It’s World Mental Health Day today: Let’s review how a healthy diet can promote mental well-being


Should you eat an apple—or a bag of Ore­os? Go to McDonald’s—or the veg­e­tar­i­an restau­rant on the corner?

When we make these every­day food choic­es, many of us think first of our phys­i­cal health and appear­ance. But there’s anoth­er fac­tor we may want to con­sid­er in pick­ing foods: their impact on our men­tal health.

A grow­ing body of research is dis­cov­er­ing that food doesn’t just affect our waist­line but also our moods, emo­tions, and even longer-term con­di­tions like depres­sion. Which makes sense, after all. Our brains are phys­i­cal enti­ties, run­ning on the ener­gy that we put into our bod­ies, affect­ed by shifts in our hor­mones, blood sug­ar lev­els, and many oth­er bio­log­i­cal processes.

Although there are many unan­swered ques­tions, the research to date can give us some guid­ance when we’re hunt­ing for an after­noon snack. What we know so far can be summed up, more or less, as this: Whole-food diets heavy on the fruits, veg­eta­bles, and unprocessed pro­tein can lift our moods and pro­tect us from depres­sion, while too much junk food and sug­ar may put our men­tal health at risk.

One-third of adults in Amer­i­ca eat fast food on a giv­en day. Many of us see French fries and choco­late cake as treats to cheer us up when we’re feel­ing down. But per­haps our per­spec­tive on food needs an update. With a few sim­ple dietary changes, you might be able to improve both your mind and your mood.

Can your diet protect you from depression?

A paper pub­lished this year in Psy­cho­so­mat­ic Med­i­cine offers one of the most up-to-date snap­shots of diet and men­tal health—specifically, how diet might play a role in depression.

The research team scoured aca­d­e­m­ic jour­nals for exper­i­ments that had asked peo­ple to change their diets and had mea­sured the effects. In all, they found 16 stud­ies with near­ly 46,000 par­tic­i­pants from the Unit­ed States, Aus­tralia, and Europe, rang­ing from ages 21 to 85.

The exper­i­ments were quite diverse, pre­scrib­ing a vari­ety of diets to boost nutri­ent intake, reduce fat intake, or encour­age weight loss. One group went on a veg­an diet, while oth­ers restrict­ed calo­ries; many peo­ple loaded up on fruits and veg­eta­bles while avoid­ing meat and processed foods. Some peo­ple attend­ed nutri­tion class­es togeth­er, while oth­ers got per­son­al­ized coun­sel­ing or sim­ply took home a set of guide­lines. They fol­lowed the diet for any­where from a cou­ple weeks to a few years.

The results? Over­all, adopt­ing a health­i­er diet did lead to reduced symp­toms of depression—less hope­less­ness, trou­ble sleep­ing, and dis­con­nec­tion from others—compared to engag­ing in oth­er self-improve­ment activ­i­ties or going about life as usual.

Includ­ing more non-processed foods, more whole foods—fruits, vegetables—is very ben­e­fi­cial in terms of your psy­cho­log­i­cal well-being, par­tic­u­lar­ly mood,” says Joseph Firth, the lead author of the paper and a research fel­low at West­ern Syd­ney University.

But the results got more inter­est­ing when the researchers start­ed to dig into the details, to see for whom and under what con­di­tions our diet might keep the bad feel­ings at bay.

Who benefits most from a healthy diet?

First off, diet pro­grams tend­ed to work bet­ter for women. Why? Besides dif­fer­ences in hor­mones and metab­o­lism, Firth con­jec­tured, women seem to be in a bet­ter posi­tion to ben­e­fit. They’re more like­ly to be depressed, and, he says, they might have more dis­ci­pline at fol­low­ing diets than men.

Also, the diet pro­grams worked bet­ter if a dietary pro­fes­sion­al admin­is­tered them—probably because the rec­om­men­da­tions were sounder and the par­tic­i­pants (believ­ing in the dietitian’s author­i­ty) were more apt to fol­low them, Firth says. An ear­li­er review of diet stud­ies came to a sim­i­lar conclusion.

One of the strongest stud­ies in the col­lec­tion sug­gest­ed that diet could help peo­ple who were right in the midst of a major depres­sive episode. Researchers recruit­ed 67 depressed peo­ple with poor diets, half of whom were instruct­ed to fol­low a healthy, Mediter­ranean-style diet favor­ing whole grains, fruit and veg­eta­bles, legumes, low-fat dairy, nuts, fish, lean red meat, chick­en, eggs, and olive oil while reduc­ing sweets, refined grains, fried and fast food, processed meats, and sug­ary drinks. Across 12 weeks, they attend­ed sev­en ses­sions with a dietit­ian who helped them set diet goals and stay moti­vat­ed; they also received recipes, meal plans, and a ham­per of food.

The oth­er half attend­ed ses­sions on a sim­i­lar sched­ule. But rather than get­ting diet advice, they sim­ply spent time with a research assis­tant who was trained to be sup­port­ive of them—talking about top­ics they were inter­est­ed in, like sports and hob­bies, or play­ing games with them for an hour.

Despite how ben­e­fi­cial social inter­ac­tion is, the diet group fared bet­ter than the social sup­port group. After 12 weeks, they had reduced their depres­sion and anx­i­ety more—and they were about four times more like­ly to expe­ri­ence a remis­sion from their depres­sion. The more they improved their diet, the more their depres­sion lifted.

What about anx­i­ety? In that par­tic­u­lar study, anx­i­ety did go down—but on aver­age, across all 16 stud­ies, health­i­er diets didn’t seem to make peo­ple less anx­ious. That actu­al­ly strength­ens the case that diet can direct­ly affect depres­sion, says Firth. If the results were sim­ply due to peo­ple feel­ing proud and accom­plished with their new healthy habits, you would expect them to feel bet­ter all around, includ­ing less anx­ious. The fact that only their symp­toms of depres­sion shift­ed means that some­thing deep­er may be going on.

What could that be? We don’t know for sure yet, but there are a vari­ety of bio­log­i­cal process­es that seem to be both influ­enced by diet and involved in men­tal health. It’s pos­si­ble that cer­tain diets may increase inflam­ma­tion and oxida­tive stress, and dis­rupt our mito­chon­dr­i­al func­tion and neu­ron pro­duc­tion, in ways that could put us at risk for psy­cho­log­i­cal prob­lems. Our gut microbiome—the colony of microor­gan­isms in our intestines that is increas­ing­ly being stud­ied as a con­trib­u­tor to men­tal health—may inter­act with many of these process­es. Also, says Firth, fol­low­ing a diet can bring us a sense of self-esteem and self-effi­ca­cy, as well as poten­tial weight loss—which can influ­ence our minds, too.

But there are still a lot of unknowns. As Pro­fes­sor Almu­de­na Sanchez-Vil­le­gas of the Uni­ver­si­ty of Las Pal­mas de Gran Canaria points out, the find­ings from diet exper­i­ments are not con­sis­tent. Many of the diet pro­grams in Firth’s review didn’t help alle­vi­ate depres­sion, nor did a new­er one that also includ­ed mul­ti­vi­t­a­mins. Researchers have much more to explore.

Can your diet make you happy?

It’s one thing to say that our diet might pro­tect us from depres­sion and oth­er men­tal health issues. But could the foods we eat actu­al­ly move the nee­dle toward more pos­i­tive emo­tions and happiness?

In a 2017 exper­i­ment pub­lished in PLoS ONE, researchers recruit­ed 171 young adults with a diet low in fruits and veg­eta­bles, which meant three or few­er serv­ings per day. These 18 to 25 year olds were split into groups: One got a bas­ket of car­rots, apples, and kiwi or oranges and was told to eat an extra serv­ing of fruit and an extra serv­ing of veg­eta­bles per day; anoth­er didn’t change what they ate.

Every day for two weeks, they answered ques­tions about their feel­ings, mood, and hap­pi­ness. At the begin­ning and the end of the exper­i­ment, they also filled out sur­veys about their anx­i­ety and depression.

The diet group only man­aged to add one extra serv­ing of fruit and veg­eta­bles to their dai­ly diet. But that made a dif­fer­ence: Com­pared to every­one else, they had more ener­gy, curios­i­ty, cre­ativ­i­ty, and moti­va­tion; and they felt more engaged and pur­pose­ful in their lives overall—a greater sense of flourishing.

Sur­pris­ing­ly, though, the diet didn’t seem to change their mood or their feel­ings of depres­sion and anx­i­ety. That might be because the exper­i­ment was so short, the authors believe; while diet can give us a pos­i­tive boost pret­ty quick­ly, it’s pos­si­ble that men­tal health prob­lems take longer to show up.

The accu­mu­la­tion of fac­tors such as low vital­i­ty, reduced moti­va­tion, and poor­er socio-emo­tion­al flour­ish­ing may pre­cip­i­tate the devel­op­ment of psy­cho­log­i­cal ill-being over time,” write researcher Tam­lin S. Con­ner and her colleagues.

Sim­i­lar­ly, in a short pilot study from 2011, a Mediter­ranean diet seemed to boost people’s feel­ings of contentment—but didn’t improve their depres­sion or anxiety.

Twen­ty-five women were sur­veyed on their feel­ings of depres­sion, anx­i­ety, anger, calm, and con­tent­ment. Some con­tin­ued eat­ing as usu­al for 10 days, while the rest adopt­ed a Mediter­ranean diet (this time with no red meat). After anoth­er round of sur­veys, the researchers found that the women on the Mediter­ranean diet felt more content.

The nutri­ents con­sumed in every­day diets are impor­tant for indi­vid­u­als’ mood,” write Lau­ra McMil­lan and her colleagues.

Of course, this was a very small study—and the women may have sim­ply felt sat­is­fied about doing some­thing good for their health. Indeed, in a few oth­er stud­ies, a healthy diet didn’t make peo­ple hap­pi­er. For exam­ple, fol­low­ing a Mediter­ranean diet for 12 weeks didn’t seem to boost people’s mood, well-being, or sense of self-effi­ca­cy com­pared to receiv­ing social support.

Despite how catchy it sounds, it might be too ear­ly to say that any par­tic­u­lar diet is going to bring us happiness.

Eating for well-being

So, how should all this research inform our gro­cery list?

Most researchers are only will­ing to say that diet does seem to influ­ence our men­tal health in some way, although they’re not sure exact­ly how. “There’s no real evi­dence to sug­gest that one diet works bet­ter than anoth­er,” says Firth.

How­ev­er, the big pic­ture is rea­son­ably clear: Try to get enough fruits and vegetables—and avoid junk food.

Sup­port­ing that per­spec­tive, one paper reviewed the results of anoth­er 16 stud­ies and found no dif­fer­ences between two rel­a­tive­ly healthy diets. Peo­ple who were eat­ing a typ­i­cal West­ern diet of fast food, salty snacks, desserts, and soft drinks became more depressed over time. But eat­ing a clas­sic healthy diet high in fruit and veg­eta­bles, seafood, and whole grains or a more Mediter­ranean diet—which includes lots of olive oil and more legumes, meat, dairy, and alcohol—both seemed to pro­tect against depression.

Since many of the research find­ings are stronger for women, Firth does have one fur­ther tip.

If you’re female, then you will ben­e­fit from adopt­ing a health­i­er diet in gen­er­al and you don’t need to wor­ry about what type of spe­cif­ic diet you’re adopt­ing,” he says. “If you’re a man and you’re not over­weight, prob­a­bly don’t bother.”

In oth­er words, at least as far as our men­tal health goes, we can stop obsess­ing about hav­ing a per­fect­ly con­sis­tent diet—or whether we should go paleo or keto—and instead focus on cul­ti­vat­ing healthy but sus­tain­able eat­ing habits. That’s the area where Firth wants to see more research, too, to fig­ure out how to help peo­ple make lifestyle changes that last.

It’s more impor­tant to actu­al­ly stick to any healthy diet than it is to try and go for some aspi­ra­tional per­fect one that’s ulti­mate­ly unfea­si­ble or dis­gust­ing for you to stick to,” he says.

– Kira M. New­man is the man­ag­ing edi­tor of Greater Good. Based at UC-Berke­ley, Greater Good high­lights ground break­ing sci­en­tif­ic research into the roots of com­pas­sion and altru­ism. Copy­right Greater Good.

Relat­ed articles:


  1. Manish sharma on July 13, 2020 at 2:25

    Thank you. Sure­ly a healthy, well-bal­anced diet can pro­mote men­tal well being and give the pow­er to fight anx­i­ety and stress. Great article.

  2. Ahazz Adnan on October 23, 2020 at 3:52

    Hey, this is amaz­ing. I am a foody per­son and when­ev­er am sad or down, eat­ing a few bits real­ly boosts up my mood. Thanks for shar­ing this.

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SHARPBRAINS es un think-tank y consultoría independiente proporcionando servicios para la neurociencia aplicada, salud, liderazgo e innovación.

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