A new study has found a relationship between the Mediterranean diet and longer telomeres in healthy, middle-aged women. Telomeres are repetitive DNA sequences at the end of chromosomes that protect against the loss of genomic DNA; shorter telomeres have been associated with lower life expectancy and certain chronic diseases. Published in the BMJ, the study examined telomere length for 4,676 women who also completed a dietary questionnaire as part of the ongoing Harvard Nurses’ Health Study. Researchers scored how closely the women followed a Mediterranean diet; a higher score meant the participant’s eating habits more closely followed the Mediterranean diet. The Mediterranean diet generally consists of fruits, vegetables, nuts, fish, whole grains, olive oil, and moderate amounts of alcohol, especially wine. It minimises meat, poultry, and dairy. Here’s what the researchers discovered when they looked at the relationship between diet and telomere length:

• The women who more closely followed the Mediterranean diet (i.e. had higher diet scores) had longer telomeres.
• On average, the women with higher diet scores also tended to smoke less and had a lower body mass index; nevertheless, the association between a Mediterranean diet and telomere length remained statistically significant even after adjusting for smoking, body mass index, physical activity, and total caloric intake.
• No single food component of the Mediterranean diet was associated with longer telomeres, suggesting that the health benefits come from the diet as a whole.
• Each one point increase in the diet score corresponded, on average, to an additional 1.5 years of life expectancy (based on the relationship between the diet score and telomere length).

Despite these positive findings, which are consistent with other research, it’s important to keep in mind a few limitations of the study. The study was observational, and therefore didn’t establish whether there was a causal relationship between diet and telomere length (the study also didn’t prove that the Mediterranean diet increases telomere length, as opposed to merely slowing telomere shortening). Additionally, while the Mediterranean diet may be a healthy diet, the question still remains as to whether it is optimal. For example, a recent pilot study found that more comprehensive changes to diet and lifestyle, as opposed to simply eating a Mediterranean diet, could lead to actual telomere lengthening.

Source: BMJ