Drinking one or more sugary sodas a day, including regular cola, caffeine-free cola, and other sugar-sweetened carbonated sodas, may significantly increase a woman’s risk of developing rheumatoid arthritis (RA), according to a study published recently in The American Journal of Clinical Nutrition.
But substituting skim milk for sugar-sweetened soda may decrease this risk, possibly because of milk’s beneficial vitamin D, researchers say, adding that the study doesn’t show that drinking sugar-sweetened soda actually causesRA, only that there’s a strong association between the two.
“We would not say soda would definitely lead to [an] increased risk of RA no matter how often people drink [it],” says lead researcher Yang Hu of the Harvard School of Public Health. Rather, people who drink “too much soda may be more susceptible to RA.”
A Mysterious Disorder
Rheumatoid arthritis is a chronic inflammatory and autoimmune disorder, which develops when the immune system erroneously attacks healthy tissue, causing long-term redness, swelling, warmth, and pain in the joints. In 2007, some 1.5 million adults over the age of 18 had RA in the United States, according to the Centers for Disease Control and Prevention (CDC).
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It’s unknown what, exactly, causes RA, but genetic and environmental factors are likely involved, including lifestyle and diet choices. It’s known, however, that cardiovascular disease and type 2 diabetes are more common in people with RA than the general population. Additionally, added sugar might contribute to the development of these two health issues by inducing obesity, insulin resistance, and inflammation — factors that may be also involved in the development of RA.
“The added sugar is different from the sugar from carbohydrates,” Hu says. “It is basically a source of sugar that exceeds the need of daily consumption.”
Sugar-sweetened soda is the primary source of added sugar in the American diet, and might increase a person’s risk of developing both cardiovascular disease and diabetes, according to a 2010 study in the journal Circulation. So Hu and his colleagues wondered if sugary soda also affects RA risk.
The Link Between Sugary Soda and RA
To find out, the team prospectively followed 186,900 women from two large cohort studies that ran from 1980 to 2008 and 1991 to 2009, respectively. Every two years, the women reported their physical activity, weight, and medical history, and every four years they reported about their diets, including what they drank.
After analyzing the data, the researchers found that women who drank one or more sugar-sweetened sodas a day were 63 percent more likely to develop RA than women who only drank less than one sugary soda a month. This risk appeared to be even stronger for women over 55 years old, suggesting the additive detrimental effects of soda over many years may cause chronic inflammation, which eventually leads to RA.
This risk is likely the same for men, but showing this would require a larger study, since the incidence of RA is two to three times higher in women than in men, according to the CDC. “Under ideal situations, I think similar findings could be found,” Hu says.
According to the study, frequently drinking diet soda, which contains artificial sweeteners rather than sugar, didn’t affect the participants’ RA risk either way. Interestingly, neither did drinking fruit juice, which often contains added sugar. But unlike sugary soda, fruit juices also contain many beneficial components, such as vitamins, minerals, and soluble fiber, which may prevent inflammation, Hu explains.
Weight gain and obesity doesn’t explain the link between sugary soda consumption and RA risk, the study found. And though the soda-RA association cannot be said to be causal at this stage, the researchers have some ideas about what’s going on.
For one thing, dietary sugar, particularly sucrose, can cause periodontal diseases, and studies have suggested a link between gum disease and RA, Hu says. Alternatively, sugary soda may increase the amount of certain molecules in the body that promote inflammation (cytokines).
Easy Ways to Reduce Your Sugar Intake
Because the study focused on healthy women, it doesn’t directly speak to people who already have RA. “But I think reducing the consumption of soda and adopting a Mediterranean diet pattern that emphasizes fruits and vegetables are helpful for relieving the symptoms [of] people who already have RA,” Hu says.
Aside from cutting out sugar-sweetened sodas, there are numerous other ways that people with RA can reduce their added sugar intake.
“Fruit is the best cure for a sweet tooth — especially fruit spaced throughout the day,” says Bethany Thayer, MS, RDN, director of Henry Ford Health System’s Center for Health Promotion and Disease Prevention and president-elect of the Michigan Academy of Nutrition and Dietetics. “Try enjoying a piece of fruit every four hours while you are awake for a week and notice your desire for other sugary treats fade away.”
But if you’re going to eat fruits, try to stick to whole fruits. Canned fruits, jams, and dried fruits sometimes contain added sugar, which you may not be aware of unless you read the ingredients label.
Aside from eating whole fruits, fill your diet with other foods that are “as close to nature as possible,” Thayer says. “The closer you can stay to the naturally occurring foods, the less sugar you are going to take in.” Avoid processed foods and beverages, and instead eat things like:
- Fresh vegetables
- Unprocessed meat
- Low-fat dairy
Soy, rice, and almond milk are healthy alternatives to regular milk if you’re lactose intolerant, but many commercial products have added sugar to improve the taste. “And if it’s flavored, there is most likely some sugar that’s added to it,” Thayer says. Check the ingredients label before deciding on a milk alternative, especially if you are looking at the chocolate, vanilla, or other flavored varieties.
If you do decide to eat processed food or ingredients, whether it’s pasta sauce, BBQ sauce, salad dressings, cereal, crackers, or even bread, “be aware of what’s in them and make your decision on that,” Thayer says. Keep in mind that there are a variety of terms to denote added sugar on food labels, including:
- Corn syrup
- High-fructose corn syrup
- Cane juice
If you want to add sweetness to your food or drink, there are numerous artificial sweeteners out there, including saccharin, sucralose, acesulfame potassium, and aspartame. “Low-calorie sweeteners are highly researched and tested for safety before they hit the market, so it really becomes a matter of taste preference and what you might be using it for,” Thayer says. “You should experiment and taste test to find the [sweeteners] that work for you.”
Finally, Thayer advises, keep a food diary that lists everything you eat and drink, and review it often to find areas where sugar is sneaking into your diet more than you’d like. For instance, you may find that you’re ingesting one too many fancy coffee drinks, snacks and treats in the office, or sweetened lemonades while eating out at restaurants.
“Having a diary and reviewing it can help you in a number of ways, not just in reducing sugar,” Thayer says.