Flickr user, Marilylle Soveran

It's not an old wive's tale: cranberry helps prevent and treat urinary tract infections. And it's not just the acidity: a compound in cranberries and blueberries keeps bacteria from sticking to bladder and urinary tract walls. Cranberries are high in several kinds of antioxidants, including proanthocyanidins, which give the ripe berries their vivid red color.

In the 1672 book New England Rarities Discovered, author John Josselyn described cranberries:

Flickr user, Jon Bunting

Among the artifacts discovered in the tomb of Egypt's Tutankhamen - objects meant to ease the boy king into the afterlife - were 3,000-year-old bulbs of garlic. Giving as well as receiving, Tut supplied daily rations of garlic to his pyramid-building slaves, for endurance and health. Garlic is a fabulous heart helper: its blood-thinning and anti-clotting abilities may slow down atherosclerosis and lower blood pressure.

Flickr user, Ali Graney

The causes of migraine aren't well understood. Neither is the mechanism behind feverfew's proven ability to stop or prevent a migraine headache. Feverfew supplements used in clinical studies to treat migraine contain a standardized dose of 0.2 to 0.35% parthenolide, so if you research this herb, pay attention to dosage details.  Pregnant women and children under the age of two shouldn't use it, and people with allergies to ragweed, chamomile and yarrow are sometimes allergic to feverfew.

Asian Ginseng

Jul 12, 2014

7/12/14: This week on The Plant Detective: Asian ginseng, Panax ginseng, helps people with Type 2 diabetes maintain healthy blood sugar levels. Both Asian and American ginseng contain ginsenosides, just in different proportions. Asian ginseng stimulates while American ginseng calms, and in the terms of Chinese traditional medicine, Panax ginseng promotes yang energy and cleans excess yin. American ginseng (Panax quinquefolius) does the opposite.

Tea II

Jul 5, 2014

7/5/14: This week on The Plant Detective: They may have different flavors but black, green, white and oolong teas all come from the same plant: Camellia sinensis. They're just processed differently; black tea is fermented, green tea isn't. Unfermented green tea is especially high in catechins, those antioxidants that scavenge the blood for free radicals and are associated with lower rates of atherosclerosis.