Leafy green vegetables are often cited as part of a healthy diet and numerous other studies have suggested that eating them to reduce the risk of developing Type 2 diabetes.
That’s why researchers in Singapore decided to investigate how eating leafy green vegetables may affect the risk of developing Type 2 diabetes in a large population study.
The Singapore Chinese Health Study looked at the effects of diet, environment, and genetics on the development of cancer and chronic disease in Singapore. Over 63,000 Chinese individuals (between the ages of 45-74 years) were enrolled in the study between 1993 and 1998. Follow-up interviews were conducted into 2010.
The researchers looked at a subgroup of the study population excluding those who had diabetes or had a very high or low-calorie intake, or who did not respond to follow-up. Over 45,400 subjects were included in an analysis investigating the consumption of green leafy vegetables and the development of Type 2 diabetes.
In comparing 5,200 cases, researchers found neither total vegetables or leafy green vegetable consumption was associated with a significantly reduced risk of developing Type 2 diabetes.
“It seems there are no specific benefits of eating leafy green vegetables for Type 2 diabetes risk,” says Dr. Rob M. Van Dam, of the National University of Singapore and one of the study authors.
“However, eating vegetables, including green leafy ones lowers blood pressure and seems to lower the risk of heart disease and stroke and is therefore advisable for other health reasons,” he tells dLife.
The researchers also performed a combined analysis of the Singapore Chinese Health Study data with ten similar studies from other countries. This larger analysis included a total of over 750,000 participants, including over 58,000 cases of Type 2 diabetes, and showed only a borderline beneficial effect of green leafy vegetables.
The researchers concluded that the consumption of green leafy vegetables is not linked to a reduced risk of developing type 2 diabetes. However, Van Dam told dLife that since people with Type 2 diabetes have a high risk of cardiovascular diseases, eating green leafy vegetables is likely to be beneficial for that reason.
In conclusion, although the research did not note any effect on risk of developing Type 2 diabetes by consuming leafy green vegetables alone, they are an important part of a healthy diet and confer other health benefits.
“I recommend consumption of green leafy vegetables for cardiovascular health,” Van Dam says. “However, if people are at high risk of T2D other lifestyle measures (e.g. physical activity, weight management, consumption of whole grains) are also needed to lower Type 2 diabetes risk,” he states.
The findings of the study were reported in the May edition of the British Journal of Nutrition.
- Chen GC, Koh WP, Yuan JM, et al. Green leafy and cruciferous vegetable consumption and risk of type 2 diabetes: results from the Singapore Chinese Health Study and meta-analysis. Br J Nutrition doi:10.1017/S0007114518000119.