A diet which includes antioxidants present in fruits, vegetables, whole grains, legumes, olive oils, fish and poultry over red meat and processed foods, can weaken the adverse effects of exposure to high levels of air pollution, says researchers.

The study showed that people who least adhered to these antioxidant-rich foods had 17 per cent higher risk of cardiovascular disease related deaths for every 10 micrograms per cubic meter increase in long-term average PM2.5 exposure, compared to 5 per cent in those who consumed such diet. "Given the benefits we found of a diet high in antioxidants, our results are consistent with the hypothesis that particle air pollution caused by fossil fuel combustion adversely affects health by inducing oxidative stress and inflammation," said George Thurston from Department of Environmental Medicine at the New York University.

The study, presented at the American Thoracic Society 2018 International Conference in San Diego, included data from 548,699 participants for over a period of 17 years. They were linked to estimates of long-term exposure to fine particulate matter (PM2.5), nitrogen dioxide (NO2) and ozone (O3) based on census tract information.

Deaths from all causes increased by 5 per cent for every 10 parts per billion (ppb) increase in long-term average NO2 exposure in those with least consumption of the diet as compared to 2 per cent among the people with higher consumption. "However the diet did not appear to protect against the harmful effects of long-term exposure to O3...the ozone effect was not significantly blunted by a Mediterranean diet, so ozone apparently affects cardiac health through a different mechanism", said Thurston.