A leading expert on immunity shares simple steps that can help protect you against dangerous infections

With the recent outbreak of the H1N1 virus (commonly known as the swine flu), most people have relied solely on public health authorities for advice on the best ways to avoid infection.

While such recommendations can be helpful, there almost always are additional steps you can take to stay healthy when a highly contagious disease threatens large numbers of people.

Overlooked infection-fighting strategy: By enhancing your body’s natural infection-fighting mechanisms (immunity), you often can avoid illness — even if you are exposed to infectious organisms that are making other people sick.

HOW INFECTIONS BEGIN

Bacteria and viruses are the main causes of potentially deadly infections. Whether bacterial or viral, these infections pass from person to person in much the same way — from people touching contaminated surfaces, through hand-to-hand contact or via coughs and/or sneezes. Hand-washing is the most widely recommended infection-control measure.

With the flu, antiviral medications can help prevent infection or at least lessen the severity of the infection, depending on the strain that has caused the illness. The antivirals oseltamivir (Tamiflu) and zanamivir (Relenza) have been shown in laboratory tests to shorten the duration of H1N1 symptoms by one to two days (when taken within 48 hours of the onset of symptoms).

As we all know, antibiotics are prescribed for bacterial infections — and should not be taken unnecessarily. Reason: Antibiotics kill not only dangerous bacteria, but also “friendly” immune-boosting bacteria that help ward off dangerous bugs. Antibiotics are not effective against viral infections.

SIMPLE LIFESTYLE STRATEGIES

Our lifestyles play a critical role in whether our immune systems are able to fight off illness.

My recommendations for reducing your infection risk…

  • Eat immune-boosting foods. Blueberries and other berries (the darker, the better), purple grape juice and pomegranate juice are rich sources of plant-based compounds (phytochemicals) that boost the immune system.
  • Cruciferous vegetables contain sulforaphane, a compound with immunity-enhancing­ properties that help fight off infection. Good sources of sulforaphane: Broccoli (especially BroccoSprouts, high-potency broccoli sprouts available at supermarkets and health-food stores)… cabbage… cauliflower… and brussels sprouts. Aim to eat at least one serving of immune-boosting foods with every meal.

  • Get eight hours of sleep a night. Lack of sleep has been shown to weaken the immune system — especially the activity of natural killer cells, a type of white blood cell that’s key to preventing infection.
  • Supplements to Consider

    Most health-conscious adults take a multivitamin to ensure that they are getting enough key nutrients. In addition, certain individual supplements (which can be taken indefinitely with your doctor’s approval) have important infection-fighting properties. For example…

  • Vitamin D. Scientists have found that vitamin D helps protect against viral infections and stimulates the body to produce natural antibiotics. Important: Studies now suggest that at least half of the people in northern latitudes (in the US, generally north of Atlanta) are vitamin D-deficient in the fall and winter, when the sun’s angle is too low to stimulate the body’s natural production of vitamin D.
  • My advice: Take a daily supplement of 2,000 international units (IU) of vitamin D-3 (the most readily absorbed form). It’s best to take this vitamin with food high in fat, such as milk or cheese, which also improves absorption.

    After two to four months, ask your doctor to order a 25-hydroxy vitamin D blood test to see if the supplement is doing its job (a healthy blood level is 40 ng/mL to 50 ng/mL). If not, you may want to increase your daily dose of vitamin D-3.

  • Probiotics. These “good” bacteria work in the gut to prime the immune system.
  • My advice: Look for a product that contains lactobacillus, acidophilus or bifidus and provides a total daily dose of 10 billion to 30 billion organisms (sometimes expressed as CFUs, or colony-forming units). Refrigerated probiotic supplements, which are sold in the supplement section of most health-food stores, are best — refrigeration helps preserve potency of the probiotics. Also helpful: Certain products, such as the yogurt Activia and the drinks DanActive and Yakult, contain high amounts of probiotics.

  • Sulforaphane. This anti­microbial compound found in cruciferous vegetables is believed to boost the immune system by replenishing nutrients in the dendritic cells in the membranes of the mouth, nose, bladder and gut. These cells bolster the body’s first line of defense against invading microorganisms.
  • Animal studies also have shown that sulforaphane is very effective at ridding the body of toxins in our environment that dampen the immune response. Such toxins could include arsenic, polychlorinated biphenyls (PCBs) and bisphenol A (BPA), the chemical used in certain plastic water and beverage bottles and the lining of many food cans.

    In addition to BroccoSprouts (described earlier), scientists at Johns Hopkins have now developed a tea called Brassica Tea — both products provide concentrated doses of sulforaphane. To learn more, visit the product Web site, www.brassica.com or call 866-747-0001.