How Food Helps Your Immune System

What you eat affects how well your immune system works. That’s because food contains the nutrients your immune cells need to fight off viruses, bacteria, and chronic diseases.

A healthy diet full of fruits, vegetables, whole grains, and lean protein can help keep your immune system running at its best. Some foods serve up plenty of these vitamins, minerals, and antioxidants. But you’ll want to steer clear of others, like those high in sugar and sodium. They could dampen your immune response.

Learn what foods you should add to your grocery list -- and which ones you should take off the menu to stay healthy.

Ways to Get Started

You want to eat healthier for your immune system. But you don’t need to overhaul your diet all at once. Experts say you should make realistic choices that you’ll be able to keep up with over time. These steps can help you make lasting changes:

Think it through. Set a goal, whether it’s revamping your entire diet or making a few smarter selections. Decide if you want to do this on your own or with your family. Then keep a food diary for a few days to help you track your eating habits and figure out where to make changes.

Make smart swaps. Replace your unhealthy picks with better ones. Choose whole-wheat bread instead of white. Or trade those French fries for roasted veggies. As you make new choices, you’ll learn what works and what doesn’t for your family.

Consider talking to a dietitian. These nutrition experts will help you set goals and design the best meal plan for you.

Boost Your Antioxidant Game

Every day, your body is under attack. Molecules called free radicals harm your cells and DNA. This damage wears down your immune system. It may play a role in aging and diseases, such as diabetes and heart disease.

To protect against free radicals, you need antioxidants. These chemicals can stop and even reverse some the damage to your cells.

Your body makes some antioxidants naturally. You also get them through the foods you eat. Some antioxidants are vitamins, while others are minerals. Plant compounds called phytochemicals also act as antioxidants.

Sure, you can take supplements, but eating a healthy diet will give you many of the antioxidants you need. Fill your plate with a mix of colorful fruits, vegetables, whole grains, and nuts. Not only do they provide antioxidants, they’re loaded with other vitamins and minerals, to boot.

Antioxidants You Get From Food

  • Beta-carotene: Your body turns beta-carotene into vitamin A. You get it from brightly colored fruits and vegetables such as sweet potatoes, spinach, carrots, and mangoes.
  • Lycopene: This nutrient gives fruits and vegetables their pink and red colors. Watermelon, tomatoes, and grapefruits are good sources.
  • Lutein: A plant compound, lutein is found in dark leafy green vegetables such as kale, collards, and spinach. It’s also in oranges, corn, peas, and broccoli.
  • Selenium: This mineral is in seafood, meat, and eggs. Other sources include bread, pasta, and grains, such as rice and wheat.
  • Vitamin A: There are two kinds of vitamin A. One is found in meat, poultry, and dairy; the other is in fruits and vegetables, like broccoli and squash.
  • Vitamin C: Most fruits and vegetables contain vitamin C. Red peppers, oranges, kiwis, broccoli, strawberries, and Brussels sprouts are top sources.
  • Vitamin E: Many nuts and seeds, such as peanuts, almonds, and sunflower seeds, are high in vitamin E. You can also find it in sunflower, corn, and canola oils, along with leafy green vegetables.

Add Omega-3 Fatty Acids

Omega-3 fatty acids aren’t only good for your heart. They also benefit your immune system.

Your immune cells use these healthy fats to strengthen the cell walls, which helps them work better. Research suggests omega-3s help white blood cells, the ones that fight off viruses and bacteria, do their job better.

Omega-3s also help your immune cells talk to each other. They prompt certain cells to make proteins that send signals telling other cells where to respond.

What foods are high in omega-3s? To get omega-3s, experts recommend eating two servings of fatty fish each week. Some plants and fortified eggs, yogurt, and milk also contain omega-3s. Top sources include:

  • Mackerel
  • Salmon
  • Herring
  • Tuna
  • Sardines
  • Flaxseed
  • Chia seed
  • Walnuts
  • Canola oil

Bulk Up Your Protein

Protein is a building block for immune cells. Your body also uses the protein from food to create antibodies. These proteins latch onto invaders, like viruses, and tell your immune system to attack.

Not eating enough protein can weaken your immune system. How much you need depends on your age, sex, and activity level. But most adults need roughly five to six 5 to 6 ounces a day.

Many sources of protein also deliver other immune-building nutrients:

  • Lean meat and poultry: They contain zinc and B vitamins, which helps your immune cells grow. Look for lean cuts. Too much saturated fat could harm immune cells.
  • Seafood: Fish is a source of omega-3 fats. Some seafood, like oysters, crab, and flounder, serve up zinc, a mineral that helps keep your immune system running.
  • Beans and tofu: They’re low in fat and high in folate and fiber, two nutrients that support your immune system.
  • Eggs: Eggs also contain selenium, a mineral that helps immune cells work and grow.
  • Nuts and seeds: They’re packed with fiber and the antioxidant vitamin E.

Pre- and Probiotics: The Keys to a Healthy Gut

About 70% percent of your immune cells are in your gut. They live alongside trillions of bacteria and other tiny organisms called microbes, which line your gastrointestinal tract. These microbes play a big role in the way your immune system works.

What you eat affects these microbes and, in turn, how well your immune function system works. Research suggests that eating foods with probiotics and prebiotics will help keep your gut microbes healthy. Probiotics are the "good" bacteria or yeasts that live in your gut. They’re often found in fermented foods. Check the labels of these foods for the words "live and active cultures."

Pair probiotic foods with those that have prebiotics. They’re a type of fiber that feeds probiotics. You can find them in fruits, vegetables, and whole grains, such as:

  • Bananas
  • Berries
  • Leafy green vegetables
  • Onions
  • Beans
  • Wheat
  • Oats

What You Drink Matters, Too

Certain drinks also support your immune system. Your body uses water to make blood, which delivers nutrients and immune cells throughout your body. It also flushes out waste and toxins. Women need 11.5 cups of water and men need 15 cups a day from liquids and foods.

But plain water isn’t the only healthy drink. Sip on these:

  • Tea: It contains polyphenols, plant-based antioxidants that help your immune system work better.
  • Pomegranate juice: This tart red fruit is also high in polyphenols. Plus, research shows that pomegranates fight viruses and bacteria.
  • Orange juice: One cup of OJ fills nearly all of your daily vitamin C needs. Look for brands fortified with vitamin D. This vitamin attaches to some immune cells and improves their response.

Reach for Healthy Seasonings

What you season and cook your food with can also keep you healthy. Spice up your dishes with these ingredients:

  • Garlic: The sulfur compounds in garlic are antibacterial. They also help immune cells work better.
  • Herbs: Ounce for ounce, herbs pack in more antioxidants than fruits and vegetables. Try oregano, parsley, sage, and dill.
  • Ginger: This spicy root has anti-inflammatory compounds. It may protect against cancer, diabetes, and heart disease.
  • Olive oil: High in healthy unsaturated fat, olive oil fights inflammation in your body.
  • Wheat germ: Wheat germ is made from the part of the grain that sprouts a new plant. It’s packed with nutrients that support the immune system, such as zinc and folate. Try it on cereals or add it to baked goods.
  • Turmeric: This golden spice contains curcumin, an antioxidant that lowers inflammation. Early research suggests that curcumin could help prevent certain diseases, such as cancer.

Immune Busters to Avoid