The Not-So-Sweet Facts About Soda

Sugar-sweetened beverages are the largest source of added sugar in American diets, and it's no surprise that soda sales in this country are huge. According to an industry report, 8.9 billion cases of the sugary drink were sold last year. Is it any wonder that more than 78 million American adults are obese? In 2013, the Harvard School of Public Health revealed that 25,000 obesity-related American deaths from diabetes, cardiovascular disease and cancer were linked to sugar-sweetened drinks. And the latest research is just as bleak.

A study published in October in the American Journal of Public Health discovered that a soda a day can age you as many as 4.6 additional years. After analyzing the data and DNA taken from 5,309 participants of an ongoing health survey between 1999 and 2002, researchers found that those who drank a daily soda had shorter telomeres than those who drank less.

Telomeres, the protective structures that cap the ends of chromosomes, sense danger in the cellular environment, says Elissa Epel, senior study author and a professor of psychiatry at the University of California--San Francisco School of Medicine. "Short telomeres predict earlier onset and worse prognosis of many diseases of aging," she says. "Aging and biochemical stressors can shorten or damage telomeres. In some studies, they also predict earlier mortality."

Drinking 8 ounces or 1 cup of soda a day was significantly associated with shorter telomeres, the researchers found, and the association was proportionately larger for the daily intake of 20 ounces or one bottle of soda. "Consuming sugary sodas leads to a rapid intake of calories and sugars and subsequent insulin response," says study author Cindy Leung, a postdoctoral scholar at UCSF's School of Medicine. "This results in several biochemical changes, such as insulin resistance, oxidative stress and inflammation. All of these processes are known to influence the shortening of telomeres, as well as increase the risk of diabetes and cardiovascular disease."

The study examined the consumption of other sugary drinks as well -- non-carbonated sports and energy drinks and 100 percent fruit juices. "The only negative association we found," Leung says, "was between drinking sugary sodas and telomere length, which we attribute to the high sugar content."

Soda consumption can also have a profound effect at the neurological level. A study published online in September in the journal Hippocampus found that adolescent rats given sweetened solutions containing sugar or high-fructose corn syrup in concentrations common in sodas suffered from memory impairment and swelling in the hippocampus of the brain, which manages memory formation. They also became prediabetic.

The rats were placed in mazes that tested their spatial memory. Adolescent rats that consumed the sugary solutions performed the worst among all the test groups, leading the study authors to believe that the inflammation of the brain may have had an effect. That's unsettling news when one considers that children ages 2 to 19 annually consume 7 trillion calories from sugar-sweetened beverages alone, according to research from the Harvard School of Public Health.

So the news is not good. If you're addicted to soda, what can you do? Danielle Capalino, a registered dietitian practicing in New York, says, "it's important to visualize what it means when a soda label says it has 65 grams of sugar in a 20-ounce drink. Every 4 grams of sugar is equivalent to about 1 teaspoon, which means there are about 16 teaspoons of sugar in a 20-ounce drink. Drinking soda is drinking empty calories. It is sugar with no nutrients -- no protein, no fiber, no vitamins."

A study published online in the American Journal of Public Health in October found that visualization tools can help influence one's dietary choices. Adolescents who saw signs conveying the fact that it would take 50 minutes of running or five miles of walking to burn the calories in a 20-ounce bottle of soda were more likely to buy a healthier or smaller size beverage, or one with less calories.

"Americans generally have poor knowledge of nutrition and are not good at mental math," says study author Sara N. Bleich, an associate professor in the department of health policy and management at Johns Hopkins University Bloomberg School of Public Health. "So, it is not reasonable to expect someone to know how the calories of a single item fit within their total recommended daily calories -- and to figure this out quickly at the point of purchase. People can relate to walking, and it's easy to understand."

To help kick the soda habit, Capalino advises folks to cut their soda intake in half -- "it can be easier to take small steps to break a habit" -- and try to avoid diet soda. "I often hear people trying to swap regular soda for diet soda as a way to transition from the sugar. I don't think that's a good idea because artificial sugar makes you seek sweetness in other foods, so in the end [you're] not saving any calories," she says. "As an alternative, I would suggest drinking unsweetened iced tea. It gives you a bottle to hold onto, without the sugar or artificial sugar, and you get the antioxidants from tea with the optional caffeine. Herbal tea is great, too." And, Capalino adds, "most of my patients don't drink nearly enough water, so plain old water should not be overlooked as the ultimate beverage choice."

Says Leung: "We know from previous large-scale studies that drinking sugary beverages increases our risk of weight gain, diabetes, cardiovascular disease, some cancers and more. There is no level of sugary soda that is healthy. We recommend drinking healthy beverages such as water and unsweetened teas and coffees instead of any sugary beverages."