A new study links diet soda consumption to increased risk of heart disease. You don't necessarily have to give up your favorite artificially-sweetened drink, but you may want to stop seeing it as a healthier alternative.
A new study published last month in the Journal of the American College of Cardiology found that soda drinkers have a higher risk of heart disease than those who do not drink sweetened beverages.
The association between sugar consumption and heart disease risk is not new. As a person’s sugar intake increases, so does their risk of cardiovascular disease. And this association is seen regardless of age, body weight, or exercise habits. Even among those with otherwise healthy diets (you know, lots of fruits and vegetables, lean meat, whole grains, and that sort of thing), heart disease risk increases with added sugar intake.
Those who drank a lot of artificially-sweetened soda had the same elevated risk as people who drank a lot of sugar-sweetened soda.
The more surprising thing about this study was that those who drank a lot of artificially-sweetened soda had the same elevated risk as people who drank a lot of sugar-sweetened soda. The risk of heart disease was about one-third higher among those who were high consumers of either type of soda, compared to low consumers. That means that if 10 out of 100 low-consumers developed heart disease, then 13 out of 100 high-consumers would.
How sugar can hurt your heart
Those who consume more added sugars are more likely to be overweight, and that certainly contributes to heart disease risk. But even when you’re not overweight, a diet high in sugar can raise your triglyceride levels, or the amount of fat circulating in your bloodstream. It may also lead to fatty deposits in the liver. And these could be some of the mechanisms that would explain the link between sugar intake and heart disease risk.
There’s no mechanism to explain how artificial sweeteners might hurt your heart.
But none of that explains how artificial sweeteners might increase cardiovascular risk. And that’s the real mystery here. There’s no mechanism to explain how artificial sweeteners might hurt your heart.
This is not the first mystery regarding zero-calorie sweeteners. Despite being low in sugar and calories, artificial sweetener use has been linked with increased rates of diabetes and obesity. Early on, theories were proposed to explain this. Perhaps the sweet taste tricks the body into responding as if it’s actually sugar. Or perhaps artificial sweeteners increase appetite or sugar cravings.
Research designed to test these theories has so far come up empty-handed. (Well, not completely empty-handed. But, as is so often the case, research in humans fails to bear out preliminary findings on lab rats.)
How do artificial sweeteners hurt your health?
The best theory we have at the moment to explain this apparent paradox is that artificial sweeteners may change the makeup of our gut microbiome in ways that promote weight gain or diabetes. Unlike the other hypotheses, there is some human research to support this. And perhaps something similar underlies this latest finding.
Artificial sweeteners may change the makeup of our gut microbiome in ways that promote weight gain or diabetes.
Suffice it to say that data consistently contradict the notion that artificial sweeteners are somehow healthier (or less unhealthy) than sugar. Both are fine in moderation, of course. But high consumption of either one is linked to poorer health outcomes.
The key word here, of course, is “linked.” As the artificial sweetener industry would very much like to remind everyone, correlation is not causation.
Most of the data that we have on this question are observational. They come from big epidemiological studies that look at dietary patterns and health outcomes over long stretches of time. Such studies cannot prove that artificial sweeteners cause any of these health problems. They just often seem to be nearby when these problems occur.
Should you quit drinking diet soda?
So, should we change what we’re doing based on this latest research? I think that depends on what you’re doing! If you occasionally have a diet soda, I don’t think you have anything to worry about. For that matter, if you occasionally have a regular soda, I don’t think that’s cause for alarm either. If you’re drinking soda (whether regular or diet) on a daily basis, it might be more of a concern.
Sweetened foods and beverages—whether sweetened with sugar or artificially—don't contribute much nutrition to your diet.
Aside from whatever effects the sugar or artificial sweeteners have on your body, sweetened foods and beverages—whether sweetened with sugar or artificially—don't contribute much nutrition to your diet. And they may be crowding out more nutritious foods.
The point is that reaching for a diet soda instead of a regular soda doesn’t really constitute a nutritional upgrade. If you really want a healthier alternative, choose water or sparkling water. And similarly, if you’re looking for a healthier sweet treat, a piece of fresh or dried fruit is a better choice than artificially sweetened brownies or ice cream.
The guidelines for added sugars are to limit them to about 25 grams per day.
My advice is to exercise the same degree of moderation with artificial sweeteners as you would with added sugars. The guidelines for added sugars are to limit them to about 25 grams per day. (And remember, we don’t count the naturally occurring sugars in fruit or dairy toward that total, but we do include honey, molasses, maple syrup, and other natural sweeteners.) The equivalent in noncaloric sweeteners would be about three packets or one diet soda per day.