It's an old folk remedy. This fruit is loaded with antioxidants and may help fight inflammation. In some test-tube studies, an extract from the berries appears to block flu viruses. But scientists caution that more study is needed.
They're a source of the mineral selenium and the B vitamins riboflavin and niacin. That can be helpful on several fronts. Low levels of selenium are linked to a higher risk of getting a more severe flu. Riboflavin and niacin play a role in a healthy immune system.
Its dark color is a sign that it's got plenty of antioxidants called anthocyanins.
There isn't any research that shows acai is good for any specific condition, but antioxidants may help your body fight aging and disease.
You can enjoy these berries in juice or smoothies, or try them dried and mixed with granola.
They've got zinc in them, which appears to have some antiviral effect, although researchers can't explain why. But they do know it's important for several immune system tasks, including healing wounds.
It's not only refreshing. When it's ripe, it's also got plenty of a powerful antioxidant called glutathione. It helps strengthen the immune system so it can fight infection.
Where can you find the most glutathione in your watermelon? Eat the red pulpy flesh near the rind.
It's a source of immune-strengthening glutamine. Try adding cabbage of any variety (white, red, Chinese) to soups and stews to sneak in extra antioxidants and boost your meal's nutritional value.
One-quarter cup has nearly 50% of the daily recommended amount of vitamin E, which helps boost the immune system. And they have riboflavin and niacin, which may help you bounce back from the effects of stress.
It's packed with flavonoids -- natural chemical compounds that have been found to increase immune system activity. They also have a good amount of vitamin C.
Don't like grapefruit? Try oranges or tangerines.
It's the part of a wheat seed that feeds a baby wheat plant, and it's packed with nutrients. It's a great way to get zinc, antioxidants, and B vitamins.
Wheat germ also offers a good mix of fiber, protein, and some good fat. You can use it instead of the regular flour that's called for in recipes.
A cup a day may reduce your chances of getting a cold. Look for labels that say "live and active cultures." Some researchers believe they may stimulate your immune system to fight disease.
Also look for vitamin D. Recent studies show a link between low vitamin D levels and an increased risk of cold and flu.
It has several antioxidants that battle immune system invaders. H. pylori is one of its targets -- the bacteria linked to some ulcers and stomach cancer.
You'll find lots of nutrients in this "super food." One of them is folate, which helps your body make new cells and repair DNA. It also boasts fiber, antioxidants like vitamin C, and more. Eat spinach raw or lightly cooked to get the most benefit.
Feel free to choose green or black. Both are loaded with disease-fighting polyphenols and flavonoids. These antioxidants seek out cell-damaging free radicals and destroy them. Caffeinated and decaf work equally well.
Like carrots, sweet potatoes have the antioxidant beta-carotene, which mops up damaging free radicals. They also have vitamin A, which may reduce the risk of some cancers and is linked to a slow-down in the aging process.
It's easy to find at the grocery store and it's an immune-boosting basic. One study shows a chemical in broccoli helped boost the immune systems of mice.
Plus, it's full of nutrients that protect your body from damage. It has vitamins A and C, and glutathione. Add some low-fat cheese to round out a side dish with immune-enhancing B vitamins and vitamin D.