It seems like the older I get, the harder it is to remember things that happened last month — or even last week. I’ve been chalking this up to what my mother laughingly calls “senior moments” and figured it’s an inevitable part of aging. But a new study makes me wonder if my recent afternoon habit of snacking on Cheez-Its is to blame for my forgetfulness, and not just my advancing years.
In a study published in the journal Brain, Behavior, and Immunity, researchers at The Ohio State University fed two groups of rats, one young and one older, a diet high in refined carbohydrates such as those found in highly processed foods. (Think potato chips, frozen pizza, preservative-laden deli meats — and yes, Cheez-Its.) After just four weeks of this junk-food fest, the older rats failed a series of cognitive tests. They couldn’t remember places they’d just been, and didn’t show fear when faced with signs of impending danger.
The younger rats who chowed down on the processed food diet showed no signs of memory loss or inappropriate responses. Neither did a control group, both young and old, who were given their normal diet, which was made up of a healthy mix of protein, complex carbohydrates, and fat.
“These findings indicate that consumption of a processed diet can produce significant and abrupt memory deficit,” the study’s lead author, Ruth Barrientos, said in a university release. And if four weeks seems like an incredibly short an amount of time to see such drastic effects, Barrientos, an associate professor of psychiatry and behavioral health and an investigator at The Ohio State University Institute for Behavioral Medicine Research, agrees. “The fact we’re seeing these effects so quickly is a little bit alarming.”
What’s happening in the brains of these rats to make them forget where they’ve been and not respond to danger? The problem lies in the hippocampus, which plays a huge role in learning and memory, and the amygdala, which regulates emotion.
Researchers found that the diet high in refined carbs triggered an inflammatory response in these regions of the older rats’ brains. This inflammation made them forget having recently spent time in an unfamiliar space, indicating problems with the hippocampus, and fail to respond to danger cues, suggesting damage to the amygdala.
Reason for Hope
Barrientos stressed that the results of this study have more significant implications for older folks. “In the aging population, rapid memory decline has a greater likelihood of progressing into neurodegenerative disease such as Alzheimer’s disease.”
In other words, those “senior moments” my mom jokes about aren’t as harmless as we might like to think. It’s one thing to accidentally put your reading glasses in the refrigerator or forget why you walked into a room, but if those small lapses in memory mean I’m more prone to develop dementia, I am inclined to take them seriously.
But before we head to our pantries determined to toss out every processed food we can find (so long, Cheez-Its), there’s reason for hope. Another group of older rats were fed the junk food diet along with DHA supplements, and in this group, the inflammatory neurological responses and signs of memory loss were not seen at all.
Is DHA supplementation the answer?
Docosahexaenoic acid, or DHA, is an omega-3 fatty acid found in cold-water fish such as tuna and salmon. We’ve long known that eating a diet high in omega-3 fatty acids is good for your heart and can even prevent signs of aging, but can taking DHA supplements also give us license to indulge in the processed foods we love, without fear of triggering inflammation and memory loss?
Barrientos says no. While DHA supplementation did seem to have a protective effect on the rats’ brains in this particular study, there are a couple of caveats.
First, scientists don’t know exactly how much DHA the rats consumed, as they had unlimited access to both food and DHA supplements. That means they’re not able to recommend a specific DHA dose that might prevent brain inflammation.
Second, all of the rats on the processed food diet gained a “significant” amount of weight — and the older rats gained “significantly more” than the younger ones. And while weight gain is obviously different than dementia, when the extra pounds come from eating junk food, not building muscle, it’s a health concern as well.
The Key to a Healthy Diet
The key to staying mentally sharp and physically healthy, says Barrientos, is staying away from highly processed foods and refined carbs. “Folks who are used to looking at nutritional information need to pay attention to the fiber and quality of carbohydrates. This study really shows those things are important.”
Want to have fewer “senior moments,” not to mention continue to fit into your favorite jeans? It could be as simple as swapping your afternoon Cheez-Its — or whatever your particular processed food weakness is — for some sliced apples (full of fiber) and a handful of walnuts (rich in omega-3 fatty acids).
If doing away with processed foods means a lower risk of dementia down the road, I’m in. Besides, getting more creative with my afternoon snacks sounds like fun! I’m thinking sugar snap peas today. What will your new go-to snack be?