22 Foods and Extracts Studied for Stress and Mood

Among 8,640 adults, the people who ate the most apples and pears had 31% lower odds of high perceived stress than the people who ate almost none.

That’s a link, not a cure.

Stressed people might just skip the fruit bowl, and the researchers said as much.

Some entries below concern mood rather than stress, and several tested concentrated extracts rather than ordinary food. The list includes dairy and mushrooms.

Across all 22 entries, you’ll see what each study measured, how much weight the finding carries and whether it applies to food you’d actually eat.

1. Dark Chocolate

For two weeks, 30 adults ate 40 grams of dark chocolate a day, and their urine showed less of the stress hormone cortisol and less of the catecholamines, another family of stress chemicals.

The catch is what got measured. This was urine and blood chemistry, not how stressed anyone felt, and the work came out of the Nestlé Research Center.

A 2024 study tested cocoa drinks and blood-vessel function. In 23 young adults, a fatty meal and cocoa drink were consumed 90 minutes before an 8-minute mental stress task. Blood-vessel function measured 30 and 90 minutes afterward was better with the high-flavanol drink (695 mg of flavanols) than with the alkalized low-flavanol drink (5.6 mg).

That finding concerns the tested drinks and a blood-vessel measurement, so it doesn’t tell you which chocolate bar to buy. Some dark chocolate also contains milk, so vegans will want to check the label.

2. Black Tea

Four cups a day for six weeks. That’s what 75 men who already drank tea signed up for, with some of them unknowingly getting a placebo drink instead.

Fifty minutes after a round of stress tasks, cortisol had fallen 47% in the real-tea group and 27% in the placebo group. The tea drinkers also felt more relaxed while recovering.

Here’s the part most headlines skipped. Blood pressure and heart rate during the tasks were the same in both groups, so tea didn’t stop the stress. The tea drinkers just bounced back faster.

Every participant was male, so this one says nothing about women yet.

3. Matcha (the Right Kind)

The placebo in this matcha study was also matcha.

Thirty-nine pharmacy students drank 3 grams of matcha in 500 mL of water daily for seven days before off-campus practice and eight days during it. The test matcha had more theanine and arginine than the placebo matcha, but similar caffeine levels.

The test-matcha group had lower anxiety scores before practice and lower morning salivary alpha-amylase, a stress marker, during the university period. During pharmacy practice, the morning marker and self-reported stress only trended lower, without statistically significant differences.

The matcha’s composition mattered, so don’t assume the matcha in your café latte is the matcha from this study.

4. Kiwifruit

Young adults low in vitamin C ate two SunGold kiwifruit a day, and within two weeks they reported less fatigue and better well-being.

The trial had 167 people aged 18 to 35, split between kiwifruit, a 250 mg vitamin C tablet and a placebo, for four weeks. Blood vitamin C levels topped out within two weeks in both active groups. Mood disturbance trended better with the kiwis too.

Two honest notes. This measured mood and energy, not stress. And the randomization had problems, so a published correction removed “randomized” from the paper’s title, leaving it as a placebo-controlled trial.

5. Apples and Pears

“The most” in that opening stat wasn’t a fruit binge. The top quarter of apple and pear eaters had a mean intake of 168 grams a day, and the bottom quarter had 7. Only fresh fruit counted, so juice, tinned and dried fruit were left out.

The data come from the AusDiab study, with diet measured back in 1999-2000. It’s one snapshot in time, so it can’t tell you whether eating fruit led to lower stress or less-stressed people ate more fruit.

6. Oranges and Other Citrus

The people with the most citrus had 25% lower odds of high perceived stress than the people with the least, and the “most” was only about 112 grams a day.

The bottom group averaged about 2 grams. Again, fresh fruit only, no juice. Same study and the same caveat, so this is a link and nothing more.

7. Bananas

Top banana eaters, at about 84 grams a day, had 24% lower odds of high perceived stress than the bottom group at about 4 grams.

Bananas also made the cut in a later “psychobiotic” diet trial as one of the prebiotic-fiber foods (more on that at number 16). You’ve probably heard a nutrient-based story about why bananas calm you down. That isn’t what anyone measured here. This is just who ate them and how stressed they said they were.

8. Blueberries

A single wild blueberry drink lifted positive mood two hours later, in kids and in young adults, compared with a matched placebo drink.

The drink was made from freeze-dried wild blueberries with 253 mg of anthocyanins. One study had 21 adults aged 18 to 21, and another had 50 children aged 7 to 10.

Negative mood didn’t budge. So this is “a better mood after one drink,” not “less stress.” The berries were wild (lowbush), not the big cultivated ones.

9. Broccoli, Cabbage and the Cruciferous Crew

Leafy greens get all the “eat your spinach for stress” press, and in this study they had nothing to show for it.

In the same 8,640-person analysis, leafy greens and allium vegetables like onions and garlic showed no significant link to stress once the researchers adjusted for other factors. Cruciferous vegetables did. The top quarter of cabbage, Brussels sprouts, cauliflower and broccoli eaters had 25% lower odds of high perceived stress.

Don’t oversell it, though. That result barely cleared the bar for statistical significance.

10. Carrots, Tomatoes, Peppers and Pumpkin

People who ate the most yellow, orange and red vegetables had 27% lower odds of high perceived stress. The group covered tomato, capsicum (bell pepper), carrot, beetroot and pumpkin.

The tempting explanation is the pigments. But in an earlier paper from the same research group, blood carotenoid levels were linked to lower stress only before the researchers adjusted for age and other factors. After that, the link vanished, so the color theory is unproven.

11. Beans, Peas and Tofu

With legumes, the middle of the pack came out ahead.

People in the third quarter of legume intake had 26% lower odds of high perceived stress than the bottom quarter. The top quarter didn’t get the headline. So “a moderate amount” is the honest reading, not “the more, the better.”

The category was broad: peas, green beans, bean sprouts, alfalfa sprouts, baked beans, soybeans, tofu and other beans. The psychobiotic diet at number 16 also included 3 to 4 servings of legumes a week.

12. Walnuts

As exams got closer, university students in the control group reported rising stress and depression symptoms. The students eating about 56 grams of walnuts a day (roughly half a cup) didn’t show that rise.

The study ran 16 weeks with 80 undergraduates, checking in at the start of semester, during exams and two weeks after. The walnut group also had better sleep quality over the longer term.

Walnuts didn’t fix every mood measure, and there weren’t enough men in the study to say anything about them. The California Walnut Commission co-funded it.

13. Pistachios

This one measured your body’s stress response, not your feelings.

In a controlled feeding study, 28 adults with elevated LDL cholesterol rotated through different diets and sat through stress tests on each one. On the lower-pistachio diet, average systolic blood pressure across resting and stress measurements fell 4.8 mm Hg.

The higher-pistachio diet reduced peripheral vascular resistance compared with the low-fat control diet.

14. Almonds

About 63 grams of almonds a day, swapped in for typical UK snacks, nudged heart rate variability during a stress test in the right direction.

Heart rate variability (HRV) tracks your “rest and digest” system. After six weeks, 105 adults aged 30 to 70 with above-average heart disease risk took a Stroop color-word test, the one where “RED” is printed in blue ink. The almond group had higher high-frequency HRV during the test than the control group.

Only that one HRV measure moved, and the others didn’t. The Almond Board of California funded the study.

15. Fermented Milk and Yogurt

Medical students heading into a national exam usually see their cortisol climb. In one study, the ones drinking a particular probiotic fermented milk every day for eight weeks didn’t.

Forty-seven students took part, 23 on the active drink and 24 on a placebo milk. The active drink was fermented with Lactobacillus casei Shirota, the Yakult strain. Salivary cortisol rose before the exam only in the placebo group, and the active group also had fewer stomach and cold symptoms.

It’s one strain in a pilot study, so not every yogurt in the dairy aisle earns this credit. Yogurt shows up again at number 18. Both are dairy, of course.

16. Sauerkraut, Kefir and Kombucha

On a four-week “psychobiotic” diet, adults’ perceived stress fell 32%, compared with 17% in the control group, but the difference between groups wasn’t statistically significant.

The diet combined fermented foods such as sauerkraut, kefir and kombucha with prebiotic-rich fruit and vegetables, grains and legumes. People who stuck to it most closely saw bigger drops, but this whole-diet study can’t attribute a benefit to sauerkraut, kefir or kombucha individually.

Only 45 people took part, and biological stress markers didn’t change.

A separate survey of 710 college students linked more fermented food to fewer social anxiety symptoms, especially in students high in neuroticism. That was also a one-time snapshot.

Kefir is usually dairy, though water kefir exists. And if you go looking for kimchi, choose vegan kimchi.

17. Saffron

The effective dose in this saffron trial was 28 milligrams a day. The slightly smaller 22 mg dose did nothing.

The study gave 128 adults with self-reported low mood (none diagnosed with depression) a branded extract called affron for four weeks. At 28 mg, negative mood and stress and anxiety symptoms dropped compared with placebo, all self-reported.

This was a standardized extract, not the threads in your spice drawer, so the results don’t translate to a pinch in your rice.

18. Lemon Balm

Researchers stirred lemon balm extract into a fruit drink and a yogurt, and found that what you mix it with matters.

In the drink study, 25 adults aged 18 to 39 did a stressful multitasking test. A 0.3 g lemon balm drink with natural fruit sweetener lowered their anxiety at both one and three hours. Cortisol rose an hour after the placebo drink, and that rise didn’t show up after any of the lemon balm drinks.

Then it got weird. The 0.6 g drink with artificial sweeteners raised anxiety. In the yogurt study with 21 adults, 0.3 g improved alertness and 0.6 g brought more fatigue.

More wasn’t better. These were single-dose tests of a standardized extract, and the yogurt version is dairy.

19. Chamomile

This is one of the few trials on the list that ran for months. It tested chamomile extract in people with diagnosed generalized anxiety disorder.

Everyone took 1,500 mg a day of a pharmaceutical-grade extract for 12 weeks. The 93 people who improved were then split between 26 more weeks of chamomile or a placebo. The chamomile group kept their symptom scores significantly lower, but relapse rates weren’t significantly different between the two groups.

So it’s a real signal and a narrow one. It came from capsules, not tea.

20. Holy Basil (Tulsi)

After eight weeks on a holy basil extract, stressed adults with poor sleep saw their perceived stress scores fall 37%, vs 19% on placebo.

The trial had 100 adults aged 18 to 65, half on 125 mg of the branded extract Holixer twice a day. Sleep quality also improved, people tolerated it well, and a writeup of the study reports lower cortisol reactivity.

Tulsi is also a popular tea. The tea wasn’t what got tested.

21. Ashwagandha

In 60 mildly stressed adults, 60 days of ashwagandha extract at 240 mg a day cut morning cortisol by 23%. The placebo group’s rose 0.5%.

The extract group’s anxiety scores fell too. A second study with 60 adults found lower perceived stress and lower blood cortisol after eight weeks at either 250 or 600 mg a day.

Ashwagandha is a root used in Ayurvedic cooking and drinks, but the evidence is for capsules. The National Center for Complementary and Integrative Health (NCCIH) says some preparations may help with sleep and stress, though the evidence on anxiety is unclear.

It also flags rare cases of liver injury from supplements and says ashwagandha isn’t for everyone, including during pregnancy and breastfeeding or for people with thyroid or autoimmune disorders. Safety data only cover the short term, up to about three months.

22. Lion’s Mane Mushroom

Technically a fungus, not a plant. It made the list anyway because the study involved cookies.

In a menopause-focused study of 30 women assigned to lion’s mane or placebo cookies, the active group ate four cookies a day for four weeks, each baked with 0.5 g of powdered lion’s mane, for 2 g a day. Their depression and “indefinite complaints” scores dropped significantly compared with where they started.

Compared with the placebo-cookie group, though, their “anxious” and “irritating” ratings only trended lower.

The Apple Still Has a Deadline

The apples-and-pears finding was about fresh fruit, the kind you might already have in your kitchen.

That association doesn’t promise a calmer afternoon.

But while you wait for science to settle the stress question, the apple in your fruit bowl isn’t getting any crisper.