Olive Oil, Fish, Veggies ... What Is It?
When the researchers looked at the individual components of the Mediterranean diet, they found no significant decrease in death with any one type of food.
In addition to having olive oil with most meals, the typical Mediterranean diet is very high in vegetables, fruits, legumes, nuts, and cereals; moderate in fish intake; and has lower amounts of meat and dairy than the typical American diet. Drinking alcohol is also a frequently practiced dining ritual.
"God knows what sorts of interactions take place within the foods, and we need further research to pinpoint them exactly," Trichopoulos tells WebMD.
"But typically, people in Greece eat twice as many vegetables as Americans -- nearly a pound a day. And you really can't eat a pound of vegetables a day unless you have olive oil to make them appetizing. My advice is to try to double the amount of vegetables and fruits you currently have, and eat more fish, legumes, and non-refined cereals."
While olive oil itself showed little benefit, the researchers note a significant reduction in death rates from a higher overall ratio of monounsaturated fats to saturated fats. Olive oil is among the best sources of monounsaturated fats -- and happens to be the main cooking oil in most Mediterranean countries -- but other oils frequently consumed by Greeks and others surrounding the Mediterranean Sea also contain these healthy fats.
Calories Versus Healthy Oils
Trichopoulos' finding may also help explain why Asians, who typically use these other cooking oils, also have lower disease and death rates. Although they rarely use olive oil, they traditionally follow other principles of the Mediterranean diet -- lots of produce, legumes, nuts, and minimally processed grains, with little saturated fat.
"The message remains the same, and is consistent with other findings: A diet lower in saturated fats and higher in monounsaturated fats, and potentially, polyunsaturates, will result in better health outcomes," says Alice H. Lichtenstein, DSc, of Tufts University and a spokeswoman for the American Heart Association.
"If the main message that Americans get is to just increase their olive or canola oil consumption, that's unfortunate because they will increase their caloric intake and they are already getting too many calories. What they need to do is eat more fruits, vegetables, and legumes and fewer foods rich in saturated fats."