A spice used in curry dishes helps to prevent infection and now scientists think they've got a lead on how.

Curcumin is a compound found in turmeric, a flavourful, orange and yellow spice that is a key ingredient in South Asian and Middle Eastern cuisine. The spice has also been used in India's traditional Ayurvedic remedies for 2,500 years.

Now American and Danish scientists have found curcumin increases levels of a protein called CAMP that helps the immune system to fight off bacteria, viruses and fungi the first time they try to attack.

CAMP is the only known antimicrobial of its type in humans, researchers say.

"This research points to a new avenue for regulating CAMP gene expression," said Adrian Gombart, an associate professor of biochemistry and biophysics at the Linus Pauling Institute in Corvallis, Ore.

"It's interesting and somewhat surprising that curcumin can do that, and could provide another tool to develop medical therapies," he added in a release.

SEE: Tips for ordering healthier Indian takeout. Story continues below:

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  • Weigh Your Carb Options

    There are a few different varieties of breads or thin, crispy, cracker-like eats you'll see on Indian menus. But one stands out among the rest, according to Bauer. "Roti is the smartest choice, because that's the whole-wheat one," she says. But even a couple of crispy, fried papadums are better than the empty calories in naan bread, she says. <br><br> <em>Flickr photo by <a href="http://www.flickr.com/photos/goosmurf/2196696055/" target="_hplink">goosmurf</a></em>

  • Start Fresh

    "Samosas are delicious, but they're deep-fried," Bauer says, so they're not a great pick for an appetizer. A soup or a green salad is a smarter starter. <br><br> <em>Flickr photo by <a href="http://www.flickr.com/photos/bitterjug/789824229/" target="_hplink">Bitterjug</a></em>

  • Don't Overdo It On Rice

    It's easy to eat more rice than you realize when you pair it with flavorful dishes brimming with tasty sauces, but keep in mind that a serving is about the size of your fist, says Bauer. <br><br> <em>Flickr photo by <a href="http://www.flickr.com/photos/raver_mikey/5561835580/" target="_hplink">Gene Hunt</a></em>

  • Go For Grilled

    It may sound obvious, but learn which dish names refer to grilled, rather than fried meats. "Anything tandoori -- that's just oven-grilled -- is always a winner," says Bauer, and there's usually a vegetarian tandoori option, as well as various dishes with lean proteins like chicken or shrimp. <br><br> If you like a little more flavor, try a chicken or shrimp tikka dish, she says, which is still grilled but prepared with tomato flavoring. <br><br> <em>Flickr photo by <a href="http://www.flickr.com/photos/galant/3268339088/" target="_hplink">thebittenword.com</a></em>

  • Skip The Creamy Sauce

    That's <em>tikka</em>, not tikka masala. The classic dish, while tasty, is drenched in sauce that's often prepared with a heavy hand on the <a href="http://allrecipes.com/recipe/chicken-tikka-masala/" target="_hplink">butter and cream</a>. <br><br> If you just <em>have</em> to dip your meat or bread in something, Bauer recommends opting for <a href="http://eatthis.menshealth.com/content/10-ways-eat-healthy-indian-restaurant?article=10&page=1" target="_hplink">raita</a>, a yogurt-based sauce similar to tzatziki, <em>Men's Health</em> explains, that's rich in protein. <br><br> <em>Flickr photo by <a href="http://www.flickr.com/photos/saucesupreme/4852025409/" target="_hplink">Ron Dollete</a></em>

  • Spice Is Nice

    Some of the classic flavors in Indian food, like turmeric, cumin and coriander, pack some pretty impressive health benefits -- and add a punch to your meal without extra calories. Turmeric may have <a href="http://www.huffingtonpost.com/2011/11/10/spices-health_n_1085099.html#s461534&title=Turmeric" target="_hplink">cancer-fighting properties</a>, YouBeauty reported. Cumin is a surprising source of iron, Health.com reported, and also may <a href="http://www.health.com/health/article/0,,20410258,00.html" target="_hplink">help with digestion</a>. <br><br> <em>Flickr photo by <a href="http://www.flickr.com/photos/patio/5219410863/" target="_hplink">comicpie</a></em>

  • Pick Paneer

    If you're on the hungrier side, Bauer recommends a <a href="http://www.food.com/recipe/palak-paneer-indian-fresh-spinach-with-paneer-cheese-25348" target="_hplink">palak</a> or saag paneer dish. Both are made with heart-healthy leafy greens (often spinach) and protein-rich paneer cheese. If you're concerned about fat content, you can even ask to hold the paneer, Bauer says. <br><br> <em>Flickr photo by <a href="http://www.flickr.com/photos/dongkwan/3453320539/" target="_hplink">VirtualErn</a></em>

  • Careful With Curries

    Curry powder and other spicy flavors in Indian dishes that contain capsaicin, the compound that gives cayenne and chili peppers their kick, are full of antioxidants and can actually <a href="http://www.huffingtonpost.com/2011/02/04/how-to-improve-your-metabolism-_n_818356.html" target="_hplink">jumpstart your metabolism</a>. In fact, eating a spicy meal can boost your body's burn <a href="http://www.huffingtonpost.com/joanna-dolgoff-md/metabolism-boosting-food_b_902121.html#s315856&title=Spicy_Peppers_Jalapenos" target="_hplink">by 25 percent for up to three hours after dessert</a>, writes child obesity specialist and HuffPost blogger <a href="http://www.huffingtonpost.com/joanna-dolgoff-md" target="_hplink">Joanna Dolgoff, M.D.</a> <br><br> Sprinkling some spice on a dish is different from using it in a creamy sauce, however, Bauer warns. Saucy takeout curries are often made with added fat and are high in calories, she says. <br><br> <em>Flickr photo by <a href="http://www.flickr.com/photos/ayk/" target="_hplink">yajico</a></em>

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In Friday's issue of the Journal of Nutritional Biochemistry, Gombart and his colleagues said curcumin caused levels of CAMP to almost triple in laboratory experiments on human cells.

Vitamin D also increases levels of CAMP but high amounts of the vitamin can lead to more calcium being released into the blood. That's one reason researchers are testing other natural alternatives like curcumin.

CAMP seems to kill a broad range of bacteria including those that cause tuberculosis and also seems to protect against the development of sepsis, a serious body-wide response to infection that patients often acquire while being treated in hospital.

Earlier this month, researchers in England announced the first human trials testing curcumin to fight cancer. They hope it will increase the effectiveness of chemotherapy while reducing side-effects.

"We've shown that [curcumin] has well over 100 mechanisms of damaging cancer cells, particularly colon cancer cells," Professor Will Stewart from England's University of Leicester told the Australian Broadcasting Corporation.

"One of the major mechanisms is affecting the way that they grow blood vessels into themselves."

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