Healthy diet may modify genetic CVD risk
Effect of genetics on CVD risk strong, but may be countered by healthy diet
Wednesday, 12 October 2011
People with a higher risk of cardiovascular disease because they have one of certain genetic variants may be able to ameliorate that risk by consuming a diet including high levels of raw fruit and vegetables, report INTERHEART investigators in PLoS Medicine today. Their study shows that there may be an important interaction between environment and genes in the development of CVD.
Researchers in Canada, involved in the INTERHEART study, investigated the effect of single nucleotide polymorphisms in the chromosome 9p21 region on people’s risk of myocardial infarction or of cardiovascular disease, as well as the interaction with environmental factors.
They genotyped four such polymorphisms in 8114 participants in the INTERHEART study, as well as analysing data on 19,129 people in the FINRISK study. The two studies had used similar criteria to categorise the ‘prudence’, or healthiness, of participants’ diet; these categories accorded largely with whether they had low, average, or high intake of fresh fruits, vegetables and berries.
The study authors found that people with at least one copy of the risk allele had a higher risk of MI or CVD compared with people without any of these variants, and that this had an especially strong effect in people with the ‘least prudent’ diets. People with two copies of the risk allele and the poorest diet, for example, had an almost doubled risk of MI (odds ratio 1.98) in the INTERHEART study, and a two-thirds increased risk (OR 1.66) of CVD in the FINRISK study, compared with people without the risk alleles and the ‘healthiest’ diet.
However, data from both the studies showed that presence of the risk allele had “very little effect” on MI or CVD risk in people whose diet was in the healthiest category.
The researchers say: “The fact that our gene-environment interaction results are consistent between the INTERHEART and FINRISK studies suggests that our results may be robust.” But they add that further research must be conducted in large study samples that have similar genetic and dietary information, to confirm the results.
They conclude: “Our findings suggest that there may be an important interplay of genes and environment in the aetiology of CVD, and could shed light on the underlying pathophysiology of 9p21.”