Interestingly fruit juice, which has a high component of sugar, did not produce the same result in these women. "Maybe that is due to the fact that juice contains a naturally occurring sugar from fruit or that the body handles it differently due to the fact that it also has some nutritional value, unlike soda," points out Porucznik.
The study followed 259 women over two menstrual cycles, who all underwent 16 blood draws and completed 8 comprehensive dietary questionnaires. While investigating the relationship between caffeine and hormones, the researchers noticed that consuming soda seemed to have an effect. So, they designed this analysis to study how drinking soda might affect hormones.
In conclusion, women who drank more than a cup of regular (not diet) soda a day had higher levels of estrogen than those who drank less regular soda, diet soda, or fruit juice.
"I think this study could raise some other potential questions if done in a group where we have longer follow-up time—many years—and then we can look at historical patterns of soda drinking and outcomes," Porucznik says.
She adds that over years, soda drinking may be a transient variable and one that is difficult to measure, yet she sees this study as a red flag worth paying attention to.
"We already know added sugar is linked to obesity and diabetes and now reproductive hormone levels. It is one more piece of evidence that needs to make us ask, 'Is this added sugar really worth it to me?'"