Better cool it on the Kool-Aid: High-fructose consumption slows brain’s processes

Rats given a diet high in processed fructose fare worse after receiving a head trauma—and show other slowed brain processes too, according to a new study out of UCLA.

This research could have major implications for the 5.3 million Americans living with traumatic brain injury (TBI), and by adding a further link between diet and brain health, could help the additional 1.7 million people each year who suffer trauma—52,000 of whom will die.

Harmful effects on rat brains

“Americans consume most of their fructose from processed foods sweetened with high-fructose corn syrup,” said Fernando Gomez-Pinilla, a professor of neurosurgery and integrative biology and physiology at UCLA’s David Geffen School of Medicine, in a press release. “We found that processed fructose inflicts surprisingly harmful effects on the brain’s ability to repair itself after a head trauma.”

The study, which was published in the Journal of Cerebral Blood Flow and Metabolism, first trained rats for five days to solve a maze. After that, the rats were randomly chosen to be fed plain water or to be fed fructose-infused water for six weeks. The fructose used in this case was crystals derived from corn, simulating a high-fructose diets in humans.

A week after the two groups were formed, and all rats were anesthetized before receiving a pulse of fluid to the head—a simulation of human TBI. Six weeks after that, the rats were placed in the maze again to test how well they could recall the correct path and escape.

As compared to the plain water rats, the fructose rats took 30% longer to find the exit to the maze.

What’s more, the fructose actually altered multiple biological processes inside their brains. It interfered with communication between neurons, with neurons’ ability to rewire their connections after the injury, with the rats’ ability to record memories, and with the ability of neurons to produce enough energy to power their base functions.

“Our findings suggest that fructose disrupts plasticity—the creation of fresh pathways between brain cells that occurs when we learn or experience something new,” said Gomez-Pinilla. “That’s a huge obstacle for anyone to overcome—but especially for a TBI patient, who is often struggling to relearn daily routines and how to care for himself or herself.”

So what should you do?

This isn’t the first time a diet high in fructose has been linked to negative health consequences; according to the authors, previous studies have made ties between a consumption of fructose and cancer, obesity, diabetes, and fatty liver.

Smug mother in this commercial promoting high-fructose corn syrup, eat your heart out.

Especially because while the notion of “everything in moderation” is grand, the reality is the average American consumed about 27 pounds of high-fructose corn syrup last year—or about eight teaspoons every day. Dang.

Of course, if you’re concerned, avoiding high-fructose corn syrup alone won’t rid fructose from your diet; it occurs naturally in fruit, but according to the authors fruit also contains antioxidants, fiber, and various nutrients that prevent such damage.

However, fructose also comes from regular cane sugar (sucrose, which is made of glucose and fructose molecules)—so people avoiding it may be onto something.

Unfortunately though, people who substitute honey for sugar aren’t better off in terms of this study; honey is high in fructose as well. “Our take-home message can be boiled down to this: reduce fructose in your diet if you want to protect your brain,” Gomez-Pinilla stressed.


Feature Image: Jonathan Cohen/Flickr