August 18, 2011 —
Tomato season is here. Last weekend, my local farmers' market at Fort Greene Park had a beautiful display of jewel-like heirloom tomatoes.
But many people avoid them. Tomatoes are part of a potentially troublesome group of veggies known as "nightshades."
Nightshades are a members of the Solanaceae family of plants. The term applies to more than 2,800 plant species, but the ones we're concerned about are, in addition to tomatoes, white-fleshed potatoes, eggplant and sweet and hot peppers.
They contain substances called alkaloids that can affect nerve and muscle function. Consider, for example, the most famous nightshade, belladonna, or deadly nightshade, Atropa belladonna. Eating ten to twenty of its little blueberry-like fruits can kill you. Belladonna poisoning symptoms include blurred vision, loss of balance, slurred speech, hallucinations and convulsions.
The steroid alkaloids in potatoes could also be related to joint damage. Do an Internet search on "nightshades," and you'll get a lot of links to arthritis Web sites. However, there's no scientific research proving a connection between potatoes and other nightshades and joint inflammation.
Did you know that eggplant and tomatoes include small amounts of nicotine, just like their nightshade cousin, tobacco? This brings a whole new series of associations for those who like to smoke cigarettes because it gives them something to fiddle with at bars and boring parties.