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Artificial Sweeteners May Increase the Risk of Depression

Sugar substitutes may be bad for your health and mood.

Key points

  • Diet sodas may increase the risk of depression.
  • Diet sodas also may increase the risk of stroke and dementia.
  • Artificial sweeteners are not a reliable strategy to lose weight.
Food Photographer/Unsplash
Food Photographer/Unsplash

Is diet soda safe? If you're concerned about sugar (and you're right to be), diet products seem a better option, sweet and not so bad for you!

Wrong. Diet soda also can be bad for you. Drinking it regularly can increase your risk of disease. Despite the fact that we call these drinks "diet," the artificial sweeteners they contain are linked to weight gain, not loss. And now there's new evidence that they increase the risk of depression, too.

The bad news about depression comes from a new analysis by researchers at Massachusetts General Hospital, Brigham and Women’s Hospital, Harvard Medical School, and the Harvard T. H. Chan School of Public Health. The team drew upon a data set of nearly 32,000 female nurses, ages 42 to 62 years when the study began. It turned out that the nurses who consumed the most diet beverages had a 37 percent higher chance of depression, compared to those who drank the least or none.

Diet soda also increases your risk of high blood pressure (and more so the more you drink), according to a separate meta-analysis that included 72 studies. In addition, that team found a higher risk of stroke and death by any cause.

Bottom line: Your best choices for beverages may be water, whole fruit and vegetable smoothies, or perhaps unsweetened iced tea.

Artificial Sweeteners and Circulation

Looking for the mechanism behind strokes, researchers took various blood measurements when 12 healthy volunteers in their 20s drank water, Mountain Dew, or Diet Mountain Dew. The Mountain Dew drinks contained caffeine. The result: both sodas slowed the flow of blood within the brain. However, the effect didn’t seem sufficient to cause stroke.

But slower blood flow could have accumulating effects. We need a constant supply of blood to the brain. Other researchers have found that artificial soda increases the risk of dementia, from data from nearly 178,000 volunteers from the United Kingdom tracked over an average of nine and a half years.

That’s not a big surprise. An earlier study of about 4,300 volunteers, aged 45 and up, concluded that drinking diet soda every day was tied to triple the risk of stroke or dementia over the next decade.

In another study from the same team, the researchers looked at brain scans and the results of cognitive tests. A daily diet soda was linked to smaller brains and poorer memory, two risk factors for dementia. And if you have two sweet beverages a day, including fruit juices, you also may end up with a smaller brain and aggravate long-term memory loss.

Yet another research team found that a daily diet soda could increase your risk of heart attacks.

Stroke, dementia, heart attacks, depression. Those are big risks to take for fizzy sweetness.

Is there any reason to use artificial sweeteners?

The short answer: No. Artificial sweeteners also seem to increase the risk of cancer, particularly breast cancer and obesity-related cancers. And they don’t reliably help you lose weight or stay thin. On the contrary. They may alter your gut in ways that make you feel less full and trigger more eating and weight gain.

What should you drink?

Skip any drinks with sherbet or fruit juice. Juices are a fast, fiber-less, shot of sugar, which may aggravate a tendency to type 2 diabetes, as well as weight gain. Whole fruits and vegetables are a better choice. You can make your smoothie healthier by including vegetables and a protein-rich milk or milk alternative.

Energy drinks aren’t healthy either—they’re often packed with sugar, and the stimulants may be dangerous. A meta-analysis of 32 studies concluded that they often lead to insomnia and low mood in children and teens. This can lead to upset stomachs and jitterness in adults as well as insomnia.

Consuming just 16 ounces of an energy drink elevates blood pressure and stress hormones in young, healthy adults, according to a study by the American Heart Association.

Sports drinks, which contain minerals and electrolytes to replace water and electrolytes lost through sweating during exercise, are a better bet, but probably unnecessary, and shouldn’t be sugary or artificially sweetened.

Avoiding depression, stroke, type 2 diabetes, heart attacks, cancer, and dementia are all obvious goals of anyone who wants to age healthily. No drink is worth those risks.


A version of this post also appears at Your Care Everywhere.

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