Scientists have finally proven what your mother always told you about eating your greens.

Canadian researchers from the Research Institute of the McGill University Health Centre (RI-MUCH) and McMaster University, inquiring into aspects of cardiovascular diseases, have now discovered that eating raw vegetables and fruits can actually modify a gene that is, perhaps, the strongest indicator of heart diseases.

The results of the study have been published in the current issue of PLoS Medicine.

Specifically, the study suggests that individuals with a high-risk version of the 9p21 gene, who consumed, consistently, a diet of raw vegetables, fruits and berries faced similar probability rates of suffering a heart attack as those with a low-risk variant of the same gene.

We know that 9p21 genetic variants increase the risk of heart disease for those that carry it, said Dr. Jamie Engert, a researcher in cardiovascular diseases at RI-MUHC, associate member of the Department of Human Genetics at McGill and joint principal investigator of the study, But it was a surprise to find that a healthy diet could significantly weaken its effect.

We found that in people with this high-risk gene who consumed a diet rich in vegetables and fruits, their risk came down to that of people who don't have that gene, said Dr. Sonia Anand, Professor of Medicine and Epidemiology at the Michael G. DeGroote School of Medicine at McMaster University and lead author of the study.

Despite having a high genetic risk for heart disease, a healthy lifestyle can actually turn off the gene, said Anand. She explained that it is as yet unclear how diet affects the 9p21 gene variant.

Our results support the public health recommendation to consume more than five servings of fruits or vegetables as a way to promote good health, said Anand.

The researchers analyzed the diets of more than 27,000 people from different parts of the world, including Europe, China and Latin America. Participants were already enrolled in two separate studies looking at heart diseases.

The study participants who lowered their risk through their diet ate at least two servings of fruits and vegetables a day. Raw fruits and vegetables played the biggest role in lowering risk, Anand said.

Our research suggests there may be an important interplay between genes and diet in cardiovascular disease, said co-author Dr. Ron Do, who conducted this research as part of his PhD at McGill and is now based at the Center for Human Genetics Research at Massachusetts General Hospital in Boston.

Future research is necessary to understand the mechanism of this interaction, which will shed light on the underlying metabolic processes that the 9p21 gene is involved in.