High Sugar Intake Can Increase Depression Risk by 28%, According to New Study

Learn what this study shows regarding the connection between excessive sugar intake and depression—and some ways to reduce your sugar intake.

Reviewed by Dietitian Jessica Ball, M.S., RD

We know we’re supposed to limit the amount of added sugar we eat, but if you have a propensity toward the sweet stuff, that can be easier said than done.

Whether you prefer something fruity, like Lemon Blueberry Bars and Easy Peach Cobbler Dump Cake, or something chocolatey, like Peanut Butter Chocolate Chip Cookies and One-Bowl Chocolate Cake, having dessert can fit into a healthy eating pattern. It’s when it’s taken to extremes that it becomes problematic.

The 2020-2025 Dietary Guidelines for Americans suggest limiting added sugar intake to less than 10% of total daily caloric intake. If you’re eating about 2,000 calories per day, that’s no more than 12 teaspoons or 48 grams of sugar a day.

The American Heart Association has even stricter guidelines, recommending that women consume no more than 6 teaspoons or 25 grams of added sugar per day and men stay under 9 teaspoons or 36 grams of added sugar per day.

What’s the fuss all about?

Excessive added sugar intake has been linked to several diseases, including heart disease, cancer, diabetes, high blood pressure, non-alcoholic fatty liver disease and metabolic syndrome. It can even increase your chance of gout, a form of arthritis in which uric acid forms very painful needle-like crystals in your joints.

And now, a study published on February 8, 2024 in BMC Psychiatry suggests that there is also a link between eating too much sugar and depression.

How Was the Study Conducted?

The data for this study was drawn from the National Health and Nutrition Examination Survey (NHANES) database. It included 18,439 men and women all over the age of 20 representing a variety of races and ethnicities, including non-Hispanic White, non-Hispanic Black and Mexican-American.

Each participant completed the Patient Health Questionnaire-9 (PHQ-9), which is a quick screening assessment for depression.

Researchers also gathered information on diet through two 24-hour dietary recall interviews—which simply involved asking the person what they ate over the past 24 hours. The first was done in person at a mobile screening center. The second was done over the phone 3 to 10 days after the in-person interview.

Once the data was collected, it was run through USDA software to calculate nutrient intakes. It was also reviewed by Food Survey Research Group (FSRG) scientists to ensure data quality. Each participant’s sugar intake was calculated by taking the average of their two 24-hour dietary recalls.

The researchers adjusted for factors that might influence depression so that they could more closely isolate sugar as a possible cause of depression since that’s what they were testing.

After running several statistical tests on the data, researchers found a linear relationship between sugar intake and depression—meaning, that the more sugar participants ate, the greater the risk of depression.

Specifically, they found that for every 100-gram per day increase in dietary sugar (about 8 tablespoons or 1/2 cup), the risk for depression increased by 28%.

The researchers state that more research needs to be done to determine the reason for this correlation but give several possible reasons—one of which is concerning how sugar can increase inflammation in the body. And increased inflammation is linked to a greater risk of depression.

Another possible reason given by the study authors is the link between gut health and depression. Excessive sugar intake can have negative impacts on gut health by disrupting the gut microbiome. And an unhealthy gut has been associated with depression and anxiety.

Excessive sugar intake can also send your blood sugar soaring and then subsequently crashing. So if you’re depending on sugar-laden drinks and refined carb foods throughout the day, you’ll be on this constant up and down cycle—and it’s going to negatively affect your mood and energy. And you don’t have to have diabetes to experience this.

How Does This Apply to Real Life?

Here’s the thing. We all have to eat to live. There is no one perfect way to eat. And life would be pretty boring without sweet treats now and then.

Behaviors are about patterns—and that includes your eating patterns. Are you regularly eating—or drinking—foods high in added sugar? Sometimes the answer to that question can be pretty obvious—like if you’re noshing on cookies and ice cream and downing a 2-liter of regular soda every day.

But added sugar can also show up in sneaky ways. For example, some “healthy” cereals have as much sugar as a doughnut and flavored yogurt can be full of the sweet stuff, too. Many energy bars are loaded with sugar, as are energy and sports drinks, and your favorite coffeehouse concoctions.

Yes, there are many sources of added sugar, some obvious, some not so much. And there are two primary ways to lower your added sugar intake: Increase the amount of whole foods you’re eating and start moderating the amount of pre-packaged and prepared foods you’re ingesting.

It’s also helpful to have a baseline of where you’re currently at with sugar intake. Take a couple of “normal eating days,” calculate the amount of added sugar in what you eat for each day (look for the amount of added sugar in each serving size on the Nutrition Facts label and calculate it based on how big your portion size was), and then take the average of the two days.

Is it above the recommended 48 grams or less a day? If so, consider what foods the sugar is coming from and ways you can reduce your intake of it. What can you swap that food with? Or if it’s a non-negotiable food, can you eat less of it?

Related: Here's Why You Should Eat Fruit Even Though It Contains Sugar

The Bottom Line

It can take some time to change an added sugar habit, as our taste buds and mouths get used to certain foods and textures. And by following the same eating patterns over time, we also condition our brains to believe certain foods go together—like having a soda with your burger—or that certain times of day are linked with certain foods—like mid-afternoon means it’s time for a sweetened coffee drink. And now and then it’s not a big deal. But considering the number of diseases that are related to excessive daily added sugar intake and the fact that many foods high in added sugar offer very little nutritional value, it’s worth putting in the time and effort to reduce your overall added sugar intake. Your teeth will thank you, too.

Read the original article on Eating Well.