Many “immune strengthening” dietary additives and vitamins have ancient origins, but ironically little hard data exist about their efficacy. Yet even without rigorous data to support their actions, many healthy people believe they would die without them and often bust their budgets to afford them.

I am a scientist, so I have only limited recommendations for these additives, but I would be remiss if I didn’t consider some of them — and any drawbacks — when it comes to being immunity strong.

Let’s start with vitamins. To be clear, foods that contain high levels of vitamins like A, C, D, and E, all support your immune system in different ways.

For example, vitamin A — found in broccoli, carrots, sweet potatoes, and fortified milk — helps regulate the immune system and keeps tissue such as those of your lungs healthy.

Other vitamins, such as C and E, have antioxidant potential, meaning they protect cells from oxidative stress or burning out from chemical exposures that oxidize and render your enzymes ineffective. You can find these vitamins in certain fish like salmon, sardines, and tuna, as well as Brazil nuts, walnuts, pumpkin seeds, mushrooms, whole grains, and many other plants.

Foods such as sweet potatoes, dark chocolate, and berries of all sorts also provide antioxidants that the body uses to keep the immune system healthy and fend off diseases and infections.

Garlic is a powerful antioxidant with antimicrobial, antiviral, and some say antibiotic properties. It’s also a potent natural decongestant.

Elderberry is packed with quercetin, an antioxidant with antihistamine and anti-inflammatory effects; a teaspoonful of elderberry syrup is used to combat flu symptoms and help people with sinus pain or chronic fatigue find relief.

Spices such as turmeric, ginger, and garlic have major antioxidant and anti-inflammatory properties, too.

Some data may be soft around these effects, but they are all delicious and nutritious, so add them away to your diet.