Two new large-scale studies published in July 2020 in the journal BMJ add to the growing body of evidence that consuming whole plant foods is one of the most effective ways to prevent type 2 diabetes.
The first study examined the impact of fruit and vegetable consumption on the risk of type 2 diabetes. The study included more than 340,000 participants in eight different countries over 10 years, with a team of more than 40 researchers.
When comparing the biomarkers of nearly 10,000 people who developed type 2 diabetes during the study with 13,500 people who remained free of the disease, they found that those who ate fruits and vegetables had a significantly lower incidence of type 2 diabetes. In fact, people who consumed a high amount of fruits and vegetables lowered their risk of type 2 diabetes by as much as 50 percent relative to those who consumed less fruit and vegetables. Even a modest increase, habitually adding just one extra serving a day, cut the relative risk of developing type 2 diabetes in the future by 25 percent.
This first-of-its-kind study offers a greater degree of confidence in findings because of its large scale and use of participants with a range of ages and dietary habits. Additionally, researchers used blood biomarkers (vitamin C and carotenoids, the plant pigments that give color to fruits and vegetables) to measure participants’ fruit and vegetable consumption, rather than relying on participants to report what they’d eaten. Researchers also controlled for factors such as age, sex, body mass index, education level, occupation, smoking, alcohol intake, physical activity and use of vitamin supplements.
Lead author Nita Forouhi, professor of public health and nutrition at the University of Cambridge, says that the results point to the importance of eating whole plant foods: “It is vital to understand that our research does not promote consuming vitamin pills, but rather it indicates the benefits of consuming fruit and vegetables,” says Forouhi. Fruits and vegetables contain vitamins and minerals, polyphenols, and fiber, and promote health through their effects on factors such as weight, inflammation, and gut health.
The second BMJ study, conducted by researchers at Harvard, used data from three large studies including nearly 195,000 participants over 24 years to assess the impact of whole grains and the risk of developing type 2 diabetes. They found that those with the highest consumption of whole grain foods had a 29 percent lower rate of type 2 diabetes compared with the lowest whole grain consumption.
Along with measuring total whole grains, the study looked at seven commonly consumed individual whole grain foods and found they were significantly associated with a lower risk of type 2 diabetes. These included whole grain breakfast cereal, oatmeal, dark bread, brown rice, added bran, and wheat germ. “These findings provide further support for the current recommendations that promote increased consumption of whole grain as part of a healthy diet for the prevention of type 2 diabetes,” write the study authors.
The average American eats less than one daily serving of whole grains, and some studies show that over 40 percent of Americans never eat whole grains at all, according to the Whole Grains Council.
An estimated 34 million Americans have diabetes, and 90 to 95 percent of these cases are type 2 diabetes, according to the CDC’s National Diabetes Statistics Report for 2020. Type 2 diabetes can damage the body and cause other serious health problems, including heart disease and kidney disease. Although type 2 diabetes most commonly develops in people over age 45, more and more children, teens, and young adults are developing it. “Type 2 diabetes is a serious and common health condition so it is vital to find solutions,” says Forouhi.