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
MAR 08, 2021
Health & Medicine
What Effect Does Using Cannabis Have on Blood Pressure?
MAR 08, 2021
What Effect Does Using Cannabis Have on Blood Pressure?
Whether cannabis use has an effect on a user’s blood pressure has until recently not been at all clear. Seeking to ...
MAR 10, 2021
Genetics & Genomics
As Diphtheria Cases Rise & More Become Drug Resistant, It May Become a Threat
MAR 10, 2021
As Diphtheria Cases Rise & More Become Drug Resistant, It May Become a Threat
Diphtheria was once a leading cause of death for children; immunization programs eventually changed that for most countr ...
MAR 16, 2021
Clinical & Molecular DX
A Blood Test for Predicting if You'll Live to 100
MAR 16, 2021
A Blood Test for Predicting if You'll Live to 100
In 2012, a United Nations report estimated that there are over 316,000 people worldwide over the age of 100. What’ ...
APR 01, 2021
Health & Medicine
Flavanol-rich Foods Protect Heart from Stress
APR 01, 2021
Flavanol-rich Foods Protect Heart from Stress
Drinking hot cocoa is comforting on cold winter nights, and new research from the University of Birmingham shows that it ...
APR 06, 2021
Cardiology
In 2020, Deaths in the US Were Over 20% Higher Than Typical Years
APR 06, 2021
In 2020, Deaths in the US Were Over 20% Higher Than Typical Years
Researchers have begun to analyze the impact of the pandemic, and their work has shown that long COVID-19 surges in the ...
APR 13, 2021
Clinical & Molecular DX
A Color-Changing "Invisible Tattoo" for Long-Term Health Monitoring
APR 13, 2021
A Color-Changing "Invisible Tattoo" for Long-Term Health Monitoring
German researchers have developed an innovative method for continuously tracking and monitoring biomarkers and drugs cir ...
Loading Comments...