Wellness Read: A Deep Dive into the Popular Mediterranean Diet

With the constant influx of new diets, detoxes, and supplements in the media, there is often confusion around the optimal way to eat for health. The Mediterranean Diet is a well-known, but often misunderstood, dietary pattern. Unlike many diets that are predicated on misleading information and bad science, the Mediterranean Diet is well-researched and recommended by numerous medical and nutrition professionals and groups. For this month’s Wellness Read, we explain what it is, what the research says regarding its impact on health, and how to implement it in your life.

What is the Mediterranean Diet and where did it come from?

Interest in the Mediterranean Diet started in the 1960s when researchers observed lower incidences of cardiovascular disease in Mediterranean-surrounding countries.¹ There is no exact definition of the Mediterranean Diet, but the components typically include:

• Daily intake of fruits, vegetables, whole grains, and heart healthy fats (mainly extra-virgin olive oil, fatty fish, nuts, and seeds)
• Weekly intake of fish, poultry, legumes, eggs, and low-fat dairy
• Limited intake of red meat
• Moderate consumption of red wine*

Research also shows that lifestyle factors, in addition to the Mediterranean Diet, play a role in producing positive health benefits. These include eating locally, feeling part of a community, eating slowly, and being physically active.⁴. The Mediterranean Diet and Lifestyle pyramid shown here is a great representation of how these components come together.

*A Note on Red Wine and the Mediterranean Diet

Traditionally, red wine is included as a core component of the Mediterranean Diet. In the media, red wine is touted as an antioxidant powerhouse due to its bioactive polyphenol content (an antioxidant that is considered anti-inflammatory).² However, when looking at how well these bioactive components translate to health outcomes, the research is unclear. Some studies have shown cardioprotective effects with moderate consumption (~5 ounces/day) of red wine.³ Other studies have shown an association between alcohol intake and increased risk of certain cancers and other diseases.² Additionally, red wine is not the only source of polyphenols. Other foods contain higher levels of phenolic compounds and do not have the same deleterious effects. Due to discrepancies in the research and the public’s misunderstanding of alcohol’s role in cardiovascular health, many researchers choose to exclude it as a major healthful component of the Mediterranean Diet. In general, the consensus among researchers is moderate consumption could be beneficial, but we should not encourage individuals to increase alcohol intake for perceived health benefit due to possible negative health outcomes.²

Evidence-Based Health Outcomes of the Mediterranean Diet

The 2020-2025 Dietary Guidelines for Americans report recommends the Mediterranean Diet to promote cardiovascular health and to prevent heart disease. The World Health Organization acknowledges the Mediterranean Diet as a healthy and sustainable dietary pattern.¹ This high-level praise is based on extensive research and evidence of this dietary pattern’s success in reducing cardiovascular disease risk and improving metrics in metabolic diseases. The body of literature is notably robust due to the rigorous and consistent methodology used across studies. For example, researchers study the Mediterranean Diet as a “dietary pattern” (i.e., investigate the quantity, variety, and overall combination of foods), as opposed to studying the individual foods. Studies that explore the overall quality of a whole food pattern provide more informative and useful information for making clinical recommendations than studies focused on single nutrients.² Nutrition studies of dietary patterns also limit confounding (variations in dietary factors between individuals that are not accounted for in a single nutrient study), provide a realistic application of nutrition, offer useful sociological information, and reveal additive and synergistic effects of nutrients.²

Recommendations regarding the Mediterranean Diet were primarily determined based on two large experimental studies (PREDIMED⁵, Lyon Heart Study⁶). In addition, researchers use smaller experimental studies and observational cohort studies when publishing meta-analyses and drawing conclusions. We reviewed several of these prominent studies and summarized the overarching conclusions below:

• Some studies support lower total mortality in those who follow a Mediterranean Diet while others yield no statistically significant conclusions. The Lyon Heart Study⁶ enrolled ~600 participants with previous cardiac events, separating them into a Mediterranean diet or Western-style diet group. After four years of follow-up, results showed that participants in the Mediterranean-diet group had a 45.4% reduced risk of all-cause mortality when compared to the participants following a Western-style diet.
• A reduced risk of cardiovascular-related deaths is consistent across the research. Studies show a reduced risk of death from heart disease (70%),⁶ a reduced risk of heart attack in individuals who have heart disease (50-75%),⁶ and a reduced risk of stroke⁵ (39%) in participants who followed the Mediterranean Diet.
• A Mediterranean diet may improve metabolic syndrome, specifically with improved blood sugar management and reduced risk of diabetes. One study showed a 52% reduced risk of developing Type 2 Diabetes,^5,7 as well as reduced insulin resistance,⁸ improvement in blood glucose and insulin levels,⁷ and a delay in the need for medication in patients with newly diagnosed Type 2 Diabetes.⁹
• While not promoted as a weight loss strategy, the Mediterranean Diet can lead to significant and long-term weight loss.^7-9
• Adopting the Mediterranean Diet may contribute to the reduction of cancer onset.¹⁰ A recent meta-analysis revealed an inverse association of adherence to a Mediterranean Diet with cancer mortality and risk of colorectal cancer.¹¹
• Newer data suggest potential mental health benefits, including improvement of depressive symptoms and remission rates of depression.¹² Some research indicates 32-40% reduced risk of developing Alzheimer’s.¹³ Note: More research is needed to make conclusions or offer clinical recommendations regarding these relationships.

The Mediterranean Diet has undergone a more comprehensive, repeated, and international assessment of its health outcomes, especially those related to cardiovascular effects than any other dietary pattern. Research demonstrates that it can be tailored to individual health conditions as well as food and cultural preferences, which makes it flexible, easy to follow, and optimal for application to many populations.

Putting the Mediterranean Diet into Practice

Unlike other diets, the Mediterranean Diet is neither based on strict rules nor does it restrict any one food or food group. Given the dose-response relationships observed in the research, beneficial outcomes occur across a spectrum of adherence levels. We recommend taking an additive approach when adopting a new dietary pattern: focus on adding in beneficial foods as opposed to avoiding “bad” foods. See our five strategies for incorporating the Mediterranean Diet below.

1. Add 1-2 additional servings of fruit/vegetables to your day.
2. Eat 1 serving nuts/seeds each day and use extra-virgin olive oil when cooking/preparing food rather than butter.
3. Include a quality protein (fish, legumes, poultry) at each meal
4. Eat whole grains, beans, lentils, and/or starchy vegetables instead of processed carbohydrates
5. Keep alcohol intake moderate.

As health experts, we take responsibility for presenting our Members with evidence-based information that addresses questions and provides education on current, relevant, and, importantly, often confusing health topics. The Mediterranean Diet is a well-researched, flexible, and sustainable dietary pattern. Incorporating more aspects of the Mediterranean Diet into your diet can be beneficial to your health, especially with respect to metabolic and heart health.

Contact your SHIFT Registered Dietitian for more information and to determine if the Mediterranean Diet is right for you.

In good health,

Lauren Hoover & Tavierney Rogan

Reference List

1. Mayo Clinic Staff. Mediterranean diet: A heart-healthy eating plan. Mayo Clinic. Published June 21, 2019. https://www.mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-eating/in-depth/mediterranean-diet/art-20047801.
2. Martinez-Gonzalez, MA., et al. The Mediterranean diet and cardiovascular health: A critical review. Circulation, 2019; 124:779-798. https://www.ahajournals.org/doi/10.1161/CIRCRESAHA.118.313348
3. Weaver, S., et al. Fine wine or sour grapes? A systematic review and meta-analysis of the impact of red wine polyphenols on vascular health. Eur J Nutr, 2021; 60(1):1-28. https://pubmed.ncbi.nlm.nih.gov/32303823/.
4. Boxterman, J. The Mediterranean diet: your complete how-to guide. Precision Nutrition. https://www.precisionnutrition.com/mediterranean-diet-food-list
5. Estruch, R., et al. Primary Prevention of Cardiovascular Disease with a Mediterranean Diet. N Engl J Med, 2013; 368:1279-1290. https://www.nejm.org/doi/full/10.1056/NEJMoa1200303.
6. Kris-Etherton Penny, Eckel Robert H., Howard Barbara V., St. Jeor Sachiko, and Bazzarre Terry L. 2001. “Lyon Diet Heart Study.” Circulation103 (13): 1823–25. https://www.ahajournals.org/doi/full/10.1161/01.CIR.103.13.1823
7. Shai, I., et al. Weight Loss with a Low-Carbohydrate, Mediterranean, or Low-Fat Diet. New Eng J Med, 2008; 359:229-241. https://www.nejm.org/doi/full/10.1056/NEJMoa0708681.
8. Esposito, K., et al. Effect of a Mediterranean-Style Diet on Endothelial Dysfunction and Markers of Vascular Inflammation in the Metabolic Syndrome: A Randomized Trial. JAMA, 2004; 292(12):1440-1446. https://jamanetwork.com/journals/jama/fullarticle/199488
9. Esposito, K., et al. Effects of a Mediterranean Diet on the need for antihyperglycemic drug therapy in patients with newly diagnosed type 2 diabetes. Ann Intern Med, 2009; 151(5):306-14. https://pubmed.ncbi.nlm.nih.gov/19721018/.
10. Mantella, M, et al. Cancer and Mediterranean Diet: A review. Nutrients, 2019; 11(9):2059. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6770822/.
11. Schwingshackl, L., et al. Adherence to Mediterranean diet and risk of cancer: An updated systematic review and meta-analysis. Nutrients, 2017; 9(10):1063. https://pubmed.ncbi.nlm.nih.gov/28954418/.
12. Ventriglio, A., et al. Mediterranean diet and its benefits on health and mental health: A literature review. Clinical Practice & Epidemiology in Mental Health, 2020; 16(1):156-164. https://benthamopen.com/FULLTEXT/CPEMH-16-156.
13. Scarmeas, N, et al. Physical activity, diet, and risk of Alzheimer disease. JAMA, 2009; 302(6):627-37. https://pubmed.ncbi.nlm.nih.gov/19671904/.