The Mediterranean diet is one of the most well-known and researched diets out there.
Since there is a lot of research, it can be difficult to make sense of it all, particularly if you’re looking for how a Mediterranean diet can affect a particular condition.
Below we have found a number of studies looking at different conditions and summarise their findings. If you are looking for a specific condition, then use the table of contents below.
What is the Mediterranean Diet?
The Mediterranean diet is based on the traditional eating habits of countries surrounding the Mediterranean Sea in the 1960s. These include countries and regions like Italy, Greece, Spain, France, Morocco, Malta, Turkey, and Israel.
The Mediterranean diet has some basic guidelines, but generally, it focuses on:
- Eating lots of healthy unsaturated fats rather than saturated ones (using olive oil as the main cooking oil)
- High consumption of fruits, vegetables, whole grains, legumes, nuts and seeds
- Eating fatty fish at least twice a week
- Moderate consumption of dairy products
- Limited intake of red meat and regular physical activity.
The Mediterranean diet pyramid below gives a rough idea of what sorts of foods you should eat more or less of:
Benefits of a Mediterranean Diet
For Weight Loss, Obesity and Endomorphs
- A study of 32,000+ people found those that who adhered to a Mediterranean diet long-term were associated with a reduced risk of gaining weight and belly fat over 5 years (1).
- A study of 180 people with metabolic syndrome (a combination of diabetes, high blood pressure and obesity) followed either a Mediterranean diet or low-fat diet for 2.5 years. The Mediterranean diet group lost 8.8 lbs (4 kg) compared with 2.6 lbs (1.2 kg) in the low-fat group (2).
- A protein-enriched Mediterranean diet followed for 8 weeks showed a significant reduction in weight (−16.7%), visceral fat (−27.4%), and fat mass (−28.1%) in men with obesity (3).
- Another short intervention study lasting 6 weeks showed that a reduced-calorie Mediterranean diet was better in reducing body fat mass and preserving fat-free mass compared to high-protein diets in young, sedentary individuals (4).
- A review of 5 studies found that the Mediterranean diet was as effective as a low-carb, low-fat, and American diabetes diet for weight loss. The Mediterranean group lost 22 lbs (10 kg) over 1 year (5).
For Lowering Cholesterol
- The same study found that the ratio of total to HDL (good) fell by 0.38 and 0.26 in the two Mediterranean groups compared to the low-fat diet, suggesting the Mediterranean diet is a better diet overall for having higher good cholesterol to total cholesterol (6).
- A study of 372 people with a high risk of heart disease found levels of LDL (bad) cholesterol decreased in the Mediterranean diet groups and didn’t reach statistical significance in the low-fat group (7).
For Fatty Liver Disease
- A study including 548 people at risk of non-alcohol fatty liver disease found that higher adherence (closely following principles of a Mediterranean diet) was preventative of non-alcohol fatty liver disease (8).
- Another study evaluating the dietary intake of 3,220 adults in Iran found that following a Mediterranean diet seemed connected to a decreased likelihood of non-alcohol fatty liver disease (9).
- The Mediterranean diet may have this protective effect against non-alcohol fatty liver disease due to its proven track record for improving many of the risk factors associated with the condition (10).
- The dietary management of PCOS, which relies on energy restriction and a Mediterranean nutritional approach, is deemed to have a beneficial impact on some reproductive and metabolic parameters, including menstrual regularity, blood pressure, glucose homeostasis, lipid profile and estimates of cardiovascular disease risk (11).
- Another study summarised that the Mediterranean diet should be promoted worldwide as new, safe and original therapy to improve the health of women with PCOS, especially in countries with high rates of obesity and metabolic syndrome (12).
- One study concluded that an optimal calcium intake, according to the recommended daily allowance, and a dietary pattern in the Mediterranean style have proven their efficacy in preventing osteoporosis and maintaining good bone health (13).
- One study found that following the diet saw an equivalent increase in bone density in one part of the body – the femoral neck. This is a particularly sensitive area for osteoporosis as loss of bone in the femoral neck is often the cause of hip fracture, which is common in elderly people with osteoporosis (14).
For the Menopause
- One study found that a traditional Mediterranean diet significantly helped estrogen levels in healthy postmenopausal women (15).
- One study of 8954 perimenopausal women found that higher adherence to a Mediterranean diet was associated with lower overweight and obesity. The occurrence of low to severe problems during perimenopause or postmenopause is positively associated with overweight and obesity (16).
- Another study concluded that adherence to a Mediterranean diet was associated with lower severity of menopausal symptoms in women with obesity (17)
- A cohort study containing 122,810 subjects, greater adherence to the Mediterranean diet was associated with a significant 19% lower risk of diabetes (18).
- One study concluded that the Mediterranean diet was associated with better glycaemic control and cardiovascular risk factors than control diets like a low-fat diet, meaning it could be suitable to manage type 2 diabetes (19).
For Gestational Diabetes
- In a study conducted in 1076 pregnant women from 10 countries, adherence to a MedDiet pattern was associated with a lower incidence of gestational diabetes and better glucose tolerance, even in women without gestational diabetes (20).
- In a study of 4430 women aged 22-44 years old who had gestational diabetes prior, participants who had the highest quartile of Mediterranean diet adherence showed a 40% lower risk of developing type 2 diabetes than those in the lowest quartile (21).
- One study found that greater adherence to a Mediterranean diet was inversely associated with uric acid levels in males but not females (22).
- Another study of 2380 men and women found that those who most closely followed a Mediterranean-style diet had a 70% lower likelihood of having hyperuricemia compared to those who followed it the least (23).
For Insulin Resistance
- One study of the 180 people that participated in the study, 44% of patients in the Mediterranean diet group still had metabolic syndrome, compared with 86% in the control group. Inflammatory markers (hs-CRP, IL-6, IL-7, and IL-18) and insulin resistance also decreased significantly in the Mediterranean diet group (24).
- Another study 584 patients with one or more cardiovascular risk factors such as type 2 diabetes, hypertension and overweight/obesity concluded that a good adherence to Med-Diet was associated with lower insulin resistance (25).
For Rheumatoid Arthritis
- One study found that the group eating a Mediterranean diet had a significant improvement in RA disease activity (reduced joint inflammation) after 12 weeks on the diet (26).
For Heart Disease and Cardiovascular Disease
- In a study 7447 people at risk of heart disease, the risk of combined heart attack, stroke, and death from heart disease were between 28-31% lower in the Mediterranean groups (27).
- Another study found that eating a Mediterranean diet was associated with an adjusted 23% rate reduction in the risk of developing acute coronary syndrome, a condition of a heart attack (28).
- One study suggested an average reduced risk of 40% for coronary heart disease, myocardial infarction, and stroke incidence for those with higher adherence to the Mediterranean diet (29).
- Similarly, another study observed that following the Mediterranean diet and eating 1 ounce (30 grams) of mixed nuts daily for a year reduced the prevalence of metabolic syndrome by nearly 14% (30).
For Cancer Prevention
- One study found that Mediterranean diets may help reduce decrease of breast cancer incidence due to regular fiber intake, antioxidants, flavonoids, vitamins and carotenoids. This is able to reduce estrogens and increase the level of sex hormones and therefore neutralize free radicals, protect from DNA damage, and reduce oxidative stress (31).
- One study found that A higher adherence to MD was able to reduce of about 30% and 45% CRC risk in men and in women respectively (32).
- High adherence to a Mediterranean diet was inversely associated with a low incidence of prostate cancer, but also it was associated with lower cancer malignancy (33).
- Some studies have been more concentrated to demonstrate how erroneous lifestyles and diet patterns (e.g., smoking, excessive alcohol assumption and low adherence to a Mediterranean diet) increased the pancreatic cancer risk. There was a positive association between a low intake of fruit and vegetable and high consumption of red meat and pancreatic risk (34).
For High Blood Pressure
- One study of 166 people found those who consumed a Mediterranean diet for 6 months had a small but significantly lower systolic blood pressure compared to those who maintained their habitual diet and improved endothelial function (35).
- In a study of 772 participants, systolic blood pressure fell by 5.9 mmHG and 7.1 mmHG in the two Mediterranean diet groups compared to a low-fat diet (36).
- One meta-analysis investigated the effects of different dietary patterns and concluded that a MedDiet lowers systolic BP by 3 mm Hg and diastolic BP by 2 mm Hg (37).
For Brain Health
- One study in 2015 following 583 older men and women with a high risk of cardiovascular disease. It found those assigned to a Mediterranean diet supplemented with nuts or olive oil showed less cognitive decline (38).
- Another study concluded that a high adherence to the Mediterranean diet was associated with slower cognitive decline (39).
For Hormonal Health
- One study concluded that the long-term consumption of plant-rich diets (such as the Mediterranean diet) with restricted caloric intake has been associated with richer and more phylogenetic diverse fecal microbiota (40).
- Higher adherence to a Mediterranean diet was associated with higher levels of adiponectin and lower levels of leptin, TNF-α, PAI-1 and hs-CRP in adults (41).
- Another study concluded that eating a Mediterranean diet even in the absence of weight loss significantly reduced inflammation (42).
- Another study suggested the Mediterranean diet has some protective effec against mild chronic inflammation and its metabolic complications (43).
- The biomarker was CRP with 10 of 13 analyses reporting an inverse association between the Mediterranean diet and CRP indicating less inflammation (44).
- In one study of women, those who adhered most closely to a Mediterranean diet containing lots of vegetables, fish, and polyunsaturated oils, had 44% lower odds of seeking medical help for difficulty getting pregnant compared to women in the lowest quartile (45).
- Another study found those following a Mediterranean diet more closely had a higher likelihood of achieving clinical pregnancy and live birth among non-obese women under 35 years of age (46).
- In men, being overweight can cause a reduced sperm count. One study found that overweight men were 11% more likely to have a low sperm count and 39% more likely to have no sperm when they ejaculate. For obese men, this jumped to 42% more likely to have a low sperm count and 81% more likely to produce no sperm (47).
- Another study of 225 men found that those most closely followed a Mediterranean diet had higher sperm concentrations and total sperm counts (48).
For Anxiety and Depression
- a 12-week nutritional trial carried out in 149 individuals with severe obesity (BMI > 35 Kg/m2) showed that daily consumption of extra virgin olive oil (52ml/day) significantly reduced depression and anxiety (49).
- One study found those who followed a Mediterranean diet closely, specifically eating lots of vegetables but less poultry and alcohol, had a lower likelihood of developing depression or symptoms associated with depression (50).
- Another study found that high consumption of polyphenols (which are found in foods common within the Mediterranean diet such as fruits, vegetables, whole grains, nuts, seeds, and legumes) is associated with decreased prevalence of depression (51).