- What it is: Thymus extracts come from thymus glands (most often from young calves); certain forms of these extracts have been shown to help the human thymus work better. Perched below the thyroid and above the heart, the butterfly-shaped thymus is a serious immune-system player, pumping out infection-fighting white blood cells called T-lymphocytes.
- How it works: Thymus extracts don't simply increase immune function, as echinacea does; they seem to balance it. During hay fever and other allergy flare-ups, the immune system overreacts to pollen, animal dander, mold, and the like, mistakenly attacking them as if they were dangerous infectious agents. In an Italian study published in Minerva Medica in 1987, taking a thymus extract daily reduced the number of allergy attacks and eased allergy symptoms. Thymus extracts can also quell food allergies. In studies, children with food allergies reacted less severely, or not at all, when exposed to allergenic foods while supplementing with thymus extract. These extracts have also been shown to improve eczema in children and reduce frequency of asthma attacks.
- Note: Many studies on thymus extract have been conducted using a particular extract (brand name Thymomodulin) that is not available in the United States. It is not known if supplements available here have the same effects as Thymomodulin.
- What it is: This water-soluble vitamin pretty much does it all—from fighting colds, healing wounds, and maintaining healthy bones and teeth, to blocking some of the damage caused by free radicals.
- How it works: During an allergy attack, mast cells are triggered to release an amino acid derivative called histamine. This produces itchy eyes, drippy noses, sneezing, headaches, and a gamut of other symptoms that plague nasal passages, eyes, throat, lungs, skin, and even the digestive tract. A natural antihistamine, vitamin C blocks the release of histamine and gets rid of histamine that's already making the rounds in your body, according to a 2000 study published in Alternative Medicine Review. For best results, start taking vitamin C several weeks before allergy season arrives, and take it along with the flavonoid quercetin.
- Note: Even high doses of vitamin C generally don't cause problems. But some people develop diarrhea after taking a few grams; if so, dial back intake in 500 mg increments until you find a more tolerable dose.
- What it is: Quercetin is a plant pigment in the flavonoid family; it's found especially in apples, onions, and black tea. A potent antioxidant, it may help combat a host of disorders, from asthma to cancer and heart disease.
- How it works: Like vitamin C, quercetin is a natural antihistamine that counteracts excessive histamine release during an allergy attack. By stabilizing cell membranes, it helps impede histamine release. As an added bonus, quercetin also dampens inflammation, which can congest allergic nasal passages.
- Note: Start taking quercetin as soon as allergies hit, and take it daily throughout allergy season. Unfortunately, quercetin's absorption isn't that great. Taking bromelain (an enzyme from pineapple) may boost how much histamine-blocking quercetin gets into your system.
Oregon-based freelancer Victoria Dolby Toews, MPH, is the author of User's Guide to Sexual Satisfaction (Basic Health, 2003) and User's Guide to Glucosamine and Chondroitin (Basic Health, 2002).