Blog

By Registered Dietitian Tawni Holmes

One of the most important ways you can keep yourself well is by eating healthy.
Eating a well-balanced diet including a variety of nutritious foods and being active are well known strategies to fight off chronic diseases such as heart disease, diabetes and cancer.
But did you know that there are foods you can eat to boost your immune system?

Keep in mind, there is no magic immune-boosting pill or food that can “cure” or even 100% prevent you from catching a virus like the coronavirus or the flu. But by building immunity, your body will be more equipped to fight off infections and viruses.

You’ll have fewer reasons to fret about getting sick if you keep your immune system healthy. How do you do that? Strengthen it by including these immune boosters when you plan your meals:

Citrus fruits and red bell peppers

Vitamin C, the superstar nutrient in citrus, is famous for its role in supporting the immune system. While vitamin C can’t prevent illness, it has been studied in people with respiratory infections, with benefits primarily seen in those who had suboptimal blood levels.
It’s unclear if this is partly cause or consequence, but research does appear to support a goal of consuming about 200 mg per day for infection prevention. This is the amount shown in studies to saturate the body, meaning any more vitamin C will be excreted. One medium orange provides 70 mg, a grapefruit contains almost 90 mg, and a medium raw red bell pepper packs 150 mg. Eat citrus alone or paired with nuts, use sliced red bell pepper to scoop up hummus or guacamole.

Sunflower seeds and almonds

In addition to vitamin C, vitamin E plays a key role in immunity. This fat-soluble vitamin boosts the activity of immune cells to support the body’s ability to fend off invading bacteria and viruses. An ounce of sunflower seeds, or a quarter cup, supplies about half of the daily recommended target for vitamin E. The same size portion of almonds contains 45% of the daily goal. Pair either with fresh fruit or whip sunflower seed or almond butter into smoothies.

Sweet potato and carrots

These veggies are top sources of beta carotene, a precursor to vitamin A. This nutrient aids the immune system by helping to produce white blood cells, which fight bacteria and viruses. It also helps form the mucous membranes that line the respiratory tract, which acts as a protective barrier to keep germs out of the body. A baked sweet potato packs over 150% of the daily vitamin A goal, and a cup of raw carrots over 100% of the recommended intake. Top a baked sweet potato with nuts or seeds, and munch on carrots with healthy dips, like nut butter or tahini.

Brazil nuts and sardines

Too little of the mineral selenium has been shown to delay immune response, and adequate amounts are known to enhance immunity. Selenium is also a potent antioxidant, meaning it acts like a bodyguard to prevent cells from being attacked in ways that damage DNA. One ounce of Brazil nuts, about six to eight whole nuts, provides nearly 1,000% of the daily value for selenium. Three ounces of sardines provides over 80%. Pop Brazil nuts as is, or chop and add to oatmeal or cooked veggies. Toss sardines with veggies, tomato sauce, and pasta, or add to salads.

Baked beans and pumpkin seeds

Zinc influences multiple aspects of the immune system. The production of certain immune cells is limited when zinc intake is low, and adequate zinc is crucial for the normal development and function of the immune system. One cup of vegetarian baked beans provides over half of the recommended daily intake for zinc, and an ounce or quarter cup of pumpkin seeds contains 20%. Combine the two: opt for baked beans as your protein source, paired with cooked veggies sprinkled with pumpkin seeds.

Turmeric

Curcumin, the natural compound in turmeric responsible for its vibrant color, is a potent anti-inflammatory compound. It has also been shown to boost immune cell activity and enhance antibody responses. Combining turmeric with black pepper significantly ups curcumin bioavailability. Sprinkle a turmeric black pepper combo onto a smoothie, soup, broth, or cooked veggies.

Dried tart cherries

The high antioxidant content in dried tart cherries is tied to a bolstered immune system, including a reduced risk of upper respiratory infection symptoms. They also support healthy sleep due to their natural melatonin content, which is crucial because research shows that people who don’t get enough quality sleep are more likely to get sick after being exposed to a virus. Eat them as is, or stir into nut butter and eat off a spoon.

Walnuts

In addition to being one of the top anti-inflammatory foods, walnuts contain several nutrients that play a role in supporting the immune system, including vitamins E and B6, copper, and folate. Walnuts have also been shown in research to reduce psychological stress, and unchecked stress weakens immunity. Pair walnuts with dried tart cherries as a snack, or chop and use as a garnish for fresh fruit or cooked veggies.

Garlic

Research lends credibility to garlic’s immune-supporting capabilities. In one older study, 146 volunteers were randomized assigned to receive either a placebo or a garlic supplement daily for 12 weeks throughout cold season. The garlic group experienced significantly fewer colds compared to the placebo group, and they recovered faster if they did get infected.
Newer research confirms that aged garlic extract may enhance immune cell function. In the study, healthy adults between 21 and 50 received either a placebo or aged garlic extract for 90 days. While there was no difference in the number of illnesses between the groups, those who received garlic had reduced cold and flu severity, fewer symptoms, and a smaller number of missed days of work or school. Reach for fresh garlic cloves rather than a supplement. Add it to cooked veggies, soup, or broth.

Pomegranate juice

Pure pomegranate juice is another food that supports immunity via its antimicrobial and anti-inflammatory activity. The flavonoid antioxidants found in pomegranate juice have also been shown to combat viruses, and decrease the length of a cold by as much as 40%. Sip on pomegranate juice, add splashes to water or chamomile tea, blend into smoothies, or freeze in BPA free molds, along with pureed banana and ginger root, to make popsicles.

Green vegetables

Green veggies provide anti-inflammatory antioxidants, as well as key nutrients known to help the immune system function, including vitamins A and C, and folate. They also provide bioactive compounds that release a chemical signal that optimizes immunity in the gut, the location of 70-80% of immune cells. Sauté veggies in EVOO along with garlic, turmeric, and black pepper, or add them to soup. You can also blend leafy greens, like kale or spinach, into a smoothie. (List compiled by Cynthia Sass, MPH, RD health.com)

Other good habits to incorporate that will keep you in tip top shape:

• Make half the grains you eat whole grains by choosing whole grain bread, whole grain pasta, or brown rice.
• Start your day at breakfast with foods that are rich in calcium and vitamins C and D.
• During your day, vegetables are great for snacking. And when you feel the urge for something sweet, have some fruit.
• Make sure you get a variety of foods each week: seafood, lean meat, poultry, beans, and nuts.
• At mealtimes, fill half your plate with fruits and vegetables… every meal.
• Choose foods that are low in calories, fat, and sodium. Limit your alcohol. And maintain a healthy weight.
• Frozen produce is a good option if you don’t have access to fresh produce year around. Just watch the added sugar and sodium when you make your choice.

Age is just a number, in fact you’re never too “seasoned” to benefit from good nutritional choices! For more information about good nutrition, find a local Registered Dietitian.

Disclaimer: With the COVID-19 pandemic, it’s especially important to understand that no supplement, diet or other lifestyle modification other than physical distancing, and proper hygiene can protect you from COVID-19.