The data, published in the BMJ​, examined whether adherence to the Mediterranean diet was associated with longer telomere length (a biomarker of aging), finding that greater adherence to the Mediterranean diet was associated with longer telomeres.

Led by Marta Crous-Bou from Brigham and Women’s Hospital and Harvard Medical School, the US-based team analysed data from more than 4,500 women from the Nurses’ Health Study cohort study with telomere length measured who also completed food frequency questionnaires.

“​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; reduced incidence of chronic diseases, especially major cardiovascular diseases; and increased likelihood of healthy aging,”​ wrote the authors.

They added that telomere length is considered to be a biomarker of aging; noting that shorter telomeres are associated with a decreased life expectancy and increased rates of developing age related chronic diseases.

“No study has examined whether adherence to the Mediterranean diet is associated with longer telomere length,”​ said Crous-Bou and her colleagues.

“In this large cross sectional study … greater adherence to the Mediterranean diet was significantly associated with longer leukocyte telomere length,”​ they concluded. “Our results further support the health benefits of adherence to the Mediterranean diet.”​

Study details​

Crous-Bou and her team analysed data from 4,676 disease-free women from nested case-control studies within the Nurses’ Health Study in order to assess any potential association between relative telomere lengths in peripheral blood leukocytes (as measured by quantitative real time polymerase chain reaction) and Alternate Mediterranean Diet score (calculated from self reported dietary data.)

After adjustment for potential confounders, greater adherence to the Mediterranean diet was associated with longer telomeres.

“​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,”​ said the team – adding that such a finding highlights the importance of examining the relationships 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.”​

Indeed, the team reported that 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), highly active women with less active women (4.4 years),and women with high phobic anxiety scores with women with low phobic anxiety (6 years),”​ the team said.

Source: BMJ​

Published online ahead of print, doi: 10.1136/bmj.g6674

“Mediterranean diet and telomere length in Nurses’ Health Study: population based cohort study”​

Authors: Marta Crous-Bou, Teresa T Fung, et al​