Yogurt can be delicious layered with fruit in a parfait or as a cooling side for a dish of spicy food, but it also packs a healthy dose of good bacteria that can protect the body against harmful bacteria and infections.
"They're like little soldiers, lining the intestinal tract to fend off invading germs," said Blatner, also an ADA spokeswoman.
These little soldiers -- the good bacteria -- are called probiotics, and studies have shown eating yogurts rich in them can lead to an improved immune response by increasing the body's white blood cell count. Probiotics are found in yogurts with live or active cultures -- the lactobacillus and bifidobacterium strains.
Traditional kefir is similar to yogurt but cultured with special kefir grains, so it contains slightly different bacteria. Originally from the Middle East, kefir has a sour, refreshing taste and is slightly effervescent from the carbon dioxide produced during fermentation. Unlike the bacteria in yogurt, which are transient and pass through the system over time, the bacteria in kefir are capable of colonizing in the intestinal tract. Kefir also contains good yeasts that help fight off pathogenic yeasts in the body.
This rich, flavorful spice has been used for centuries as part of Ayurvedic and traditional Chinese medicines, in addition to being used for cooking. Turmeric is found in every yellow curry, and its golden color is the result of curcumin, a polyphenol with strong cold and flu-fighting properties.
Although the mechanism is unclear, a 2008 study published in Biochemical and Biophysical Research Communications found that curcumin prevents some immune cells from responding to stimulants and so has modulating and anti-inflammatory effects. Other studies have also shown the immune-boosting properties of curcumin in turmeric, however these have not been confirmed in humans.
Turmeric is found naturally as the rhizome part of the turmeric plant and it looks very similar to ginger. The powdered spice is made by boiling, drying and grinding the root. The powder has antiseptic qualities when applied topically and often is used on cuts, burns and bruises.
Garlic may be the wunderkind of the plant world, its properties ranging from medicinal to mystical to culinary. Ancient Egyptians considered garlic holy and used it as currency. Indeed, the pungent smell is a small price to pay for the health benefits garlic can confer.
"Garlic has been a miracle food for everything," Neville said.
Much of the immune-boosting properties of garlic come from its sulfur-containing compounds, which also give the bulb its aroma, particularly one called allicin. These compounds are effective against bacterial, viral, fungal and parasitic infections. They also enhance the immune system and have anti-tumor and antioxidant features, which help guard cells from everyday wear and tear.
Americans are growing increasingly aware of the powerful properties of garlic. According to an article in the Journal of Nutrition, garlic is the second most used supplement in the United States.
In some parts of the world, particularly the Balkans, garlic is considered so powerful it is thought to guard against vampires and witches. In 1994, a group of scientists decided to test the protective effect of garlic against vampires using leeches as a stand-in for the blood-sucking monsters. They offered their leeches two arms, one bare and the other covered in a garlic paste.