As we enter the height of cold and flu season, it’s increasingly important to stay healthy and protect yourself from getting a cold. After all, no one wants to spend their holiday break feeling under the weather.
Filling up on fruits and vegetables is an effective way to provide support to your immune system and ward off illness, according to health research.
“What we eat can support the immune system by providing the body with the nutrients required to build a protective response and counteract oxidative stress including antioxidants, phytonutrients, vitamins, minerals and fiber,” reports BBC Good Food.
Let’s take a look at six fruits and vegetables known to help boost the immune system.
1. Citrus fruits
Vitamin C is essential to health, but your body cannot produce it and must rely on food sources to reap its benefits. Eating vitamin C-rich citrus fruits such as oranges, grapefruit, clementines, tangerines and lemons can help boost your immune system. While vitamin C may not prevent illness, it can combat lingering symptoms in credit to the vitamin’s ability to stir up white blood cells, reports the Mayo Clinic.
“Vitamin C is involved in many parts of the immune system,” according to Healthline. “First, vitamin C helps encourage the production of white blood cells known as lymphocytes and phagocytes, which help protect the body against infection.”
“Second, vitamin C helps these white blood cells function more effectively while protecting them from damage by potentially harmful molecules,” Healthline continues. “Third, vitamin C is an essential part of the skin’s defense system. It’s actively transported to the skin, where it can act as an antioxidant and help strengthen the skin’s barriers.”
A study published in the Cochrane Library found that patients suffering from pneumonia had lower than typical vitamin C levels. Researchers also found that consuming vitamin C reduced recovery time.
2. Bell peppers
Bell peppers are another excellent source of vitamin C, and they also offer vitamins A and E, per Healthline.
“Red bell peppers are a great source of vitamins C and E. Just half a cup of sliced red bell peppers provides more than 100 percent of the recommended daily amount of vitamin C,” Colette Micko, RDN, registered dietitian at Top Nutrition Coaching, told Real Simple.
Vitamin C plays several important roles in keeping the body healthy, such as: healing wounds, forming connective tissue, supporting the immune system and providing the body with essential antioxidants, per Medical News Today.
3. Ginger
Ginger has long been known for its medicinal properties. For thousands of years, ginger has been used to treat cold and flu symptoms, headaches, nausea and other uncomfortable health conditions, per Mount Sinai. This may be due to ginger’s anti-inflammatory properties.
“Ginger root contains a variety of antioxidants that help reduce inflammation and has natural antimicrobial and antibiotic properties to help ward off infection,” Colette Micko, registered dietitian at Top Nutrition Coaching, told Real Simple.
A test-tube study found that fresh ginger enhances immune response against human respiratory syncytial virus (HPSV) — a virus which can cause respiratory infections. The fresh ginger also exhibited antiviral effects, which protected people against contracting HPSV.
4. Blueberries
Blueberries are packed with a flavonoid known as anthocyanin, an antioxidant proven to help boost the immune system, particularly the respiratory tract’s immune system.
“Blueberries are full of antioxidants which protect the body from damage caused by harmful molecules called free radicals. Many experts believe this damage is a factor in the development of blood vessel disease (atherosclerosis), cancer, and other conditions,” reports the University of Arkansas Division of Agriculture.
One cup of wild blueberries provides 13,427 antioxidants, roughly 10 times the recommended daily intake, the university notes.
In a 2016 study, researchers found that individuals who ate more flavonoid-rich foods, such as blueberries, were significantly less likely to contract a cold.
5. Broccoli
Cruciferous vegetables, like broccoli, are packed with essential vitamins and minerals, and they also offer lots of fiber. Something that sets broccoli apart from other cruciferous vegetables is glutathione, a powerful antioxidant which can protect against disease, per Medical News Today.
“The stalky vegetable is full of vitamins A, C and E, plus it’s a good source of fiber. But when it comes to boosting your immune system, you’ll have to thank its sulfur compounds that aid in the production of glutathione,” according to Cleveland Clinic.
“Research shows that glutathione, an antioxidant, attacks free radicals, reducing their damage to your immune system,” the article said.
Additionally, a study from the University of California, Los Angeles, reports that broccoli sprouts are the highest natural source of sulforaphane — a chemical that fights free radicals, reducing inflammation and warding off disease. Researchers noted that sulforaphane was especially effective in combating respiratory inflammation.
6. Garlic
Known for its ability to fight infection, garlic lives up to its reputation as a home remedy for prevention against colds and other illnesses.
“Garlic contains compounds that help the immune system fight germs in a variety of ways by stimulating cells important to fighting disease and helping to regulate the immune system,” reports UC Health. “It helps boost the production of virus-fighting T-cells and can reduce the amount of stress hormones your body produces which can help keep your immune system functioning at full strength.”
A large review published in the Canadian Medical Association Journal found that taking garlic supplements decreases your risk of contracting a cold. Participants taking the placebo experienced double the number of colds between them than participants taking garlic supplements. However, researchers noted that more research is necessary to prove garlic can prevent colds.