A major study involving nearly 800,000 Japanese individuals shows that consuming fizzy drinks can “significantly” increase your risk of heart disease and stroke. The study found that the more people spent on fizzy beverages, the more likely they are to suffer cardiac arrest outside of the hospital. 
During cardiac arrest, the heart suddenly stops pumping blood around the body. It is different from a heart attack in that during a myocardial infarction, the supply of blood to the heart is suddenly blocked, usually by a blood clot. Cardiac arrest renders an individual unconscious and stops their breathing.
According to the study’s lead author, Keijiro Saku, professor of cardiology at Fukuoka University in Japan, the acids found in sodas may play a major role in raising cardiac arrest risk.
“Some epidemiologic studies have shown a positive correlation between the consumption of soft drinks and the incidence of cardiovascular disease (CVD) and stroke, while other reports have demonstrated that the intake of green tea and coffee reduced the risk and mortality of CVD.
Carbonated beverages, or sodas, have frequently been demonstrated to increase the risk of metabolic syndrome and CVD, such as subclinical cardiac remodeling and stroke.
However, until now the association between drinking large amounts of carbonated beverages and fatal CVD, or out-of-hospital cardiac arrests (OHCA) of cardiac origin, was unclear.”
Saku noted that this is the first time that the association between drinking large amounts of carbonated beverages and fatal CVD, or out-of-hospital cardiac arrests (OHCA), has been made clear.
Researchers used data obtained from the Ministry of Health, Labour and Welfare of Japan to identify the types of drinks people usually purchased, as well as how much they spent on the various kinds of beverages between 2005 and 2011. No link was found between CVD and OHCA and green tea, black tea, coffee, cocoa, fruit or vegetable juice, and milk and water.
“Carbonated beverage consumption was significantly and positively associated with OHCAs of cardiac origin in Japan, indicating that beverage habits may have an impact on fatal CVD.
“The acid in carbonated beverages might play an important role in this association.”
The professor made sure to clarify that the team of scientists had not concluded that drinking fizzy beverages raised the risk of cardiac arrest, merely that the more people buy the drinks, the more likely they are to suffer one.
“Our data on carbonated beverage consumption is based on expenditure and the association with OHCA is not causal. But the findings do indicate that limiting consumption of carbonated beverages could be beneficial for health.”
Although the study did not show a causal relationship, it certainly suggests one, and we already know that drinking a lot of soda can lead to obesity and Type 2 diabetes, which can cause heart disease.