Mediterranean diet and nuts may help manage heart risks

Mediterranean diet and nuts may help manage heart risks

A Spanish study of over 1,000 older adults comparing low fat versus two types of Mediterranean diet found that a Mediterranean diet enriched with nuts could be helpful in managing metabolic syndrome, a collection of risk factors for heart disease such as belly fat, high cholesterol, high blood pressure and high blood sugar.

The study was the work of Dr Jordi Salas-Salvadó, of the University of Rovira i Virgili in Spain, and colleagues from many other research centres throughout Spain, and is published in the December 8/22 issue of Archives of Internal Medicine.

Metabolic syndrome is a collection of cardiovascular disease risk factors comprising metabolic abnormalities like abdominal obesity, high cholesterol, high blood pressure and high blood glucose. It arises from a complex interaction of largely unknown inherited and environmental factors such as diet, wrote the authors, who commented that studies have shown that a traditional Mediterranean diet with high intakes of cereals, vegetables, fruit, and olive oil and moderate amounts of fish and alcohol, coupled with low intakes of dairy, meat and sweets or desserts, is linked to lower risk of metabolic syndrome.

In this study, Salas-Salvadó and colleagues compared the one-year effect of two types of Mediterranean diet, one enriched with virgin olive oil and the other enriched with nuts, with a low fat diet on symptoms of metabolic syndrome.

They recruited a total of 1,224 participants aged 55 to 80 at high risk of cardiovascular disease who were already taking part in the PREDIMED (Prevención con Dieta Mediterránea) Study, a multicenter, three-arm randomized clinical trial that is testing the effect of the Mediterranean diet on primary prevention of cardiovascular disease.

The researchers randomized the participants to one of three groups: the low fat diet group, the Mediterranean diet plus virgin olive oil group, and the Mediterranean diet plus nuts group.

The low fat diet group (the controls) were given advice on low fat diets, while the Mediterranean diet groups received quarterly education about the Mediterranean diet and either 1 litre a week of virgin olive oil or 30 grams a day of mixed nuts to consume. None of the participants were asked to increase their physical activity.

Salas-Salvadó and colleagues assessed participants' lifestyle and symptoms of metabolic syndrome using criteria from the National Cholesterol Education Program Adult Treatment Panel III.

The results showed that:

  • At the start of the study, 61.4 per cent of the participants had symptoms of metabolic syndrome.
  • After one year, the researchers were able to assess 409 participants in the Mediterranean diet plus olive oil group, 411 in the Mediterranean diet plus nuts group and 404 in the low-fat diet (control) group.
  • Metabolic syndrome went down by 13.7 per cent in the Mediterranean diet plus nuts group, 6.7 per cent in the Mediterranean diet plus olive oil group, and 2 per cent in the low fat diet (control) group.
  • There was no change in weight in any of the groups over the one year period.
  • But there was a significant drop in the number of participants with large waists, high blood fats (triglycerides) or high blood pressure in the the Mediterranean diet plus nuts group compared with the low fat diet (control) group.
The authors concluded that a traditional the Mediterranean diet enriched with nuts could be a useful tool in the management of metabolic syndrome.

Salas-Salvadó and colleagues suggested that the nuts may have reversed metabolic syndrome symptoms by reducing oxygen-related cell damage, chronic inflammation, and insulin resistance.

The participants on both the Mediterranean diets will have benefitted from a diet high in unsaturated fatty acids, but the ones on the nuts will also have benefitted from additional nutrients such as fibre, arginine (an essential amino acid), potassium, calcium and magnesium.

The authors commented that:

"Traditionally, dietary patterns recommended for health have been low-fat, high-carbohydrate diets, which generally are not palatable."

But the results of this study show that it is possible to manage metabolic syndrome with a tasty, non-energy restricted diet which is high in fat and high in unsaturated fat, and that is the traditional Mediterranean diet enriched with nuts.

They said that a longer follow up of the PREDIMED study may show stronger evidence on the cardiovascular benefits of such a diet.

"Effect of a Mediterranean Diet Supplemented With Nuts on Metabolic Syndrome Status: One-Year Results of the PREDIMED Randomized Trial."

Jordi Salas-Salvado; Joan Fernandez-Ballart; Emilio Ros; Miguel-Angel Martinez-Gonzalez; Montserrat Fito; Ramon Estruch; Dolores Corella; Miquel Fiol; Enrique Gomez-Gracia; Fernando Aros; Gemma Flores; Jose Lapetra; Rosa Lamuela-Raventos; Valentina Ruiz-Gutierrez; Monica Bullo; Josep Basora; Maria-Isabel Covas; for the PREDIMED Study Investigators.

Arch Intern Med. Vol. 168 No. 22, pp 2449-2458, Dec 8/22, 2008.

Click here for Abstract.

Sources: JAMA.

PREDIMED: Does Eating Nuts Prevent Strokes? (Video Medical And Professional 2020).

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