Sweetened sodas are hugely popular throughout America. Because they are consumed in such volume, any negative health effects should be thoroughly investigated. In this article, we ask whether soda does indeed increase the risk of diabetes.
The average can of soda is roughly 20 ounces and contains 15-18 teaspoons of sugar and more than 240 calories.
These high levels of quick-digesting carbs do not lower calorie intake at mealtimes. In other words, they are an addition to the daily calorie intake, rather than a replacement.
In modern society, the effects of this excessive energy intake are worsened by people's lower levels of physical activity. Because of sedentary lifestyles, the energy sodas provide is often not needed and is stored in the body instead.
Contents of this article:
Fast facts on soda and diabetes
Here are some key points about soda and diabetes. More detail and supporting information is in the main article.
- Although there is a link between diabetes and soda consumption, the reasons why are still unclear
- Soda that is cola-flavored my carry additional risks
- Some studies show a relationship between excess soda in the diet and heart problems
- There appear to be links between drinking sweetened beverages and gout
Soda and diabetes
People who drink one, two, or more cans of soda a day are much more likely to develop type 2 diabetes than people who rarely drink soda.
In fact, according to a study published in 2010, the risk of developing diabetes is 26 percent higher for people who have one or more sugary drinks each day.
Young adults and Asians who consume one or more sweetened drinks daily are at an even greater risk of developing type 2 diabetes.
How does drinking sweetened drinks lead to diabetes?
The biology behind the soda/diabetes relationship is still up for debate.
Drinking too many sweetened drinks means that the body stores excess energy in the form fat, so, drinking too much soda can play a part in people becoming overweight or obese.
Research has shown that being overweight or obese is a risk factor for type 2 diabetes and other conditions.
Although research has proven a clear association between high-sugar consumption and diabetes, the scientists involved in the research are still unsure of the reasons behind it.
A review of relevant studies, compiled in 2015, confirmed the relationship between diabetes and sweetened drinks, however, the exact biological mechanisms were still unclear.
One study, published in The American Journal of Clinical Nutrition, investigated relationships between the diet and health of 91,249 female nurses over 8 years. They found a link between a high glycemic index diet and type 2 diabetes.
Foods with a high glycemic index, such as sugary foods or sweetened soft drinks, are digested more quickly than low glycemic index foods, causing a quicker spike in blood sugar levels.
The risk for diabetes was high even after taking into account other known risks and dietary factors involved in diabetes. In fact, the diabetes risk associated with high energy intake was greater than that of trans fatty acid intake or an unhealthy ratio of polyunsaturated to saturated fats.
The authors explained possible ways in which high sugar intake could lead to diabetes:
- Higher blood glucose concentrations from a high load of quick-digesting carbs mean more demand for insulin, the hormone produced by the pancreas to regulate these blood sugars
- Higher demand for insulin in the long-term creates "pancreatic exhaustion that can result in glucose intolerance"
- High-glycemic-index diets may directly increase insulin resistance
Soda link to diabetes may not be direct
The 2015 review, mentioned above, is one of many papers to claim that the association between obesity and diabetes is clearer than a more direct link between a high-sugar diet and diabetes.
The review also backed the idea that obesity is caused by high sugar intake via an increase in total energy consumed. In other words, since people tend to add sugared beverages to their daily caloric intake, it is likely the increase in calories that leads to the increase in weight.
Published in the journal Nutrition Reviews in 2015, the paper also investigated the idea of sugar-sweetened drinks causing type 2 diabetes more directly. They concluded that research in this area had not yet been able to rule out other factors, such as obesity, and that further research is needed.
Another recent article, investigating the relationship between sugar-sweetened drinks and diabetes, used soda consumption data from 11,684 people with type 2 diabetes and compared it with 15,374 people without diabetes.
The team found that those who drank one or more sweetened drinks every day had a higher risk for diabetes versus the people who drank less than one glass a month. Even when energy intake and body mass index (a measure of weight) were accounted for, the high soda drinkers still had a higher risk for type 2 diabetes.
The authors of the report speculated how sugar-sweetened drinks could potentially cause type 2 diabetes, but, like other researchers, could offer no firm conclusions. Their study could not prove causation, only correlations.
The authors did, however, suggest that the link could be due to "an effect on weight gain," as well as the "glycemic effects" of sugar-sweetened drinks "inducing rapid spikes in glucose and insulin and causing insulin resistance."
Other health risks of drinking too much soda
Diabetes is not the only health issue related to soda consumption.
If soda is drunk to excess, it is not just type 2 diabetes that becomes more likely. One study, published in The New England Journal of Medicine, took data about lifestyle and disease over the course of 20 years, starting in 1986.
Their risk of heart attack was 20 percent higher than the men who rarely drank soda. Other studies have found a similar increased risk in women soda drinkers, too.
Another disease that is more common in people who drink a can of soda each day is gout, a painful inflammatory arthritis condition.
A study from 2008 that followed 80,000 women over 22 years found that those who consumed a can of soda a day had a 75 percent higher chance of gout when compared with those who rarely drank soda. Further investigations by the same team uncovered a similar risk for men; they also found that the risk for gout was not present if diet soft drinks replaced sweetened sodas.
Cola-color cancer risk
Cola-colored sodas present another potential health hazard due to the process of manufacturing the caramel color. This process can create cancer-causing levels of a chemical known as 4-MEI, short for 4-methylimidazole.
While high levels are outlawed in some places, such as California, a study published in the journal PLoS One found high levels among 110 samples of various soda brands purchased in California.
In California, products with 4-MEI levels that that pose a cancer risk of more than one case per 100,000 exposed persons, should carry a warning label. An intake of 29 mcg or more of 4-MEI, per day, is considered to produce this level of cancer risk.
The research team, from the Johns Hopkins Center for a Livable Future in Baltimore, MD, found that the drinks they analyzed had 4-MEI levels ranging from 9.5 micrograms per liter (mcg/L) to 963 mcg/L.
Is diet soda harmful?
The study mentioned above, which followed over 90,000 female nurses over 8 years, found that the risk of type 2 diabetes disappeared when they replaced sugar-sweetened soft drinks with diet ones.
Another study followed thousands of people's sweet drink habits and compared those who developed diabetes with those who did not. They did find a link between artificially sweetened drinks and diabetes. However, further analysis showed that those with higher diet soda intake were more likely to already have, or be at higher risk for, diabetes. The effect also disappeared from the analysis when their higher BMI was taken into account.
Not all researchers are convinced by diet soda, though. One reviewer, writing in 2013, said "frequent consumption of high-intensity sweeteners" may have an effect opposite to that desired. It may create "metabolic derangements."
The author, Susan Swithers, writing while at the Ingestive Behavior Research Center of Purdue University, West Lafayette, IN, concluded:
"Current findings suggest that caution about the overall sweetening of the diet is warranted, regardless of whether the sweetener provides energy directly or not."
Overall, as with so many aspects of nutrition, moderation is key. Too much of any product is likely to be unhealthy, especially if it contains high levels of sugar.