Sugar-sweetened beverages are the largest source of added sugar in the American diet. The over consumption of sugar-sweetened beverages is linked to insulin resistance and to multiple diseases including obesity, type 2 diabetes, cardiovascular disease, and gout. One group of investigators aimed to determine the relationship between sugar-sweetened beverage consumption and serum testosterone.
Testosterone is essential for masculine development during puberty and reproductive capacity in adult males. Epidemiological evidence has revealed higher serum testosterone levels in males without diabetes compared to males with diabetes and in active males compared to sedentary males. Previous clinical research has reported a relationship between sugar-sweetened beverage consumption and decreased sperm motility and fertility; however, its relationship with testosterone has not yet been demonstrated.
The authors reviewed data from the 2011-2012 National Health and Nutrition Examination Survey, a large-scale survey research project that tracks the health and nutrition of adults and children in the United States over time. Research staff for this project administer an interview to participants to collect dietary and demographic information and medical, dental, and laboratory tests to collect physiologic measures.
The investigators of this report specifically chose a sample of younger males (between ages 20 and 39 years) because this is the period when fertility is highest. They categorized participants (545 males total) into four levels of sugar-sweetened beverage consumption with participants in the lowest level consuming 137 calories of sugar-sweetened beverages or less per day and the highest consuming 442 calories or more per day.
Ninety percent of participants had a normal testosterone level, defined as greater than 231 nanograms per deciliter. Participants in the highest level of sugar-sweetened beverage consumption were more than twice as likely to have low serum testosterone. After taking into account other factors, including age, race/ethnicity, poverty/income, tobacco and alcohol consumption, and physical activity the authors also found that participants with overweight and obesity were nearly four times more likely to have low serum testosterone compared to lean males, independent of sugar-sweetened beverage consumption.
This report demonstrates that sugar-sweetened beverage consumption and higher body mass index were both associated with lower testosterone levels in males. These associations were independent of each other and not due to other demographic and lifestyle factors.