Does “Diet Soda Dementia” Exist? What The Research Says

For people who drink soda regularly, diet versions may be appealing because they aren’t made with sugar and, therefore, have few or no calories. However, some experts have suggested that the artificially sweetened soft drinks may come with their own risks, including a potential link to dementia. Understanding whether “diet soda dementia” exists and what recent research says about the connection between these drinks and cognitive challenges may help you make informed choices about your health. If you’re looking for support in changing your habits, consider connecting with an in-person or online therapist.

The history of diet soda

Diet soda is a soft drink flavored using artificial sweeteners, such as aspartame, sucralose, or stevia, instead of the real added sugar used in beverages like non-diet soda. These non-nutritive sweeteners generally contain no real sugar. Sugar can contribute to most of the calories in soda, so by taking it away, companies can produce a product that’s at or close to zero calories to appeal to those who are trying to lower their caloric intake. 

One of the earliest diet sodas on the market in the US was No-Cal, which was designed to support the taste and preferences of people living with diabetes, who couldn’t regularly enjoy mainstream sugary beverages. Eventually, other diet sodas entered the market, including Diet Rite cola, Diet Dr. Pepper, Tab, and Diet Pepsi. These drinks were originally sweetened with cyclamates and saccharin until some studies linked these ingredients to cancer, though more recent research has called those findings into question. Today, aspartame, Splenda, and stevia are common sweeteners in diet sodas.

What is dementia?

Dementia is an umbrella term that describes a set of cognitive symptoms rather than a particular disease. Dementia can have several different underlying causes, and the course of symptoms can depend on the case. 

In general, dementia symptoms are progressive, meaning they get worse over time. A person with dementia will often need increasing support to complete daily tasks, typically requiring full-time care for full-blown symptoms. Dementia is often eventually fatal, though some treatments may help slow symptom progression or reduce their impact.

Dementia symptoms

Cognitive dementia symptoms tend to include things like:

• Memory loss
• Misplacing items
• Getting lost in familiar places
• Trouble planning ahead
• Confusion
• Paranoia
• Changes in personality or behavior

Note that it's also possible for a person to experience cognitive symptoms that look like dementia but aren't, such as a vitamin deficiency or another type of brain disorder. The underlying cause of dementia informs prognosis and treatment, so it can be important to receive an accurate diagnosis.

What causes dementia?

There are several underlying conditions that can cause dementia symptoms. Alzheimer’s disease is the most common, accounting for around 70% of all dementia cases, and some others include vascular dementia, frontotemporal dementia, and Lewy body dementia.

Research on the exact cause of Alzheimer’s and other dementia-related conditions is ongoing, but experts believe a complex combination of factors may often be involved. For example, the following may increase a person's risk of developing dementia from one or more causes:

• Age
• Genetics
• Hearing loss
• Depression
• Cardiovascular conditions, such as heart disease, heart attack, or high blood pressure
• Metabolic syndrome
• Diabetes
• A traumatic brain injury
• Poor sleep
• Eating patterns that lack sufficient nutrients
• Smoking
• Drinking alcohol
• Social isolation
• Ischemic stroke (when blood vessels in the brain get blocked by blood clots, potentially causing brain damage) 

Since certain lifestyle factors like eating habits may be linked to dementia risk, some people may wonder about potential connections between dementia and diet soda. 

Research on diet soda, stroke, and dementia

Researchers have conducted several studies on diet soda and dementia risk. Some include:

• A 2017 study of 2,888 participants, which suggests that consumption of artificially sweetened soft drinks over a period of seven years was linked to a higher risk of stroke and dementia, even when controlling for factors like age, sex, education, and lifestyle
• A 2026 study of 947 participants, which shares that frequent diet soda consumption may be linked to dementia via its potential connection to obesity and diabetes
• Another 2026 study of 118,963 participants, which proposes that “replacing sugar-sweetened beverages or artificially sweetened beverages with coffee or tea” may reduce dementia risk

The need for more research on the topic

One key limitation is that these studies are mostly observational. This type of research can give insights into where to focus future studies, but it’s not typically considered strong evidence. The main reason is that correlation does not necessarily imply causation. In other words, there could be a connection between diet soda and dementia, or there could be other factors at play that are largely responsible for these research observations.

For example, a Harvard Health Publishing analysis suggests that a person with a family history of diabetes might choose sugar-free sodas most of the time, but that it may be the family history that increases their dementia risk rather than the beverage choice. In summary, double-blind studies may be needed to confirm any possible links.

That said, drinking lots of soda in general has been linked to various health risks. In many cases, doctors recommend limiting or avoiding soda consumption.

Alternative beverages to drink instead of diet soda

While the exact connection between diet soda and dementia remains unclear, current research findings may make some people interested in exploring alternative beverages to reduce potential health risks. Those looking for alternatives to diet soda have several options.

Breaking a heavy soda habit may be difficult at first, but it can be possible to make the switch. For help changing your habits, consider working with a therapist.

First, it can be important to drink enough water throughout the day. Proper hydration has been linked to mood stability, sleep quality, mental health, brain health, and more. Some studies even suggest that dehydration may be associated with global reductions in cognitive function in adults with other risk factors. If you’re looking for added flavor when you hydrate, you might try seltzer water or water with cucumber, lemon, frozen fruit, or mint in it.

Also, some research suggests that natural fruit and vegetable juices high in polyphenols may reduce the risk of dementia, though more studies are needed. Or, when you want a drink with caffeine, turning to coffee or green tea may be a positive alternative to soda. For alternative sweeteners, some propose using sugar alcohols (like sorbitol), novel sweeteners (like monkfruit), or natural sweeteners (like honey) in moderate amounts, depending on your needs and health restrictions.

Drinking diet soda: Moderation and safety

For those who are looking to reduce but not eliminate their diet soda consumption, how much is safe to drink each day? The answer is hard to determine, since each person is different and research on the topic is ongoing. Many sources say to avoid drinking more than one can of diet soda per day, though others suggest that avoiding diet soda altogether is best for overall health. 

Individual health considerations can be key when setting limits on diet soda. For example, someone with diabetes, a family history of dementia, or another risk factor may decide to significantly cut back on diet soda or eliminate it altogether to protect their brain health. Talk to your doctor or a nutritionist to learn more about your unique risk factors and get accurate dietary information.

Lifestyle factors that may support cognitive health

The beverages you drink are just one potential contributing factor to your cognitive health. Other lifestyle factors that may help reduce your risk of dementia include:

• Get regular physical activity. Research suggests that high levels of exercise in mid-life and late-life, especially, may be associated with a reduced risk of dementia.
• Eat nutrient-rich foods. In particular, research suggests that fruits, leafy green vegetables, fish, nuts, and olive oil may be especially beneficial for cognitive health in many people.
• Get regular check-ups. High blood pressure and diabetes may increase your risk of dementia. Seeing your doctor for routine check-ups can allow them to monitor for or help you manage these conditions.
• Avoid alcohol and smoking. Both may increase your risk for dementia and other serious health challenges. Help quitting is available.
• Stay connected. Studies suggest that social isolation and loneliness may also be risk factors for developing Alzheimer’s. Spending regular time with family and friends or making new connections may support cognitive health and overall well-being.

Seeking help through online therapy

If you want to change your lifestyle habits, have a loved one who is living with dementia, or otherwise might benefit from having someone to talk to, you may want to reach out to a licensed therapist. A therapist can offer emotional support, teach coping strategies, and guide you in developing healthy habits.

If you’re interested in working with a therapist but don’t want to travel to and from in-person appointments, you might consider online therapy. When you connect with a therapist online, you can save yourself time and money associated with going to and from in-person appointments. You can join virtual sessions from your own home, which can make the experience feel more comfortable and approachable for many, in addition to being more convenient.

Is online therapy really effective?

Researchers have been studying the effectiveness of online therapy for years. In general, the growing body of research suggests that online therapy can often be similarly effective to in-person therapy for treating many types of mental health concerns.