People at high risk for heart attacks, strokes, and death from heart disease can significantly cut their risk if they eat a Mediterranean diet that’s high in fish, nuts, fruits, vegetables, olive oil, and even red wine, according to a major new study published in New England Journal of Medicine.
This groundbreaking research is the first large, randomized clinical trial to evaluate the diet’s effects on cardiovascular risk, and the results were so dramatic that they amazed experts. In fact, the study was halted early (after 4.8 years) because the benefits of this eating plan were so obvious that it would be unethical to continue.
The study included 7,447 participants who were randomly assigned to eat one of three diets: a Mediterranean diet including extra virgin olive oil, a Mediterranean diet including extra nuts, or a low-fat diet.
The researchers found that eating a Mediterranean diet reduced overall risk for major cardiovascular events (heart attack, stroke or death from cardiovascular causes) by 28 to 30 percent, compared to a low-fat diet.
The researchers reported the following results:
- Eating a Mediterranean diet reduced overall risk for major cardiovascular events (heart attack, stroke or death
- A Mediterranean diet including extra servings of nuts cut stroke risk by 46 percent.
- A Mediterranean diet including extra servings of extra virgin olive oil trimmed stroke risk by 33 percent.
What was particularly impressive was the diet powerfully lowered cardiovascular disease (CVD) risk even though most of those who followed it were already taking statins, ACE inhibitors, diabetes medications, or other drugs to cut their heart disease danger.
In addition, the study participants were all at very high risk for CVD, due to being diabetic or having at least three major risk factors, such as smoking, high blood pressure, obesity, high cholesterol, or a family history of developing CVD at an early age. None of the participants had CVD at the start of the study.
Surprising Finding About Cholesterol
One of the biggest surprises was that the low-fat diet lowered cholesterol the most, yet proved least effective at preventing heart attacks, strokes, and death from CV causes. “These results will shock many cardiologists, because high cholesterol has traditionally been considered the leading risk factor for arterial disease,” says Bradley Bale, MD, medical director of the Heart Health Program for Grace Clinic in Lubbock, Texas.
However, new research shows that chronic inflammation—not just high cholesterol—is what drives CVD, adds Dr. Bale. “This explains the puzzle of why many people who have heart attacks or strokes have normal or even optimal cholesterol, while other people with very high cholesterol never suffer these events.”
Foods in the Mediterranean diet, particularly nuts and olive oil, have been shown in earlier studies to reduce inflammation, offering one explanation of why this diet proved so astonishingly effective even though it didn’t lower cholesterol and the people in the study didn’t lose weight—nor did they receive any instructions about exercise.
The Best Food to Stave Off Stroke
Another startling finding was that eating a Mediterranean diet including extra servings of nuts trims stroke risk by a whopping 46 percent, compared to eating a low-fat diet. “That’s a huge risk reduction,”says Dr. Bale. “It’s truly astonishing to see such a powerful effect from one food.”
The group who ate extra nuts also had a 30 percent lower rate of heart attacks, compared to the low-fat group, but the drop wasn’t large enough to be statistically significant. Overall, both groups who ate a Mediterranean diet had about a 30 percent reduction in major cardiovascular events.
In earlier studies, nuts have been shown to have several protective powers, adds Dr. Bale. “We known that nuts are particularly effective at reducing high blood pressure, which is the number one risk factor for stroke, and can also improve the health of the endothelium (blood vessel lining),” making arteries more resistant to plaque buildup.
In addition, nuts have powerful antioxidant properties, adds Dr. Bale.“This study gives a very strong signal that people can significantly reduce stroke risk by eating nuts. The study design is impressive because the researchers controlled for all sorts of cardiovascular risks and also used lab tests to make sure people were eating the assigned diet.”
Benefits of Extra Virgin Olive Oil
The group who ate a Mediterranean diet supplemented with extra servings of extra virgin olive oil had a 34 percent drop in stroke risk, compared to the low-fat group. Heart attack risk fell by about 30 percent in the two groups who ate a Mediterranean diet, but the reduction wasn’t large enough to be statistically significant.
“Extra virgin olive oil contains a compound called oleocanthal that is both a powerful antioxidant and also has an anti-inflammatory effect similar to NSAIDs (nonsteroidal anti-inflammatory drugs) like aspirin or ibuprofen,” says Dr. Bale. Based on scientific research, the European Food Safety Authority has approved the claim that olive oil protects LDL (bad) cholesterol molecules from oxidative damage.
The Healthiest Diet for Your Heart
In the study, the two groups who ate a Mediterranean diet were given these guidelines, all of which are believed to have contributed to the astonishing reduction in cardiovascular danger observed in this very high risk group:
- Eat white meat instead of red.
- Eat fish and legumes (such as beans, lentils and peas) at least 3 times a week.
- Avoid sweets (such as sugary beverages and baked goods) and limit consumption of dairy products and processed meats.
- Those who drank alcohol were advised to have at least 7 glasses of red wine with meals per week. Dr. Bale recommends discussing the risks and benefits of wine consumption with your healthcare provider.
- Eat at least 3 servings of fruit and 2 servings of vegetables daily.
- The group whose diet was supplemented with extra virgin olive oil was told to use at least 4 tablespoons per day.
- The group whose diet was supplemented with nuts ate one ounce of mixed nuts (walnuts, almonds and hazelnuts) daily