Even moderate consumption of fruit and vegetables can reduce the risk of heart attacks and other coronary events, researchers said yesterday, confirming the need for promotion of plant foods in public health campaigns.
The researchers, presenting a multicentre case control study involving around 2000 people, also found that risk was progressively lower as daily consumption of fruits or vegetables increased.
In the CARDIO2000 study, a team from the University of Athens in Greece explored the association between several demographic, nutritional, lifestyle, clinical and biochemical risk factors with the risk of developing non-fatal acute coronary syndromes. From January 2000 to March 2002, 848 coronary patients and 1078 healthy control subjects were randomly selected from throughout Greece to take part.
A questionnaire measured the consumption of several food items as an average per week during the past year. The frequency of consumption was quantified approximately in terms of the number of times per month this food was consumed.
After adjusting for several cardiovascular risk factors, the data revealed that those in the upper quintile of fruit consumption (five or more items each day) had 72 per cent lower relative cardiac risk compared with those in the lowest quintile of intake (less than one item daily). Similarly, consumption of vegetables more than three days per week was associated with 70 per cent lower relative cardiac risk compared with those who did not consume vegetables.
"Of particular interest, a 10 per cent reduction in coronary risk was observed for every additional piece of fruit consumed per day," said Dr Demosthenes Panagiotakos and Dr Christina Chrysohoou from the School of Medicine at the University of Athens, speaking at the European Society of Cardiology meeting in Vienna this week.
"Moreover, in an analysis of the overall trend, considering vegetable intake as a continuous variable, we found a 19 per cent reduction of the risk for developing coronary syndromes per each additional serving per day of vegetable consumed."
However, the benefits from both fruits and vegetables reach a plateau with high intake (equivalent to more than 2.5 servings a day), reported the scientists.
Their evidence offers further support for public health education and promotion aimed at a substantial increase in the consumption of fruits and vegetables. However, the data do not provide evidence for causality, added the researchers, noting the need for population trials to provide scientific proof of their efficacy.
While cross-cultural comparisons, case-control and prospective observational studies provide strong evidence of the relationship between diet, blood pressure and lipids levels, there is still considerable scientific uncertainty about the relationship between specific dietary components and cardiovascular risk, especially in Mediterranean populations.
Numerous trials to assess the role of vitamins, present in high quantities in fruit and vegetables, in protecting heart health have produced a body of inconsistent results. There seems to be more consistent evidence linking a diet high in fruit, vegetables, and legumes to cardiovascular benefits, suggesting that other constituents besides vitamins may explain the ability of such diets to protect the heart.