I write this beside a box of tissue and a mug of hot lemon tea. This is the worst time of year for an office worker: everyone has a cold, and it’s getting passed around like a birthday card that no one wants to sign. Some escape with a few sniffles, others suffer the gamut of mucus, cough, aches and pains. What makes some people more immune to colds than others?

There’s more to a healthy immune system than good hygiene – like muscles, the immune system needs proper nutrition to make it a bad-ass butt-kicker of foreign objects like bacteria, viruses, and cancerous cells. There are three fundamental parts of your immune system, each of which depend on a balanced diet to operate optimally:

• Structural barriers like skin and the gastrointestinal tract keep foreign objects from invading healthy cells
• Immune cells found in the blood stream and lymph nodes that fight invading cells, produce antibodies, and remove toxins
• Messenger molecules detect foreign invaders and tell the immune cells to go to work

Research shows that protein, antioxidants, essential fatty acids, and specific vitamins and minerals are especially important to maintain the above functions. Specifically

• Fiber, vitamin A and essential fatty acids support the gastrointestinal track
• Protein is essential for growth and repair
• Vitamin C supports immune cells and provides antioxidants
• B-vitamins (B5, Flolate, B6, B1, B2, B12) enable healthy T-cell functioning
• Vitamins A, E and K are important to overall immune health
• Minerals like zinc, iron, copper, selenium, and manganese help support immune cell functioning and healing
• Antioxidants and phytonutrients like vitamins C and E help free the body of damaging free radicals

I put together a printable table[1] of these nutrients and the 17 foods that provide the highest potency of these nutrients. Each food and nutrient is hyperlinked to a more extensive discussion provided by the World’s Healthiest Foods website.

[ HTML | Excel spreadsheet ]

The table illustrates that a variety of foods and nutrients work together to make our immune system happy and healthy.

There’s no one superfood, but of the 17, here are the six most dense in immune-boosting nutrients:

6 Superfoods That Will Rock Your Immune System

1. Greens – If there is a singular superfood out there, it’s gotta be greens. Mustard greens, spinach, swiss chard, turnip greens – all of these are excellent sources of Vitamins A, C, E, K, Folic Acid, and manganese
2. Mushrooms are an excellent source of vitamins B2 and B5 and the minerals copper and selenium.
3. Cauliflower is an excellent source of vitamins C, K, and folate, as well as fiber. It is also contains B5, B6 and manganese.
4. Romaine Lettuce. We don’t often think of romaine as a health food, but it’s an excellent source of vitamins A, C, K and folate, and a very good source of fiber, B1, B2, and iron.
5. Carrots are an excellent source of the antioxidant vitamins A and E and a very good source of Vitamin C and fiber.
6. Whole grains like oats, bulgar wheat, and barley have loads of fiber. Oats in particular are also a very good source of selenium.

There’s no one magic food out there that will keep you from catching a cold. The message is this: eat a variety of colorful, nutrient-dense whole foods and your immune system will be stronger for it.

[1] The table was derived from the USDA nutrient database, and used the World’s Healthiest Food‘s classification system to rate the foods