Plant foods intake and risk of type 2 diabetes: Findings from a registry-based prospective cohort study

Background Lifestyle intervention or dietary modification has been the cornerstone of primary prevention and management of type 2 diabetes (T2D).

Objective To investigate the associations of plant foods intake with the risk of incident T2D.

Methods Based on a general population cohort, the Shanghai Suburban Adult Cohort and Biobank (SSACB), dietary data were collected for each participant in Songjiang District of Shanghai at enrollment with a validated Food Frequency Questionnaire (FFQ), and plant-based diet index (PDI), healthful plant-based diet index (hPDI), and unhealthful plant-based diet index (uPDI) were calculated. Incident T2D cases were identified according to physician diagnosis (fasting blood glucose ≥7.0 mmol·L⁻¹, or 2 h value during a 75-g oral glucose tolerance test ≥11.1 mmol·L⁻¹, or glycosylated hemoglobin ≥6.5%, or with typical symptoms of hyperglycemia or hyperglycemic crisis, accompanied by a random plasma glucose ≥11.1 mmol·L⁻¹) or medication records, obtained from the electronic information system for residents' medical insurance. Multivariable-adjusted Cox proportional hazards models and restricted cubic splines were used to evaluate the associations of foods from different sources with the risk of incident T2D.

Results A total of 29016 participants age at baseline (55.3±11.6) years with a median follow-up duration of 5.688 years until 21 September 2022 were included. Plant foods (unprocessed) intake was associated with a decreased risk of incident T2D HR (95%CI): 0.983 (0.969, 0.998). In comparison with participants in the highest quartile (≥859.3 g) of plant foods daily intake, the risk of incident T2D for those in the lowest quartile (<500.9 g) was higher HR (95%CI): 1.250 (1.012, 1.544). No significant associations of animal foods HR (95%CI): 1.006 (0.987, 1.026) and processed foods HR (95%CI): 0.978 (0.944, 1.014) intakes were found with the risk of incident T2D. Replacing 50 g animal foods HR (95%CI): 0.982 (0.968, 0.996) or processed foods HR (95%CI): 0.983 (0.969, 0.998) with 50 g plant foods was associated with significantly decreased risks of incident T2D. Additionally, non-linear associations of PDI (P_nonlinear=0.023) and hPDI (P_nonlinear=0.016) with the risk of incident T2D were found in the SSACB.

Conclusion Plant foods intake, especially healthful plant foods intake, is significantly associated with a decreased risk of incident T2D.