While most of us are aware that we need to include important vitamins and minerals in our diet such as vitamin C and zinc, there is a lesser-known compound that doesn’t get the attention it deserves: quercetin.

If you aren’t familiar with quercetin, it belongs to a group of plant compounds called flavonoids, which act as an antioxidant in your body and hunts for free radicals. Quercetin has been found to provide allergy-relief and reduce inflammation, as well as boost immunity. Board-certified internist Vincent Pedre, M.D. says part of the reason quercetin supports your immune system is because it acts as a prebiotic, which feeds the good bacteria in your gut.

Although there is no magic number for how much quercetin you should be getting daily, most supplements recommend dosages between 500 and 1,000 milligrams per day. If you simply make sure to include the following 21 foods in your diet, it should be more than easy to get your daily dose of quercetin.

1. Capers (most concentrated source)
2. Red onion (highest vegetable source)
3. Shallots
4. Red apples
5. Grapes
6. Berries
7. Cherries
8. Scallions
9. Kale
10. Tomatoes (organically grown tomatoes have up to 79% more than conventional fruit)
11. Broccoli
12. Brussels sprouts
13. Cabbage
14. Citrus fruits
15. Bell peppers (green and yellow)
16. Nuts (almonds and pistachios)
17. Asparagus (cooked has slightly more)
18. Buckwheat
19. Black tea
20. Green tea
21. Elderberry tea

The average person typically gets a maximum of 40 milligrams of quercetin per day, but by including these foods in your diet, you can up your intake to at least 500 milligrams and gain the most health benefits.