New research has been published Diabetes (Journal of the European Association for the Study of Diabetes [EASD]) show that consumption of healthy plant-based foods, including fruits, vegetables, nuts, coffee, and legumes, is associated with a lower risk of developing type 2 diabetes (T2D) in generally healthy people and supports their role in diabetes prevention.
The study was conducted by Frank Hu, professor of nutrition at the Harvard TH Chan School of Public Health, Boston, MA, USA, and colleagues, and aimed to identify metabolic profiles associated with different plant-based diets and investigate possible associations between them. Profile and risk of developing T2D.
A metabolite is a substance used or produced by the chemical processes of a living organism and includes the large number of compounds found in various foods as well as the complex molecules formed as a result of those compounds being broken down and converted for use by the body. Differences in the chemical makeup of foods mean that a person’s diet should be reflected in their metabolite profile. Recent technological advances in high-throughput metabolomics profiling have ushered in a new era of nutrition research. Metabolomics is defined as the comprehensive analysis and identification of all the different metabolites present in a biological sample.
More than 90% of diabetes cases are type 2 and this condition poses a major health threat worldwide. The global prevalence of the disease in adults has more than tripled in less than two decades, from approximately 150 million cases in 2000 to over 450 million cases in 2019 and is projected to rise to nearly 700 million in 2045.
The global health burden of T2D is exacerbated by the numerous complications arising from the disease, both macrovascular, such as cardiovascular disease, and microvascular, which damage the kidneys, eyes, and nervous system. The diabetes epidemic is primarily caused by unhealthy eating habits, overweight or obesity, genetic predisposition and other lifestyle factors such as lack of exercise. A plant-based diet, particularly one rich in healthy foods such as whole grains, fruits and vegetables, is associated with a lower risk of developing T2D but the underlying mechanisms are not fully understood.
The team conducted an analysis of blood plasma samples and dietary intake of 10,684 participants from three prospective cohorts (the Nurses’ Health Study, the Nurses’ Health Study II and the Health Professionals Follow-up Study). Participants were predominantly white, middle-aged (mean age 54 years) and had a mean body mass index (BMI) of 25.6kg/m2.
Study participants completed food frequency questionnaires (FFQs) that were scored according to adherence to three plant-based diets: an overall plant-based diet index (PDI), a healthy plant-based diet index (hPDI), and an unhealthy plant-based Food Index (uPDI). Dietary indices were based on the person’s intake of 18 food groups: healthy plant foods (whole grains, fruits, vegetables, nuts, legumes, vegetable oils, and tea/coffee); unhealthy plant foods (refined grains, fruit juices, potatoes, sugar-sweetened beverages and sweets/sweets); and animal foods (animal fat, dairy, eggs, fish/seafood, meat, and miscellaneous animal-based foods). The team distinguished between healthy and unhealthy plant foods according to their association with T2D, cardiovascular disease, some cancers and other conditions including obesity and high blood pressure.
The researchers examined blood samples taken in the early 1980s and late 1990s in the early stages of the three studies mentioned above to create metabolite profile scores for participants and recorded the incidence of T2D during the study’s follow-up period. Analysis of these data along with diet index scores enabled the team to find any association between metabolite profiles, diet indices and T2D risk.
The study found that compared to participants who did not develop T2D, those who were diagnosed during follow-up had lower intakes of healthy plant-based foods as well as lower scores for PDI and hPDI. Additionally, they had a higher average BMI, and were more likely to have high blood pressure and cholesterol levels, use blood pressure and cholesterol medications, have a family history of diabetes, and be less physically active.
Metabolomics data revealed that plant-based diets were associated with unique multi-metabolite profiles and that these patterns differed significantly between healthy and unhealthy plant-based diets. Additionally, metabolite profile scores for both overall plant-based diet and healthy plant-based diet were inversely associated with incident T2D in the general healthy population, independent of BMI, and other diabetes risk factors, while no association was observed. Unhealthy plant-based diets. Consequently, higher metabolite profile scores for PDI and HPDI indicate both closer adherence to those foods and lower risk of developing T2D.
Further analysis showed that after adjusting for levels of trigonelline, hippurate, isoleucine, a small set of triacylglycerols (TAGs) and other intermediate metabolites, the association between a plant-based diet and T2D largely disappeared, suggesting that They can play a key role. Facts to link those foods with diabetes. For example, trigonelline, found in coffee, has shown beneficial effects on insulin resistance in animal studies, while higher levels of hippurate are associated with better glycemic control, increased insulin secretion, and lower risk of T2D. The team suggests that these metabolites can be further investigated and provide a mechanistic explanation for how plant-based diets may have beneficial effects on T2D risk.
Professor Hu explained: “Although it is difficult to tease out the contributions of individual foods because they were analyzed together as a pattern, individual metabolites from consuming polyphenol-rich plant foods such as fruits, vegetables, coffee and legumes are closely related. A healthy plant-based diet and diabetes. The risk is low.”
The authors concluded: “Our results support the beneficial role of a healthy plant-based diet in the prevention of diabetes and provide new insights for future investigations… Our findings on intermediary metabolism are interesting at the moment but further studies are needed to confirm their causal role. Plant- Based on dietary resources and the risk of developing type 2 diabetes.”
Because they only collected blood samples at one point in time, the authors also believe that long-term repeated metabolic data are needed to understand whether dietary changes are associated with changes in metabolism, thereby affecting T2D risk.