If you drink two or three cups of coffee a day, then do continue to do so. This habit may just delay the aging process at molecular level. Epidemiologists at the University of Harvard will soon publish their findings in the Journal of Nutrition. Yep, we’re writing about telomeres again.
The researchers used data that had been gathered during the 1976 Nurses Health Study. This provided them with data on the lifestyle of 4780 women – including their coffee consumption. They also knew the length of the telomeres in their blood cells.
Put simply, telomeres are a kind of biological clock. The longer your telomeres are, the longer you still have to live. Here we explain exactly what telomeres are.
There was no relation between the intake of decaf coffee – that disgusting stuff that has had the caffeine removed – and telomere length. But the participants who drank a couple of cups of real coffee every day were more likely to have a longer than average telomere length, as the graph below shows.
The researchers corrected their data for age, smoking, bodyweight, physical exercise, alcohol and quality of diet.
The chance of an above-average telomere length was optimal at an intake of 2-3 cups of real coffee per day.
Why decaf coffee does not protect telomere length the researchers don’t know. They suggest that caffeine forms complexes with bioactive substances in coffee that are broken down less quickly in the body or have greater bioavailability. [Food Biophys 2009;4:321-30.]
“Our findings suggest that higher consumption of coffee – especially caffeinated coffee – is associated with longer telomeres, but additional studies are needed to clarify how coffee consumption is involved in telomere biology”, the researchers summarised. “Future studies can provide mechanistic understanding by examining how specific compounds in coffee are involved in telomere maintenance.”
“In addition, conducting observational and randomized clinical studies that examine other populations or obtain repeated measurements of telomere length for each participant will further clarify the shape of the dose-response curve for coffee consumption and telomere length.”
“Understanding coffees effect on telomeres may help us discover new pathways by which coffee consumption influences health and longevity.”
Coffee Consumption Is Positively Associated with Longer Leukocyte Telomere Length in the Nurses’ Health Study1,2
Coffee is an important source of antioxidants, and consumption of this beverage is associated with many health conditions and a lower mortality risk. However, no study, to our knowledge, has examined whether varying coffee or caffeine consumption levels are associated with telomere length, a biomarker of aging whose shortening can be accelerated by oxidative stress.
We performed a large comprehensive study on how coffee consumption is associated with telomere length.
We used data from the Nurses’ Health Study (NHS), a prospective cohort study of female nurses that began in 1976. We examined the cross-sectional association between coffee consumption and telomere length in 4780 women from the NHS. Coffee consumption information was obtained from validated food-frequency questionnaires, and relative telomere length was measured in peripheral blood leukocytes by the quantitative real-time polymerase chain reaction. Unconditional logistic regression was used to obtain ORs when the telomere length outcome was dichotomized at the median. Linear regression was used for tests of trend with coffee consumption and telomere length as continuous variables.
Higher total coffee consumption was significantly associated with longer telomeres after potential confounding adjustment. Compared with non-coffee drinkers, multivariable ORs for those drinking 2 to <3 and ≥3 cups of coffee/d were, respectively, 1.29 (95% CI: 0.99, 1.68) and 1.36 (95% CI: 1.04, 1.78) (P-trend = 0.02). We found a significant linear association between caffeine consumption from all dietary sources and telomere length (P-trend = 0.02) after adjusting for potential confounders, but not after additionally adjusting for total coffee consumption (P-trend = 0.37).
We found that higher coffee consumption is associated with longer telomeres among female nurses. Future studies are needed to better understand the influence of coffee consumption on telomeres, which may uncover new knowledge of how coffee consumption affects health and longevity.