Protein intake affects constipation differently across genders: Study
The authors from Wenzhou Medical University, Hangzhou, China, assessed data from 14,048 participants over the age of 20 (7,072 men and 6,976 women) and found that women were more likely to suffer from constipation and more susceptible to the impact of high protein intake on constipation.
“These insights are crucial for guiding dietary protein recommendations for different genders and have significant clinical implications,” they wrote in the journal Frontiers in Nutrition.
Chronic constipation
Chronic constipation is reported to affect up to 27% of adults in Western countries and around 14% of the global population.
Dietary factors have been shown to be a modifiable risk for chronic constipation. Soluble fiber and minerals like phosphorus, magnesium and selenium can reduce the risk, while high saturated fat intake and low energy consumption increase it, particularly in women.
Protein has been shown to affect intestinal enzyme activity, microbiota composition and immune response, but according to the researchers of the recent report, its role in chronic constipation has been under-researched.
Protein responses
The researchers assessed data collected from the National Health and Nutrition Examination Survey (NHANES) 2005–2010 and used The Bristol Stool Form Scale to define constipation, as well as using a 24-hour dietary recall technique to measure dietary protein intake.
The association between protein consumption and constipation risk was examined using multivariable logistic regression, smooth curve fitting and testing for gender interaction effects.
Results showed that constipation was present in 7.49% of people overall, with a higher proportion among women (10.19%) than among males (4.82%).
“In men, higher protein intake was significantly associated with a lower rate of constipation, however, in women, higher protein intake correlated with an increased risk of constipation,” the authors concluded.
They found that the threshold for men was 119.42 gm/day, and below that level, an increase in dietary protein significantly reduced the risk of constipation; above this level, no significant correlation was observed.
For women, the threshold was 40.79 gm/day. Below this threshold, protein intake did not significantly correlate with constipation; however, exceeding the threshold led to a significant increase in constipation risk.
Mechanisms of action
The authors suggested that several mechanisms may explain the findings, noting that dietary protein could "differently affect the gut microbiome composition in males and females, favoring different bacterial species, which may influence constipation risk oppositely across genders."
They added that hormonal differences between genders could regulate the breakdown of amino acids in proteins leading to the production of metabolic byproducts such as ammonia, branched-chain fatty acids (BCFAs) and short-chain fatty acids (SCFAs), which can alter the pH of feces and change its consistency.
As Emily Prpa PhD, science manager at Yakut UK & Ireland, explained during the recent NutraIngredients editorial webinar on Women’s Health, stool consistency changes throughout the 28-day menstruation cycle.
“Sex hormone receptors, specifically those for estrogen and progesterone, are located on your gastrointestinal cells, and so the fluctuating levels of hormones during your cyclical changes can cause changes in gastrointestinal function and symptoms,” she noted. “That is why women might have harder stools during ovulation, and ‘period poops’ or looser stools or diarrhea during menstruation.”
Journal: Frontiers in Nutrition
doi:10.3389/fnut.2024.1393596
“Gender differences in the association between dietary protein intake and constipation: findings from NHANE”
Authors: Hong, Y. Et al.
