MEDICAL MATTERS:Not long after publication of the study showing that people who are a tad overweight have a lower mortality rate than those whose body mass index (BMI) is in the normal range (Medical Matters, January 23rd, 2013), comes even more good news, this time on the dietary front.
Decrease in mortality
In the first major trial to measure whether a Mediterranean diet can prevent cardiovascular disease, Spanish researchers found that switching to a diet rich in extra virgin olive oil and nuts lowers a person’s risk of heart attack, stroke and death.
The study is significant for a number of reasons: it is the first large prospective trial of this kind of diet as a primary prevention tool; the magnitude of the diet’s benefits came as a surprise; it didn’t involve weight loss; and most of those who participated were already taking cholesterol-lowering or blood pressure drugs.
Researchers recruited some 7,500 people who were overweight, were smokers or had other risk factors for heart disease.
They then divided them into three groups: one group was asked to follow a low-fat diet; another was given a Mediterranean diet rich in extra virgin olive oil; and one group was also given a Mediterranean diet with added walnuts, almonds and hazelnuts.
Participants’ compliance with the diet was measured objectively, using urine tests for a marker of olive oil consumption and a blood test to assess the amount of nuts being eaten.
They then followed up all three groups for five years. Those assigned to the Mediterranean-type diets had a 30 per cent lower risk of having a heart attack or stroke compared with those selected for the low-fat diet. They were also less likely to drop out of the study.
In terms of absolute numbers, the energy-unrestricted Mediterranean diet supplemented with either extra-virgin olive oil or nuts resulted in an absolute risk reduction of approximately three major cardiovascular events per 1,000 people who followed the diet.
Eat chocolate
For those of us who have tired of calorie counting and low-fat diets, other elements of the diet recommended by lead researcher Dr Ramon Estruch and his colleagues sound almost too good to be true.
It allows people to eat as many nuts and eggs as they want. And there is no restriction on chocolate consumption as long as it is chocolate with more than 50 per cent cocoa.
The diet also permits unlimited consumption of fish, seafood, whole-grain cereals and low-fat cheese. Oh, and if you drink, please have at least one glass of wine a day with a meal, the researchers suggest.
No weight gain
Perhaps most surprising of all, the researchers say, there is no need to worry about weight gain as a result of consuming the nuts and olive oil.
They report that studies show people do not gain weight when they add those foods, probably because they make people feel full so they eat less of other things.
The study is supported by previous research showing how a traditional Mediterranean diet lowers certain risk factors for heart disease, including inflammation, oxidation and instability in the inner lining of blood vessels.
So what should you eat based on these findings?
Use extra virgin olive oil (at least four teaspoons a day) on salads and vegetables. Eat half a cupful of mixed nuts daily.
Have at least three servings of fresh fruit and two of vegetables every day. Eat beans, peas and lentils at least three times a week.
Have fish three times a week (fatty fish like tuna or salmon at least once) and eat white meat such as chicken or turkey rather than red.
And, of course, there are also foods that should either be avoided or eaten sparingly: these include french fries, pate, sugared drinks and what the researchers intriguingly refer to as “industrial desserts” – custard-based desserts and puddings.
Finally, for those already prescribed cholesterol-lowering drugs – don’t stop taking them but do modify your diet. Bon appétit.