Plant versus animal based diets and insulin resistance, prediabetes and type 2 diabetes: the Rotterdam Study

Abstract

Vegan or vegetarian diets have been suggested to reduce type 2 diabetes (T2D) risk. However, not much is known on whether variation in the degree of having a plant-based versus animal-based diet may be beneficial for prevention of T2D. We aimed to investigate whether level of adherence to a diet high in plant-based foods and low in animal-based foods is associated with insulin resistance, prediabetes, and T2D. Our analysis included 6798 participants (62.7 ± 7.8 years) from the Rotterdam Study (RS), a prospective population-based cohort in the Netherlands. Dietary intake data were collected with food-frequency questionnaires at baseline of three sub-cohorts of RS (RS-I-1: 1989–1993, RS-II-1: 2000–2001, RS-III-1: 2006–2008). We constructed a continuous plant-based dietary index (range 0–92) assessing adherence to a plant-based versus animal-based diet. Insulin resistance at baseline and follow-up was assessed using homeostasis model assessment of insulin resistance (HOMA-IR). Prediabetes and T2D were collected from general practitioners’ records, pharmacies’ databases, and follow-up examinations in our research center until 2012. We used multivariable linear mixed models to examine association of the index with longitudinal HOMA-IR, and multivariable Cox proportional-hazards regression models to examine associations of the index with risk of prediabetes and T2D. During median 5.7, and 7.3 years of follow-up, we documented 928 prediabetes cases and 642 T2D cases. After adjusting for sociodemographic and lifestyle factors, a higher score on the plant-based dietary index was associated with lower insulin resistance (per 10 units higher score: β = −0.09; 95% CI: − 0.10; − 0.08), lower prediabetes risk (HR = 0.89; 95% CI: 0.81; 0.98), and lower T2D risk [HR = 0.82 (0.73; 0.92)]. After additional adjustment for BMI, associations attenuated and remained statistically significant for longitudinal insulin resistance [β = −0.05 (− 0.06; − 0.04)] and T2D risk [HR = 0.87 (0.79; 0.99)], but no longer for prediabetes risk [HR = 0.93 (0.85; 1.03)]. In conclusion, a more plant-based and less animal-based diet may lower risk of insulin resistance, prediabetes and T2D. These findings strengthen recent dietary recommendations to adopt a more plant-based diet.Clinical Trial Registry number and website NTR6831, http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=6831.Electronic supplementary materialThe online version of this article (10.1007/s10654-018-0414-8) contains supplementary material, which is available to authorized users.

Dietary protein intake and all-cause and cause-specific mortality: results from the Rotterdam Study and a meta-analysis of prospective cohort studies

“…For the current analysis within the Rotterdam Study, of the 14,926 participants who participated at baseline, we had dietary data available for 9701. Main reasons for absence of valid dietary data among the 5225 participants were: no dietary data available (n = 4890) including not having received dietary assessment because of logistic reasons, living in a resident home for elderly or suspected dementia, and not having completed the dietary assessment; or excluded as invalid dietary data (n = 335) defined as an estimated energy intake of < 500 or > 5000 kcal/day) [18,19]. From these 9701 participants, we further excluded 1914 participants with CVD, diabetes, or cancer at baseline, and 1 participant without follow-up data on mortality, leaving 7786 participants for the main analyses (Supplemental Figure 1).…”

“…Dietary intake in the Rotterdam Study was assessed at baseline in all three sub-cohorts using a semi-quantitative food questionnaire (FFQ) as described in more details elsewhere [19,20]. Briefly, we used an FFQ with 170 food items to assess dietary intake at baseline of RS-I (1989RS-I ( -1993 and at baseline of RS-II (2000-2001.…”

Improving the scientific rigour of nutritional recommendations for adults with type 2 diabetes: A comprehensive review of the American Diabetes Association guideline‐recommended eating patterns

“…All controlled studies except one had fewer than 100 participants. Overall, as recommended by ADA guidelines, a plant‐based diet may be effective in improving glycaemic control for some people with T2D, especially in those with a personal preference for such an eating pattern, at least in the short term; however, some of the studies that showed improvements in glycaemic endpoints were restricted in energy intake; therefore, it is not clear exactly what generated the beneficial outcomes—the composition of the diet or the weight loss resulting from energy restriction . Further, the decrease in HDL cholesterol and higher triglyceride levels seen in some studies need to be considered.…”

“…Overall, as recommended by ADA guidelines, a plant-based diet may be effective in improving glycaemic control for some people with T2D, especially in those with a personal preference for such an eating pattern, at least in the short term; however, some of the studies that showed improvements in glycaemic endpoints were restricted in energy intake 51,53 ; therefore, it is not clear exactly what generated the beneficial outcomes-the composition of the diet or the weight loss resulting from energy restriction. [63][64][65] Further, the decrease in HDL cholesterol 57,58,66,67 and higher triglyceride levels 66,67 seen in some studies need to be considered. Whether these changes in CVD risk markers are clinically meaningful or associated with poor CVD outcomes needs to be closely assessed; any worsening in atherogenic dyslipidaemia, which has been found to indicate worsening insulin resistance status, 68 RCTs, five found a significant between-group advantage for the lowcarbohydrate arm for glycaemic control.…”

Improving the Scientific Rigor of Nutritional Recommendations for Adults with Diabetes: A Comprehensive Review of the American Diabetes Association Guidelines Recommended Eating Patterns

“…However, some of the studies that showed improvements in glycemic endpoints were restricted in energy intake; 51,53 therefore, it is not clear exactly what generated the beneficial outcomes-the composition of the diet or, rather, the weight loss resulting from energy restriction. [63][64][65] Further, the decrease in HDL-C 56,59,66,67 and higher triglyceride levels 66,67 seen in some studies need to be considered. Whether these changes in CVD risk markers are clinically meaningful or associated with poor CVD outcomes needs to be closely assessed;…”