In 2022, the number of people living with diabetes was 830 million globally, according to the World Health Organization (WHO). 95% of these have type 2 diabetes (T2D). A chronic metabolic disease, type 2 diabetes can cause serious damage to the heart, blood vessels, eyes, kidneys, and nerves, over time. Early diagnosis is crucial to prevent the worst effects of T2D. Lifestyle factors such as diet and exercise play a key role in preventing and controlling T2D. A new study has now found that a particular diet combined with some lifestyle changes can significantly reduce the risk of T2D.
A recent study led by researchers at Harvard T.H. Chan School of Public Health found that a certain diet combined with calorie reduction and exercise may reduce the risk of type 2 diabetes by nearly one-third. The findings of the study are published in the Annals of Internal Medicine.
A diet that can lower the risk of T2D
Type 2 diabetes is a chronic metabolic condition where the body either doesn't produce enough insulin or the cells don't respond properly to the insulin produced, leading to elevated blood sugar levels. According to the Harvard T.H. Chan School of Public Health researchers, a Mediterranean diet, in combination with reduced caloric intake, moderate physical activity, and professional support for weight loss, may cut the risk of type 2 diabetes (T2D) by 31%.
“We’re facing a global epidemic of diabetes. With the highest-level evidence, our study shows that modest, sustained changes in diet and lifestyle could prevent millions of cases of this disease worldwide,” co-author Frank Hu, Fredrick J. Stare Professor of Nutrition and Epidemiology and chair of the Department of Nutrition, said in a statement.
Previous research has also linked the Mediterranean diet, rich in fruits, vegetables, whole grains, and healthy fats, moderate intake of dairy and lean proteins, and little to no intake of red meat, to better health outcomes, including lowered risk of T2D through improved insulin sensitivity and reduced inflammation.
The study
To understand how a Mediterranean diet can lower the risk of T2D, researchers from 23 Spanish universities and Harvard Chan School studied 4,746 people in the PREDIMED-Plus trial for six years. The participants were aged 55–75, overweight or obese, and had metabolic syndrome, but no type 2 diabetes at the start. The study aimed to understand how the diet’s benefits may be enhanced with additional healthy lifestyle changes. The participants were divided into an intervention group and a control group. The intervention group followed a Mediterranean diet; reduced their caloric intake by about 600 calories per day; engaged in moderate physical activity, such as brisk walking and strength and balance exercises; and received professional support for weight loss control. The control group stuck to a Mediterranean diet without calorie restriction, exercise guidance, or professional support.
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The findings
The researchers found that those in the intervention group had a 31% lower risk of developing T2D compared to those in the control group. Also, the intervention group lost an average of 3.3 kilograms and reduced their waist circumference by 3.6 centimeters, compared to 0.6 kilograms and 0.3 centimeters in the control group.
“In practical terms, adding calorie control and physical activity to the Mediterranean diet prevented around three out of every 100 people from developing diabetes—a clear, measurable benefit for public health,” co-author Miguel Martínez-González, professor at the University of Navarra and adjunct professor of nutrition at Harvard Chan School, said.