Taking B vitamins may reduce some of the adverse effects of air pollution, suggest results of a limited human trial.

The study reveals how individual-level prevention may be used to control the potential mechanism underlying adverse effects of the particles PM2.5, where particles have a diameter of less than 2.5 micrometres.

Ambient PM2.5 pollution is one of the most prominent air pollutants because they get deposited in the respiratory tract resulting in both lung and systemic inflammation and stress.  "Our study launches a line of research for developing preventive interventions to minimise the adverse effects of air pollution on potential mechanistic markers," said Andrea Baccarelli, Professor at the Mailman School of Public Health, Columbia University in the US.

The World Health Organisation (WHO) estimates that 92 per cent of the world's population currently lives in places where air quality levels exceed safety guidelines.

The new findings, published online in the journal Proceedings of the National Academy of Sciences (PNAS), could have a significant public health benefit in regions of the world with frequent PM2.5 peaks. "As individuals, we have limited options to protect ourselves against air pollution. Future studies, especially in heavily polluted areas, are urgently needed to validate our findings and ultimately develop preventive interventions using B vitamins to contain the health effects of air pollution," Baccarelli said.

The researchers administered one placebo or B-vitamin supplement (2.5 mg of folic acid, 50 mg of vitamin B6, and 1 mg of vitamin B12) daily to each adult recruited for the trial. To take part in the intervention, volunteers were required to be healthy non-smokers, 18 to 60 years old, who were not taking any medicines or vitamin supplements.The researchers found that B vitamins may play a critical role in reducing the impact of air pollution on the epigenome.

While the genes in our DNA contain the instructions for life, epigenetics influence how the instruction are utilised.