First, there’s the not-so-great news. Despite claims you may have seen on the Internet, there’s no magic food or pill that is guaranteed to boost your immune system and protect you against coronavirus.
But there’s uplifting news, too: There are ways to keep your immune system functioning optimally, which can help to keep you healthy and give you a sense of control in an uncertain time.
We’re going to tackle immunity boosting in two parts. Here we’ll focus on your diet, and in a second part publishing on Thursday we’ll discuss other ways to help yourself.
Begin by filling your plate with immune-boosting nutrients. One of the best ways to stay healthy is to eat a nutritious diet. That’s because our immune system relies on a steady supply of nutrients to do its job.
For a starter dose of immune-boosting vitamins, minerals and antioxidants, fill half of your plate with vegetables and fruits.
Here are some key nutrients that play a role in immunity, and food sources of them:
Carrots, kale and apricots for beta carotene
Beta carotene gets converted to vitamin A, which is essential for a strong immune system. It works by helping antibodies respond to toxins and foreign substances, Majumdar said.
Good sources of beta carotene include sweet potatoes, carrots, mangoes, apricots, spinach, kale, broccoli, squash and cantaloupe.
Oranges, strawberries and broccoli for Vitamin C
Vitamin C increases blood levels of antibodies and helps to differentiate lymphocytes (white blood cells), which helps the body determine what kind of protection is needed, Majumdar explained.
You can easily consume 200 milligrams of vitamin C from a combination of foods such as oranges, grapefruit, kiwi, strawberries, Brussels sprouts, red and green peppers, broccoli, cooked cabbage and cauliflower.
Eggs, cheese, tofu and mushrooms for Vitamin D
Vitamin D regulates the production of a protein that “selectively kills infectious agents, including bacteria and viruses,” explained Dr. Michael Holick, an expert on Vitamin D research from Boston University who has published more than 500 papers and 18 books on Vitamin D.
Vitamin D also alters the activity and number of white blood cells, known as T 2 killer lymphocytes, which can reduce the spread of bacteria and viruses, Holick added.
Winter-associated vitamin D deficiency — from a lack of sun-induced vitamin D production — can weaken the immune system, increasing the risk of developing viral infections that cause upper respiratory tract infections, said Holick.
Good food sources of vitamin D include fatty fish, including canned fish like salmon and sardines; eggs, fortified milk and plant milk products; cheese, fortified juice, tofu and mushrooms.
And while there is no evidence to prove that vitamin D supplements will protect you from coronavirus, it’s wise to consider a D supplement if you feel you are not getting enough of this important vitamin, which can be measured by a blood test.
Beans, nuts, cereal and seafood for zinc
Zinc helps cells in your immune system grow and differentiate, Majumdar explained.
Sources of zinc include beans, chickpeas, lentils, tofu, fortified cereals, nuts, seeds, wheat germ, oysters (including canned), crab, lobster, beef, pork chop, dark meat poultry and yogurt.
Milk, eggs, nuts and more for protein
Protein comes from both animal and plant-based sources and includes fish, poultry, beef, milk, yogurt, eggs and cottage cheese, as well as nuts, seeds, beans and lentils.
Majumdar recommends protein-rich snacks, such as roasted chickpeas, which can be eaten in place of snacks devoid of protein, such as animal crackers, for example.
Bananas, beans and more for prebiotics
Probiotics and prebiotics help boost the health of the microbiome, which in turn supports our immune system, explained Majumdar.
Sources of probiotics include fermented dairy foods such as yogurt and kefir, and aged cheeses, as well as fermented foods such as kimchi, sauerkraut, miso, tempeh and sourdough bread. Sources of prebiotics include whole grains, bananas, onions, garlic, leeks, asparagus, artichokes and beans.
“While it hasn’t been studied specifically with coronavirus, it may be good for general immune health,” Majumdar said. If you are interested in taking any herbs, check with your doctor first.
Water, fruit, soup and more for hydration
Finally, stay hydrated.
Lisa Drayer is a nutritionist, an author and a CNN health and nutrition contributor.