Green tea has undergone minimal oxidation during drying and processing, and it has been subject to many scientific studies. Some of the more convincing studies highlight a compound called epigallocatechin gallate, or EGCG, a powerful antioxidant and anti-cancer agent. EGCGs have been shown to inhibit the growth of cancer cells without harming healthy tissues.
Tea can also be physically beneficial.
"Some of the helpfulness of tea is the fact that it's warm and therefore kind of soothing," La Puma said.
The soothing, steamy effect can apply to any warm drink or soup, as well, including chicken soup.
And Neville said some studies have shown that EGCGs can inhibit a virus' ability to replicate, which may offer an offensive strategy for preventing a cold, as well as improving the body's overall immune response.
Pumpkins are good for more than a lighted jack-o-lantern on the front porch. Their rich, orange flesh is packed with beta carotene, a nutrient that the body breaks down to make vitamin A.
Vitamin A helps the proteins that regulate cell-to-cell communication, which is the foundation of the immune system. Vitamin A also aids in cancer prevention, because cell-to-cell communication breakdown is one of the primary causes of cancer.
Research suggests that vitamin A may help keep the respiratory system healthy, Blatner said, which can be particularly helpful when you have a cold or the flu.
"The good news is we're in beta carotene season now," Kavenagh said, referring to the abundant orange fall vegetables such as squashes, carrots and sweet potatoes, all good sources of the nutrient. And the more intense the color, the higher the levels of beta carotene.
But experts caution against too much vitamin A. Because it is fat-soluble, excess vitamin A can be stored in the body's fat cells and large quantities can be toxic, Blatner said. Eating beta-carotene-rich foods should provide the FDA recommended nine milligrams each day and may be safer than taking a vitamin A supplement directly.
Perfumed and flavorful, the word 'ginger' comes from the Sanskrit word meaning 'horn shaped,' referring to the root's branched structure.
While it can be sweet, ginger also has some heat from a compound called gingerol, a relative of capsaicin, the compound that gives chili peppers their zing and heat. When it is dried, ginger contains less gingerol and more shoagol, an anti-inflammatory agent.
Ginger is often recommended as a tea or a bath for those with a cold or flu because it is helpful in increasing sweat production, which may help us get rid of germs and "sweat out" toxins.
"It might be an old wife's remedy, but people do swear by it," Blatner said.
Ginger has also been shown to reduce nausea and vomiting, making it a very useful food to have around when you have the flu.
Oysters are widely thought to be one of nature's most potent aphrodisiacs. This fact probably has to do with their high zinc content, which is necessary for testosterone production, one of the most important hormones behind the human sex drive for both men and women.
Oysters may or may not give you a boost in bed, but there is no doubt that zinc is very good at protecting the body against colds and flu.