Prepregnancy adhrence to plant-based diets lowers risk of gestational diabetes mellitus

05 Jan 2022 bởiStephen Padilla
Prepregnancy adhrence to plant-based diets lowers risk of gestational diabetes mellitus

Women with greater adherence to a healthful plant-based diet before pregnancy appear to have a reduced risk of gestational diabetes mellitus (GDM), suggests a recent study. On the other hand, adherence to an unhealthful plant-based diet is not associated with GDM risk.

“These findings not only further highlight the importance of diet and lifestyle before pregnancy for the prevention of GDM but also may provide an alternative dietary approach that may reduce the population burden of GDM,” the researchers said.

A total of 14,926 women from the Nurses’ Health Study II (1991‒2001), who reported at least one singleton pregnancy and without previous GDM before the index pregnancy, were included in this prospective cohort study.

The researchers measured prepregnancy adherence to plant-based diets by an overall plant-based diet index (PDI), healthful plant-based diet index (hPDI), and unhealthful plant-based diet index (uPDI), as assessed by food frequency questionnaires every 4 years. They determined incident first-time GDM from a self-reported physician diagnosis, which was validated previously by review of medical records.

Finally, log-binomial models with generalized estimating equations were used to calculate risk ratios (RRs) and 95 percent confidence intervals (CIs) for associations of PDIs with GDM.

Over 10 years of follow-up, 846 incident GDM cases were documented among 20,707 pregnancies. High adherence to PDI and hPDI correlated with lower GDM risk. [Am J Clin Nutr 2022;114:1997-2005]

For PDI, the multivariable-adjusted RR of the highest (Q5) vs lowest (Q1) quintiles was 0.70 (95 percent CI, 0.56‒0.87; ptrend=0.0004); for each 10-point increase, the RR was 0.80 (95 percent CI, 0.71‒0.90). For hPDI, the RR of Q5 vs Q1 was 0.75 (95 percent CI, 0.59‒0.94; ptrend=0.009), and for each 10-point increase, the RR was 0.86 (95 percent CI, 0.7‒0.95).

After adjusting for prepregnancy body mass index, such associations weakened but remained significant: for PDI, the RR for each 10-point increment was 0.89 (95 percent CI, 0.79‒1.00), and for hPDI the corresponding RR was 0.89 (95 percent CI, 0.80‒0.99). The uPDI did not correlate with GDM.

“A plant-based diet, particularly one rich in healthy plant-based foods, tends to emphasize more intake of minimally processed plant foods, such as whole grains, fruits, vegetables, and nuts, leading to an increased intake of dietary fibres, plant protein, unsaturated fats, and antioxidants such as vitamin C,” the researchers said. [N Engl J Med 2011;364:2392-2404; Circulation 2016;133:187-225]

“These components have been linked to less adiposity, improved insulin sensitivity, reduced inflammation, and improved gut microbiome composition, and hence lead to the reduced GDM risk,” they added. [Eur J Clin Nutr 2009;63:921-933; Nutrients 2014;6:4822-4838; Am J Clin Nutr 2006;83:567-574; Nat Rev Dis Primers 2019;5:47]

In contrast, prepregnancy consumption of red and processed meat, animal protein, saturated fat, and heme iron were found to be associated with increased risk of GDM through various pathways, including weight gain, oxidative stress, and increased inflammation. [Diabetes Care 2013;36:2001-2008; Asia Pac J Clin Nutr 2017;26:1092-1106]

“Future studies in other populations are warranted to confirm our findings,” the researchers said.