Purple asparagus is rich in vitamin B.[Photo provided to China Daily]

Taking B vitamins may help reduce some of the harmful effects of air pollution, a new study said Monday.

The study, led by Jia Zhong of Columbia University's Mailman School of Public Health, showed that B vitamins such as folic acid, vitamin B6 and vitamin B12 may play a critical role in reducing the impact of air pollution on a specific type of epigenetic modification called DNA methylation, which has been linked to cardiovascular disease and even cancer.

"The molecular mechanistic underpinnings of the health effects of air pollution are not fully understood, and the lack of individual-level preventative options represent a critical knowledge gap," Zhong and her colleagues wrote in their paper.

"Our?study demonstrated the epigenetic effects of air pollution and suggested that B vitamins might be used as prevention to complement regulations to attenuate the impact of air pollution on the epigenome."

The study, conducted with researchers at Harvard's T. H. Chan School of Public Health, in Sweden, China, Singapore, Mexico and Canada, was published online in the US journal Proceedings of The National Academy of Sciences.

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 that included 10 participants.

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 results showed four-week B-vitamin supplementation may reduce the damage caused by exposure to the particles PM2.5, particles with an aerodynamic diameter of 2.5 um or less, by between 28 percent and 76 percent.

Zhong told Xinhua that the study is still in its early stage and that currently they were unable to recommend the supplementation of B vitamins.

Instead, she suggested maintaining a healthy, balanced diet with sufficient sources of B vitamins.

Overall, such supplementation should be considered based on an individual's self-condition and in consult with a doctor's recommendation, she added.

"While emission control and regulation is the backbone of prevention, high exposures are, unfortunately, the rule still in many megacities throughout the world," study author Andrea Baccarelli, professor and chair of Environmental Health Sciences at the Mailman School, said in a statement.

"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," said Baccarelli.