Feeling down in the dumps? That slice of pizza or that piece of pie might be to blame. More and more research points to sugar, gluten, and other dietary ingredients as culprits behind sad moods. Here’s what scientists have found out about the link between gluten, fats, sugar, and depression. Plus, how to be happier when you indulge in occasional cheats.
Can Sugar Cause Depression?
More and more research suggests that a sweet tooth may lead to a sour mind. In one study, researchers looked at the amount of sugar eaten by people from a number of countries. They then compared the sugar intake with the rate of major depression.1 The result? The more sugar people ate, the higher the rate of depression.
In another study, men who consumed the most sweet food and drinks were 23 percent more likely to have mental health issues over five years. Because depression might cause someone to eat more sugar, the study authors looked into whether this was the case in their study subjects. They found that being depressed in and of itself was not linked to eating more sugar. That made it more likely that the sugar might be causing the depression rather than the depression spurring the subjects to eat more sugar.2
Here’s why scientists believe sugar can make you sad:
- Eating sugar causes inflammation, which is known to trigger depression.2
- Eating lots of sugar and fat is linked to low levels of brain derived neurotrophic factor (BDNF).2 Low levels of this brain-boosting molecule may trigger depression.
- Diets high in sugar may kick your blood sugar and insulin levels out of whack. There’s a relationship between depression and a condition known as insulin resistance.3 In this condition, cells start ignoring insulin’s message to lower blood sugar. When that happens, the body must produce more and more insulin in order to get blood sugar down.
The Glycemic Index and Your Mood
Carbs by themselves aren’t the villains. The problems are carbs that raise your blood sugar levels too high. The glycemic index (GI) measures a food’s ability to boost blood sugar. The index gives each food a number. The lower the number, the less the food raises blood sugar. Foods with refined carbs and sugar have higher GI numbers. Foods higher in fiber and protein have lower numbers.
If you’re chowing down on high-glycemic index foods, it can increase the risk of depression. For example, in one study of postmenopausal women, the more high glycemic foods the women ate, the more likely they were depressed.4 Eating food with more added sugars also upped the risk of depression. On the other hand, eating foods with lactose (dairy) and fiber as well as non-juice fruit and vegetables was linked to a lower risk of depression.
Processed Foods and Your Mood
Eating a diet high in processed foods can also destroy your positive attitude. In a study of 3,486 men and women, researchers compared the effects of eating a whole food diet that included a lot of vegetables, fruit, and fish or a processed food diet loaded with sweet desserts, fried food, processed meat, refined grains (especially cereals), and high-fat dairy products.5 People who ate the most whole foods were less likely to become depressed compared to people who ate a processed food diet.
Does Gluten Intolerance Cause Depression?
And then there’s gluten. If you have non-celiac gluten sensitivity, eating gluten may cause your mood to take a tumble. Non-celiac gluten sensitivity is a condition where people who don’t actually have celiac disease still react to gluten. If you have this condition, you won’t have the intestinal damage seen in celiac disease. And you won’t test positive for the disease. But you will have symptoms similar to people who have celiac disease. Plus, these symptoms go away when you take gluten out of the diet. Research shows that eating gluten may trigger feelings of depression in people with non-celiac gluten sensitivity.6
There are a few reasons why gluten may affect your mood. First, it may cause levels of serotonin, a feel-good hormone, to take a nosedive.6 Your body makes serotonin from tryptophan. Animal research suggests tryptophan levels in the brain may fall after eating wheat.6
Another reason why gluten may affect your happiness? It contains proteins that react similar to opioid drugs. These proteins can get into your brain and impact your emotions and memory.6 What’s more, gluten gets in the way of your happiness by interacting with what scientists call the gut-brain axis.6 Through the gut-brain axis, the gut sends messages to the brain and vice versa. Gluten can cause changes in your gut microbiota, the collection of tiny organisms that live in your GI tract. These changes can mess up the signals your gut is sending to your brain. This in turn may affect your emotions and mood.
How to Make Yourself Happy with Foods That Improve Mood
The key in discovering how to be happier? Eat a healthy diet most of the time. By healthy we mean little added sugar and few processed foods. Try using organic stevia as a good sugar substitute since it doesn’t affect blood sugar. Plus, avoid gluten if you’re sensitive. And opt for lots of veggies and fruits.
The types of fat you eat are also important. Trans unsaturated fatty acids are linked to a higher risk of depression. The Food and Drug Administration banned artificial trans fats in foods. But if a food has less than .5 grams of trans fats per serving, the label can claim it has no trans fats. That’s why you might still find some of these mood-busting fats in some varieties of microwave popcorn, vegetable shortening, margarines, fried fast foods, some baked goods, and non-dairy coffee creamers. On the other hand, polyunsaturated fatty acids (think fish oil) and monounsaturated fatty acids (found in olive oil) are mood-enhancing foods.
It’s also a good idea to know which foods don’t agree with your body. You might be intolerant or sensitive to even the most “healthy” of foods. These food intolerances/sensitivities are different from outright food allergies in that the symptoms may not appear for hours or even days after you eat the food. This means even an apple or broccoli could cause your mood to take a turn for the worse or cause other symptoms. It’s best to work with a functional medicine doctor, who can order a blood test to identify your own personal dietary culprits.
Foods That Improve Mood
Here are the best mood-boosting foods to work into your diet:
• Fish, especially salmon
• Low-glycemic fruits like strawberries, apples, oranges, and peaches
• Low-glycemic vegetables. Avoid potatoes.
• Olive Oil
• High-fiber foods that don’t contain gluten. Think brown rice or quinoa.
Help for Those Occasional Cheats
That slice of cake sitting in the bakery case calls to you. You know it’s not good for you. But the temptation becomes too much. So you give in. Doing this every day won’t be good for your mood or your body. But if you indulge occasionally, digestive enzymes are the answer. Enzymes like lactase, amylase, invertase, xylanase, and maltase support healthy digestion of carbs. DPPIV can help your body leap over the hurdle of eating gluten. A low-carb, low-gluten diet is probably going to contain lots of fiber. To the rescue are fiber-digesting enzymes like alpha galactosidase, glucoamylase, hemicellulase, beta glucanase, pectinase, cellulase, and phytase.
The dairy sugar lactose hasn’t been linked to mood problems. But for people whose bodies can’t digest lactose, taking a digestive enzyme supplement with lactase can stop digestive problems that don’t exactly put you in a good mood. Meanwhile, lipase can break down the fatty foods. That’s why you’ll want to take a good digestive enzyme complex supplement that contains all of these enzymes.
Food and Mood
The bottom line? If you want to know how to be happier take a look at your diet. Sugar, gluten, and processed foods might be the only thing standing in the way of your feeling joy. Consider replacing those items with foods that improve mood. And for those times when you indulge, take a digestive enzyme supplement to support the breakdown of the biggest offenders like carbs and gluten.
- Westover AN, Marangell LB. A cross-national relationship between sugar consumption and major depression? Depress Anxiety. 2002;16(3):118-120.
- Knüppel A, Shipley MJ, Llewellyn CH, Brunner EJ. Sugar intake from sweet food and beverages, common mental disorder and depression: prospective findings from the Whitehall II study. Sci Rep. 2017;7(1):6287.
- Singh MK, Leslie SM, Packer MM, et al. Brain and behavioral correlates of insulin resistance in youth with depression and obesity. Horm Behav. 2019;108:73-83.
- Gangwisch JE, Hale L, Garcia L, et al. High glycemic index diet as a risk factor for depression: analyses from the Women's Health Initiative. Am J Clin Nutr. 2015;102(2):454-463.
- Akbaraly TN, Brunner EJ, Ferrie JE, Marmot MG, Kivimaki M, Singh-Manoux A. Dietary pattern and depressive symptoms in middle age. Br J Psychiatry. 2009;195(5):408-413.
- Peters SL, Biesiekierski JR, Yelland GW, Muir JG, Gibson PR. Randomised clinical trial: gluten may cause depression in subjects with non-coeliac gluten sensitivity - an exploratory clinical study. Aliment Pharmacol Ther. 2014;39(10):1104-1112.