Drinking milk is associated with a lower risk of type 2 diabetes in people who are lactose intolerant, according to new research from the United States.
Dr Qibin Qi and colleagues from the Albert Einstein College of Medicine in New York published the findings of their research in Nature Metabolism.
Dr Qi is professor of epidemiology and population health at the college and a member of the National Cancer Institute-designated Montefiore Einstein Comprehensive Cancer Center.
Previous studies investigating the relationship between milk intake and risk for developing type 2 diabetes had yielded conflicting results, prompting the researchers to look at it from a different angle.
They analysed data from about 12,700 adults enrolled in the Hispanic Community Health Study/Study of Latinos.
About half of these people were able to digest lactose.
The other half were lactase non-persistent.
This meant they were likely to be lactose intolerant because they had inherited a variant of the lactase gene that made them unable in adulthood to synthesise lactase, the enzyme needed to digest the milk sugar lactose.
The researchers observed increased milk intake appeared to lower the risk of type 2 diabetes only among people who might have trouble digesting lactose in adulthood.
Digging deeper, the researchers found this might be related to changes in the gut microbiota of lactose-intolerant people when they drank milk.
It could also be related to change in circulating metabolite profiles.
For those who could digest lactose, no association with type 2 diabetes risk was observed.
Researchers said if these findings were validated, they could reshape dietary recommendations for lactose-intolerant people and lead to targeted use of probiotics to reduce the risk for type 2 diabetes in the general population.