The widely revered Mediterranean diet has remained a favorite among dietitians and experts for decades. Often called the MedDiet for short, this healthful way of eating emphasizes fruits, vegetables, whole grains, legumes, seafood, and healthy fats like olive oil.
It has been linked to a number of benefits including boosting heart health and preventing cognitive decline, TODAY reported previously.
Now, there's even stronger evidence that following a Mediterranean diet is associated with a lower risk of developing Type 2 diabetes. The findings were published in the journal PLOS Medicine on Thursday, Apr. 27.
Previous studies have shown that people who adhere closely to a Mediterranean diet have a moderately lower risk of developing Type 2 diabetes, but these relied on subjective reporting, Dr. Nita Forouhi, study co-author and leader of the nutritional epidemiology program at the University of Cambridge, tells TODAY.com.
This means study participants self-report their diet habits in a questionnaire, for example. "Self-reports are prone to reporting errors, and these errors can give rise to biased estimates of associations between diet and future disease risk," Forouhi says.
A team of researchers at University of Cambridge overcame this limitation by developing a new way to objectively measure how closely a person follows the Mediterranean diet using a blood test.
The blood test looked at levels of molecules like carotenoids and fatty acids, or "biomarkers" of the Mediterranean diet. A total of 23 nutritional biomarkers were combined into an overall score, says Forouhi, which measured a person's level of adherence to the Mediterranean diet instead.
The biomarker score was applied in a study of over 22,000 people across eight countries in Europe, says Forouhi. Using this method, researchers found that people whose biomarker score indicated they stuck to a Mediterranean diet were less likely to develop Type 2 diabetes, she adds.
"The 20% of participants with the highest biomarker score had a 62% lower risk of new-onset Type 2 diabetes relative to the 20% of participants with the lowest biomarker score values," says Forouhi.
Based on these findings, the researchers argue that even a small improvement in people’s adherence to a Mediterranean diet could meaningfully reduce the incidence of Type 2 diabetes.
"Our research strengthens the case for recommending the Mediterranean diet for the prevention of Type 2 diabetes," says Forouhi, adding that there were limitations to this study.
"The study does not allow us to draw conclusions as strong as to say that the Mediterranean diet is a causal factor in lowering the risk of type 2 diabetes," Forouhi says.
However, the research underscores the importance of the diet as a part of one's prevention strategy and supports the use of blood-based biomarkers to pick up associations that may be underestimated when using only self-reporting, Forouhi says.
"Type 2 diabetes can occur due to a combination and varying degrees of insulin resistance and defective insulin secretion," Dr. Priya Jaisinghani, endocrinologist and obesity medicine specialist at NYU Langone Health, tells TODAY.com. There are many environmental factors (including inactivity, weight or medications) and genetic factors that can contribute to Type 2 diabetes, Jaisinghani adds.
“Along with medication therapy and lifestyle changes, nutrition is a cornerstone of treatment of Type 2 diabetes,” says Jaisinghani. If it is not managed, Type 2 diabetes can increase the risk of other problems such as stroke, kidney disease, nerve damage and vision problems, Jaisinghani adds.
"It’s important to see your doctor and nutritionist to create an individualized plan when treating Type 2 diabetes," says Jaisinghani, adding that the Mediterranean diet might need to be tailored to other health conditions such as high blood pressure.
The Mediterranean diet is less about dieting and more about eating whole foods you already love, which makes it accessible and sustainable, TODAY previously reported. While there aren’t strict rules, the Med diet does minimize meat, dairy, and processed foods.
"It's packed with fiber-rich plant foods and doesn’t include many processed sweets, which is helpful for reducing insulin resistance," Frances Largeman-Roth, registered dietitian nutritionist, tells TODAY.com. "That is beneficial for blood sugar management and lowering A1C levels, which measures your average blood sugar levels over the last 3 months," says Largeman-Roth.
Low levels of HDL, the good cholesterol, are associated with increased risk of developing Type 2 diabetes, Largeman-Roth notes. The MedDiet helps increase good cholesterol levels, she adds, which is why it's a great choice for anyone.
In addition to plant-based whole foods, other mainstays of this diet include omega-3 rich fatty fish (salmon, tuna, sardines, black cod) and walnuts. "Those foods provide anti-inflammatory benefits, decrease blood pressure, and reduce the risk of heart disease," Largeman-Roth.
In addition to following a Mediterranean diet, Largeman-Roth recommends trying to eat a wide variety of fruits and vegetables, getting enough fiber (25-35mg per day), and trying to stay physically active and move every day.