Men who drink Coca-Cola have higher levels of testosterone compared to their peers.
A new study from Minzu University in China found that men who drink Coca-Cola have higher levels of testosterone than others.
The new study contradicts research that sugary drinks make people less fertile.
A high caffeine intake boosts testosterone production in the body.
The study found drinking Pepsi had a similar effect, but the long-term effects have yet to be established.
Experts are not suggesting that men should rush out and drink lots of Coca-Cola or Pepsi, as previous studies have linked sugary sodas to other health problems.
These include obesity, diabetes, heart disease, high blood pressure and tooth decay.
The experiment was carried out using mice.
A group of 30 male mice was kept in a cage, and their water bottle was filled with 50 percent Pepsi mixed with tap water.
Another 30 mice were kept in a different cage and given pure Pepsi, and the same was done for two groups of mice but with Coca-Cola.
A fifth group was used as a control and given pure water.
The mice drank the different liquids over 15 days.
The mass of the mice's testicles was measured on days zero, five, seven, 10, 13 and 15.
On day 15, the mass of the mice's testicles was significantly higher in the groups that drank Coca-Cola and 100 percent Pepsi, compared to the 50 percent Pepsi and control groups.
The findings were published in the journal Acta Endocrinol.