Lactose digestion capacity and perceived symptomatic response after dairy product consumption in Tokelau Island migrants

When lactose-malabsorbing individuals use dairy products decreased lactase activity and the subsequent reduction in hydrolysis of ingested lactose can result in gastrointestinal and gaseous symptoms (lactose intolerance). This article examines lactose malabsorption, perceived gastrointestinal symptoms, and dairy product consumption in a Tokelau Island migrant population in New Zealand. Questionnaire data were collected and lactose digestion capacity was determined for 58 individuals 15-71 years of age. Additional questionnaire data were collected for 137 Tokelau migrants, 18-50 years of age. Breath hydrogen analysis indicated that 63.8% (CI = 51.4-76.2%) of Tokelau migrants were lactose malabsorbers, while 22.4% (11.7-33.1%) can absorb lactose [results are inconclusive for 13.8% (4.9-22.7%) of the population]. This was consistent with results reported for other Polynesian populations. Tokelau Island migrants reported relatively low levels of gastrointestinal distress after the consumption of daily products. Less than 50% of those with lactose malabsorption perceived gastrointestinal symptoms after a 50 g of lactose in 300 ml of water, while one third of this group reported symptoms after approximately 240 ml (one glass) or less of milk. However, without confirmation by double-blind studies, it is difficult to state the extent to which symptoms are actually due to lactose. Neither the ability to absorb lactose nor perceived gastrointestinal symptoms are associated with the frequency or quantity of dairy product consumption (P > 0.05). Patterns of dairy product consumption are just as likely due to other physiological, psychological, cultural, and social factors. Am. J. Hum. Biol. 9:233-246, 1997.