In a 2018 study of Estruch and others that was published in the new England Journal of Medicine more than 7,000 individuals with high risk of heart disease followed either a Mediterranean diet with added olive oil, a Mediterranean diet with added nuts, or a low fat control group. The study lasted four years and eight months and the main focus was on diet's potential effects on heart attack stroke and death from cardiovascular causes. The results showed that the risk of combined heart attacks stroke and death from heart disease was lowered by 31% in those that followed the Mediterranean diet with additional olive oil and 28% in those that followed the Mediterranean diet with additional nuts.