Med diet better than low-fat for heart health says "landmark" trial
significantly better for heart health than a low-fat diet, says a
"landmark" clinical trial from Spain.
"The results to date make us believe, long term, the Mediterranean diet enriched with walnuts or olive oil will indeed reduce heart disease. The size, duration and clinical basis of this study make it landmark," said researcher Dr. Emilio Ros, from the Hospital Clinic of Barcelona.
The Med diet, rich in cereals, fruits, legumes and whole grains, fish and olive oil, has been linked to longer life, less heart disease, and protection against some cancers. The diet's main nutritional components include beta-carotene, vitamin C, tocopherols, polyphenols, and essential minerals.
But Dr. Ros said that the previous results on Med diets and heart health were merely "scattered pieces of evidence from prospective studies".
"The early results of this clinical trial indicate that the Mediterranean diet pattern is ideal for cardiovascular disease prevention," he said.
The PREDIMED study, results published in the Annals of Internal Medicine (Vol. 145, pp. 1 to 11), recruited 772 adults at high risk of cardiovascular disease (CVD), and divided the volunteers into three groups. One group (257 subjects) was assigned to a low-fat diet, and the other two groups to a Mediterranean diet.
One Med diet group was given additional free virgin olive oil (one litre per week), and the second Med diet group was given additional nuts (30 grams per day). Measurements and outcome changes were evaluated every three months (body weight, blood pressure, lipid profile, glucose levels and inflammatory molecule levels).
Almost 100 per cent of the participants completed the four-year trial.
Compared to the low-fat diet subjects, the researchers found that both Mediterranean diets resulted in significant benefits for plasma glucose levels, systolic blood pressure and the ratio of total cholesterol to HDL cholesterol.
The Med diet with extra olive oil was associated with decreases in plasma glucose levels of 0.39 millimoles per litre, while the extra nuts Med diet was associated with a decrease of 0.30 millimoles per litre.
Systolic blood pressure decreased 5.9 mmHg for the Med diet plus olive oil group, and 7.1 mmHg for the Med diet plus nuts group.
The ratio of total cholesterol to HDL cholesterol, reported to be the most specific lipid risk factor for CVD, also decreased for both Med diet groups compared to the low-fat group (reductions of 0.38 and 0.26 for the olive oil and nut groups, respectively).
The Med diet plus olive oil also produced significant reductions in the levels of C-reactive protein, a pro-inflammatory protein linked to heart disease.
"Compared to a low-fat diet, Mediterranean diets supplemented with olive oil or nuts have beneficial effects on cardiovascular risk factors," concluded the researchers.
Dr. Ros went further with in a video interview today and said: "We expect it to reduce the rates of heart attacks and strokes and other cardiovascular diseases by 50 per cent."
"I'm saying that a diet that incorporates walnuts will surely reduce the risk of heart disease in the long term."
CVD causes almost 50 per cent of deaths in Europe, and is reported to cost the EU economy an estimated €169bn ($202bn) per year. According to the American Heart Association, 34.2 per cent of Americans (70.1m people) suffered from some form of cardiovascular disease (CVD) in 2002.
