Nightshade Foods

Nightshades have a reputation as bad actors in a variety of chronic conditions, such as arthritis, fibromyalgia, and IBS. But what do we really know about how these foods affect our health?
The Nightshade (Solanaceae) Family: 

Tomatoes
Eggplant
Potatoes
Goji Berries
Tobacco
Peppers (bell peppers, chili peppers, paprika, tamales, tomatillos, pimentos, cayenne, etc) 

At first glance, the nightshades may look like a random collection of foods that couldn’t possibly be related. However, every nightshade plant produces fruits that all sport that same adorable little green elfish hat.  Of the foods above, only tomatoes, eggplants, goji berries and peppers are “fruits” (the potato is a tuber and tobacco is a leaf).  The fruits of potato and tobacco plants wear the same telltale hat, but we don’t eat the fruits of those plants. 

Nightshades of all types were considered inedible prior to the 1800’s, because some varieties, such as “deadly nightshade” (atropa belladonna) were known to be so toxic.  However, today most Americans eat “edible” nightshades every day in the form of French fries, mashed potatoes, salsa, spaghetti sauce, ketchup, and many other popular foods.

Because nightshades are only a problem for a small number of people, it’s overkill to suggest that everyone should avoid them.

People with arthritis are sometimes advised to avoid all nightshade plants because they are said to cause inflammation.  But this advice really only applies to people who have a sensitivity to solanine.  For these folks, eating nightshade plants causes an inflammatory reaction—including joint pain. 

Because most people are not sensitive to solanine, however,  it may be misleading to characterize nightshade plants as “inflammatory,” and it’s certainly overkill to suggest that everyone with arthritis should avoid them—especially because they have so much going for them nutritionally.

Nightshade plants are high in antioxidants, which actually help reduce inflammation.  And chili peppers also contain capsaicin, a strongly anti-inflammatory compound. 

If you are an individual with no existing health problems potentially related to nightshade intake, you will want to take precautions to avoid excessive intake of alkaloids from these foods. Handling of potatoes is especially important in this regard, and the following practices will help you avoid excessive intake of potato alkaloids:

- Store your potatoes for 1-3 weeks only in a dark cupboard, preferably in a cool and dry part of the house such as a basement (if your basement is dry). It's important not to keep potatoes in a lighted area; the exposure to light will increase alkaloid formation.

- Wash all potatoes before cooking so you'll be better able to spot the green areas, if any.

- Thoroughly cut out all green areas, especially green areas on the peel, before cooking. and cook the rest for safe eating. If you're sensitive to nightshades in the first place, it's best to discard the whole potato. After cooking, if the potato tastes bitter, do not eat it.

- Do not purchase potatoes that have been waxed or apply wax to potatoes yourself. Waxes do not help reduce greening and can increase potato decay by cutting down on gas exchange in and out of the potato.

Source: Georgia Ede, M.D.