We’ve been hearing how bad sugar can be for years, but an alarming new study from researchers at Harvard’s School of Public Health shows just how serious the risks can be. According to a report from the Independent, drinking just one beverage sweetened with sugar can raise the chances of getting a heart attack by 35 percent.

The study also showed that just one sugary beverage can increase the risk of developing type 2 diabetes by 26 percent, and increases the risk of stroke by 16 percent. Sugar is nearly impossible to avoid when choosing a beverage, and is putting a serious number of people at risk of life-threatening health issues.

Scientists examined data from a large collection of studies to determine what health effects sugary drinks with added high fructose corn syrup or sucrose (table sugar) actually had.

They found that the way the body metabolizes fructose, by far the most common type of sugar added to sweeten beverages, is a large part of the problem. Metabolizing fructose creates byproducts that can cause disease to the fatty liver tissues or resistance to insulin, both of which increase the risk of developing diabetes or heart disease.

The study also found that half of the U.S. population consumes at least one drink with sugar added to it daily. This, they say is the single biggest source of added sugar consumption in the entire country.

The study’s lead author, Dr. Frank Hu, explained that the findings should be sounding alarms for public health strategists seeking to cut down on national consumption of these beverages. Even though reducing the intake of these beverages isn’t going to decrease the obesity problem faced by the country, making this simple change would almost certainly produce a measurable impact on national weight levels and reduce the overall instances of cardiovascular diseases.

The study also revealed a frightening aspect of sugary drinks; they have nothing in them that would make a consumer feel satisfied or “full.” In spite of containing an outrageous number of calories, these sugary drinks do little to reduce the calories a person would consume during their next meal. If you’ve ever heard the term “empty calories,” it refers primarily to products with this quality.

Despite uncertainty about their overall health effects, Dr. Hu suggested that “diet” or artificially sweetened drinks could be better for people in the short-term for losing weight and reducing the risk of heart attacks and strokes. There is little available research about the long-term effects of drinking diet sodas.

The Scientific Advisory Committee on Nutrition advised the British government this July to cut the current recommended daily consumption of sugar in half, to a level of just five percent of the total daily calorie intake. This would mean that a single serving of soda could exceed the daily-recommended values, which could have serious implications for the beverage packaging industry.

We have known that sugar poses serious risks to overall health for quite some time. Previous studies indicate that this problem has been ongoing for many years. As of 2014, added sugars accounted for at least 10 percent of the calories consumed by an average American in a given day. This average is skewed, however, when we learn that roughly ten percent of Americans get more than 25 percent of their daily calories from added sugar.

A 15-year study showed that participants who consumed 25 percent or more of their calories from added sugar were twice as likely to die from cardiovascular disease when compared to people who consumed less than 10 percent of their calories from added sugars. The chances of dying from cardiovascular disease rose alongside the percentage of sugar in a person’s diet regardless of factors like age, sex, physical fitness, and body-mass index.

The real killers are beverages with sugar added, like sodas, sports drinks, and energy drinks. Many Americans fail to perceive these products as being crammed to the lid with added sugars, and treat them as if they are simply another part of a balanced meal. Together, the beverages we choose as a country account for more than one third of the added sugar the United States consumes as a whole. Other major sources of added sugars are typical sweets, including cakes, cookies, pastries, fruit drinks, ice cream, candy, and sugary cereals.

There are two major reasons that nutritionists have warned against sugar until the implications for cardiovascular health became apparent. First, sugar is known to cause both weight gain and cavities in the teeth. The second readdresses the issue of “empty calories.” By filling up yourself with sugary foods and beverages, you actually take up dietary space and resources that could have been devoted to more healthy options with essential nutrients like fiber, vitamins, and minerals that your body needs.

It isn’t as simple as just swapping out the sugar, with better foods, however. Reversing the ill effects of sugar has proven extremely difficult, as it appears to have a negative effect on cardiovascular health across the board, regardless of other aspects of a person’s diet. People who scored high on the Healthy Eating Index, but still consumed a higher amount of sugar, faced increased risk of mortality from cardiovascular disease.

It remains unclear as to whether or not there is still a “safe” level of sugar to consume. Research has shown that drinking beverages with sugar added can increase blood pressure as well as the level of harmful fats from the liver in the bloodstream.

Federal guidelines seek to cap the amount of salts and fats people consume, but there is no guideline for added sugar. According to the Institute of Medicine, added sugars should make up no more than 25 percent of total calories consumed. This advice was issued in 2002, however, and recent research indicates that people who consume more than 25 percent of their daily calories from added sugar face a significantly higher risk of mortality from cardiovascular issues.

The American Heart Association recommends that women consume fewer than 100 calories of added sugar per day, about six teaspoons. Men were suggested to limit sugar consumption to less than 150 calories per day, or about 9 teaspoons.

A single 12-ounce can of soda has an average of 9 teaspoons of sugar, so a woman drinking a can of coke with lunch is already exceeding this safe level. Doctors and nutrition experts recommend quenching the desire for sweet flavors with natural sugars that come from fruit. One of the best ways to cut down on soda is to mix carbonated water, or seltzer, with a little bit of fruit juice to provide the flavor and feel without any of the added sugar.

There are clearly way too many sources of added sugar available in American diets today, and with each subsequent study the health risks become more apparent. Tougher guidelines paired with a stronger push to educate people about the real risks of sugar would go a long way in reducing overall obesity and mortality rates in the country.