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It’s supposed to be “the most wonderful time of the year,” but the holidays, for many people, can actually lead to higher levels of depression than usual. A recent study suggests that added sugars may be the culprit. Researchers at the University of Kansas say that the added sugars found in pretty much every sweet holiday treat can induce metabolic, inflammatory, and neurobiological processes linked to depression and negative feelings.

These sugary treats mixed with decreasing amounts of sunlight in the wintertime resulting in sleep pattern variations make for a recipe for depression during the holidays.

In a KU release, Associate Professor of Clinical Psychology Stephen Ilardi says, “For many people, reduced sunlight exposure during the winter will throw off circadian rhythms, disrupting healthy sleep and pushing five to 10% of the population into a full-blown episode of clinical depression.”

According to the research team, it’s a possibility that seasonal-depression symptoms will push individuals to start eating more sweets. 

“One common characteristic of winter-onset depression is craving sugar,” Ilardi continues. “So, we’ve got up to 30% of the population suffering from at least some symptoms of winter-onset depression, causing them to crave carbs – and now they’re constantly confronted with holiday sweets.”

It can be especially tough for people to resist sweets because they offer an initial mood boost.

“When we consume sweets, they act like a drug,” Ilardi says. “They have an immediate mood-elevating effect, but in high doses, they can also have a paradoxical, pernicious longer-term consequence of making mood worse, reducing well-being, elevating inflammation and causing weight gain.”

After analyzing a large assortment of previous research, the research team came to their findings focused on the physiological and psychological effects of eating added sugar. 

Overwhelmingly, what they found was the inflammation caused by excess sugar is the number one contributor to depressive thoughts.

“A large subset of people with depression have high levels of systemic inflammation,” the Prof says. “When we think about inflammatory disease, we think about things like diabetes and rheumatoid arthritis – diseases with a high level of systemic inflammation. We don’t normally think about depression being in that category, but it turns out that it really is – not for everyone who’s depressed, but for about half. We also know that inflammatory hormones can directly push the brain into a state of severe depression. So, an inflamed brain is typically a depressed brain. And added sugars have a pro-inflammatory effect on the body and brain.”

He goes on to explain how sugar impacts the bacteria already present in our bodies, “Our bodies host over 10 trillion microbes, and many of them know how to hack into the brain. The symbiotic microbial species, the beneficial microbes, basically hack the brain to enhance our well-being. They want us to thrive so they can thrive. But there are also some opportunistic species that can be thought of as more purely parasitic – they don’t have our best interest in mind at all. Many of those parasitic microbes thrive on added sugars, and they can produce chemicals that push the brain in a state of anxiety and stress and depression. They’re also highly inflammatory.”

Not surprisingly, the researchers recommend a diet of non-processed foods, particularly rich in plant-based foods and Omega-3 fatty acids, to combat depression on a dietary level. Furthermore, the study’s authors recommend staying away from added sugars year-long, not just during the holidays.

But never fear, like we said last week, dark chocolate can be the exception! Just be intentional as to what you reach for this holiday season. Be mindful of what you’re feeding your body, soul, and spirit. And don’t overdo it on the sweet treats. We can hear grandmothers everywhere, saying, “You’re already sweet enough!’