By Nour Zibdeh, MS, RD, CLT
Soda may be your drink of choice at the movie theater, or perhaps it’s your middle-of-the-day caffeine boost with lunch. But that same sweet, flavorful liquid that tickles your taste buds wreaks havoc on your health. Every time you reach for a soda, you’re putting yourself at risk for a fuller waist, weaker bones and several other health problems — including heart disease. Here are seven reasons to stop mid-sip, and put down the soda for good.
Soda drinkers are more likely to gain weight and become obese than those who prefer other beverages to quench their thirst. No surprise there: a 12-oz can of pop packs between 140 and 180 calories, and it’s easy to chug down a 16- or 20-oz bottle a day. Calories from soda are essentially “empty calories” — they don’t carry any nutritional value, and won’t satisfy your hunger.
But did you know that reaching for calorie-free diet soda instead may be just as bad for your waistline? In one study that followed 474 people for 10 years, diet soda-drinkers packed on more belly fat than soda abstainers. As a whole, diet-soda drinkers had a 70 percent greater increase in waist circumference than those who didn’t drink any soda; the "heavy drinkers" — people who averaged two or more diet sodas a day — had 500 percent larger increases in waist circumference than people who avoided soda altogether. Belly fat is worse than fat stored elsewhere on your body: it dramatically increases your risk for cardiovascular disease, type 2 diabetes and other health problems.
How do artificial sweeteners lead to weight gain? They increase sweet cravings and appetite for food. When you drink diet soda, the sweetness you taste makes you feel good. This drives you to want more sweets to get the same feel-good sensation you just experienced. However, when you drink diet soda, no sugar reaches the brain. Studies show that sucrose (regular sugar) and artificial sweeteners affect sweet receptors differently in your brain, and the pathways that give you pleasure from eating don’t get fully activated. The result? Your brain is not satisfied, and you will end up eating more sweets to get satiated.
Weight gain and belly fat increase your chances of developing a disease that is becoming all-too common in the U.S.: type 2 diabetes. Being overweight — particularly around your middle — is one of the biggest risk factors for type 2 diabetes. A study of more than 6,000 middle-aged adults found that people who consumed one or more soft drinks a day were over 50 percent more likely to have metabolic syndrome than people who drank soda less than once a week. Metabolic syndrome is a host of symptoms, including large waist circumference, obesity, abnormal lipid level and high blood pressure, that dramatically increases risk for type 2 diabetes.
In a study that followed 42,000 men for 22 years, frequent regular soda consumers had elevated levels of triglycerides, C-reactive protein and other inflammatory factors, and lower levels of heart-protective, "good" cholesterol — all signs that soda hurts heart health. Notably, soda drinkers were much more likely to suffer a heart attack over the course of the study: each soda that participants drank on a daily basis increased their chances of heart attack by 19 percent, even after other variables, like diet quality and BMI, were taken into account. These results were limited to people who consumed sodas sweetened with sugar: diet soda drinkers did not have increased chances of cardiovascular disease.
The link between added sugars and cardiovascular disease is serious enough that the American Heart Association suggested limiting intake of added sugars to 100 calories a day for women and 150 calories a day for men. Just one regular 12-ounce soda would push you over that daily limit.
Want to build strong bones? Put down your soda. Colas, like Coke or Pepsi, contain phosphoric acid to give the drink a tangy flavor and to prevent mold and bacteria from growing. However, phosphoric acid has been shown to interfere with calcium absorption, which is needed for strong bones. The Framingham Osteoporosis Study found that women who drank regular, diet or even decaffeinated cola had bone mineral density almost four percent lower than that of women who weren’t soda drinkers. The effect was only observed in soda types that contained phosphoric acid, like cola drinks, but not in clear carbonated sodas. Even though clear sodas didn’t affect bone mineral density, such drinks still pose a risk to bone health when they replace bone-building milk in children's and adolescent's diets.
Phosphoric acid does more than weaken bones: phosphoric-containing beverages change the way kidneys process urine, and can increase your risk of developing kidney stones. After comparing the diets of more than 400 chronic kidney disease patients to the diets of a similar number of healthy individuals, researchers concluded that drinking two or more colas a day doubled the risk for kidney disease. Both regular and diet soda had this disease-promoting effect.
In addition, drinking regular or diet soda might cause fat to accumulate around the liver, a condition known as non-alcoholic fatty liver disease (NAFLD). NAFLD affects 30 percent of Americans, and is the most common cause of chronic liver disease. In one study that followed more than 300 patients with NAFLD, 80 percent of those who had it consumed excessive amounts of soft drinks a day, which dumped more than 50 grams of added sugar to their daily diets.
Both regular and diet soda are acidic and can erode the protective layer of enamel that coats healthy teeth, leaving your teeth more sensitive and susceptible to decay. Additionally, when you drink regular soda, you bathe your teeth in sugar. This feeds bacteria that live on your teeth, which secrete even more enamel-eating acid as they digest the sugar.
And don’t fall for commercials urging you to reach for a can of pop to quench your thirst. When thirsty, you have less saliva, which normally protects enamel by neutralizing the acidity from carbonated beverages and bacteria. As a result, chugging soda when you’re thirsty bombards your teeth with acid and sugar while its defenses are down.
If the harmful ingredients in soda aren’t enough to make you think twice about your beverage choice, consider this: The soda cans themselves contain a chemical you should avoid. Nearly all soda cans are lined with bisphenol A (BPA) to prevent contamination and extend the shelf life of the product. This chemical mimics the hormone estrogen and is harmful to developing fetuses and infants. Additional evidence links high levels of BPA to a long list of conditions, such as diabetes, heart disease, hormonal cancers, decreased sensitivity to chemotherapy, miscarriages and male infertility through damage to the DNA of sperm. When assessing sources of BPA in the American diet, soda is a major one, along with school lunches and fast food and restaurant meals.
Published October 15, 2012.
Nour Zibdeh is a registered dietitian and nutrition coach specializing in weight management, cardiovascular disease, food sensitivities, and digestive health. She coaches individuals by merging nutrition science, intuitive and mindful eating, and healthy cooking in her counseling approach. Nour shares recipes and nutrition tips at www.nourition.com/blog.