| Hou et al. 2009 (53) | Case-control | 716 Polish participants (300 cases of GC and 416 controls; 65.4% men and 34.6% women) | PCR | Fruit, vegetables | Controls consuming fruit several times per month or more have a higher TL mean compared with those who rarely or never consume. This association was not observed in the case of vegetables |
| Mirabello et al. 2009 (24) | Case-control | 612 advanced prostate cancer cases and 1049 healthy US men from the PLCOCST, 55–74 y | PCR | Fruits, vegetables | No significant associations between TL and fruits and vegetables in all participants combined was reported |
| Lian et al. 2015 (54) | Case-control | 271 hypertensive and 455 normotensive Chinese men and women participants, 40–70 y | PCR | Vegetables, fruit, meat, fish or seafood, poultry, milk, soya milk, egg, fried food, dessert | Higher vegetable intake was associated with longer aged-adjusted relative telomeres. Regular fried food and soya milk intake were associated with short aged-adjusted relative telomeres. No other significant associations were observed |
| Kahl et al. 2016 (55) | Case-control | 124 healthy Brazilian participants (18.5% nonexposed-pesticide men, 31.5% nonexposed-pesticide women, 29.8% exposed-pesticide men, and 20.2% exposed-pesticide women), 17–78 y | PCR | Drinking status, fruit, and vegetables | Farmers not exposed to pesticide mixtures and consuming fruits and vegetables 3–4 d/wk or daily showed longer telomeres than farmers who were exposed to pesticides |
| Bekaert et al. 2007 (35) | Cross-sectional | 2509 Belgian adults (48.5% men and 51.5% women) from the Asklepios study cohort, aged 35–55 y | SB | Fruit and vegetables | Fruit and vegetable consumption was not associated with TL |
| Nettleton et al. 2008 (56) | Cross-sectional | 840 white, black, and Hispanic US adults from the MESA study, 45–84 y | PCR | Whole and refined grains, fruit, vegetables, low-fat and high-fat dairy, seeds or nuts, nonfried fish, red meat, processed meat, fried foods, coffee, nondiet soda | Nonfried fish and processed meat consumption was associated with shorter telomeres after adjusting for age and energy. Only processed meat consumption was associated with shorter telomeres after multivariate adjustment including other food groups. Participants in the highest quartile of processed meat intake had a lower T/S ratio. In the case of the food group including ham, hot dogs, salami, and other lunchmeats, an inverse association was reported with TL |
| Cassidy et al. 2010 (12) | Cross-sectional | 2284 US females from the NHS | PCR | Whole grains, fruit, and vegetables | Participants in the highest quintile of whole grains consumption had significantly higher TL (as changes of z score) than participants in the lowest quintile. Fruit and vegetable intake were not significantly associated |
| Chan et al. 2010 (57) | Cross-sectional | 2006 elderly Chinese (48.6% men and 51.4% women) | PCR | Cereals, meat and poultry, egg and egg products, fish, milk and milk products, fruit and nuts, vegetables, legumes/seeds and nuts, pickled vegetables, dim sum, fast food, fats and oils for cooking, tea | Chinese tea was positively associated in men with TL. Fats and oils for cooking in women were negatively associated with TL. No other associations were noted |
| Marcon et al. 2012 (44) | Cross-sectional | 56 Italian subjects (44.6% male and 55.4% female) | TRF | Cereals, vegetables, fruits, eggs, dairy, oils and butter, meat, fish | Only the vegetable food group was positively associated with TL. The amount of fruit, vegetables, peppers, carrots, and spinach was correlated with longer TL inside of this food group |
| Tiainen et al. 2012 (26) | Cross-sectional | 1942 Finnish men and women from the HBCS, 57–70 y | PCR | Fats (total, butter, margarine, oil), vegetables, roots, legumes, fruits (total, berries, fruit juice) | Butter intake was significantly associated with shorter telomeres in men. Vegetable intake was associated with longer telomeres in women. Men with the highest butter intake and the lowest fruit intake had shorter telomeres. In the analysis stratified by BMI, margarine intake was associated with longer telomeres in overweight and obese men; and higher vegetable intake was associated with longer telomeres in overweight/obese women. No other food group associations were found |
| Song et al. 2013 (25) | Cross-sectional | 4029 white, black, Hispanic, and Asian healthy US postmenopausal women from the WHI observational study | PCR | Fat added on bread, butter use only, use of other fat only, cheese, low-/no-fat cheese, other cheeses | The use or consumption of total milk, nonskim milk, butter for cooking, total fat added on bread, total cheese, and high-fat cheese were inversely associated with TL in the model adjusted for age. Nonskim milk (whole milk and reduced-fat milk), and high-fat cheese intake were inversely associated with TL in the fully adjusted model |
| Crous-Bou et al. 2014 (58) | Cross-sectional | 4676 healthy US women from the NHS, 42–70 y | PCR | Vegetables, fruit, whole grains, fish, meats, legumes, nuts | There were no differences in TL between quartiles of food groups consumption |
| Leung et al. 2014 (59) | Cross-sectional | 5309 white, black, Hispanic, and other ethnic US adults (46.6% men and 53.4% women) from the NES, 20–65 y | PCR | Sugar-sweetened soda, noncarbonated sugar-sweetened beverages, diet soda, fruit juice | Sugar-sweetened soda consumption was associated with shorter telomeres; consumption of 100% fruit juice was marginally associated with longer telomeres. No significant associations were observed between the consumption of diet sodas or noncarbonated sugar-sweetened beverages and TL |
| Gu et al. 2015 (60) | Cross-sectional | 1743 US elderly individuals (68.3% women and 31.7% men) from the WHICAP, aged ≥65 y | PCR | Fruit and nuts, vegetables, fish, dairy, meat, legumes, cereal, nuts, whole-grain cereals | Vegetable consumption was associated with longer telomeres and cereal intake with shorter telomeres. In non-Hispanic whites, dairy and meat intake was associated with longer telomeres |
| Lee et al. 2017 (45) | Cross-sectional | 1958 Korean adults from the KGES, 40–69 y | PCR | Refined white and mixed rice noodles, dumplings, and flour products, cereal, and snacks, fish and other seafood, red and processed meat, poultry, eggs, legumes, nuts, green and yellow vegetables, seaweed, fruits, dairy products, sweetened carbonated beverages, green tea, coffee, other types of tea or beverages | LTL was negatively associated with red meat and processed meat, and sweetened carbonated beverage consumption. TL was positively associated with legumes, nuts, seaweed, fruit, and dairy products in the full-adjusted models |
| Fretts et al. 2016 (61) | Cross-sectional | 2846 American Indians (60.2% women and 39.8% men) from the SHF | PCR | Processed meat, unprocessed meat | Processed meat intake was negatively associated with TL. However, there was no association with unprocessed red meat intake |
| Kasielski et al. 2016 (62) | Cross-sectional | 28 healthy subjects (25% men and 75% women), 18–65 y | PCR | Cereal, fruit, vegetables, dairy, red meat, poultry, fish, sweets, salty snacks, juices, coffee, tea, mineral water, alcoholic beverages, sweetened carbonated beverages | Red meat consumption was associated with relative higher average TL. There were no associations between other food groups and TL |
| Liu et al. 2016 (63) | Cross-sectional | 4780 US females from the NHS | PCR | Coffee | Those who drank the most coffee had longer telomeres than noncoffee drinkers in the adjusted model. Women who drank 2 or more cups of caffeinated coffee had longer telomeres than noncoffee drinkers. There was no linear association with decaffeinated coffee consumption |
| Zhou et al. 2016 (20) | Cross-sectional | 556 Chinese participants (200 normoglycemic, 197 prediabetic, and 159 incident diabetic. 61.7% women and 38.3% men) | PCR | Cereal and cereal products, tuber crops, legume products, meat, dairy products, seeds or nuts, vegetables, fruit, fish and other seafood, seaweed, sweetened carbonated beverages | The consumption of legumes, nuts, fish, and seaweeds were correlated with longer TL. The consumption of a sweetened carbonated beverage was associated with shorter TL |
| Tucker 2017 (64) | Cross-sectional | 5582 healthy US adults (52.6% women and 47.4% men) from the NHANES | PCR | Nuts and seeds | Nuts and seeds were significantly related to TL in the fully adjusted models |
| Tucker 2017 (65) | Cross-sectional | 5826 US adults (55.3% women and 44.7% men) from the NHANES, aged ≥60 y | PCR | Coffee | Coffee intake was associated with longer TL in the total population. When analyzing only coffee drinkers, similar results were obtained. In the analysis by coffee intake categories, adults who consumed high levels of coffee had longer telomeres than moderate or low groups |
| De Meyer et al. 2018 (66) | Cross-sectional | 2509 Belgian subjects (51.5% women and 48.5% men) from the Asklepios study, aged 35–55 y | SB | Beverages, milk and milk products, fruits, sweet and salty biscuits, breakfast cereals, whole wheat bread, white bread, low-fat butter/margarine, whole fat butter/margarine, seafood salad or fish products, meat salad or products, cheese, sweet spreads, eggs, fish/seafood, meat substitution products, meat/poultry/game, whole wheat pasta/whole-grain rice, white pasta or rice, deep-fried potato products, vegetables, sauces | In the total population, sweet and salty biscuits, whole wheat bread, and meat salad were positively associated with TL, whereas deep-fried potato products were negatively associated with TL. In the analysis stratified by sex, in women, a longer TL was associated with sweet and salty biscuits, meat salad and products, and a shorter TL was associated with deep-fried potato products. Regarding men, a longer TL was related to whole wheat bread and cheese, whereas a shorter TL was related to meat/poultry/game and deep-fried potato products |
| Karimi et al. 2018 (67) | Cross-sectional | 300 healthy Iranian men, aged 25–40 y | PCR | Whole grains, refined grains, vegetables and fruit, fish products, dairy products, nuts and seeds, meats, produced meats, liquid oils, solid fats | Processed meats and solid fats were negatively associated with the T/S ratio in the completed study population. Fish products were positively associated only in office workers. Whole grains were positively associated, whereas nuts and seeds, meats, produced meats, and solid fats were negatively associated with this ratio in waste recyclers |
| Bethancourt et al. 2017 (68) | Prospective cohort | 1459 Philippine young adults (41.7% women and 58.3% men) from the CLHNS | PCR | Processed meat, grilled/fried meat, nonfried fish, coconut oil, fruit and vegetables, bread and bread products, soft drinks and juice | No associations with food groups were reported |
| Cardin et al. 2013 (69) | RCT (crossover) | 40 participants with chronic hepatitis C | PCR |
1) 4 cups of coffee/d; 2) abstinent from coffee for 30 d. After 30 d, they were switched to another group for 30 more days | Compared with the noncoffee consuming period, the coffee consuming period had significantly longer TL at the end of 30 d |
| Borresen et al. 2016 (70) | RCT (parallel) | 29 colorectal cancer survivors (41.4% men and 58.6% women) | PCR | Control snacks + normal diet (placebo group), dry beans + normal diet (intervention group), rice bran + normal diet (intervention group) | No associations with intervention food groups were reported |
| Pawelcyk et al. 2018 (31) | RCT (parallel) | 71 schizophrenia patients, aged 16–35 y | Telomerase ELISA | Olive oil (placebo group), ω-3 (intervention group) | A significantly greater increase in PBMC telomerase levels in the ω-3–supplemented intervention group compared with olive oil–supplemented placebo was observed. In addition, PBMC telomerase concentrations were significantly higher in both groups after 26 wk |
| Freitas-Simoes et al. 2018 (71) | RCT (parallel) | 149 elderly participants (70.5% women and 29.5% men) from the WHAS, 63–79 y | PCR | Normal diet (placebo group), normal diet + walnuts (intervention group) | TL was significantly shorter in the control group after 2-y intervention whereas the walnut group did not have significant changes in TL |