Who knew? Research says colds, flu and other viral infections are common during the spring and summer. Yup, I've had my share of nasty colds in the summer. How about you?

Here's why they show up during this time of year: Winter, which tends to be long, wears on our immune systems, leaving them low and prone to colds, flu, and other viral infections. (Viruses are tiny particles of nucleic acids that invade living cells and divert the resources of those cells in order to make more copies of themselves.) And when the warmer weather hits, we tend to do more, go more, and often sleep less. The combination-a weakened immune system and lack of rest are dangerous to good health.

Science aside, it's well known that some nutrients are immune-supporting and help build resistance to viral infections.

But what about nutrients that can actually kill viruses and shorten the duration of the illnesses they cause? There are some with strong antiviral properties that can do just that; most of them are herbs.

So while prevention is best, when a virus strikes, consider these power-packed foods that can stop it in its tracks:

ELDERBERRY: The common black elderberry has long been used as a food and is also one of nature's oldest remedies. It appears to be particularly effective against flu virus-in fact, naturopaths call it "the flu-fighting fruit." More science: Elderberry extract is believed to act by binding to, and so disarming, the tiny protein spikes on the surface of the virus, by which it penetrates living cells.

This berry is also full of flavonoids, powerful antioxidants that rigorously protect cells against invading viruses and all sorts of cell damage. I've never found it fresh in any grocery store produce department, but you can find it as an extract online or in health and natural food stores

GREEN TEA: The Chinese have used this tea for over 4000 years and scientists are now consistently validating its power. Green tea also contains flavonoids that inhibit viral infections by binding to the haemagglutinin of the influenza virus and so preventing the virus from entering the host cells.

And green tea has also been proven to effectively inhibit HIV, herpes simplex and hepatitis B virus.

LICORICE: Back in 2003 when the SARS epidemic hit, scientists tested all sorts of foods and herbs to see what would combat it. Licorice root reigned supreme in not only standing up to colds and flu, but to other viruses as well!

There is a caveat to using licorice root, however: the key to using licorice is moderation. Licorice root can elevate blood pressure, lower potassium, and cause water retention. And it's not for those who have hypertension, kidney problems, diabetes, or heart problems.

Lastly, GARLIC: No surprises here. Most of us know this. Garlic has been cultivated for more than 5000 years and has been prized for its medicinal properties since the days of the pharaohs. And in most cultures today it's prized for its ability to protect against colds and influenza. But the important thing to note here is that we're talking about fresh garlic, not garlic powder or garlic salt, or even liquid garlic. It's the sulphur compounds found in the fresh version that do the job.

So how about a cup of green a few nights a week before bed? Or at least keep some on hand when you start to feel a cold coming on. And same with licorice root-stash some away. And fresh garlic, well that's easy. Just start cooking with it on a regular basis. As was already mentioned, prevention is always the best way to go. But how awesome is it that prevention AND cure involve herbs and foods we know and love!

    Alice Osborne
    Weekly Newsletter Contributor since 2006
    Email the author! alice@dvo.com