Study co-author Dr. Frank Hu, the Frederick J. Stare Professor of Nutrition and Epidemiology at the Harvard T.H. Chan School of Public Health (HSPH), puts this finding in perspective.

“This study adds to the evidence to support the benefits of healthy fat sources like avocados to help prevent cardiovascular disease,” he says. A key take-home message is to substitute avocados for less-healthy foods such as butter, cheese, and processed meats, he adds.

Who was in the study?

The study included more than 110,000 people involved in two long-running Harvard studies: the Nurses’ Health Study and the Health Professionals Follow-up study. Most of the participants were white; they ranged in age from 30 to 75 and were free of heart disease and cancer when the study began.

“Nihil hic munitissimus habendi senatus locus, nihil horum? Contra legem facit qui id facit quod lex prohibet. Cum sociis natoque penatibus et magnis dis parturient. Praeterea iter est quasdam res quas ex communi.”

John Smith, 2011

Researchers assessed the participants’ diets via questionnaires given at the start of the study and then every four years. One question asked how much and how often people ate avocado. A serving was considered a half an avocado or one-half cup, cubed.

What were the findings?

During the 30-year follow-up, researchers documented 9,185 heart attacks and 5,290 strokes among the participants. Compared with people who never or rarely ate avocados, those who ate at least two servings each week had a 16% lower risk of cardiovascular disease and a 21% lower risk of experiencing a heart attack or related problem due to coronary artery disease. Coronary artery disease refers to a narrowing or blockage in the blood vessels that supply the heart; it’s the most common type of cardiovascular disease.

Oleic Acid

This monounsaturated fat is also plentiful in olives. Half an avocado has around 6.5 grams of oleic acid, or about the same amount found in a tablespoon of olive oil. Research shows that replacing foods high in saturated fat (such as butter, cheese, and meat) with those rich in unsaturated fats (such as avocados, nuts, and seeds) helps lower blood levels of harmful LDL cholesterol, a key culprit in coronary artery disease.

Fibre

One serving of avocado provides up to 20% of the daily recommended dietary intake of fiber, a nutrient that’s often lacking in the typical American diet. Fiber-rich diets may lower heart disease risk as much as 30%, probably because fiber helps lower not only cholesterol, but also blood pressure and body weight.

Vitamins, Minerals and more

Half an avocado provides 15% of daily recommended intake of folate (vitamin B9), 10% of potassium, and 5% of magnesium, as well as various plant-based compounds called phytochemicals. All of these nutrients — along with oleic acid and fiber — have been independently linked to better heart health.

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The good news is that there are so many delicious ways to add avocado to your meals, says Dr. Hu. “I make avocado toast for breakfast, use avocado as a spread for sandwiches, and add them to salads,” says Dr. Hu. Some people add avocado to their smoothies — and of course, there’s always guacamole (try this recipe from the HSPH’s Nutrition Source).

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