Eating vegetables may prevent hardening of the arteries, research suggests.
Different coloured veg contain different minerals
US researchers found 38% less build up of fatty deposits in the arteries of mice who were fed a mixture of vegetables, including carrots and peas.
Evidence on the effects of diet on atherosclerosis in humans is not clear but eating fruit and vegetables is known to protect against heart disease.
The study in the Journal of Nutrition said the average person only eats three portions of fruit and veg a day.
The researchers from the Wake Forest University School of Medicine assessed the effect of diet on heart disease by studying mice that had been specially bred to rapidly develop atherosclerosis - the formation of fatty plaques in the arteries which can eventually block blood flow leading to heart attacks and strokes.
Half the mice were fed a vegetable-free diet and half the mice were fed a diet which included broccoli, green beans, corn, peas and carrots.
After 16 weeks, researchers measured cholesterol content in the blood vessels and estimated that plaques in the arteries of the mice were 38% smaller.
Although there was also a reduction in total cholesterol and body weight in mice fed the vegetable-rich diet, analysis showed that this could not explain the reduction in atherosclerosis.
Lead researcher Dr Michael Adams said: "While everyone knows that eating more vegetables is supposed to be good for you, no-one had shown before that it can actually inhibit the development of atherosclerosis."
He added that there was a 37% reduction in serum amyloid - a marker of inflammation in mice - suggesting that vegetable consumption may inhibit inflammatory activity
"Although the pathways involved remain uncertain, the results indicate that a diet rich in green and yellow vegetables inhibits the development of hardening of the arteries and may reduce the risk of heart disease," he said.
"It is well known that atherosclerosis progression is intimately linked with inflammation in the arteries."
Dr Adrian Brady, consultant cardiologist at Glasgow Royal Infirmary, said: "It's an interesting study and it is encouraging. There is a public health message that dietary interventions are helpful.
"And now this animal model shows maybe there is long-term dietary involvement that could lead to less plaques."
He added more work was needed to look at the development of plaques and confirm the protective effect of eating fruit and veg.
Dr Charmaine Griffiths, spokesperson for the British Heart Foundation, said: "This study supports the recommendation of eating at least five portions of fruit and vegetables a day.
"Different coloured fruit and vegetables contain different vitamins and minerals, so the more types of fruit and vegetables you can include in your diet the better."