APR 24, 2017 12:12 PM PDT

Is soda making your brain age faster?

New research suggests that excess sugar—especially the fructose in sugary drinks—might damage your brain.

Researchers using data from the Framingham Heart Study (FHS) found that people who drink sugary beverages frequently are more likely to have poorer memory, smaller overall brain volume, and a significantly smaller hippocampus—an area of the brain important for learning and memory.

But before you chuck your sweet tea and reach for a diet soda, there’s more: a follow-up study found that people who drank diet soda daily were almost three times as likely to develop stroke and dementia when compared to those who did not.

Researchers are quick to point out that these findings, which appear separately in the journals Alzheimer’s & Dementia and Stroke, demonstrate correlation but not cause-and-effect. While researchers caution against over-consuming either diet soda or sugary drinks, more research is needed to determine how—or if—these drinks actually damage the brain, and how much damage may be caused by underlying vascular disease or diabetes.

“Maybe good old-fashioned water is something we need to get used to…”

“These studies are not the be-all and end-all, but it’s strong data and a very strong suggestion,” says Sudha Seshadri, a professor of neurology at Boston University School of Medicine and a faculty member at the university’s Alzheimer’s Disease Center. “It looks like there is not very much of an upside to having sugary drinks, and substituting the sugar with artificial sweeteners doesn’t seem to help.”

“Maybe good old-fashioned water is something we need to get used to,” adds Seshadri, who is senior author of both papers.

Excess sugar has long been associated with cardiovascular and metabolic diseases like obesity, heart disease, and type 2 diabetes, but little is known about its long-term effects on the human brain, says Matthew Pase, a fellow in the university’s neurology department, an investigator at the FHS, and lead author of both papers.

He chose to study sugary drinks as a way of examining overall sugar consumption. “It’s difficult to measure overall sugar intake in the diet,” he says, “so we used sugary beverages as a proxy.”

For the first study, researchers examined data, including magnetic resonance imaging (MRI) scans and cognitive testing results, from about 4,000 people enrolled in the Framingham Heart Study’s Offspring and Third-Generation cohorts. (These are the children and grandchildren of the original FHS volunteers enrolled in 1948.)

The researchers looked at people who consumed more than two sugary drinks a day of any type—soda, fruit juice, and other soft drinks—or more than three per week of soda alone. Among that “high intake” group, they found multiple signs of accelerated brain aging, including smaller overall brain volume, poorer episodic memory, and a shrunken hippocampus, all risk factors for early-stage Alzheimer’s disease. Researchers also found that higher intake of diet soda—at least one per day—was associated with smaller brain volume.

In the second study, the researchers, using data only from the older Offspring cohort, looked specifically at whether participants had suffered a stroke or been diagnosed with dementia due to Alzheimer’s disease. After measuring volunteers’ beverage intake at three points over seven years, the researchers then monitored the volunteers for 10 years, looking for evidence of stroke in 2,888 people over age 45, and dementia in 1,484 participants over age 60.

Here they found, surprisingly, no correlation between sugary beverage intake and stroke or dementia. However, they found that people who drank at least one diet soda per day were almost three times as likely to develop stroke and dementia.

Although the researchers took age, smoking, diet quality, and other factors into account, they could not completely control for preexisting conditions like diabetes, which may have developed over the course of the study and is a known risk factor for dementia.

Diabetics, as a group, drink more diet soda on average, as a way to limit their sugar consumption, and some of the correlation between diet soda intake and dementia may be due to diabetes, as well as other vascular risk factors. However, such preexisting conditions cannot wholly explain the new findings.

“It was somewhat surprising that diet soda consumption led to these outcomes,” says Pase, noting that while prior studies have linked diet soda intake to stroke risk, the link with dementia was not previously known. He adds that the studies did not differentiate between types of artificial sweeteners and did not account for other possible sources of artificial sweeteners.

Pase says that scientists have put forth various hypotheses about how artificial sweeteners may cause harm, from transforming gut bacteria to altering the brain’s perception of sweet, but “we need more work to figure out the underlying mechanisms."

This article was originally published on futurity.org

About the Author
  • Futurity features the latest discoveries by scientists at top research universities in the US, UK, Canada, Europe, Asia, and Australia. The nonprofit site, which launched in 2009, is supported solely by its university partners (listed below) in an effort to share research news directly with the public.
You May Also Like
MAY 06, 2020
Cardiology
MAY 06, 2020
Can Alcohol Consumption Increase Your Risk of Peripheral Arterial Disease?
Peripheral Arterial Disease (PAD) is a chronic disease where plaque builds up in the arteries in the legs. This buildup ...
MAY 12, 2020
Clinical & Molecular DX
MAY 12, 2020
Could Catching the Flu Be Linked to an Increased Cancer Risk?
Results from a new research study suggest that a spike in infections such as influenza could be linked to the risk of de ...
MAY 14, 2020
Chemistry & Physics
MAY 14, 2020
Do Organic Chemists Speak an Alien Language?
Have you ever read a detergent label and got confused? Or had trouble understanding a medication recall? Certain ch ...
MAY 18, 2020
Cell & Molecular Biology
MAY 18, 2020
Just One Fatty Meal Can Impair Focus
Many tasty and convenient foods are high in fat, and new research has suggested that just one fatty meal may hinder our ...
MAY 22, 2020
Health & Medicine
MAY 22, 2020
Smart Speakers can Identify Cardiac Arrest
Smart devices can control your lights, make your grocery list, and play songs on command. Researchers are now developing ...
MAY 21, 2020
Chemistry & Physics
MAY 21, 2020
Scientists produce multi-component biomaterial-based ex vivo cartilage substitute
New research published in Science Advances identified a novel composition of materials that hopes to improve the options ...
Loading Comments...