Eating two or more servings of avocado a week may cut your risk of cardiovascular disease by 16%, according to a new study.
Researchers at Harvard University analysed data from two large US studies: the Health Professionals Follow-Up Study and the Nurses’ Health Study. Between 1986 and 2016, researchers followed more than 41,000 men from the Health Professionals Follow-Up Study (aged 40-75 years) and more than 68,000 women (aged 30-55 years) from the Nurses’ Health Study.
To take part in the study, participants had to be free of cancer, coronary heart disease and stroke. Every two years after that, they completed a questionnaire on their health and lifestyle. And every four years, they completed a questionnaire on what they ate.
The researchers recorded the number of cardiovascular disease cases, including coronary heart disease and stroke, that occurred during the 30-year study period. Those who ate two or more servings of avocado each week had a 16% lower risk of cardiovascular disease and 21% lower risk of coronary heart disease compared with those who avoided or rarely ate the fruit. (A serving of avocado was defined as half an avocado – about 80g.)
Replacing half a serving a day of egg, butter, cheese, margarine or processed red meat with the same amount of avocado was associated with a 16%-22% lower risk of cardiovascular disease. But substituting half a serving a day of avocado for the same amount of olive oil, nuts and other plant oils showed no extra benefit.
The strengths of the study are that it involved over 110,000 participants and had a long follow-up period. The researchers also took many things into account that could affect the results, such as whether or not people smoked, their body weight, how active they were, and the medicines they took.
However, one of the big limitations is that the participants were mostly white healthcare professionals, which means the findings might not apply to other population groups. Racial and ethnic differences in cardiovascular disease were not acknowledged in the study. Yet people from ethnic minority groups experience a disproportionately greater burden of cardiovascular disease.