Does the Mediterranean diet really improve longevity?
Advocates of the Mediterranean diet have long celebrated it for its health benefits, linking it to improved immune function, a lower risk of chronic diseases and reduced inflammation.
So, what does this diet consist of and can it, in fact, boost life expectancy?
What is the Mediterranean diet?
The Mediterranean diet is a diet consisting of foods grown in the countries surrounding the Mediterranean Sea. These include Spain, Greece, Italy and France.
The Mediterranean diet is a diverse, plant-based plan, rich in fruits, vegetables, nuts, seeds, wholegrains and legumes. There is a moderate intake of fish, poultry, dairy, eggs, and alcohol. There is also the occasional consumption of meats, sweets, and processed foods. The main fat is olive oil.
Does the Mediterranean diet help you live longer?
A new study, carried out by researchers at Brigham and Women’s Hospital in the US state of Massachusetts, has sought to determine if adopting the Mediterranean diet could boost life expectancy, and the potential reasons for this.
The study, published in the medical journal JAMA, followed the diets of more than 25,000 women over a period of 25 years. All participants were categorised as healthy at the beginning of the study.
The research team found that participants who subscribed to the Mediterranean diet had up to 23% lower risk of all-cause mortality, with benefits for both cancer mortality and cardiovascular mortality.
Furthermore, the researchers found evidence of biological changes that may help explain why they detected changes in biomarkers of metabolism, inflammation, insulin resistance, and more.
“For women who want to live longer, our study says watch your diet,” says Samia Mora, MD, a cardiologist and the director of the Center for Lipid Metabolomics at the Brigham and Women’s Hospital. “The good news is that following a Mediterranean dietary pattern could result in about one quarter reduction in risk of death over more than 25 years with benefit for both cancer and cardiovascular mortality, the top causes of death in women (and men) in the US and globally.”
The study investigated the long-term benefits of adherence to the Mediterranean diet as part of the Women’s Health Study and explored the biological mechanisms, which may explain the diet’s health benefits. The study investigators evaluated a panel of approximately 40 biomarkers representing various biological pathways and clinical risk factors.
What is the Women’s Health Study?
The Women's Health Study (WHS) at Brigham and Women's Hospital and Harvard Medical School is a landmark trial, which began in 1993. It’s original aim was to test the benefits and risks of low-dose aspirin and vitamin E in the primary prevention of cardiovascular disease and cancer in 39,876 US women. The trial ended in 2004, however, the female health professionals who took part, continue to help advance knowledge on the prevention of cardiovascular disease, cancer, and other chronic diseases in women, by completing annual study questionnaires. The Women's Health Study has published over 700 research reports.
Biomarkers of metabolism and inflammation made the largest contribution, followed by triglyceride-rich lipoproteins, adiposity, insulin resistance. Other biological pathways relate to branched-chain amino acids, high-density lipoproteins, low-density lipoproteins, glycemic measures, and hypertension have smaller contribution.
“Our research provides significant public health insight: 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,” says Shafqat Ahmad, associate professor of Epidemiology at Uppsala University Sweden and a researcher in the Center for Lipid Metabolomics and the Division of Preventive Medicine at the Brigham. “This finding underscores the potential of encouraging healthier dietary habits to reduce the overall risk of mortality.”
The study identified important biological pathways, which may help to explain all-cause mortality risk. However, the authors note that there are key limitations to the study, including the fact that the majority of participants were middle-aged or older, non-Hispanic and white women. They were also well-educated health professionals, which could lead to informed dietary decisions and fast identification of any symptoms of poor health.
The study also relied on food-frequency questionnaires and other self-reported measures, such as height, weight, and blood pressure, which could lead to inaccuracies.
Source: Mediterranean Diet Adherence and Risk of All-Cause Mortality in Women
Published online: 31 May 2024
DOI: https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2819335
Authors: Shafqat Ahmad, M. Vinayaga Moorthy, I-Min Lee et al.
