You might think of food as fuel, in a physical sense: The nutrients you soak up from your diet allow your heart to beat, your muscles to flex, your bones to stay strong and supportive. What’s often less obvious is the way food powers mental well-being. But your brain’s constant flurry of activity hinges on energy from what you consume. And scientists are increasingly unpacking the organ’s response to different nutrients in our diet—or lack thereof—and the trickle-down effects on our mental health.

Research has found that people who stick to a high-quality diet of mostly whole foods (like the Mediterranean diet) or double down on fruits and veggies are less likely to develop depressive or anxiety symptoms over a period of several years, while those who eat mostly ultraprocessed foods, or UPFs (like packaged snacks and frozen meals), have a greater chance of winding up with either condition. A couple of small trials have even shown that following the Med diet for a few weeks may soften the severity of depressive symptoms in people who already have them.

And there are a handful of potential reasons why. For starters, the vitamins and minerals in whole foods can power up reactions in your brain that affect how you feel—namely, ones that produce neurotransmitters like dopamine (which drives reward and motivation), serotonin (which regulates mood) and GABA (which promotes calm), Bonnie J. Kaplan, PhD, a semi-retired professor at the University of Calgary’s Cumming School of Medicine and co-author of The Better Brain, tells SELF. Your diet can also shift the ecosystem of bacteria living in your gut, called your microbiome, which communicates with your brain via nerve signals. Taking in ample nutrients, particularly fiber, vitamins, and minerals from plants, can help your good gut bugs (a.k.a. probiotics) thrive—which may, in turn, support your levels of the above neurotransmitters.

Additionally, the foods you eat could affect the degree of inflammation in your body, which, if left unchecked, may contribute to depression and anxiety. While UPFs and fast food are packed with ingredients that can spark an inflammatory response (like sugar and salt), fruits and veggies naturally contain antioxidants and fiber that can, instead, put a chill on inflammation. That’s not to say any specific dietary tweak can cure depression (or any other mental disorder), nor is it a substitute for medical treatment. Still, it’s becoming clear that what you eat has the power to sway your mental state over time.

Below, dig into the types of foods that can benefit your mental health and the reasons why they can deliver such mood-boosting support.

The best foods to eat to support your mental health long-term

And other sources of B vitamins like legumes, whole grains, nuts, and seeds

“B” vitamins might as well stand for “brain vitamins,” since many of them have important impacts on this organ, Uma Naidoo, MD, director of nutritional and lifestyle psychiatry at Massachusetts General Hospital and author of Calm Your Mind With Food, tells SELF. And leafy greens like spinach, kale, and arugula contain a handful of them, including lots of B₉ (folate) as well as B₁, B₂, and B₆. Both B₉ and B₆ help fuel the creation of those friendly neurotransmitters serotonin and dopamine. And B₁ and B₂ help ensure the brain has adequate energy to function at its prime. (In fact, research suggests various B-vitamin deficiencies could up your risk for depression.)

Not to mention, leafy greens are loaded with antioxidants—in particular, vitamins A, C, and E—which can help shield your brain from the effects of lingering inflammation. (And as a quick note: Experts generally agree, it’s better to get these micronutrients from foods versus pills since they’re easier for your body to access and use in that state.)

And other sources of omega-3 fatty acids like flaxseeds, chia seeds, and walnuts

The omega-3s in salmon, tuna, trout, and similar swimmers are often labeled “healthy fats,” and it turns out, the positive effect extends to your mental state too. These omegas are anti-inflammatory powerhouses, known to reduce body and brain inflammation through a bunch of different pathways that researchers suspect may have antidepressant effects.

Separately, omega-3s are also “critically important in building [brain] cell walls,” Dr. Kaplan says, which we’ve long known plays a role in brain development but we’re also learning can support neuroplasticity—the brain’s ability to spark new connections between neurons—throughout life. Researchers think this effect could buffer against or repair some of the weaker ties between neurons in a depressed brain. And that’s not all: Omega-3s also lend a hand to a bevy of other brain activities, among them the ability of several mood-affecting neurotransmitters to successfully do their jobs.

Different berries, like strawberries, blackberries, and blueberries, have varying amounts of distinct antioxidants (like flavonoids and vitamin C), Dr. Naidoo points out, so it’s worth mixing it up to maximize the anti-inflammatory benefit for your brain. Some research suggests berries might also support certain aspects of nerve signaling and function, which could benefit your mood. And these fruits are a tasty snack for the critters in your gut, helping to maintain the balance of this ecosystem—and its influence on the gut-brain axis.

You might not think of alliums (like onion and garlic), root vegetables (like sweet potatoes), and whole grains (like oats and barley) in the same food group, per se, but what they all have in common is plenty of prebiotic fiber—which especially nourishes your good gut bugs, Dr. Naidoo says. (FYI, berries also fall into this group as do a few other plant foods.) The result is a happy, balanced microbiome, which again, helps maximize the availability of mood-regulating serotonin and other neurotransmitters in your brain.

When your gut microbes nosh on prebiotics, they also release compounds called short-chain fatty acids (SCFAs) as a byproduct, which can tamp down on inflammation, including in your brain, with potential upsides for mood disorders. Not to mention, these powerful SCFAs can also spur gut cells to pump out serotonin and activate your parasympathetic (a.k.a. rest and digest) nervous system, which may calm down an overactive stress response.

These funky foods, like kimchi, kefir, yogurt, and sauerkraut, are naturally teeming with beneficial bacteria, which can help improve the balance of your microbiome, and as with the prebiotics, bump up your levels of key neurotransmitters that support mood. Plus, research suggests eating a good deal of fermented items may lower inflammation, Dr. Naidoo notes. In fact, both the live probiotics they contain and the byproducts of those bugs in your system can have anti-inflammatory perks with upstream benefits for your brain.

While, again, food can’t stand in for medical treatment, filling up on the above items—and eating plenty of plants, more broadly—is a stellar way to support your gut, your brain, and the close ties between the two.

Related:

• 5 Things That Can Help When You Feel Irritable and Depressed
• The Meal I Eat When I Want to Feel Rejuvenated: Watermelon and Feta Salad
• 17 Energizing Afternoon Habits for When You Need a Pick-Me-Up

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