Associations of the lactase persistence allele and lactose intake with body composition among multiethnic children

Abstract

Childhood obesity is a worldwide health concern with a multifaceted and sometimes confounding etiology. Dairy products have been implicated as both proand anti-obesogenic, perhaps due to the confounding relationship between dairy, lactose consumption, and potential genetic predisposition. We aimed to understand how lactase persistence influenced obesity-related traits by observing the relationships among lactose consumption, a single nucleotide polymorphism (SNP) near the lactase (LCT) gene and body composition parameters in a sample of multiethnic children (n = 296, 7-12 years old). We hypothesized that individuals with the lactase persistence (LP) allele of the LCT SNP (rs4988235) would exhibit a greater degree of adiposity and that this relationship would be mediated by lactose consumption. Body composition variables were measured using dual X-ray absorptiometry and a registered dietitian assessed dietary intake of lactose. Statistical models were adjusted for sex, age, pubertal stage, ethnic group, genetic admixture, socio-economic status, and total energy intake. Our findings indicate a positive, significant association between the LP allele and body mass index (p = 0.034), fat mass index (FMI) (p = 0.043), and waist circumference (p = 0.008), with associations being stronger in males than in females. Our results also reveal that lactose consumption is positively and nearly significantly associated with FMI.

Association of Lactase Persistence Genotypes with High Intake of Dairy Saturated Fat and High Prevalence of Lactase Non-Persistence among the Mexican Population

“…Corella et al [18] described that their finding of LCT -13910 C>T SNP associated with obesity was modulated by lactose consumption, namely with a moderate or high lactose intake of more than 8 g/day. Since milk and dairy products are often rich in energy and fat content, there is a likelihood of an increased risk of obesity and metabolic syndrome to an immoderate consumption of these products [41]. In accordance with this data, in our study population, a higher intake of dietary SFAs and a daily or frequent intake of milk and dairy products were associated with the LP genotype.…”

Association of lactase persistence genotype with milk consumption, obesity and blood pressure: a Mendelian randomization study in the 1982 Pelotas (Brazil) Birth Cohort, with a systematic review and meta-analysis

“…For some studies 13 , 16 , 19 , 30 , 43–52 it was necessary to calculate the standard error of the mean difference (SE). This was performed as follows: $\text{SE\hspace{0.17em}=\hspace{0.17em}}\sqrt{{\text{s}}_{\text{CC}}^{\text{2}}{\text{/n}}_{\text{CC}}{\text{+s}}_{\text{LP}}^{\text{2}}{\text{/n}}_{\text{LP}}}\text{,}$ where and s i and n i are the standard deviation and sample size, respectively, for non-LP (i = CC) and LP (i = LP) individuals.…”

Complex Interactions of Obesity, Dairy Food Intake and Genetics of Lactase

“…In addition to lactase persistence associated with BMI, 2 studies concluded that dairy consumption was also increased in lactase persistent persons [99,101].The reports by Corella et al and by Malek et al also found increased lactose intake to be also associated with obesity in addition to lactase persistence [100,103]. In the study by Corella et al men were more affected than females [100].…”

“…One caveat is there should be no horizontal pleiotropy, where the genetic trait affects the outcome independent of exposure [97]. Table 2 outlines 10 studies which have examined the association between lactase persistence, features of obesity and dairy intake [98][99][100][101][102][103][104][105][106][107]. Three studies only evaluated relationship between lactase persistence status and obesity [98,102,106].…”

“…Seven of the studies also included dairy consumption [99-101, 103-105, 107]. Three of the 10 studies were restricted to children or young adults [102,103,106]. Three studies carried out Mendelian randomization methods [104,105,107].…”