The diets of native populations are generally considered to be healthy despite large differences in their nutrient composition. Records suggest that before the introduction of refined white flour, refined white sugar and alcohol, diseases such as cancer and cardiovascular disease were almost unheard of amongst indigenous populations. Many of these populations have now been wiped out (such as the Native North and South Americans) or been ‘Westernised’ by the encroaching trade of the white Western European settlers. However, there still exists indigenous populations who consume their native diets, and many of these have been extensively researched in an attempt to try to understand the health benefits they may have. One such diet is the Mediterranean diet, which is consumed in areas surrounding the Mediterranean sea such as Italy, Greece, Spain, Cyprus and some areas of Northern Africa.
The Mediterranean diet has been analysed and shown to be composed of foods that contain high concentrations of antioxidant nutrients. Antioxidants are chemical compounds that can prevent oxidation of biological components because their structure allows the donation of hydrogen atoms in scavenging reactions. Many antioxidants in plants belong to a chemical group called the polyphenols, the most important sub-group of which are the flavonoids. The free radical theory of disease states that it is oxidation of lipids, proteins and other cellular components that leads to the formation of disease, because oxidised tissues and cells are not able to function correctly. Over time the oxidised damage increases until physiology in certain areas of the body is affected and disease ensues. Foods such as extra virgin olive oil, herbs, tomatoes, grapes, red wine, fruit and green vegetables are rich in antioxidants and eaten in large amounts in the Mediterranean diet.
In addition to its antioxidant component, the Mediterranean diet contain a very different fatty acid profile to that which you might associate with Western diets. The classic Western diet is high in animal proteins from cattle and sheep, and as a result has high quantities of saturated fatty acids represented mainly by stearic acid. In addition, deodorised and hydrogenated vegetable oils are use extensively in the processed food that make up large portions of the diet with the result that Westerners consume high amounts of n-6 polyunsaturated oils. In contrast the Mediterranean diet contains high quantities of fish as its primary animals protein source, and because of this the diet is high in the n-3 marine oils eicosapentanoic and docosahexanoic acid. The main vegetable oil is extra virgin olive oil which contains the n-9 monounsaturated fatty acid oleic acid.
One of the benefits seen with a switch from the standard Western diet to the Mediterranean diet is substantial which loss. Weight gain is complex and not completely understood, but is known to involve a slow deterioration of the sensitivity of the insulin receptor to insulin, and therefore a gradual descent towards insulin resistance. The Mediterranean diet is known to improve insulin sensitivity for a number of reasons including its high content of n-3 marine fatty acids, its high antioxidant component and its low levels of saturated fatty acids. In addition, research has demonstrated that the Mediterranean diet is associated with lower rates of cardiovascular disease, cancer and diabetes. Again, this has been theorised to be due to the high levels of antioxidant nutrients from plant foods and the high n-3 fatty acid content of the diet.
One often overlooked component of the Mediterranean diet is the lifestyle of those indigenous populations that consume it. They tend to live in extended families, in rural areas, and have extensive social networks. They also tend to work fewer hours and spend large proportions of time with family and friends, with food and meal time playing an important role in this interaction. There is little doubt in my mind that many of the health benefits of living in the Mediterranean area come from the stress-free lives many of the inhabitants follow, the high vitamin D levels from the extensive sun exposure in combination with the healthy food. Western populations in contrast tend to be isolated socially, live is disconnected families and spend large amount of time working in offices away from the sun. The Mediterranean diet should really be thought of as the Mediterranean lifestyle.
RdB
