A recently published study investigated the association between the consumption of dairy products, particularly nonfermented milk and those with high-fat content, and all-cause mortality rates.
Dairy products are often viewed as healthy, providing nutrients and energy to the consumer. There are, however, studies that contradict this claim, suggesting that dairy products may be associated with certain medical conditions. It is important to keep in mind that, as of now, results on the issue vary by study and have been generally rendered inconclusive. A research study conducted in Sweden, a country with high dairy product consumption, found a positive correlation between nonfermented milk and all-cause mortality for both women and men. The study published in the American Journal of Clinical Nutrition places emphasis on the fat content of dairy products and nonfermented milk and studies their association with all-cause mortality.
Conducted in Northern Sweden, the study consisted of 103,256 participants, of which 51% were women. All-cause mortality was compared with the intake of nonfermented milk, fermented milk, butter, and cheese. The data was adjusted to factor in age, sex, education, intake of energy, body mass index, amount of physical activity, and smoking status. Dietary lifestyle information was gathered through a questionnaire which each participant was required to complete. A single nucleotide polymorphism associated with lactose tolerance was genotyped for analysis of the role of genetics in any correlations. Data pertaining to mortality was acquired from the Swedish national cause-of-death registry.
Increased consumption of nonfermented milk, equal to or more than 2.5 times a day, equated to a 32% increase in the risk of all-cause mortality in comparison to the consumption of less than or equal to one time a week. In a similar consumption trend for butter, there was a corresponding increase of 11% in the risk of all-cause mortality. Hazard ratios varied among different types of nonfermented milk fats, however, a positive correlation was identified in each case. Lower fat content exhibited lower hazard ratios for milk products. In contrast, fermented milk and cheese consumption was inversely correlated to all-cause mortality. Increased consumption of these products indicated lower hazard ratios for all-cause mortality. No evident association was determined between the genotype of the single nucleotide polymorphism and mortality.
The results of this research study further add to the inconclusive nature of risk factors associated with dairy products. While the study found dairy products with high-fat content to be positively correlated with mortality risk, fermented milk, and cheese products displayed opposing trends. Despite the differing results, the study provides evidence for potential risk factors associated with dairy products. The study portrays the multi-faceted and complex impact of dairy on the human body, consisting of benefits and risks simultaneously. Dietitians and nutritionists may find the information beneficial in recommending specific types of dairy over others. With further research conducted in a larger population and placing emphasis on lifestyle factors, we may reach a conclusion on the long-held debate about the consequences of dairy consumption.
Reference
- Tognon G, Nilsson LM, Shungin D, et al. Nonfermented milk and other dairy products: Associations with all-cause mortality. The American Journal of Clinical Nutrition. 2017;105(6):1502-1511. doi:10.3945/ajcn.116.140798
