The Startling Effects of Sugar on the Brain – and Our Mental Health

Ah, sugar. No matter how vigilant we try to be in curbing our consumption of it—or dodging it entirely—it seems to appear everywhere, from that fresh pear glistening in a basket at your local farmer’s market to the leading ingredient in the beverage masquerading as “juice.” Its mere prevalence is enough for us to question: Is sugar genuinely as addictive as drugs and alcohol, as older reports implied? And is it really that bad for you?

The quick answer is no and yes. On one hand, sugar functions as a fast-acting carbohydrate, which our brains and bodies fundamentally need to function. Sugar is also found in a host of nutrient-rich eats (like that pear); further, it can provide a boost of energy during moments of mental and physical fatigue.

On the other hand, excessive sugar consumption is associated with a boatload of health complications, including obesity, inflammation, type 2 diabetes, fatty liver disease, and high blood pressure, all of which may bump up your risk for a heart attack or stroke.

But there’s one particular drawback to sugar that doesn’t get nearly as much press as, say, weight gain, or accelerated skin aging: Its potential effects on your cognitive fitness and mental health. Let’s investigate.

Your brain on sugar

Anyone who has ever taken a bite of a warm chocolate souffle knows that sugar can deliver its own very specific brand of bliss.

It’s not just due to the delectable taste of such desserts, either: Sugar fires up the reward system in the brain, primarily by triggering a surge of dopamine—a key neurotransmitter that elicits feelings of pleasure. While this “hit” sugar provides isn’t nearly as addictive as heroin or cocaine (as some sensationalists might suggest), the human brain is wired to seek out the most basic of things: what feels good. The result? An increased desire for sugar, wherein the more you eat it, the more often you might crave it…and the more uncontrollable those cravings may become.

Other mechanisms are at work within all of this. Sugar is famous for its highs, yes, but it’s just as notorious for its crashes. Why does this occur? Because while your brain and body require a certain amount of simple carbohydrates (or simple sugars) to operate at their peak, these sugar levels must be consistent. Eating a glut of sugar, or that entire piece of souffle, spurs your body to pump out insulin to regain optimal blood sugar levels and equilibrium. In turn, blood glucose plummets. Your energy follows suit right alongside with it along with symptoms like:

• Irritability
• Anxiety
• Shakiness
• Exhaustion
• Trouble concentrating

For many, the solution seems easy enough: Reach for an energy drink (which are laden with sugar) or another cookie. The cycle thus begins. And while you might find yourself annoyed with the slack skin you find in the mirror—the palpable outcome of a process known as glycation, which weakens your collagen and elastin—or the number creeping up on the scale, the love-hate relationship you have with sugar may more dangerously disrupt the way your mind actually works in the long run.

The effects of sugar on the brain & mental health

That bite of cheesecake at a holiday soiree or an occasional bear claw likely won’t be cause for alarm. Continually ingesting refined sugars, however, has been linked to more than acne flare-ups and tooth decay. Research demonstrates that sugar may contribute to:

1. Depression

We’re only now beginning to unlock the relationship between an abundance of dietary sugars and depression, but even preliminary data reveals that sugar can provoke this oh-so-ubiquitous mental health condition: A cross-sectional study published by BMC Psychiatry discovered that participants who ate a high intake of sugar were 28% more likely to develop depression—a potentially debilitating disease that affects 21 million US adults per year. Additional research supports this, with slightly older studies pointing to sugar consumption and mood disorders that include depression.

How could something that causes a burst of sheer delight cause the most common mental health condition? One theory is that overindulging sugar can wreak havoc on the delicate ecosystem of bacteria in the gut, which generates a whopping 95% of the “feel good” neurotransmitter, serotonin. Put simply, sugar offsets this fragile balance and may contribute to depression. Accordingly, you may experience some or all of its chief symptoms, such as persistent emptiness and a loss of interest in activities you once relished.

2. Anxiety

Anxiety and sugar consumption have an intricate connection. Low blood sugar (which, for the record, isn’t exactly dictated by sugar consumption but can be impacted by low caloric intake) may stir up some of the symptoms of anxiety, such as shakiness, trouble concentrating and nausea. At the same time, a diet that’s rampant with sugar can exacerbate symptoms of anxiety.

How? Because of blood sugar instability: When your glucose levels reach their peak then drop precipitously, the desire for more sugar skyrockets. These continual ups and downs, in turn, can trigger the release of stress hormones like cortisol and adrenaline, thus worsening the situation.

To further complicate matters, withdrawing from sugar can ignite symptoms that mirror a panic or anxiety attack, such as:

• High anxiety
• Confusion
• Irritability
• Fatigue

3. Stress

“Stress” isn’t technically a mental health condition; indeed, study after study confirms that we need some stress in our lives to meet our daily demands and tasks.

Chronic stress, though, is directly connected to a myriad of health complications, including decreased immunity, obesity, and heart disease. And while you may actively, even ravenously seek out sweets when you’re under a killer deadline or dealing with a difficult teenager (we call it “stress eating” for a reason), that temporary relief may not be worth the long-term damage it could be causing: You may repeatedly reach for sweets to quell the discomfort stress spawns and weaken your capacity to deal with it mindfully.

This may start a pattern that could result in the very health conditions stress creates. A smarter option than snacking on Oreos: Lacing up your sneaks and heading outside for a walk or run.

4. Mood disorders

According to a study featured in Scientific Reports, adhering to a diet where sugar is a primary ingredient may raise the risk of mood disorders in men, and cyclical mood disorders in both men and women.

What is a mood disorder, you might ask? Broadly speaking, it refers to a mental health condition in which there’s incongruity between a person’s feelings and state of mind and their genuine life circumstances. Several conditions exist under its umbrella, including bipolar disorder, substance use disorder and what’s known as dysthymia—a condition characterized by low-grade depression coupled with irritability (if ever there’s another reason to use a light hand when sweetening your morning coffee).

5. Impaired brain power

As we touched upon earlier, sugar and cognitive activity also have an unusual bond: On one end of the spectrum, your mind needs sugar to perform even the most basic tasks. (In fact, glucose is the chief source of energy for the brain.) On the other end, overconsumption of free sugars—such as high-fructose corn syrup—can make you susceptible to:

• Memory issues
• Attention problems
• Decreased problem solving skills
• Reduced cognitive function

Worrisome? You bet, and it doesn’t take long for sugar to get its claws in you, either: One study indicates that even a single week of dining on eats high in sugar and saturated fat led to poor scores on memory tests and diminished appetite control—an impulse governed by the hippocampus.

How much sugar is too much?

It’s the $64,000 question and one that’s frequently up for debate, in large part because each person’s caloric requirements hinge on a host of factors, such as height, age, and activity level. A good rule of thumb, though, is to keep your intake of sugar at no more than 10% of your daily calories. Concerned about your cardiovascular health? Slash it to 6%, the limit set forth by the American Heart Association.

If you’re at a loss of how to start calculating your sugar consumption, make a habit out of reading food labels and taking note of how many grams of added sugar are lurking in your products.

When your sweet tooth strikes: savvy alternatives to sugar

Few of us are immune to sugar cravings, especially during times of exhaustion, a bout of the blues (which, it bears mentioning, is distinct from clinical depression), or, for women, when estrogen takes a nosedive post-ovulation. Rather than give in to your urge for a caramel sundae, however, consider these swaps:

• A bowl of plain Greek yogurt topped with berries, slivered almonds and a drizzle of honey
• A few squares of dark chocolate
• Baked apple slices sprinkled with cinnamon
• Steel cut oats crowned with a sliced banana and dried coconut flakes
• Unreal Almond Butter Cups

And if you do go for the “real thing” every once in awhile? By all means, savor it. Life, after all, is meant to be sweet.