The Mediterranean diet
The Mediterranean diet is one of the most studied and well-known dietary patterns in the world. Registered dietitian Rebecca Deeley looks at the benefits and mechanisms that make this diet so important.
Extensive research has shown that the Mediterranean diet supports a wide range of health benefits, namely:
- Reduction in risk of cardiovascular disease (1), (5)
- Reduced risk of type 2 diabetes (1)
- Reduced risk of neurodegenerative disorders, especially Alzheimer’s disease. (4), (6)
- Improvement in Cognitive health and function (1), (6)
- Reduced risk of Cancers e.g. prostate, breast and colon (8), (7)
What makes the diet unique?
The Mediterranean diet is a dietary pattern characterized by the plentiful consumption of plant based foods such as vegetables, whole grains, legumes and seeds with a moderate intake of dairy products. It is primarily a plant-based diet, however does allow for some fish and poultry with infrequent use of red meat. The diet provides a good intake of fibre, unsaturated fats, antioxidants, polyphenols, vitamins and minerals including choline, vitamin C, potassium, B-vitamins, vitamin D from fish in addition to high levels of protein. It is distinctive from other healthy diet patterns due to the use of olive oil, especially extra virgin olive oil, as the predominant fat source and key ingredient within the diet.
There is exciting new evidence emerging for further suggested health benefits, for example the Med diet has been shown to benefit the neurodevelopment of babies if consumed during pregnancy.
It’s been suggested as a potential source of helping to lower menopause symptoms and could be an ideal holistic and diet proposition in future for the management of menopause.
The Med diet is also linked to better metabolic health - a recent study indicated the diet may have similar health benefits to physical activity, one of the study’s compared it’s health benefits to doing 4,000 extra steps a day!
But how does it work to support better health outcomes?
There are a number of Mechanisms thought to be behind the health benefits:
Lowering lipids
- Protection against oxidative stress and inflammation (2), (3)
- Modifying hormone and growth factors involved in cancer pathologies
- Influencing the gut microbiome
- Improved glycaemic control
- Prevention and potential to counteract DNA damages due to antioxidants and anti-inflammatory components within the diet which is particularly important for cancer patients.
There are also environmental benefits
The core of the Mediterranean diet focuses on foods which support the EAT-lancet commission to encourage health and environmentally sustainable living for the global population by 2050.
The diet boasts relatively low environmental impact – water, nitrogen and carbon footprint which is an additional advantage on top of the numerous health benefits.
The well-known benefits of the Mediterranean diet against certain diseases
Cognition and neurodegenerative disorders
Individuals who ate a Mediterranean-like diet had up to 23% lower risk for dementia than those who did not. (4).
This study was one of the biggest of its kind and provided weight to the fact that following this diet may help to reduce the risk of neurodegenerative disorder development in later life. Even for those with higher genetic risk, having a better diet reduced the likelihood of developing dementia.
Another study (6) , also published in March 2023, which looked at postmortem Alzheimer’s pathology, found that those who had followed a Mediterranean or MIND diet, particularly one rich in leafy greens, had a much lower beta-amyloid load. Beta-amyloid is thought to be responsible for many of the symptoms of Alzheimer’s disease.
Cardiovascular health, hypertension and dyslipidaemia
Recent studies (1) have provided strong evidence for the benefits of the Mediterranean diet on cardiovascular health. This includes a decline in the incidence of cardiovascular disease, in addition to reducing the prevalence of including obesity, hypertension, metabolic syndrome, and dyslipidaemia.
A meta-analysis of several studies from 2003 – 2021, published in March 2023, with a sample of more than 700,000 female participants, found that, by closely following a Mediterranean diet, women reduced their risk of CVD by 24%, and their risk of death from any cause by 23% (5).
Anti - Inflammatory diet & immune system
The Mediterranean diet has shown benefits in relation to the development of inflammatory diseases. Several clinical, epidemiological and experimental studies suggest that consumption of the Mediterranean diet reduces the incidence of certain pathologies related to oxidative stress, chronic inflammation and immune system diseases. (2)
Research from a 2016 review (3) summarised evidence relating to the beneficial effects of extra virgin olive oil and its benefit on immune-inflammatory diseases such as rheumatoid arthritis, systemic lupus erythematosus, inflammatory bowel disease and sclerosis.
The ratio of fats recommended in addition to the consumption of wholegrains, fruit and vegetables can lead to anti-inflammatory changes in the body, this is due to the variety within the diet in addition to the beneficial effects of unsaturated fats.
Cancer
Given its protective effects in reducing oxidative and inflammatory processes of cells and avoiding DNA damages, cell proliferation, and their survival, inflammations and metastasis, the Mediterranean diet is considered a powerful and manageable method to fight cancer incidence.
Dietary patterns based on regular intake of fruit, vegetables rich in selenium, folic acid, vitamins (B-12 or D), and antioxidants (e.g., carotenoids and lycopene) play a significant role in the onset of cancers.
A potential risk reduction of protective role in the onset of breast cancer, colorectal cancer and prostate cancer of 60–70% and of lung cancer - 40–50%. (8)
A high intake of products rich in fibre and a moderate intake of milk and dairy may reduce the incidence of different types of cancer (e.g., colorectal cancer, lung cancer, stomach cancer, breast cancer, colorectal cancer, oesophagus cancer and oral cancers).
The Mediterranean diet may be beneficial for men with localised prostate cancer on active surveillance because of its anti-inflammatory, antilipidemic, and chemo preventive properties.(7)
Observational studies indicate that men who follow the med diet are less likely to develop prostate cancer overall and aggressive prostate cancer. Limited evidence also suggests that overall survival may be improved in men who adhere to the diet after their diagnosis.
In summary
The Mediterranean diet has been associated with cardiovascular health for many years, yet it’s impact on other areas of the body and many health conditions is now being recognised. It is now one of the most widely studied diets and adherence to its main principles can help to prevent the main public health issues, many clinical conditions and provide a more sustainable way of living.
