Healthy plant-based diet could reduce risk of developing type two diabetes by 24%

Research conducted by the Medical University of Vienna’s Center for Public Health has identified improvements in metabolism, and liver and kidney function, when a healthy plant-based diet is consumed. The study, led by Dr Tilman Kühn, Professor of Public Health Nutrition at Medical University Vienna and the University of Vienna, found that a healthful plant-based diet reduces the risk of diabetes by 24%, even in the presence of a genetic predisposition and other diabetes risk factors such as obesity, advanced age and lack of physical activity.

What did the study involve?The research, published in the Diabetes & Metabolism journal, involved 113,097 participants, aged 40 to 69 years, in a large-scale British cohort study (UK Biobank) over an observation period of twelve years. Associations between healthful and unhealthful plant-based indices (hPDI and uPDI) and type two diabetes risk were analysed by multivariable Cox regression models, followed by causal mediation analyses to investigate which cardiometabolic risk factors explained the observed associations.

Of 113,097 study participants 2,628 developed type two diabetes over 12 years. Participants with the highest hPDI scores, had a 24% lower risk of developing type two diabetes. This association was mediated by a lower BMI, lower waist circumference and lower concentrations of HBA1c (average blood glucose). Higher uPDI scores were associated with a 37% higher risk of developing type two diabetes, with higher waist circumference, higher BMI and higher concentrations of triglycerides potentially playing mediating roles.

The study concluded that a healthful plant-based diet could help to protect against type two diabetes, via lower body fatness, normoglycaemia (normal concentration of sugar in the blood), lower basal inflammation and improved kidney and liver function.

“We were surprised that several factors other than body fatness alone explained associations between a healthy diet and lower diabetes risk. While obesity is still the most important risk factor for diabetes, we found it interesting that better kidney function, for example, may mediate beneficial dietary effects,” Dr Kühn told FoodNavigator.

What is type two diabetes?

Formally called ‘non-insulin dependent’, type two diabetes affects how the body uses sugar (glucose) for energy and stops it from using insulin properly. This can lead to high levels of blood sugar if not treated. In time, type two diabetes can cause serious damage to the body, in particular to the nerves and blood vessels. This type of diabetes was previously seen only in adults, but it is now also occurring increasingly frequently in children.

Over 33 million people in the EU suffer from diabetes. According to International Diabetes Federation (IDF) data, the absolute number of diabetics in the EU will rise from approximately 33 million in 2010 to 38 million in 2030.

What you eat mattersThe positive results were based on the consumption of a healthy plant-based diet, which incorporated plenty of fresh fruits, vegetables, wholegrains, pulses, nuts and seeds. Conversely, there is an increased risk of developing type two diabetes when an unhealthy plant-based diet, with a high proportion of sweets, refined grains, and sugary drinks, is consumed.

When asked if the study incorporated plant-based meat alternatives, Dr Kühn said, “We were not able to assess meat and dairy alternatives in our analyses. At the moment, there is a complete lack of data from population-based studies on the consumption of such products in relation to health outcomes. This is because meat and dairy alternatives are a rather new trend.”

He continued, “many of these foods are ultra-processed, although products on the market are very diverse. More research is needed on real-world consumption patterns and health.”

Dr Kühn and his team have plans to further investigate different types of plant-based foods to better understand how they relate to this research and how healthy or unhealthy they are. “We are planning new studies with a more detailed assessment of current plant-based dietary patterns. The quality and health aspects of dairy and meat replacements will be one key area of our future work.”

However, it is important to also understand that a plant-based diet does not mean eating only plant products, as the British Nutrition Foundation explains, “although you may think of plant-based diets as being vegetarian or vegan, they do not have to be plant-only. Such diets do not have to completely exclude animal foods such as meat, poultry, fish, eggs and dairy products, but proportionally more foods are chosen from plant sources. Other examples of plant-based dietary patterns include the Mediterranean Diet and the Nordic Diet.”

How could this research affect dietary guidelines?Research and innovation on diabetes, and related factors such as obesity, has been a longstanding priority for the European Union (EU) over the past decade, with over €1.25 billion invested into research projects. “Except for genetic conditions or special types of diabetes (like type-1 diabetes), it is often a preventable chronic disease through a healthy lifestyle starting in childhood,” says the European Commission.

“Our study is well in line with existing dietary recommendations such as the Eatwell Guide,” added Dr Kühn. “However, studies show that it is difficult for many people to adopt such recommendations into their daily lives.

“Future nutrition policies with a focus on better food environments to facilitate healthy choices are needed in addition to dietary guidelines.”

Source: A healthful plant-based diet is associated with lower type 2 diabetes risk via improved metabolic state and organ function: A prospective cohort study
Published online: 28 November 2023
DOI: https://doi.org/10.1016/j.diabet.2023.101499
Authors: Alysha S. Thompson, Catharina J. Candussi, Anna Tresserra-Rimbau, Amy Jennings, Nicola P. Bondonno, Claire Hill, Solomon A. Sowah, Aedín Cassidy, Tilman Kühn