A new study found that a Mediterranean diet may reduce the risk of cardiovascular events by as much as 30% in people who are at a high risk for developing heart disease, as compared to people who switched to a diet low in fat.
Researchers presented their findings at the International Congress on Vegetarian Nutrition. They found that a Mediterranean diet featuring extra virgin olive oil and mixed nuts significantly lowered a person’s risk of a cardiovascular event.
“These results support the benefits of the Mediterranean diet for cardiovascular risk reduction [and] are particularly relevant given the challenges of achieving and maintaining weight loss,” researchers said.
Dr. Marc Gillinov, who wrote about the study in Heartwire, said the results of the study should not be ignored.
“This randomized controlled trial is by far the best in class when it comes to dietary studies,” said Gillinov. “We should take its results seriously: if you have risk factors for cardiovascular disease–and the majority of adult Americans do–your best bet is to follow a Mediterranean diet.”
Diet Study
For their study, researchers gathered 7,447 men and women between the ages of 55 and 80 years old. None of the subjects had experienced a previous cardiovascular event, but they were considered at high risk for cardiovascular disease.
The participants were separated into three groups. The first group was asked to eat a diet supplemented with olive oil, the second group had a diet rich in mixed nuts, and the third group was asked to eat a reduced fat diet.
Participants in the Mediterranean-diet groups were invited to attend regular dietary training sessions, while the control group was sent informational leaflets explaining the benefits and composition of a low-fat diet. After three years, subjects in the control group were invited to the regular group sessions and received the same level of advice as the Mediterranean groups. The study lasted 4.8 years.
The study was called off after it was revealed that participants in the Mediterranean-diet groups showed significant reduction in their risk of heart disease compared to the control group. Researchers saw that the olive-oil based diet reduced the likelihood of stroke or cardiovascular death by 30%, while the mixed nut group saw a 28% decrease compared to the control group. Some other findings included:
- Study dropouts were twice as likely in the low-fat group as the Mediterranean groups (11.3% vs. 4.9%)
- “Favorable trends” were seen for stroke rates among both Mediterranean diet groups
- 288 participants experienced a cardiovascular event during the study. 96 in the olive oil diet, 83 in the nut diet, and 109 in the control group
Good Fat vs. Bad Fat
Dr. Ramon Estruch, who co-authored the study, said one of the biggest reasons why the Mediterranean diet was successful was because it focused on good fat over bad fat.
“Animal fat should be avoided,” Estruch said. “Vegetal fats–extra virgin olive oil and nuts–should be recommended [within] a healthy food pattern such as the Mediterranean diet.”
He also stressed the importance of educating people to the importance of healthy fats in a diet.
“People should know that the Mediterranean diet is a diet healthier than others and should know the key components of this food pattern,” he said. “The plan should be to increase the intake of the key foods (vegetables, fruit, nuts, fish, legumes, extra virgin olive oil, and red wine in moderation), also increase the intake of white meat, and decrease the intake of red and processed meat, soda drinks, whole dairy products, commercial bakery goods, and sweets and pastries.”
Dr. Steven Nissen, who works at Cleveland Clinic, said the findings could change the recommendations doctors provide to patients.
“The findings are compelling and should alter the dietary advice we give patients. The currently popular ultralow-fat diets . . . are clearly not best for patients,” he said. “The standard American Health Association recommended diet should be modified to reflect these findings: fat is not the problem with the American diet, we just eat the wrong types of fats.”
Dr. Silverman comments
Finally, evidence beyond refute. Fat is healthy and low fat is not. Not only was this shown in the results, but researchers decided to call off the study before it was complete because continuing would have posed an elevated risk of heart attack, stroke and death to the control group.
What is the major take away point from this study that is applicable to everything in medicine? Don’t treat symptoms, treat the cause.
Doctors originally prescribed low-fat diets and then added lipid lowering drugs as they saw fit, but now we see that treating a disease in this way is nonsensical.
Instead, treating the disease cause (aka “the diet”), is a much better approach.
In my office I treat ankle and foot troubles. Many times I see patients who have undergone symptom modification, which only partly addresses the problem. They suffer recurring injuries, and the wonder why the symptom modification was unsuccessful. Unless the cause of the problem is addressed, whether through surgical or non-surgical treatment, the problem will recur and worsen.