Association between dietary patterns including fruits & vegetables and incident type 2 diabetes in a UK cohort

The prevalence of diabetes is projected to reach 700 million by 2045 worldwide (Chan, 2021). Type 2 diabetes is predominant and associated with higher morbidity and mortality risks from other noncommunicable diseases (Shah, 2015). It is well known that the risk of type 2 diabetes can be reduced by modifying unhealthy behaviours, such as a poor diet (Neuenschwander, 2019). In previous research focused on nutrients, associations were reported between poor diet quality and the incidence of type 2 diabetes and its comorbidities, particularly for diets high in saturated fat (Van Dam RM, 2002) and low in fibre (Reynolds AN, 2002). There is also some evidence for positive associations between single foods and an increased risk of developing type 2 diabetes, such as low intakes of fresh fruit and vegetables (Zheng JS, 2020). However, the impact of individual nutrients or foods on health outcomes may not adequately reflect the health effects of a whole diet in which foods are eaten in combination. Our study identifies the association between dietary patterns (DPs) and incident type 2 diabetes

Diets particularly low in fruit and vegetables are associated with a higher risk of developing type 2 diabetes

Our study identified DPs explaining high variability in known dietary risk factors, such as energy density, free sugars, saturated fat, and low fibre intakes and aimed to assess the association between DPs and incident type 2 diabetes. Two DPs were studied; the main one was characterized by high consumption of chocolate and confectionery, butter and other animal-fat spreads, and low-fibre bread, and reduced consumption of fresh fruit, vegetables, and high-fibre breakfast cereals. Over 8.4 years of follow-up from the latest dietary assessment, 2,878 participants of the UK Biobank developed T2D. There was positive association between adherence to this DP and incident type 2 diabetes after sequential adjustment for demographics, sociodemographic, behavioural risk factors, and health history and conditions, and remained statistically significant after adjustment for BMI.

Older people tend to consume more fruit and vegetables

There was a significant interaction between the DP and age, with significantly higher risks among younger people (<60 years; DP1: HR 1.13 [95% CI 1.09–1.18]). That result suggests that, when all other things are held constant, a poor diet could increase the risk of type 2 diabetes in younger people. There are also age-related differences in healthy food consumption such as fruit and vegetables, with older adults consuming more fruit and vegetables than do younger adults — a pattern that has been observed in several U.K. national surveys. In the National Diet and Nutrition Survey (2016–2017 to 2018–2019), adults (aged 19–64 years) consumed, on average, 4.3 portions of fruit and vegetables per day and older adults (≥65 years) consumed 4.5 portions per day (Bates B, 2020). Reports in the wider literature also have suggested that older people tend to consume more fruit and vegetables and other healthy foods (Reininger, 2017), which may be the case among the UK Biobank participants.

Dietary guidelines should be based on foods instead of nutrients

Current dietary guidelines in the U.K. and many other countries are still based predominately on nutrient recommendations. Although this reflects the underlying evidence base, especially experimental and mechanistic research, it does not reflect the way people eat. Food-based dietary guidelines may help accelerate behaviour change compared with nutrient-based recommendations by providing targeted and simpler advice on foods, which make it more, or less, likely to achieve an overall healthy diet (Van Horn L, 2016). Moreover, this may help reduce the risk of conflicting messages regarding the relative importance of one or another nutrient, particularly saturated fat and free sugars, and recognize that there are many foods that are important sources of both. This large population based cohort study has shown that the effects of a poor diet are especially pronounced in younger people and those living with obesity.

Based on : Gao M, Jebb SA, Aveyard P, Ambrosini GL, Perez-Cornago A, Papier K, Carter J, Piernas C. Associations Between Dietary Patterns and Incident Type 2 Diabetes: Prospective Cohort Study of 120,343 UK Biobank Participants. Diabetes Care. 2022 Jun 2;45(6):1315-1325. doi: 10.2337/dc21-2258. PMID: 35299247.