Brigham and Women’s Hospital researchers reveal long-term benefits of the Mediterranean diet, linking it to significant reductions in mortality among U.S. Women through positive metabolic and inflammation changes

Researchers at Brigham and Women’s Hospital have explored why the Mediterranean diet reduces the risk of death by 23% among American women. Their landmark 25-year study reveals that this diet, rich in plant-based foods and healthy fats, leads to beneficial changes in metabolism and inflammation markers, improving public health outcomes.

The health benefits of the Mediterranean diet have been documented in many studies, but long-term data on its effects on U.S. women have been limited. This new study followed more than 25,000 initially healthy American women for up to 25 years. Researchers discovered that those with higher Mediterranean diet adherence had up to a 23% lower risk of all-cause mortality, showing benefits for cancer and cardiovascular mortality.

Senior author Dr. Samia Mora, a cardiologist and director of the Center for Lipid Metabolomics at Brigham, emphasized the study’s significance. She stated, “For women who want to live longer, our study says watch your diet! Following a Mediterranean dietary pattern could result in about one-quarter reduction in risk of death over more than 25 years with benefits for both cancer and cardiovascular mortality, the top causes of death in women (and men) in the US and globally.”

The Mediterranean diet includes a diverse array of plant-based foods such as nuts, seeds, fruits, vegetables, whole grains, and legumes. Olive oil serves as the primary fat source. The diet also incorporates moderate amounts of fish, poultry, dairy, eggs, and alcohol, with minimal consumption of meats, sweets, and processed foods.

This study evaluated the long-term benefits of adherence to a Mediterranean diet in a U.S. population recruited as part of the Women’s Health Study. Researchers explored the biological mechanisms underlying the diet’s health benefits. They analyzed approximately 40 biomarkers representing various biological pathways and clinical risk factors.

Changes in biomarkers of metabolism and inflammation were the most significant contributors to the observed benefits. Other factors included triglyceride-rich lipoproteins, adiposity, and insulin resistance. Smaller contributions came from pathways related to branched-chain amino acids, high-density lipoproteins, low-density lipoproteins, glycemic measures, and hypertension.

Lead author Dr. Shafqat Ahmad, an associate professor of Epidemiology at Uppsala University, Sweden, highlighted the public health implications of their findings. “Even modest changes in established risk factors for metabolic diseases—particularly those linked to small molecule metabolites, inflammation, triglyceride-rich lipoproteins, obesity, and insulin resistance—can yield substantial long-term benefits from following a Mediterranean diet. This underscores the potential of encouraging healthier dietary habits to reduce the overall risk of mortality.”

However, the study had limitations, including its focus on middle-aged and older well-educated female health professionals who were predominantly non-Hispanic and white. The reliance on self-reported measures such as food-frequency questionnaires, height, weight, and blood pressure also posed potential biases. Despite these limitations, the study’s large scale and long follow-up period provided robust insights.

The Mediterranean diet’s global popularity has led to various adaptations across different cultures. Dr. Mora noted, “Public health policies should promote the healthful dietary attributes of the Mediterranean diet and discourage unhealthy adaptations. Our study offers insights into why the diet may be so beneficial.”

The study, titled “Mediterranean Diet Adherence and Risk of All-Cause Mortality in Women,” was published in JAMA Network Open on May 31, 2024. The research was supported by various grants from the NIH and Swedish Research Council, among others. LabCorp provided LipoProfile IV results at no additional cost.

Analysis: 

This landmark study highlights the Mediterranean diet’s significant potential to improve public health outcomes. From a political perspective, the findings could influence health policies and dietary guidelines, encouraging governments to promote healthier eating habits. By highlighting the Mediterranean diet’s benefits, policymakers can develop programs and incentives to make such diets more accessible, especially to lower-income populations.

Sociologically, the study underscores the importance of cultural dietary practices. The Mediterranean diet, rooted in traditional eating habits of Mediterranean countries, contrasts with typical Western diets high in processed foods and unhealthy fats. Promoting such traditional, plant-based diets can encourage communities to reconnect with cultural heritage while improving health outcomes.

Economically, the findings suggest potential healthcare cost savings by reducing the incidence of chronic diseases such as cancer and cardiovascular conditions. A shift towards Mediterranean dietary habits could decrease healthcare expenses associated with treating these diseases, benefiting both individuals and healthcare systems.

Locally, communities can leverage these findings to promote urban gardening, farmers’ markets, and local produce consumption. These initiatives can make Mediterranean diet staples more readily available, fostering healthier communities. Additionally, public health campaigns can focus on educating residents about the diet’s benefits, making healthier choices more mainstream.

Gender-specific insights reveal that women, the primary focus of the study, stand to gain significantly from the Mediterranean diet. Given that women often make dietary choices for their families, promoting this diet among women could have a multiplier effect, improving health outcomes for entire households.

From a race and minority perspective, the study’s limitations highlight the need for more diverse research. Future studies should include varied racial and ethnic groups to understand the diet’s benefits across different populations fully. Ensuring inclusivity in dietary research can lead to more tailored and effective public health strategies.

Theoretical perspectives such as health behaviour theory can help explain the diet’s impact. By understanding the cognitive and social factors influencing dietary habits, public health initiatives can better design interventions to promote the Mediterranean diet. For example, social support and community-based programs can play crucial roles in encouraging dietary changes.

In conclusion, the Mediterranean diet’s long-term benefits, as evidenced by this comprehensive study, offer valuable insights for improving public health. By considering political, sociological, economic, local, gender, and minority perspectives, stakeholders can develop holistic strategies to promote healthier eating habits and reduce mortality rates.