Swedish researchers examined diets of 30,000 women and found that those with the highest antioxidant intake were 20 per cent less likely to have suffered a heart attack than those with the lowest intake, the Telegraph reported.
Antioxidants are naturally occurring substances which mop up molecules called reactive oxygen species (ROS), better known as 'free radicals'.
These prompt inflammation, can damage cells, and have been implicated for triggering cancer and heart disease.
The study which included Swedish women aged 49 to 83 found that older women who ate seven fruit and vegetable portions a day, were between 20 and 29 per cent less likely to have a heart attack over a decade, than those who ate just 2.4.
Women who ate a lot of fruit and vegetables also tended to eat less saturated fat. When the researchers adjusted for intake of fats, the difference in heart attack rates rose to 29 per cent.
Lead researcher Dr Alicja Wolk from the Karolinska Institute in Stockholm, said their research contrasted with tests of single antioxidant supplements, which have largely failed to find evidence that they cut heart attacks or mortality rates.
The study was published in the American Journal of Medicine.