Over the past 50 years, it has been hard to escape reports about the benefits of a Mediterranean diet, embodied perhaps by consumption of olive oil. Historically the diet entered mainstream medical literature following publication of research showing low incidence and mortality from heart disease in Mediterranean countries. This was associated with lower consumption of saturated fat, but not total fat in the diet.
What exactly is the Mediterranean diet, does it have any health benefits and should we be encouraging this type of dietary approach for our service users?
There is in fact no one ‘Mediterranean’ diet. Diets vary between the many countries that border the Mediterranean Sea, and also between regions within a country. The traditional Mediterranean diet is based on the dietary pattern found in the olive tree growing regions like Greece and Southern Italy, and shares the following fundamental characteristics:
- High consumption of plant foods; vegetables and fruit, legumes, cereals, nuts and seeds
- Low consumption of red and processed meat
- High consumption of olive oil which is an important monounsaturated fat source
- Rich monounsaturated fat intake compared to saturated fat intake
- Fish eaten in moderate amounts
- Wine consumed in moderate amounts
Mediterranean dietary pattern and health
An ever-expanding body of research has taught us that the quality of what we eat strongly influences our health. But, whilst we have concentrated on specific isolated nutrients or total quantities of foods consumed, the most relevant characteristics of healthy diets may lie in the overall pattern of foods consumed.
Research has typically found associations between a high adherence to a Mediterranean dietary pattern and reduced risk of chronic diseases such as heart disease, cancer and type 2 diabetes. More recent research has also suggested a benefit in cognitive health. For example, a 2013 meta-analysis showed that high adherence to a healthful dietary pattern, such as the Mediterranean diet, may be beneficial in the prevention of various conditions linked to the aging brain, including cognitive decline and stroke. Another meta-analysis also found that greater adherence to a Mediterranean diet was associated with slower cognitive decline and a lower risk of developing Alzheimer’s disease.
Results of studies are positive but caution is needed in making firm recommendations
The evidence for the health benefits of the Mediterranean diet does need a more systematic approach. Varying definitions of the diet exist, and there may also be a lack of detail and differentiation of foods in these studies that may be important. For example, wine is the main form of alcohol traditionally consumed in the Mediterranean but often total alcohol, rather than wine is measured in studies. Similarly moderate amounts of fermented dairy products may be consumed, but the role of dairy in Mediterranean diets is ill-defined.
The applicability of Mediterranean diets to non-Mediterranean countries has not been well established. What it means in the context of other countries with distinct cultural diets and lifestyles (e.g. China, India, parts of Africa) is unclear. More trials are needed to see which interventions might work in different populations.
There is a danger of the science being oversimplified. Popular proponents of the Mediterranean diet tend to single out the health benefits of olive oil. However, research has not shown that the benefits of the Mediterranean diet on chronic disease risk can be clearly attributed to any one component. Studies have also reported benefit when key elements of the Mediterranean diet (such as olive oil, oily fish and nuts), as well as other oils high in monounsaturated fats are incorporated into non-Mediterranean European dietary patterns. Indeed, the reported health benefits may well result from the synergistic combination of foods that make up the diet, with omega-3 fatty acid and the large number of vitamins, antioxidants and polyphenols (bioactive plant nutrients) all working together to have positive benefit.
Finally in nutrition research it is important to recognise that there are many variables that may not be measured (for example physical activity, social support, sitting down together to eat meals). These may have an important effect in disease prevention, and it may be that those who followed a Mediterranean-like diet are likely to have other healthful habits too.
Should catering to service users follow the Mediterranean diet?
It is worth mentioning the similarity of the Mediterranean diet to other ‘healthy dietary patterns.’ The DASH dietary pattern for reducing blood pressure resembles the Mediterranean diet in its emphasis on fruits, vegetables, wholegrains, legumes, nuts and fish. Both are limited in red and processed meats and foods high in saturated fats. Perhaps what is less recognised is that the Mediterranean diet also encompasses many of the messages in current UK healthy eating advice. This includes advice to eat plenty of fruit and vegetables, starchy foods including wholegrains, to increase fish consumption and reduce intake of saturated fat. The fat profile in the Mediterranean diet also reflects current scientific advice to reduce saturated fat and replace with unsaturated fats. We also have recommendations around moderate alcohol consumption.
We should already be working towards this dietary pattern but in any case it is a good reminder to keep increasing the amount of fruit and veg, pulses, wholegrain and fish, and to choose ‘good’ unsaturated fats.
To make your diet or that of your service users more Mediterranean you can:
- Increase consumption of fruit and vegetables
- Increase consumption of whole grains, pulses, nuts and seeds
- Increase consumption of fish
- Decrease consumption of meat
- Choose products made from vegetable and plant oils, such as olive oil
What can’t be discounted is that a Mediterranean dietary pattern provides health benefits, even if we cannot yet pinpoint the exact benefits of its various components. So why not try and adopt some of its characteristics – try and reduce the meat in some dishes and replace with beans or pulses, make sure fish particularly oily fish is served and use plant oils rather than fats rich in saturated fat (e.g. butter, lard, ghee) in your cooking.
