Study on influence of age, gender and genetic variants on lactose intolerance and its impact on milk intake in adult Asian Indians

Background: Lactase non-persistence (LNP) has been associated with the CC genotype of -13910C>T and GG genotype of -22018G>A polymorphisms present upstream of the lactase gene. Lactose intolerance (LI) is caused when gastrointestinal symptoms develop in individuals with low lactase activity. Objective: To analyse association of LNP genotype and LI symptoms with milk intake and determine whether factors such as age, gender and genotype affect LI status. Subjects and methods: Genetic analysis and lactose tolerance test (LTT) were performed on 205 healthy Indian adults. The pattern of milk consumption was recorded using a dietary questionnaire. Results: LI was strongly associated with -13910CC genotype (OR = 10.28, 95% CI = 2.32-45.55, p = 0.002). Females were found to be at a higher risk of developing LI (OR = 2.47, 95% CI = 1.33-4.59, p = 0.004). The association of the >= 50 years age group with LI was marginally significant (OR = 1.86, 95% CI = 0.995-3.47, p = 0.05). Frequency and quantity of milk intake were lower in subjects belonging to the LNP genotype and LI groups (p<0.05). Conclusions: Subject study suggests that gender and genotype may be associated with development of LI. Association of age with LI was marginal. The data also indicate that LNP genotype and LI may play a role in influencing milk intake in individuals.