BOOST YOUR IMMUNITY WITH YOUR DIET

“The doctor of the future will no longer treat the human frame with drugs, but rather will cure and prevent disease with nutrition.” - Thomas Edison

Now that winter is upon us, people are coming down with all sorts of colds, viral infections and nasty little bugs that make the cold weather that extra little bit more miserable. While taking good care of our hygiene, ensuring that we do not come into contact with infectious people, dressing well and getting vaccinated, it is essential to also take care of our diet, as what we eat can protect us from infections by boosting our immune system and building up our body’s defences.

Oats and barley are two grains rich in beta-glucan, a type of fibre with antimicrobial and antioxidant capabilities more potent than echinacea, as reported by a Norwegian study. When animals were fed beta glucan, they were less likely to contract influenza, herpes, even anthrax; in humans, it boosts immunity, speeds wound healing, and may help antibiotics work better. At least one in your three daily servings of whole grains should be of barley or oats. Excellent in soups, in cereals and in bread made from their flour.

We all know of the health benefits of garlic, especially as they relate to helping lower blood pressure and promoting cardiovascular health. However, this potent relative of the onion contains the active ingredient allicin, which fights infection and microbial growth. British researchers gave 146 people either a placebo or a garlic extract for 12 weeks; the garlic takers were two-thirds less likely to catch a cold. Other studies suggest that garlic-lovers who eat more than six cloves a week have a 30% lower rate of colorectal cancer and a 50% lower rate of stomach cancer. The optimal dose for these health effects is two raw cloves a day and add crushed garlic to your cooking several times a week.

Fish and shellfish have been staples of human diet for millennia and with good reason. Selenium, plentiful in shellfish such as oysters, lobsters, crabs, and clams, helps white blood cells produce cytokines, which are proteins that help the immune response and which clear viruses out of the body. Salmon, mackerel, and herring are rich in omega-3 fats, which reduce inflammation, increasing airflow and protecting lungs from colds and respiratory infections. Two servings a week are optimal, except if you are pregnant or planning to be. In the latter case, consult your doctor.

Tea drinking in China and Japan has a long and venerable history. People who drank 5 cups a day of black tea for at least two weeks had 10 times more virus-fighting interferon in their blood than others who drank a placebo hot drink, as published in a Harvard study. The amino acid responsible for this immune boost, L-theanine, is abundant in both black and green tea (decaf versions have it, too). Try to drink several cups of tea daily. To get up to five times more antioxidants from your tea bags, dunk them up and down while you brew.

The benefits of lean meat for omnivores like humans cannot be underestimated. One of the commonest dietary deficiencies in developed countries is zinc deficiency, especially for vegetarians and those who have cut back on beef, a prime source of this immunity-bolstering mineral. This is unfortunate as even a mild zinc deficiency can increase risk of infection. Zinc in your diet is very important for the development of white blood cells, those immune system cells that recognise and destroy invading bacteria, viruses, and assorted other microbes, says William Boisvert, PhD, an expert in nutrition and immunity at The Scripps Research Institute in La Jolla, CA. a 100 gram serving of lean beef provides about 33% of the daily dietary requirement for zinc. That is enough to make the difference between deficient and sufficient. If you are not a beef eater, try zinc-rich oysters, fortified cereals, pork, poultry, yogurt, or milk.

Sweet potatoes, carrots, squash, pumpkin, honeydew melons and other bright orange foods are rich in vitamin A, as beta carotene. “Vitamin A plays a major role in the production of connective tissue, a key component of skin.” Says David Katz, MD, prevention advisor and director of the Yale-Griffin Prevention Research Center in Derby, CT.  You may not think of skin as part of your immune system, however, this crucial organ, covering an impressive 1.5 square metres, serves as a first-line defence against the entry of bacteria, viruses, and other microbes. To stay strong and healthy, your skin needs vitamin A. One of the best ways to get vitamin A into your diet is from foods containing beta-carotene (like sweet potatoes, carrots and pumpkin), which your body turns into vitamin A. The optimal dose is a half-cup serving, delivering only 750 Joules, but 40% of the daily dietary requirement of vitamin A as beta-carotene.

For centuries, people around the world have consumed mushrooms because of the delicious taste and multiple culinary uses. My grandfather always used to call the wild mushrooms that he used to gather “…the poor man’s meat”. Mushrooms are excellent for promoting a healthy immune response. Contemporary research explains the reason: “Studies show that mushrooms increase the production and activity of white blood cells, making them more aggressive. This is a good thing when you have an infection.” Says Douglas Schar, DipPhyt, MCPP, MNIMH, director of the Institute of Herbal Medicine in Washington, DC. Shiitake, maitake, and reishi mushrooms appear to pack the biggest immunity punch; experts recommend at least 10 to 30 grams a few times a day for maximum immune benefits. They can be added to pasta, in omelettes, salads, soups and sauces.