat, long chain (n-3) fats, polyunsaturated fatty acids, sodium, and alcohol) has a minimum score of 0 (worst) and a maximum score of 10 (best), according to component specific criteria reflecting either the current dietary guidelines or associations reported in the literature. Details of component selection and Alternative Healthy Eating Index calculation have been previously described. 32 
 
 We used principal component analysis of the food frequency questionnaires to identify prudent and Western dietary patterns. 30 31 The prudent dietary pattern is characterized by high intakes of fruits, vegetables, legumes, fish and other seafood, poultry, and whole grains; the Western dietary pattern includes high intakes of red and processed meats, butter, high fat dairy products, eggs, sweets and desserts, French fries, and refined grains. Details of the reproducibility and validity of dietary patterns assessed with a food frequency questionnaire have been previously described. 30 31 
 
 Trichopoulou adapted the Alternate Mediterranean Diet score from the Mediterranean Diet Score to assess adherence to the traditional Mediterranean diet. 2 The Alternate Mediterranean Diet score includes the following nine components: vegetables (excluding potatoes), fruits, nuts, whole grains, legumes, fish, monounsaturated:saturated fatty acid ratio, red and processed meats, and moderate alcohol intake. The possible score range is 0-9, with a higher score representing a closer resemblance to the Mediterranean diet. We dichotomized each of the nine dietary components at the median. We gave participants with intake above the median 1 point each for vegetables, fruits, nuts, whole grains, legumes, fish, and monounsaturated:saturated fatty acid ratio; we scored intake equal to or below the median as 0 points for each component. We scored red and processed meat consumption below the median as 1 point, with 0 points for intake equal to or above the median. Participants received 1 point for alcohol intake between 5 and 15 g/day; otherwise, they got 0 points. Details of the Alternate Mediterranean Diet scoring system are described elsewhere. 3 
 
 In 1980 participants completed a 61 item semi-quantitative food frequency questionnaire to assess their diet in the previous year. In 1984, 1986, and every four years thereafter, an expanded food frequency questionnaires containing 116-130 food items was sent to the nurses to update their dietary information. Participants were asked about the frequency of consumption of each food item of a pre-specified standard portion size in the previous year. The validity of these questionnaires has been previously described. 29 We calculated all dietary patterns and diet quality scores from self reported dietary data on the 1990 food frequency questionnaire, the closest to the blood draw (1989-90). 
 
 Multiple nested case-control studies have been conducted within the Nurses’ Health Study blood sub-cohort to investigate the association between leukocyte telomere length and cancer, cardiovascular disease, and cognitive function, among others. 23 24 25 26 27 28 The analysis reported here included data on 4676 women selected as healthy controls (free of major chronic diseases, including cancer and cardiovascular disease) from nested case-control studies, with previously measured leukocyte telomere length and completed food frequency questionnaires at the time of blood draw. 
 
 The Nurses’ Health Study is a prospective cohort study of 121 700 female registered nurses in 11 US states, aged 30-55 years at enrollment. The study was established in 1976; since then, participants have completed biennial questionnaires to update information on demographic characteristics, lifestyle factors, and newly diagnosed diseases. 20 21 Between 1989 and 1990 32 825 cohort participants provided blood samples. Details of the blood collection and archival methods have been described previously. 22 
 
 Multivariable adjusted least square means of leukocyte telomere length z scores (and their corresponding confidence intervals) by diet score quarters. All dietary patters are represented: prudent pattern, Western pattern, Alternative Healthy Eating Index (AHEI) score, and Alternate Mediterranean Diet (AMED) score 
 
 The figure ⇓ shows the association between other dietary patterns and leukocyte telomere length. Similar to the Alternate Mediterranean Diet score, a higher Alternative Healthy Eating Index (that is, healthy eating) showed a weak positive association with longer telomere length (P=0.02), but we found no statistically significant associations for the prudent (P=0.09) or Western dietary patterns (P=0.32) (fig ⇓ ). Additional adjustment for body mass index, pack years of smoking, physical activity, and total caloric intake did not alter the estimates. 
 
 We also evaluated the association between leukocyte telomere length z score and each component in the Alternate Mediterranean Diet score (table 4 ⇓ ). None of the individual components was significantly associated with telomere length, even after adjustment for multiple confounders (age, body mass index, pack years of smoking, physical activity, total caloric intake, and mutual adjustment for other components of the Alternate Mediterranean Diet score) (table 4 ⇓ ). 
 
 Table 3 ⇓ shows the association between adherence to a Mediterranean diet and telomere length. Higher Alternate Mediterranean Diet scores were associated with higher age adjusted mean leukocyte telomere length z scores (P for trend=0.02). The association remained statistically significant after inclusion of body mass index, pack years of smoking, physical activity, and total caloric intake in the models; the multivariable adjusted least squares mean leukocyte telomere length z score across Alternate Mediterranean Diet groups (≤2, 3, 4, 5, ≥6) was −0.038, −0.049, −0.010, 0.039, and 0.072 (P for trend=0.004) (table 3 ⇓ ). Additional adjustment for postmenopausal hormone therapy, age at menopause, history of hypertension, socioeconomic status, and case-control study set (batch), did not change the estimates (data not shown). 
 
 Table 2 ⇓ shows the baseline characteristics of the study participants across Alternate Mediterranean Diet score groups. The highest score group (score ≥6) represents the closest resemblance to the Mediterranean diet. Compared with women in the lowest score group (score ≤2), those in the highest score group were older at blood collection (P<0.001), had slightly lower body mass index (P=0.01), smoked less (P<0.001), had higher intake of total energy (P<0.001), and were more physically active (P<0.001). As expected, women with the highest Alternate Mediterranean Diet score also had higher intakes of vegetables, fruits, grains, fish, legumes, nuts, and total fat, as well as lower meat intake. 
 
 Table 1 ⇓ shows the main age standardized characteristics of the study population by quarters of telomere length. The mean age of the participants was 59 (SD 6.6) years, and the exact age range of the participants included in our study was 42-70 years. As expected, a statistically significant inverse correlation existed between age at blood draw and telomere length: younger women had longer telomeres (P<0.001). Moreover, women with shorter telomere length smoked slightly more (P=0.02). Distributions of main lifestyle factors between the study participants (n=4676), in comparison with the rest of the Nurses’ Health Study blood sub-cohort (n=32 825) after age standardization, were largely similar (results not shown). 
 
 Discussion 
 
 In this large cross sectional study of 4676 healthy middle aged and older women from the well characterized Nurses’ Health Study, greater adherence to the Mediterranean diet was significantly associated with longer leukocyte telomere length. Notably, whereas higher Alternate Mediterranean Diet score was significantly associated with longer leukocyte telomere length, none of the individual components showed an association with leukocyte telomere length, emphasizing the importance of examining the relation between dietary patterns, in addition to separate dietary factors, and health. This suggests that the association may be a consequence of the global effect of the overall Mediterranean diet. The Alternative Healthy Eating Index was also associated with longer telomere length; however, the strongest association was observed among women with greater adherence to the Mediterranean diet. 
 
 The difference in telomere length for each one point change in the Alternate Mediterranean Diet score corresponded on average to 1.5 years of aging. A three point change in the Alternate Mediterranean Diet score would correspond to on average 4.5 years of aging, which is comparable to the difference observed when comparing smokers with non-smokers (4.6 years),35 highly active women with less active women (4.4 years),16 and women with high phobic anxiety scores with women with low phobic anxiety (6 years).17 
 
 Comparison with previous literature To our knowledge, this is the largest population based study specifically looking at the association between adherence to the Mediterranean diet and telomere length in healthy, middle aged women. Our results are consistent with previously published literature on the benefits of a healthy lifestyle, particularly diet, and telomere length. To date, only one study has assessed the association between telomere length, telomerase activity, and different adherence to a Mediterranean diet.40 The 217 older people in this study had a mean age of 77, and the upper age limit for reliable assessment of telomere length is 75.41 Using an older age group is considered inappropriate because of “survivor” bias42 43: people who live longer tend to be more resilient to chronic disease and possess longer telomeres. The authors may be capturing survivor bias rather than an association between telomere length and adherence to a Mediterranean diet. García-Calzón et al studied the association between telomere length and changes in adiposity indices after a five year intervention study with a Mediterranean diet,44 in the context of the PREDIMED-NAVARRA trial.5 In this particular study, the outcome was obesity, and the association between telomere length and the whole Mediterranean diet was not specifically examined. Only two studies have examined the relation between a healthy lifestyle pattern and leukocyte telomere length.19 34 Mirabello et al observed a positive association between a healthy lifestyle (defined by low risk factors including low or no smoking, higher intakes of fruits and vegetables, lower body mass index, and greater physical activity) and leukocyte telomere length in men.34 Similarly, Sun et al reported that a healthy lifestyle pattern (defined by five components: smoking, physical activity, adiposity, alcohol use, and Alternative Healthy Eating Index) was associated with longer leukocyte telomere length in women.19 One of the first studies to show a strong relation between physical fitness and telomere length in a large sample of patients with existing coronary heart disease was conducted by Krauss et al.45 They found that poor physical fitness was associated with shorter leukocyte telomere length in patients with coronary heart disease. Du et al reported, in the Nurses’ Health Study, that physical activity (even moderate amounts of activity) was associated with longer telomeres.16 Moreover, Ornish et al recently published an intervention trial on the effect of comprehensive lifestyle changes (diet, activity, stress management, and social support) on telomerase activity and telomere length in men with low risk prostate cancer.46 Results from this pilot study showed that a comprehensive lifestyle intervention was associated with increases in relative telomere length after five years of follow-up, compared with controls. Studies on the association between specific dietary factors and telomere length have yielded inconsistent results.34 47 48 49 50 Cassidy et al, for instance, reported a positive association between leukocyte telomere length and dietary fiber intake but an inverse association between total fat intake (particularly, polyunsaturated fatty acids) and leukocyte telomere length. No significant associations were observed for intakes of vitamin D or fruits and vegetables.50 These findings support the importance of examining an overall lifestyle dietary pattern, rather than individual food components. The Mediterranean diet score has been used to evaluate the association between the Mediterranean diet and overall mortality, as well as Alzheimer’s disease, diabetes mellitus, coronary heart disease, and cancer overall.2 51 52 53 54 55 Trichopoulou A et al evaluated the contribution of the nine widely accepted components, which are used to build the Mediterranean diet score, and reported an inverse association of this diet with all cause mortality in a population based cohort in Greece.56 More interestingly, they found additive associations among components. The authors report that one of the advantages of using a Mediterranean diet score rather than focusing on the food components is the generation of fairly consistent results with respect to health benefits, whereas studies focusing on the components or food groups are often contradictory. As summarized by Trichopoulou et al,56 chance, non-differential misclassification, and residual confounding may have more important consequences when individual food items are evaluated rather than a multi-component, unidimensional score. The benefits on health and aging from a greater adherence to the Mediterranean diet have been largely described. Adherence to the Mediterranean diet has been linked to lower all cause mortality, reduced incidence of major cardiovascular diseases and other chronic diseases, and greater health and wellbeing in people surviving to older ages.2 3 4 5 6 
 
 Possible biologic mechanisms Oxidative stress and inflammation have been reported to accelerate telomere attrition.10 11 57 Moreover, given human telomere composition, these DNA regions are more sensitive to damage by oxidation.58 59 In contrast, high antioxidative capacity slows telomere shortening.58 60 61 62 The established protective effects of the Mediterranean diet on oxidative stress and chronic inflammation may explain the favorable influence of the Mediterranean diet on telomere length, pointing to a potential biologic mechanism behind the well known anti-aging effects of the Mediterranean diet. The lack of an association with individual components is not surprising. Studies have proposed a possible synergy among the nutrient rich foods included in the Mediterranean diet that fosters favorable changes in intermediate pathways of cardiometabolic risk, such as insulin sensitivity and resistance to oxidation and inflammation,5 63 supporting the role of the Mediterranean diet as a whole. 
 
 Strengths and limitations of study The strengths of our study include the large and well characterized study population, detailed assessment of dietary habits as well as other sociodemographic and lifestyle characteristics, and validated food frequency questionnaires and dietary scores. However, potential limitations should be considered. The cross sectional design precludes us from establishing a temporal association between dietary habits and telomere length. Leukocyte telomere length was assessed using a single measure, preventing the estimation of associations between Mediterranean diet and telomere attrition rate; assessing this requires a prospective study with repeated assessments of leukocyte telomere length. Although all analyses were adjusted for multiple covariates, unmeasured or residual confounding could still be present. Validation of self reported variables potentially associated with telomere length, such as self reported diabetes, hypertension, and obesity, has been done previously.64 65 66 Finally, the Nurses’ Health Study population predominantly includes women of European ancestry, and telomere dynamics may differ among other ethnicities67 68 69; therefore, results may not be generalized. However, the homogeneity among Nurses’ Health Study participants strengthens the internal validity of these findings by maximizing the quality of reported data.
– Harvard researchers say five things will help you live longer, and the list isn't all that surprising: exercise, eat a healthy diet, maintain a healthy body weight, don't drink too much, and don't smoke. More surprising is just how much of an effect those five combined factors have on longevity—an extra 14 years for women and 12 for men, according to the study in Circulation. Researchers looked at about 30 years of data on more than 78,000 women and 44,000 men and found that those who were five-for-five on the aforementioned list had a significantly better life expectancy at age 50 than those who didn't abide by any of the healthy habits. For women, it meant an additional 43 years for the healthiest group, compared to 29 years. For men, it meant an additional 37.6 years, compared to 25.5 years. “When we embarked on this study, I thought, of course, that people who adopted these habits would live longer," says co-author Meir Stampfer, per the Guardian. "But the surprising thing was how huge the effect was." The two big factors: Those with the healthiest lifestyles were less likely to get cancer or heart disease, notes CNN. The Harvard Gazette provides some specifics: Researchers defined regular exercise as 30 minutes or more per day of moderate to vigorous physical activity; moderate drinking is roughly one 5-ounce glass of wine per day for women and up to two for men; and the target body-mass index is between 18.5 and 24.9. Scientists say they undertook the study to better understand why the US has a shorter life expectancy (79.3 years) than most high-income countries. (Another study says it's all about eating smaller portions.)