My last few blog posts have had a Mediterranean theme so I decided to continue it through to this post…..last week I mentioned the Mediterranean diet in relation to prevention of heart disease, cholesterol lowering and the reduction of triglyceride levels, a risk factor for heart disease. I also mentioned that low fat, high carbohydrate diets were not necessarily successful in reducing the overall risk of heart disease and could often contribute to an increase in triglyceride levels. A study published in the December issue of the Archives of Internal Medicine (1) found that a Mediterranean diet supplemented with nuts could potentially play a significant role in reducing in the risks of heart disease.
The researchers were investigating the effects of a Mediterranean diet on the metabolic syndrome. Metabolic syndrome is a term used to describe a cluster of risk factors for heart disease, diabetes and stroke which includes: high blood pressure, abdominal obesity (excess weight around the waist), high triglyceride levels, high blood sugar levels and high levels of SD-LDL cholesterol (a particularly damaging form of cholesterol) as well as other factors.
The study (1) lasted for a year and included a total of 1224 participants aged 55-80 which were split into 3 groups. The aim was to determine the efficacy of diet on the prevention of cardiovascular/heart disease. One group was given information about the Mediterranean diet including the use of 1L of virgin olive oil per week, the second group was advised to consume a Mediterranean diet including 30g of mixed nuts per day and the third group acted as a control group and advised to eat a low-fat diet.
After a year the prevalence of metabolic syndrome among the participants was reduced by almost 7% in the Mediterranean + olive oil group, almost 14% in the Mediterranean + nuts group and only 2% in the low fat group. In the nut group there was also a significant drop in the number of participants with abdominal obesity, high blood triglyceride levels or high blood pressure when compared to the low fat diet (control group). The authors conclude that “A traditional Mediterranean diet enriched with nuts could be a useful tool in the management of the metabolic syndrome”
The benefits of a Mediterranean diet may be greater when nuts are included as a fat source since nuts also provide nutrients, in addition to healthy fats, such as fibre, potassium, calcium and magnesium – which are linked to a reduction in blood pressure and may also help to regulate blood sugar levels through an effect on the hormone insulin. Walnuts are also fairly rich in omega 3 fatty acids, not provided by olive oil, which are known to help reduce the risk of heart disease.
Typically a Mediterranean diet is rich in olive oil, vegetables, fruits, oily fish (a great source of omega 3 fatty acids) and low in refined carbohydrates, sugar and processed foods. I have written extensively about the Mediterranean diet previously so please search through my blog posts for further information.
The study did not assess the dietary potential for weight loss nor did the scientists look at advising an increase in physical activity. The results were achieved with diet alone. In combination with education on increasing physical activity I expect that the results could have been further improved. Just 30 minutes of walking a day seems to be highly beneficial to health, even if this is broken down into two fifteen minute sessions.
From this study and from my previous posts I think it is important to note that dietary fat is not necessarily the ‘bad guy’ that many people assume. Perhaps refined carbohydrates, foods with a low GI (glycaemic index) which release sugar quickly into the blood stream and sugar represent huge problems to health. Naturally high-fat foods such as nuts and seeds, avocados, olives and oily fish are great for our health and, I would suggest, far more nutritious than many of the low fat refined cereal foods that are on offer in our supermarkets.
(1)Salas-Salvado J et al. 2008. Effect of a Mediterranean diet supplemented with nuts on metabolic syndrome status one-year results of the PREDIMED randomized trial. Arch Intern Med. 168:2449-2458
Written by Ani Kowal
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- Mediterranean diet may help to reduce the risk of type 2 diabetes
- Mediterranean diet shown to help those with heart problems
- Study looks into how olive oil and a Mediterranean diet might be working to improve health
- Mediterranean diet comes up top again
- More benefits seen from following Mediterranean style diets
