Food for your mood: How what you eat affects your mental health

Cory Metzler used to be what she called a "closet eater." The 58-year-old Lake Worth, Florida, woman said she managed to pass up the donuts and pizza frequently on hand in her workplace, but later "rewarded" herself with cookies and carb-laden treats at home. Cory, who suffered from depression at the time, says the treats gave her "a two-second lift, then hours of hateful regret."

"That sad cycle continued for years," she says.

What Cory didn't realize at the time was that her food choices weren't just bringing her regret – the connection between sugary treats and her mood may have been even stronger. While it's widely known that nutrition plays a key role in a person's physical health, it directly affects emotional well-being, too.

"We tend to separate our brain from the rest of our body, but good health means good health from a holistic perspective – from head to toe," says Dr. Gabriela Cora, a board-certified psychiatrist and a medical director for Aetna Behavioral Health. "Why wouldn't we think eating well would also impact our mental health?"

The science behind food and mood

The connection between diet and emotions stems from the close relationship between your brain and your gastrointestinal tract, often called the “second brain.”

Here’s how it works: Your GI tract is home to billions of bacteria that influence the production of neurotransmitters, chemical substances that constantly carry messages from the gut to the brain. (Dopamine and serotonin are two common examples.)

Eating healthy food promotes the growth of “good” bacteria, which in turn positively affects neurotransmitter production. A steady diet of junk food, on the other hand, can cause inflammation that hampers production. When neurotransmitter production is in good shape, your brain receives these positive messages loud and clear, and your emotions reflect it. But when production goes awry, so might your mood.

Sugar, in particular, is considered a major culprit of inflammation, plus it feeds “bad” bacteria in the GI tract. Ironically, it can also cause a temporary spike in “feel good” neurotransmitters, like dopamine. That isn't good for you either, says Rachel Brown, co-founder of The Wellness Project, a consultancy that works with corporations to promote good health among employees. The result is a fleeting sugar rush that is followed shortly thereafter by a crash "that's terrible for your mood," she says.

When you stick to a diet of healthy food, you’re setting yourself up for fewer mood fluctuations, an overall happier outlook and an improved ability to focus, Dr. Cora says. Studies have even found that healthy diets can help with symptoms of depression and anxiety. Unhealthy diets have been linked to an increased risk of dementia or stroke.

Foods that help you be healthy

So what should you put in your cart and on your plate? Here’s a quick overview of what to look for next time you’re in the grocery store. You’ll want to aim for a mix at meal time.

Whole foods
Some studies have shown that preservatives, food colorings and other additives may cause or worsen hyperactivity and depression. "So if you have one thing to remember, it's to eat real food," or food that’s minimally processed and has a few healthy ingredients, says Sarah Jacobs, holistic nutritional counselor and co-founder of The Wellness Project. Think fresh fruits and vegetables.

Fiber
Plant-based foods are full of fiber, which helps your body absorb glucose – or food sugars – more slowly and helps you avoid sugar rushes and crashes. Fiber-rich foods include fruits, vegetables, and nutrient-filled carbs like whole grains and beans.

Antioxidants
These inflammation fighters are especially plentiful in berries, leafy green vegetables, the spice turmeric and foods with Omega-3 fatty acids, including salmon and black chia seeds. Dark chocolate also contains antioxidants – and sugar – so indulge in moderation.

Folate
This type of B vitamin helps with dopamine production without forcing it to surge the way sugars do. Find it in leafy greens, lentils and cantaloupes.

Vitamin D
Vitamin D helps with the production of serotonin, and we usually get it from exposure to sunlight. But mushrooms – especially reishi, cordycep and maitake – are another good source, Jacobs says. (If you are deficient in vitamin D, your doctor may also recommend taking a supplement. Aetna members may receive discounts on supplements; check your plan’s benefits for details.)

Magnesium
This essential mineral helps with everything from nerve and muscle function to keeping a heartbeat steady. But it’s also vital to the food-mood connection: A mineral deficiency can hurt the bacteria in your gut and cause depression and anxiety-like symptoms. Load up with natural sources such as dark chocolate, cacao nibs, almonds and cashews, spinach and other dark leafy greens, bananas and beans.

Fermented foods
Fermented foods are packed with probiotics, which are certain live bacteria that are good for your digestive tract. Examples include sauerkraut, kimchi, miso, tempeh and the fermented drink kombucha. (These foods also tend to be high in sodium, so consume in moderation or skip altogether if you have high blood pressure.)

On your plate and on with your life

Incorporating good-for-your-mood foods into your diet may take some extra effort at first, Brown and Jacobs say. They suggest preparing a week’s worth of chopped veggies and soaked and cooked beans ahead of time, so DIY meals are easier to whip up and just as tempting as take-out. Strapped for time? Dr. Cora suggests using frozen or canned vegetables without the salt and 10-minute brown rice, quinoa or whole-grain couscous.

You can also try making small healthy food swaps, like trading white rice, pasta and bread for whole-grain versions. This helps increase good fiber in your body, which aids in digestion. And instead of a bag of chips, choose a side salad packed with nuts, seeds and colorful vegetables for extra flavor.

General nutrition rules still apply. This means staying hydrated, not skipping meals and being mindful of your caffeine and alcohol intake. Both can directly impact your mood or anxiety level, Dr. Cora says. “You may want to discuss with your doctor if you can drink caffeine or alcohol, and if so, how frequently and how much in order to stay healthy,” she adds.

You don't have to make every healthy change immediately, Dr. Cora points out. You may find it easier to take it week by week. For instance, you could start by adding more vegetables to your diet one week, cutting down on sweets the next, replacing some meats with beans in week 3, and so on. "There's no right way of doing it," she says.

Being mindful of the healthy foods entering your body is also effective, especially when it comes to combating cravings. "Appreciate each smell, food texture and taste for each food," Dr. Cora says. And take note of how the nutritious snacks and meals make you feel afterward. Some people who move to a mostly plant-based diet, for instance, often notice that their energy and focus are sustained throughout the day.

It may take days or week before you start to feel the mood-boosting effects of a better diet, depending on how many changes you implement. But as Cory discovered, it can happen. Over time, healthy eating, along with regular exercise and medication, helped her overcome depression. (Read more about Cory’s story.) "As I repeatedly made healthier food choices, I noted my body responding more favorably," she says. "That gave me the inspiration to continue."