Women who drink regular soft drinks every day are much more likely to have a stroke than women who rarely drink pop or other sweetened beverages, say Japanese researchers.

Though many studies have linked sugary drinks to a number of health concerns, including heart attacks, obesity and diabetes, none has been able to prove that soft drinks caused any of the health ills. This study too was not able to prove a cause and effect relationship between soft drinks and the increased stroke link the researchers noticed.

Still, the study is a large once, published in the American Journal of Clinical Nutrition, and involving nearly 40,000 Japanese men and women.

For the study, researchers asked the participants to fill out questionnaires listing their typical daily food and drink choices , first in 1990, then in 1995 and again in 2000.

They then split the participants into four groups based on how much pop they drank. those who rarely drank soft drinks, those who had one to two drinks a week, those who had three to four a week, and those who had a soft drink every day or nearly every day.

The researchers focused on all sugar-sweetened pop and fruit drinks, but not diet sodas or 100 per cent fruit juices.

During 18 years of follow-up, the researchers noted more than 1,900 strokes among the participants.

They found that women who drank sugary drinks almost every day were 83 per cent more likely than those who rarely drank them to suffer an ischemic stroke, the most common kind of stroke caused by clogged arteries.

Interestingly, they found no such link in men. Nor did they find that high soft drink consumption was linked to higher heart disease rates in either gender.

The American Beverage Association, which represents soda and other soft drink makers, dismissed the study, saying it didn’t add much new information.

"This study does nothing to educate people about the real causes of heart disease or heart health issues," the association said in a statement.

"It only shows what we already know to be among the risk factors for heart disease: ethnicity and age. There is nothing unique about soft drinks when it comes to heart disease, stroke or any other adverse health outcomes."