The Truth About Diet Soda

Is diet soda bad for you? Or does it actually help you lose weight?

A Purdue researcher says public health officials should tell people to avoid diet soda much like they do with regular, sugar-sweetened soda. Susan E. Swithers, PhD, a professor of psychological sciences and a behavioral neuroscientist at Purdue says warnings may need to be expanded to include limiting intake of all sweeteners, including no-calorie sweeteners. (1)

Swithers reviewed a set of recent studies aiming to answer the question, “Is diet soda bad for you?” She found that about 30 percent of American adults and 15 percent of American children ingest artificial sweeteners, including aspartame, sucralose and saccharin.

There is a lot of pressure from the public health sector to find solutions to counter the rise of obesity and chronic disease, and there is a lot of money and business at stake for the food industry as it develops and promotes these products. Beverages are becoming political issues as government leaders and politicians seek regulation and taxing to limit their availability and consumption, but most of these measures exclude diet soft drinks because they are perceived as healthy. When it comes to making policy decisions, it’s more important than ever that the science is considered and that the public understands what the science says in order to help them make the best health decisions.

Artificial sweeteners seem to confuse the body’s natural ability to manage calories based on tasting something sweet. People tend to them overeat even if they drink diet soda. And get this: People who consume artificial sweeteners are twice as likely to develop metabolic syndrome, too. (2)

Findings from an April, 2019 study published in the journal Circulation tell us that high consumption of artificially sweetened beverages can actually increase the risk for total mortality (death caused by any condition), especially from cardiovascular diseases. Women in this study were found to have the highest intake levels of diet soda.

And if you’re thinking that it seems like a better idea to simply drink regular sugar-sweetened beverages, think again: In the same study it was found that the more regular soda that participants drank, the higher their risk for total mortality, especially from from heart disease and cancer.

Is Diet Soda Bad for You?

There’s lots of research linking diet soda drinking to all sorts of health troubles, even death. As mentioned above, research now links diet soda consumption (and regular soda consumption too) with higher risk for total mortality and heart disease. Artificially sweetened beverages (or ASBs, as they are called in some studies) are often suggested as alternatives to regular soda, and intake levels of ASBs have increased in the United State in recent year.

These findings about the negative health effects of ASBs come from a review of two large scale studies that included over 37,000 middle-aged adult men and 80,000 middle-aged adult women that were followed for about 30 years. The most significant health impacts were observed among those with “high intake levels” of diet soda, which were considered equal to or greater than 4 servings per day.

It was found that participants who had higher intakes of ASBs were also more likely to be younger than those who infrequently drank ASBs, and more likely to have hypertension, a greater BMI, and a tendency to be overweight. Researchers believe that these confounding conditions, and potentially other lifestyle choice too, may be the reason ABSs are linked to mortality. The analysis also points out that some research suggests that ASBs may increase body weight and contribute to cardiometabolic risk despite containing few to no calories because of the “intense sweetness of artificial sweeteners, which may habituate toward a preference for sweets or stimulate an insulin response”, in addition to altering gut microflora in ways that have been linked to insulin resistance.

What were the researchers’ conclusions about the implications of their findings? As the study states, “ASBs (artificially sweetened beverages) could be used to replace SSBs (sugar sweetened beverages) among habitual SSB consumers, but higher consumption of ASBs should be discouraged. Policies and recommendations should continue to call for reductions and limits on SSB intake but should also address alternative beverage options with an emphasis on water.”

Drinking diet soda may also contribute to the following health problems, according to studies:

1. Depression

Drinking more than four cans a day of soda is linked to a 30 percent higher risk of depression. On the flip side, drinking four cups of coffee a day seemed to offer protective effects, lowering depression risk 10 percent. The risk appeared to be greater for people who drank diet soda compared to regular soda. (3)

2. Kidney Damage

Harvard researchers found long-term diet soda drinking causes a 30 percent greater reduction in kidney function. The study looked at people who regularly consumed diet soda over 20 years. (4)

3. Type 2 Diabetes and Metabolic Syndrome

A 2009 study published in the journal Diabetes Care found drinking diet soda daily is linked to a 36 percent higher risk of metabolic syndrome and a 67 percent higher risk of type 2 diabetes compared to non-diet soda drinkers. (5)

In fact, the artificial sweeteners may tamper with the gut-brain connection. This can lead to brain trickery that leads to “metabolic derangements.” Weizmann Institute of Science in Israel researchers were surprised when they found diet soda actually alters gut microbes in a way that increases the risk of metabolic diseases. When researchers fed mice zero-calorie sweeteners found in these drinks, including saccharin, aspartame and sucralose, they developed glucose intolerance. (6)

4. Cardiovascular Disease

Another study sounds similar findings about the connection between heart disease and diet soda. University of Miami and Columbia University researchers followed more than 2,000 adults for 10 years and found that those drinking diet soda daily were more likely to suffer a stroke or heart attack. They were also more likely to die from cardiovascular disease. This increase risk remained even when researchers adjusted for smoking, exercise, weight, sodium intake, high cholesterol, and other factors that could have contributed to the difference. (7, 8)

5. Compromised Lungs

Drinking soda, including diet soda, increases your risk of developing asthma and COPD symptoms. The more soda a person drinks, the higher the risk. (That’s called a “dose-response relationship.”)

An Australian study found that 13.3 percent of surveyed participants with asthma and 15.6 percent of those with COPD drank more than two cups of soda each day. (9, 10)

6. A Less Protected Brain

Aspartame, a common artificial sweetener in diet sodas, seems to chip away at the brain’s antioxidant defense system. The results of an animal study found long-term consumption of aspartame leads to an imbalance in the antioxidant/pro-oxidant status in the brain, mainly through the mechanism involving the glutathione-dependent system. (11)

Aspartame is also linked to: (12)

• migraines & headaches
• depression
• anxiety
• short term memory loss
• multiple sclerosis
• fibromyalgia
• hearing loss
• weight gain
• fatigue
• brain tumors
• epilepsy
• chronic fatigue syndrome
• birth defects
• Alzheimer’s disease
• lymphoma
• diabetes
• arthritis (including rheumatoid)
• chemical sensitivities
• ADHD
• Parkinson’s

Final Thoughts

• Diet soda is not a healthier alternative to regular sugar-sweetened soda.
• Diet soda does not promote weight loss, contrary to popular belief.
• Diet soda is linked to higher risk for mortality in some studies, metabolic damage, heart disease, weight gain and other health problems.
• If you’re in the mood for a fizzy drink, consider a much healthier option: kombucha.