‘Tis the season: for colds, flu and other respiratory infections. Viruses cause most of those but strep throat — caused by bacteria — is also making the rounds. What can you do? When it comes to immune function, be proactive. Support your immune system by giving it all the critical building blocks it needs to suppress viral and bacterial invaders.
I wrote about the nuts and bolts of the immune system a year ago. It’s a multi-step response, starting with barriers, moving on to specialized cells that identify and kill invading pathogens. Every step along the way depends on a steady supply of key nutrients to keep the system working. If your supply of one or more of these nutrients is depleted, the immune response will be less robust, leaving you at risk for a more severe or long-lasting infection.
Immune-supporting nutrients
I’m not suggesting that you need to take supplements to boost your immune function. I am suggesting that you should focus on foods that provide those nutrients, as seen in the table below. You might decide to supplement if you don’t consume enough of those key foods.
| Nutrient | Good food sources |
|---|---|
| zinc | meats and poultry, fish (oysters) |
| vitamin C | citrus fruits, tomatoes, broccoli, melons, strawberries, peppers, dark leafy greens, cranberries |
| vitamin A | dark leafy greens, carrots, winter squash, sweet potato, liver |
| vitamin E | wheat germ, nut and seed oils, nuts, seeds, nut butters, |
| vitamin D | fortified dairy products like milk, cod liver oil, egg yolk, high fat fish |
| omega3 fats | high fat fish like salmon, mackerel and sardines |
| B12 | meat, poultry, fish, eggs, dairy products |
| folate | dark green leafy vegetables, citrus fruits, berries, tomatoes, legumes |
| selenium | seeds (flax, sunflower, sesame), seed butters, tuna, oats, dairy, mushrooms, melon |
Gut Microbes
Your digestive system plays a very important role in immune function, and gut microbes have an impact. While microbes aren’t nutrients, you need to include them in your immune support plan. This isn’t complicated; you don’t need probiotic supplements or fiber tablets. It’s all about making healthy food choices. Emphasize unprocessed whole foods, especially high fiber vegetables, fruit and whole grains. Include fermented foods like yogurt, kefir, sauerkraut and kimchi.
Immune Supplements?
I’ve looked at lots of so-called immune-supporting supplement products and I have yet to see one worth buying. Most of them have extraneous herbs or food extracts that aren’t known to impact immune function. Amounts of important nutrients may be tiny and insignficant. Other key nutrients are MIA. I won’t be spending money on those.
Certain supplements may help some people.
- If you eat little or no meat/poultry/fish, you could benefit from extra zinc and B12.
- If you avoid high vitamin C fruits, vegetables and juices, extra vitamin C might be helpful. Keep in mind, you might be getting it in a multiple you already take. But the Big Picture is this: why are you avoiding all those fruits and vegetables? They’re loaded with so many nutrients and fiber. Better to improve your diet than take vitamin C.
- By the way, the same advice applies to vitamin A and folate, found in the same food.
- Milk and some other dairy foods are fortified with vitamin D. You can also get vitamin D from high fat fish and egg yolk.
- If you eat lots of salmon, mackerel, herring or sardines, you may be getting sufficient omega-3 fats. Otherwise you might consider a supplement, but you don’t need fancy high dose amounts. I discuss omega-3 supplements in detail in my book Food Wisdom for Women, so pick up a copy. The revised edition has an entire chapter on immunity and nutrition.
- Nuts, seeds, and nut butters contain vitamin E and selenium. They’re also good sources of fiber, healthy fats and protein.
Take Away Message
Don’t wait around for an infection to boost your intake of immune-critical nutrients. You need to be prepared. Your immune system works better if it doesn’t have to play catch-up when an invading pathogen shows up.
