We touched on the dangers of artificial sweeteners, particularly in diet sodas, back in Issue #301

And since that time diet soda consumption in the United States has continued to increase. Among children, consumption of diet soda has doubled in the last 15 years.1

This is bad news.

Especially since a growing body of research on the artificial sweeteners in diet soda shows they can cause a long list of health problems ranging from obesity to dementia. (Yes, you heard right – diet soda causes obesity.)

Read on to discover the link between low-calorie soft drinks (aka diet soda) and dementia.

Diet Soda Ruins Your Gut Health

Artificial sweeteners such as sucralose, aspartame and saccharine have been linked to a wide variety of health problems.

Many diet sodas are now sweetened with sucralose (brand name Splenda) following public outcry against aspartame. Unfortunately, studies from Duke University show that Splenda acts like a nuclear bomb in your gut’s microflora.

At small doses (amounts the FDA says are safe) it can destroy the majority of the good bacteria you need to stay healthy and fend off disease, according to one study. What’s worse, after a 12-week follow-up period the good bacteria still hadn’t come back.2

Many scientists have called the gut the “second brain” because it plays such an important role in mental health, including prevention of Alzheimer’s disease and other dementias. (See Issue #205 for more details about the connection between the gut and brain health.)

Diet Soda Increases Risk of Type 2 Diabetes

Studies show drinking diet soda can increase the incidence of metabolic disorders, including diabetes. It’s kind of ironic, because many people with a blood sugar problem choose sugar-free drinks, thinking these will help them manage it. But the opposite is true.

A study published in the journal Diabetes Care found that daily diet soda consumption is associated with a “36% greater relative risk of incident metabolic syndrome and a 67% greater relative risk of incident type 2 diabetes compared with non-consumption.”3

An increased risk and/or incidence of type 2 diabetes also raises the risk of developing Alzheimer’s disease.

Alzheimer’s disease is often referred to as “type 3 diabetes” because evidence points to impaired insulin signaling as one of the triggers for the disease.4

Proven Link Between Diet Soda Consumption and Dementia

A study published in the April 2017 issue of the journal Stroke reviewed the soda and diet soda consumption habits of 2,888 participants age 45 and older, and 1,484 people age 60 and older.

The researchers found that, after adjusting for things like age, diet, physical activity, smoking, etc., those who drank diet soda have an increased risk of all-cause dementia, Alzheimer’s disease and ischemic stroke (where damage results from blood flow restriction to the brain caused by a clot in a blood vessel).5

The most interesting part of the study, in my opinion, is that sugar-sweetened drink intake was not associated with stroke or dementia. Only artificially sweetened drinks created this link.

How to Break the Diet Soda Habit

By now I hope you’re looking for ways to drop the diet soda habit, if you have one.

It can be hard at first, in no small part because the hyper-sweetness of artificial sweeteners can make the natural sweetness of fruit juices and tea taste bland and unsatisfying in comparison.

But as your palate readjusts to natural flavors, you will enjoy them more. Here are a few suggestions for replacement sweet drinks:

  • Fruit-infused water. Put citrus fruits, or any of your favorites, in a pitcher of refrigerated water overnight.
  • Pure fruit juice. I suggest the really flavorful kinds like pomegranate and tart cherry. They are also rich in nutrients. But go easy because these can spike blood sugar. One glass a day.
  • Mix equal parts pure fruit juice with club soda for a sweet fizzy drink that’s like soda, but better for your brain.
  • Iced tea sweetened with honey. You may need a decent amount of honey at first, but as your taste buds adjust you can cut the amount back.
  • If you’re needing a soda fix, try an artisanal soda like grapefruit, ginger ale made with real ginger, or blood orange flavors. They’re sweetened with sugar and use real ingredients, unlike commercial soda brands. Again, they spike blood sugar so practice moderation.

My preferred drink is water – and during the warm months of the year, sparkling water. Many people don’t know it, but for some reason carbonated water is much more satisfying than still water. I think it’s not just the sweetness but the bubbles that cause so many people to develop a soda habit.

Meaning, you can still keep half the fun of soda, or more, by drinking sparkling water. And you may find you don’t miss soft drinks at all.

Any way you do it, your brain will benefit greatly from cutting out diet soda from your life.


  1. Low-calorie sweetener consumption is increasing in the United States.
  2. Splenda alters gut microflora and increases intestinal p-glycoprotein and cytochrome p-450 in male rats.
  3. Diet soda intake and risk of incident metabolic syndrome and type 2 diabetes in the multi-ethnic study of atherosclerosis (MESA).
  4. Impaired insulin and insulin-like growth factor expression and signaling mechanisms in Alzheimer’s disease – is this type 3 diabetes?
  5. Sugar- and artificially sweetened beverages and the risks of incident stroke and dementia.