Photo by Wikipedia.org
A variety of immune-boosting foods
A variety of immune-boosting foods

What you eat profoundly affects your ability to fight disease. With all the nasty bugs going around this cold and flu season, it’s especially important to pay attention to boosting your immune system through nutrition. While every nutrient is important in your body’s ability to prevent and fight disease – from colds to cancer - certain nutrients play key roles:

Protein

Protein is one of the most important nutrients in the human body, second only to water. Bone health, muscle function, muscle strength, muscle mass and immune function -- all are impaired with a low protein intake. In fact, the antibodies which are essential to protecting your body against pathogens, are made of protein, so without enough protein, your body has no chance. Certain vulnerable populations, such as the elderly, children, and those who already have compromised immune systems, should be particularly careful to eat enough protein – in fact, even more than the recommended dietary allowance – for maximized protection.

Protein can be found in a wide range of foods. Animal protein is in seafood, dairy, meat, poultry and eggs. Vegetarian protein can be found in legumes, soy, vegetables and grains. And while it's true that high-protein foods often bring fat and calories along as uninvited guests, it doesn't have to be that way. The lowest-calorie animal protein sources are the leanest. Go for eggs, seafood, poultry with no skin, skim milk, nonfat or lowfat yogurt, and lowfat cheeses are also great options. Soy products also provide great low-calorie options and are high quality proteins similar to animal protein.

Protein foods have other benefits. Fish, legumes, seeds, nuts contain immune-boosters zinc and iron (but in too high quantities, for instance in megadose vitamin pills, can backfire and suppress the immune system). Dairy products (keep them fat-free or low fat) are naturally loaded with magnesium, potassium and calcium – all important for immune function. Beans and soy beans are high in iron, zinc and magnesium.

Fats and Oils
The type of fat you eat can improve the effectiveness of your body’s immune response because fat ends up in all of your body’s cell walls. It acts as a cell lubricant, improves flexibility and communication between cells, and is important for cell metabolism and gene expression. If the fat you eat is saturated – solid at room temperature – as in butter or animal fat – this decreases cellular flexibility and functioning. So, to maximize your immune response, use oils in your cooking, such as olive and canola oil and stick with foods high in heart-healthy fats, such as nuts, avocados and fatty fish, which is high in omega-3-fatty acids. Minimize animal fats in dairy products, red meats, butter, cream and desserts.

Vitamins and Minerals
Studies show all nutrients are involved in your immune response but taking high doses of certain nutrients can cause imbalances, backfire, and actually suppress your immune response. So it’s ideal to get your vitamins and minerals from a nutrient-rich, balanced diet. Though you may benefit from taking a basic multi-vitamin and mineral supplement to cover your bases. And there may be some exceptions depending on your own nutritional status (best to get personalized advice from your dietitian and doctor)...

Vitamin D

New research has found Vitamin D augments the body’s ability to eliminate disease-infecting microbes, and most of us are deficient in Vitamin D, which we get from the sun and very few foods. Your doctor should check your vitamin D status at your next visit to make sure your blood values are adequate to fight infection, among other things. That said, most of us need a vitamin supplement with vitamin D, usually somewhere between 1,000 and 4,000 IU/day. But check your blood values first. They should be somewhere between 50 and 75 for most people. Click my "Vitamin D" article above...

For Those Over 50

Vitamin E
Studies from Tufts University found that vitamin E supplementation may help fight the common cold and other upper respiratory tract infections. The recommendation is about 400 IU/day

Zinc
Zinc helps fuel the production of infection-fighting white blood cells so a lack of zinc reduces immune response and illness recovery time is prolonged. The elderly are particularly vulnerable to deficiencies and may even need more than normal. So here’s another case where a supplement may be useful. When zinc supplements were given in a nursing home, residents reduced their risk of contracting pneumonia, according to researchers from the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University.

Vitamin B 12
Vitamin B 12, another nutrient important for immune function, is poorly absorbed in many elderly patients (and is missing from the diet of vegans) which is why your vitamin B 12 status should be checked by your doctor and you may need a supplement - in the form of an injection. For most of us, though, B 12 is easily obtained and absorbed by eating any animal products.

Probiotics
Ground-breaking research in the past decade shows the good bacteria in the gut, which aids immune response, reduces insulin resistance - a precursor to diabetes, reduces body fat, maintains muscle, improves absorption of important nutrients, and lowers as we age, making us susceptible to many diseases from cold to cancer. There is evidence that eating more of the good bacteria, such as lactobacillus in yogurt and kefir, may help your immune response. Check out my article about probiotics for more info.

The following is a list of foods containing key immune-boosting nutrients.

Include them in your diet every day:

High Beta Carotene Foods
Orange and deep green veggies and fruits, particularlyCarrot juice, carrots, butternut squash, pumpkin (or any orange-colored winter squash), sweet potato, greens such as spinach, collards, kale, turnip greens, beet greens, orange melons such as cantaloupe, red peppers, apricots, broccoli, plums, mangos papayas, plantains, Brussels sprouts, watermelon, asparagus

High Vitamin C Foods
Citrus fruits such as orange, lemons and grapefruit, peaches, sweet and hot peppers, papayas, pineapple, strawberries, broccoli,kiwi fruit, sweet potatoes, Brussels sprouts, kohlrabi,

High Zinc Foods
Oysters, lobster, crab, clams, fortified whole grain cereals, beans (legumes such as lentils, chick peas, black-eyed peas, soy beans, kidney beans, limas, pintos), turkey, whole grains such as buckwheat, whole wheat, cracked wheat (bulgur), oats, whole grain cornmeal, wild rice, yogurt, pine nuts, sunflower seeds, mixed nuts, peanuts

High Magnesium Foods
Whole grains such as buckwheat, wheat, oats, cornmeal, barley, brown rice, Also soybeans, pumpkin seeds, brazil nuts, cashews, greens such as spinach, beet greens, fish such as halibut, haddock and flounder and sole species, beans (legumes such as black beans, white beans, soy beans, navy beans, limas, black-eyed, great northern, kidney, chick peas,. lentils)

High Vitamin E Foods

Sunflower seeds, almonds, sunflower oil, safflower oil, canola oil, hazelnuts, pine nuts, spinach, turnip greens, beet greens, dandelion greens, canned pumpkin, carrot juice, broccoli, sweet potato, sweet red peppers, mangos, papayas

Cranberries

Have antibacterial qualities. Eat them dried for the highest levels of nutritious compounds

Mushrooms

Have a myriad of beneficial health effects. They've been shown to boost the immune system, especially in relation to cancer. Called a "drug-botanical interaction," mushrooms appear to increase the effects of chemotherapy, and lengthen survival.

Mushrooms also reduce fatigue.They act on the muscular system, body antioxidant system, cardiovascular system, hormone system, and immune system, all of which improve liver function, blood circulation, and blood glucose regulation, among other benefits.

Immune-Boosting Eating Strategies

* Eat a lean protein source at every meal – including breakfast, lunch and dinner. 20 grams for women and 30 grams for men is the amount most bio-available per sitting.
* Eat 5 cups of fruits and veggies per day – especially colorful varieties, eat at every meal and snack

* Eat a vegetarian meal every day using beans or soy beans for protein,

* Eat fish high in omega-3-fatty acids, such as salmon, herring, anchovies and sardines, at least two to four times per week, and vegetarian sources such as walnuts, ground flax seeds and canola oil,

* Use canola oil in your cooking and a fresh, newly harvested olive oil for drizzling,

* Eat whole grains at breakfast (such as cereal with skim milk or soy milk) and with sandwiches or wraps at lunch,

* Snacks: Try fat-free yogurt and fruit, fat-free yogurt dip or hummus with veggies,

* Toss nuts/seeds/dried cranberries in your whole grain cereal, your salad or your afternoon yogurt snack

* Skim milk or Soy lattes or teas are great snacks, too…

* Take a multivitamin-mineral supplement daily.

* Take a Vitamin D Supplement so that you are getting  1,000 to 2,000 IU/day

* If you are over 50, but particularly 65, look into supplementing your diet with Vitamin E, Vitamin B12, Zinc and probiotics such as lactobacillus in yogurt.

Of course, don’t forget to keep your blood moving by being moderately physically active with plenty of walking, yoga, etc. Get plenty of rest, wash your hands frequently, drink fluids (especially warm fluids which will send light steam into your nasal passages) and spend time with friends and loved ones. Studies have shown these habits increase your ability to conquer diseases - from colds to cancer.