The Mediterranean Diet has been studied extensively for its proposed health benefits and improvement in overall longevity. In this blog post, we’ll discuss what types of foods are part of the Mediterranean Diet and what research is saying about its’ effects on mortality, cardiovascular disease, and cancer.
What is the Mediterranean Diet?
The Mediterranean Diet is a model based on traditional foods consumed in the basin of the Mediterranean. The diet is typically comprised of:
What Makes The Mediterranean Diet Healthy?
Most of the research on the Mediterranean Diet is from observational or short-term interventional studies. The Cambridge Journal of Public Health published an updated research article in 2014 after collecting a vast number of research studies -inclusive of 4,000,000 subjects- that correlated the adherence to a Mediterranean Diet with specific health outcomes (mortality, cardiovascular disease, and cancer risk).
As a whole, these studies suggest protection against cancer, diabetes, obesity, atherosclerosis, metabolic syndrome, and brain disorders.
The reason the Mediterranean Diet may be protective against these chronic diseases relates to the level of inflammation induced in the body from the food and drinks we consume. The Mediterranean Diet is low in inflammation. This is due to the low consumption of refined starches, sugar, and saturated / trans-fatty acids. In exchange, it is replaced by a greater consumption of protective anti-inflammatory nutrients like antioxidants and fiber from fruits, vegetables, whole grains, and omega-3 fatty acids.
Protection Against Cardiovascular Disease
Several clinical studies have shown the Mediterranean Diet to be protective against diabetes, high blood pressure, high cholesterol, and metabolic syndrome- all risk factors for the development of heart disease. This correlates to drops in cholesterol and blood pressure.
When adherence to a Mediterranean diet is high, the change in these two variables can occur relatively quickly (within 3 months). The overall reduction in inflammation throughout our body takes roughly 1 year to accumulate to maximum effects. The Mediterranean Diet’s effect on cardiovascular disease has a lot to do with the integrity of the inside lining of our blood vessels.
The development of plaques on the inside of our blood vessels (atherosclerosis) begins with activation of our immune system. Our immune cells bind to the inner lining of our blood vessels. Through a series of events, they essentially make our blood vessels “sticky.” This encourages lipids (fat like substance) to build up and form a plaque.
The danger with these plaques is in their ability to stack up and completely block the flow of blood. They can also break off and travel throughout the bloodstream until they get lodged “down the road”. Both of these scenarios are well known to us. This is what causes myocardial infarctions, or heart attacks.
[For those interested in the scientific data, read on. Others- feel free to skip ahead!]
Many of the foods in the Mediterranean Diet have been demonstrated to reduce inflammation in the body. Data from the PEDIMED study (randomized controlled trial), observational studies (N=3,000), the Nurses’ Health Study, and a recent meta-analysis of 17 trials was collected. Inflammatory markers (CRP, IL-6/7/8, ICAM-1 and VCAM-1) were monitored. Here are the results:
- According to the article The Immune Protective Effect of the Mediterranean Diet against Chronic Low-grade Inflammatory Diseases – by authors from the Department of Internal Medicine at the University of Barcelona Spain:
- Greater adherence to the Mediterranean Diet was associated with a ~20% reduction in immune markers compared to those who were the least compliant with maintaining a Mediterranean Diet
- A Western diet (higher intake of red meat, sweets, fries and refined grains) was positively associated with inflammatory markers (CRP, IL-6, E-selectin, ICAM-1 and VCAM-1)
- Adherence to the Mediterranean Diet was associated with improvement in endothelial function (cells lining the inside of blood vessels)
- Within 3 months of transitioning to the Mediterranean Diet, high risk cardiovascular patients were noted to have lower activation of the immune system that affected plaques from developing in their blood vessels
The Mediterranean Diet And Cancer
Based on the high consumption of plant-based foods in the Mediterranean diet, consumption of vitamins and antioxidants is naturally high. These nutrients are key in repairing damaged cells. They also work hard to prevent cancer causing chemicals and toxins (exposed to us from our environment) from stirring up an inflammatory response.
Since the Mediterranean diet is high in olive oil, vegetables, fruits, legumes, and complex carbohydrates, those who consume this diet are receiving lots of phytochemicals such as Vitamin C + E, folate, carotenoids, and polyphenols. These all help battle inflammation in our bodies.
A 2007 study from the World Cancer Research Fund & American Investigation of Cancer Research, Food, Nutrition, and the Prevention of Cancer relates a high consumption of red meat with increased risk of colorectal (intestinal) and gastric (stomach) cancer. Therefore, since the Mediterranean diet is low in red / processed meat consumption, the extrapolation is that consumers of a Mediterranean diet tend to have lower rates of these two types of cancers.
A 2014 updated meta-analysis on the Mediterranean diet from the Cambridge Journal of Public analyzed recent studies over the past three years that expanded beyond Greece and Spain and included Italy and Scandinavian countries with a total of 4,000,000 subjects. They reported that those who were the most adherent to the Mediterranean diet had the highest protection in overall mortality (8% reduction), cardiovascular disease (10%), and cancer (4%) relative to those with the least adherence.
Take Away Points
Unfortunately, there are not a lot of randomized controlled trials that offer strong supporting clinical evidence behind the health claims linked to the consumption of the Mediterranean Diet. There is extensive evidence, however, from very large prospective and epidemiological studies. With that said, consuming a diet rich in fruits, vegetables, and anti-inflammatory nutrients is safe and has been linked with significant health benefits- especially when compared to the Western Diet. The Mediterranean Diet has been proposed to be protective against overall mortality (death), cardiovascular disease, and cancer.
Are there any small changes you could make in your own diet to better align with the Mediterranean diet?
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Casas, Rosa, Emilio Sacanella, and Ramon Estruch. “The Immune Protective Effect of the Mediterranean Diet against Chronic Low-Grade Inflammatory Diseases.” Endocrine, Metabolic & Immune Disorders Drug Targets 14.4 (2016): 245–254. PMC. Web. 7 June 2018.
Sofi F, Macchi C, Abbate R, Gensini GF, Casini A. Mediterranean diet and health status: an updated meta-analysis and a proposal for a literature-based adherence score. Public Health Nutrition. 2014;17(12):2769-2782. doi:10.1017/S1368980013003169.