In a recent study published in the Environmental Research Journal, researchers assessed the impact of environmental pollutants on body composition.
Study: The role of environmental pollutants in body composition: Systematic review and meta-analysis. Image Credit: vectorfusionart/Shutterstock.com
Studies have consistently shown that pollution significantly impacts increased morbidity, deaths, and years of life lost. Systematic reviews have examined the association of pollution with body composition measurement.
Studies have mainly examined how air pollutants impact body mass index (BMI). Most evidence is provided by cross-sectional studies, which doesn't eliminate the likelihood of reverse causality.
About the study
In the present study, researchers compiled evidence on the link between pollutants and various estimates of body composition.
The study determined whether there is a correlation between environmental pollution and body composition through a systematic review and a meta-analysis. A strategy was developed to include participants of any sex, age, or ethnicity with a higher environmental pollution level, body composition measurements, and longitudinal studies.
The study analyzed various body composition parameters such as body fat, trunk fat, fat mass, total subcutaneous fat, abdominal subcutaneous adipose tissue, android fat, visceral fat, umbilical circumference, gynoid fat, skinfold, adiposity, waist-to-hip ratio, BMI, and waist circumference.
Exposure to environmental pollution included ethanol, lead, chemosterilants, solvents, synergists, rodenticides, 1-octanol, and dimethyl glycol, volatile organic fungicides, turpentine, chloroform, pesticide glycol, acetone, quinolines, ether, 2-bromopropane, dicofol, eucalyptol, compounds defoliants, 2-propanol, molluscacides, trichloroethylene, black organophosphates, repellents, residues, coal, eugenol, toluene, chloride, or mercuric pesticide polyethylene insect herbicides, propylene insecticides, formaldehyde, glycerol, chemical methanol, triacetin, sulfoxide, 4-butyrolactone, and tetrachloroethylene.
The authors utilized various databases to locate relevant studies from the beginning of the database's existence until January 2023. These databases include MEDLINE, Excerpta Medica Database, Scientific Electronic Library Online, Latin American and Caribbean Health Sciences Literature, Web of Science, Scopus, SPORTDiscus, and gray literature.
Out of 3,069 studies found in the initial search, 250 were duplicates. The final systematic review included 18 articles, with 13 of them being used in the meta-analysis. The study comprised 18 articles and 8,563 participants, from young adults to older individuals. Among these, one study involved newborns, 14 involved children, two involved adolescents, and one involved young adults.
The studies reported a total of 47 environmental pollutants. Six studies reported findings on perfluorooctanoate concerning endocrine disruptors.
Five studies involved perfluorooctanoate, p,p-Dichlorodiphenylethylene, and perfluorooctane sulfonate; four involved perfluorohexane sulfonate; and three involved polychlorinated biphenyls.
The studies provided data on BDE-28, BDE-100, BDE-153, o,p-Dichlorodiphenyltrichloroethane, hexachlorobenzene, perfluorodecanoic acid, and p,p-Dichlorodiphenyltrichloroethane.
The study examined the effects of various chemicals, including 2,2-dimethyl cyclopropane carboxylic acid, 2-(N-methyl perfluorooctane sulfonamido) acetate, BDE-154, BDE-47, BDE-99, BDE-207, BDE-209, carbofuranphenol, 3-phenoxybenzoic acid, cyclopropanecarboxylic acid, chlordecone, trans-3-(2,2-dimethyl) cyclopropane carboxylic acid, 3-(2,2-dichloroethenyl), bis(1,3-dichloro 2-propyl) phosphate (BDCPP), dioxin, bis(2-butoxyethyl) phosphate (BBOEP), bis(1-chloro-2-propyl) phosphate (BCIPP), dibutyl phosphate (DBP), bis(2-ethylexyl) phosphate (BEHP), bis(2-chloroethyl) phosphate (BCEP), diphenyl phosphate (DPP), di-o-cresyl phosphate (DCP) perfluoroundecanoic acid and, polycyclic aromatic hydrocarbons.
Sixteen body composition measures were listed. 14 studies reported waist circumference, while BMI was reported in 13 studies. Body fat percentage was described in eight studies. Four studies reported findings on the sum of four skinfolds and waist-to-hip ratio.
The studies reported data on arm circumference and trunk fat percentage. An article described various measures of adiposity, including % adiposity, android fat percent, body fat index Z-score, gynoid fat percent, waist-to-height ratio, the sum of subscapular and tricep skinfold thicknesses, visceral fat, and subscapular-to-triceps skinfold thickness ratio.
Several studies have found a positive correlation between various environmental toxins and measures of body composition, such as waist circumference, BMI Z-score, and body fat percentage.
These toxins include perfluorobutanesulfonic acid, bis(1-chloro-2-propyl) phosphate (BCIPP), polychlorinated biphenyls, hexachlorobenzene, dioxin, p,p-Dichlorodiphenylethylene, perfluorooctanoate, perfluorooctane sulfonate, monoethyl phthalate (MEP), monobenzyl phthalate (MBzP), and bis(2-butoxyethyl) phosphate (BBOEP).
The study found positive correlations between various body measurements and certain chemicals, such as BMI and perfluorooctanoate and perfluorooctane sulfonate, and between fat mass and perfluorobutanesulfonic acid.
Other correlations were found between the waist-to-hip ratio and perfluorobutanesulfonic acid and between subscapular-to-triceps skinfold thickness ratio and perfluorononanoate.
The study revealed a positive correlation between hexachlorobenzene and BMI Z-score, p,p-Dichlorodiphenylethylene, and the sum of skinfolds, polychlorinated biphenyls, and waist circumference. Trunk fat percent was negatively associated with perfluorooctanoate.
No correlation was observed between other pollutants and body composition measures. The study found high heterogeneity in the association between pesticide exposure and waist circumference, with a β value of 1.00.
The study findings indicated that pollutants, particularly endocrine-disrupting chemicals such as dioxins, furans, and pesticides, are linked to alterations in body composition, particularly in waist circumference and the sum of four skinfolds.
The authors suggest that future research should aim to strengthen and solidify the current scientific knowledge regarding various pollutants and their effects on body composition measurements. The influence of factors like physical activity and diet on the association should also be considered.