Available online 28 November 2023, 101499

Author links open overlay panel, , , , , , , , ABSTRACTBackground

Plant-based diets are becoming increasingly popular due to favourable environmental footprints and have been associated with lower risk of type 2 diabetes (T2DM). Here, we investigated the potential mechanisms to explain the lower T2DM risk observed among individuals following plant-based diets.

Methods

Prospective data from the UK Biobank, a cohort study of participants aged 40 to 69 years at baseline, was evaluated. Associations between healthful and unhealthful plant-based indices (hPDI and uPDI) and T2DM risk were analysed by multivariable Cox regression models, followed by causal mediation analyses to investigate which cardiometabolic risk factors explained the observed associations.

Results

Of 113,097 study participants 2,628 developed T2DM over 12 years of follow-up. Participants with the highest hPDI scores (Quartile 4) had a 24% lower T2DM risk compared to those with the lowest scores (Quartile 1) [Hazard Ratio (HR): 0.76, 95% Confidence Interval (CI): 0.68-0.85]. This association was mediated by a lower BMI (proportion mediated: 28%), lower waist circumference (28%), and lower concentrations of HBA1c (11%), triglycerides (9%), alanine aminotransferase (5%), gamma glutamyl transferase (4%), C-reactive protein (4%), insulin-like growth factor 1 (4%), cystatin C (4%) and urate (4%). Higher uPDI scores were associated with a 37% higher T2DM risk [HR: 1.37, 95% CI:1.22- 1.53], with higher waist circumference (proportion mediated: 17%), BMI (7%), and higher concentrations of triglycerides (13%) potentially playing mediating roles.

Conclusion

Healthful plant-based diets may protect against T2DM via lower body fatness, but also via normoglycaemia, lower basal inflammation as well as improved kidney and liver function.

Section snippetsINTRODUCTION

The global prevalence of diabetes was 6.1% in 2021 with a projection to increase to over 10% by 2050, with Type 2 Diabetes Mellitus (T2DM) accounting for approximately 95% of cases [1], [2], [3]. In the UK alone, approximately 4.7 million individuals are living with T2DM, costing the National Health Service around £10 billion annually [4].

At least 75% of all T2DM cases could be preventable by a healthy lifestyle [5]. Moreover, adopting a healthy lifestyle can reduce the risk of cause-specific

Study Population

The present analyses are based on data from the UK Biobank, a large-scale prospective study among over 500,000 volunteers between the age of 40 to 69. Recruitment occurred from 2006 to 2010 across centres in England, Scotland and Wales, and included a variety of comprehensive baseline assessments. A detailed description of the study protocol can be found elsewhere [18] .

The UK Biobank study obtained ethical approval from the Community Health Index Advisory Group for Scotland, the North West

RESULTS

Participants who had missing dietary data or covariate information (n=372,173), implausible energy intakes (> 17,573KJ or < 3,347KJ for men and > 14,644KJ or < 2,092KJ for women (n=3,953), prevalent diabetes (all types) (n=5,008), a diabetes diagnosis (all types) between baseline and the last dietary assessment (n=301), prevalent cancer (n=5,920), or prevalent cardiovascular disease (n=1,868) were excluded, resulting in 113,097 individuals for the present analyses (Figure S1; see supplementary

DISCUSSION

In this large UK-based study, a healthful plant-based diet was associated with a 24% lower risk of T2DM, irrespective of genetic risk and other established T2DM risk factors. This association was in part mediated by lower body fatness, but also by better glucose metabolism, lower basal inflammation and better kidney and liver function. By contrast, adherence to an unhealthful plant-based diet was associated with a higher risk of T2DM, with greater body fatness and higher triglyceride levels

CONCLUSION

This study suggests that a healthy plant-based diet is associated with a lower T2DM risk due to several mechanisms beyond beneficial effects on body fatness and blood glucose including improved renal and liver function, and lower basal inflammation. Our findings suggest that high quality plant-based diets, characterised by high consumption of fruits, vegetables, nuts, legumes, wholegrains, tea and coffee, are beneficial for T2DM prevention, in line with existing dietary recommendations to

Authors’ contributions

Design and concept: AT, CC, AC, TK; database development: AT, AJ, AC, ATR, TK; analysed and interpreted data: AT, CC, TK, AC; drafted manuscript: AT, CC, TK, AC; provided critical review of the manuscript: AJ, NB, ATR, SS, CH; guarantors of the work: AT, CC, AC and TK.

Data sharing

UK Biobank data can be requested by all bona fide researchers for approved projects, including replication, through https://www.ukbiobank.ac.uk/.

Declaration of Competing Interest

The authors declare the following financial interests/personal relationships which may be considered as potential competing interests:

Alysha S. Thompson reports financial support was provided by Northern Ireland Department for the Economy (PhD Studentship). Aedin Cassidy acts as an advisor to the US Highbush Blueberry Council (USHBC with oversight from the USDA) and has received funding for them for clinical trials and population-based research.

Acknowledgements

This research has been conducted using UK Biobank data (application 64426). We thank all the UK Biobank participants for their participation in this study.

Sources of funding

This research was conducted using UK Biobank funded and sourced data (application 64426). The UK Biobank was established by the Wellcome Trust, the Medical Research Council, the UK Department of Health, and the Scottish Government. The UK Biobank has also received funding from the Welsh Assembly Government, the British Heart Foundation, and Diabetes United Kingdom, Northwest Regional Development Agency, Scottish Government. In addition, Alysha S. Thompson holds a PhD studentship of the

References (43)BA Swinburn et al.The global syndemic of obesity, undernutrition, and climate change: the Lancet commission report

Lancet

(2019)

Global, regional, and national burden of diabetes from 1990 to 2021, with projections of prevalence to 2050: a systematic analysis for the Global Burden of Disease Study 2021

Lancet

(2023)

CA Whicher et al.Diabetes in the UK: 2019

Diabet Med

(2020)

Y Zhang et al.Combined lifestyle factors and risk of incident type 2 diabetes and prognosis among individuals with type 2 diabetes: a systematic review and meta-analysis of prospective cohort studies

Diabetologia

(2020)

L Schwingshackl et al.Food groups and risk of type 2 diabetes mellitus: a systematic review and meta-analysis of prospective studies

Eur J Epidemiol

(2017)

D Pollakova et al.The Impact of vegan diet in the prevention and treatment of type 2 diabetes: a systematic review

Nutrients

(2021)

Statista. Do you avoid eating meat?,...A Satija et al.Plant-based dietary patterns and incidence of type 2 diabetes in us men and women: results from three prospective cohort studies

PLoS Med

(2016)

H Kim et al.Plant-Based diets and incident CKD and kidney function

Clin J Am Soc Nephrol

(2019)

RS Najjar et al.Plant-based diets in the reduction of body fat: physiological effects and biochemical insights

Nutrients

(2019)

NE Allen et al.The associations of diet with serum insulin-like growth factor I and its main binding proteins in 292 women meat-eaters, vegetarians, and vegans

Cancer Epidemiol Biomarkers Prev

(2002)

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