Ever been hangry? Of course you have. That’s when hunger makes you feel irritable or bad-tempered — hungry and angry. Food, or lack of it, clearly affects our moods in both healthful and harmful ways. Perhaps no food has been implicated more in the diet-mood connection than sugar.
Britain’s Brain Bio Centre is as plain as can be on this matter. “There is a direct link between mood and blood sugar balance,” it writes. “Poor blood sugar balance is often the single-biggest factor in mood disorders amongst the people that seek our advice.”
The key word in that claim is “balance.” Sugar, most naturally consumed as complex carbohydrates found in fruits and vegetables, is a necessary component of a healthy diet. But the Western diet is far from balanced. Too many people get their carbs not from complex, plant-based sources but from refined, processed foods such as white bread and other baked goods, soda, pasta and candy. Many foods today have sugar added directly to them, for no other reason than to make them appeal to our naturally evolved sweet tooth. Not only do these sources pile on too much of a sweet thing, they replace more important vitamins and nutrients that maintain physical and mental health.
[See: 6 Darn Good Reasons to Eat Sugar and Not Apologize for It.]
The link between sugar consumption and depression, in fact, is clear.
The Evidence Is Strong
Here’s a rundown of just a few of the studies implicating sugar as a risk factor for depression:
— A 2002 study looked at the overall sugar consumption per person in six nations — Canada, France, Germany, South Korea, New Zealand and the U.S. — and directly linked sugar consumption to higher rates of major depression.
— A study of 3,456 middle-aged adults found that those who ate a diet consisting of a lot of processed foods had a 58 percent increased risk for depression, while those who ate more whole foods had a 26 percent reduced risk for depression.
— A study tracking 8,000 people over 22 years that used surveys about what the participants ate and why they saw their doctor found that men who consumed 67 grams or more of sugar per day were 23 percent more likely to be diagnosed with depression than men who ate 40 grams or less.
— Data from more than 70,000 postmenopausal women and their diets examined the glycemic index, or GI, of the foods they ate and discovered that the higher their dietary GI scores and consumption of added sugars and refined grains were, the higher was the association with increased risk of new-onset depression. On the other hand, greater consumption low-GI foods, which contain more dietary fiber and nutrients, such as whole grains, vegetables and non-juice fruits, was associated with decreased risk of new-onset depression.
[Read: Mental Health Experts Recommend Their Favorite Depression Books.]
This last study was conducted by James Gangwisch and his colleagues in the department of psychiatry at Columbia University Medical Center. “It has long been known that people with depression tend to crave sweets,” he says. He wondered if the reverse was true as well: If you take someone who is not depressed and give them lots of sugar, will it increase risk?
Not only was the answer yes, the study was able to drill down to the types of sugars that most increase risk, and the finger pointed directly at high-GI foods, such as processed foods and sugar-added soft drinks. The reason, he surmises, is that the sugars in higher-GI foods are absorbed faster than in lower-GI foods with more complex carbohydrates. With fresh fruit, for example, “you also get all the fiber and pectin, which slows down the rate blood sugar rises,” Gangwisch says. “We feel [the increased risk for depression] is most likely due to spikes and troughs in blood sugar. When blood sugar is low, you can have a hypoglycemic reaction. The body sends out stress hormones to realign the chemistry, which can make you feel anxious, nervous and lower mood.”
Empty Calories Replace Important Nutrients
“The main link with simple sugars is in that they are empty calories,” says Dr. Drew Ramsey, an assistant clinical professor of psychiatry at Columbia University and co-author of “The Happiness Diet” and other books that explore nutrition and mental health. “I see it clearly related to a host of mental health disorders, along with obesity, diabetes and Alzheimer’s.”
While empty calories tend to replace the nutrients our bodies need, they also deplete the stores we already have of important brain- and mood-dependent B vitamins and chromium. Sugars also cause inflammation, which has been implicated in a host of medical problems, from cardiovascular disease to dementia. A high-sugar diet “doesn’t include the nutrients we need to deal with the metabolic stressors in life,” Ramsey says. The body is not able to process and remove stress-related hormones like adrenaline and cortisol. “It’s like sticking a banana in your car’s tailpipe, that is kind of how I think about it,” he says. “Your car still gets you there, but it doesn’t have as much power.”
Diets with fewer simple sugars, on the other hand, act just the opposite. “If you look at the [low] sugar content of a typical Norwegian or Japanese diet, they all confer tremendous protection against depression and dementia,” Ramsey says. The Mediterranean diet, which features high-GI plant-based foods, has been shown to decrease depression risk by 40 to 50 percent and dementia by 40 percent, he says.
[See: 7 Reasons to Choose a Plant-Based Diet.]
The best way to prevent depression is to reduce risk factors and increase protective factors, and sugar is high on the list of action steps. If you aren’t depressed, watch your sugar consumption. “If you are depressed and eating a lot of sweets, that could be part of problem, and that may be a target for treatment,” Gangwisch says.
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What Is the Link Between Sugar and Depression? originally appeared on usnews.com
