“Controversy persists on the association between dairy products, especially milk, and cardiovascular diseases (CVD). Genetic proxies may improve dairy intake estimations, and clarify diet-disease relationships,” the study stated.
Nutritional biomarkers provide objectivity
The study identified a method of measuring a patient’s intake of milk and dairy products that goes beyond traditional methods of questionnaire and interview-based research. Instead, the team of scientists discovered a specific nutritional biomarker or genetic proxy - the minichromosome maintenance complex component 6 (MCM6) - that can objectively measure food intake without relying on patient memory recall of his or her diet.
“As far as we know, this is the first time that a meta-analysis in multi-ethnic populations has shown a strong association of the MCM6 with total dairy intake, mainly milk.”
Using the identified genetic proxy, MCM6, researchers were able to accurately estimate dairy intake estimations, and better evaluate the associations between lactase persistence, dairy intake, and CVD biomarkers of 20,031 patients. The participant pool was comprised of Americans including African American, Latino, and Caucasian test subjects and Mediterranean populations.
According to the study’s findings, MCM6 was strongly associated with higher milk intake, but scientists saw little or no correlation with glucose and lipid levels, and no association with CVD or mortality in the whole population.
Sex-specific results
“We confirmed that the MCM6-rs3754686, previously identified as a widely-distributed marker of lactose tolerance, is a good proxy for milk intake in Southern European (Mediterranean from Spain) and American populations (including African Americans, Hispanic Americans, US Puerto Ricans and whites), the T-allele being associated with higher dairy intake, especially with milk,” the study stated.
The researchers also said that the results of the study’s meta-analysis also suggest a greater association of the T-allele with milk intake in women than men. Due to these observations, researchers said they intend to research the women and men separately in a follow-up study.
“Although we observed the association between the MCM6 and milk intake to be statistically significant on studying men and women jointly, we wished to also investigate the associations in men and women separately given that previous studies had not provided these data in detail and that prior evidence exists for sex-based heterogeneity both in milk intake and CVD risk.”
Smith, C. E. et al.
Associations of the MCM6-rs3754686 proxy for milk intake in Mediterranean and American populations with cardiovascular biomarkers, disease and mortality:Mendelian randomization.
Sci. Rep. 6, 33188; doi: 10.1038/srep33188 (2016).