NIGHTSHADE VEGETABLES AND YOUR HEALTH
by Lawrence Wilson, MD
© September 2010, The Center For Development
The nightshades are a botanical family or group of plants the include some of the most familiar of our vegetables. They include:
á All tomatoes, including red and green tomatoes, and the larger and smaller varieties.
á All peppers, including red and green sweet peppers, dried table pepper and hot spicy peppers, also called chile peppers. It also includes cayenne and most hot sauces or Tabasco sauces.
á Red and white varieties of potatoes. However, the sweet potato is in a slightly different family of plants
á Others. These include tomatillos, tamarios, pepinos, pimentos, and paprika. Tobacco is also a nightshade plant.
PROBLEMS WITH NIGHTSHADE VEGETABLES
The nightshades are not recommended on nutritional balancing programs for two reasons:
1. They are very yin in Chinese medical terminology. In fact, all of the nightshades except potatoes are actually fruits. Fruits, as a class of foods, are all very yin. A fruit is defined as the expanded ovary of a plant, and most fruits contain seeds. Of course, tomatoes, eggplant and peppers contain seeds. Vegetables, by contrast, are the stems, roots and leaves of plants. Potatoes are actually tubers, which are growths on the roots of the plant.
(Other vegetables that are really fruits include cucumbers, okra, peas, and squashes. However, okra, peas and winter squashes are much less yin than the others.)
2. Nightshades contain various alkaloids that have definite toxic effects on the body. Nightshades may contain up to four types of alkaloids, although only two are of major importance. These are called steroid alkaloids, and are toxic to the nervous system and affect calcium metabolism. The two that have been studied the most are solanine and chaonine.
The nervous system effect of these chemicals is to act as a cholinesterase inhibitor. Some pesticides kill insects by this means. A cholinesterase inhibitor can cause agitation, twitching, tremors and other harmful effects upon the nervous system. This is damaging for most people, whose nervous systems are already overactive and stressed.
The effect upon calcium metabolism appears to be to contribute to excessive loss of calcium from bone and excessive depositing of calcium in soft tissue. Once again, this is a very harmful effect. Solanine is also a very pro-inflammatory substance. In particular, it irritates the joints.
Nicotine in the nightshade vegetables. Tomatoes and eggplant also contain small amounts of nicotine, another alkaloid that has drug-like effects. While the amount is very small, it is another toxin that is not needed or helpful for the body.
Arguments for the nightshades. Most readers are familiar with the fact that tomatoes are high in vitamins C, lycopene and perhaps other chemicals that are beneficial for our health. Potatoes are rich in some minerals, particularly their skins and just under the skin. Cayenne and other peppers are also nutritious foods, containing a lot of vitamin C and carotenes.
Those who enjoy these foods also argue that cooking the nightshade vegetables removes about half of the alkaloid content. While this is true, it is also true that the yin quality of the nightshades cannot be changed much by cooking and overall, these are not our best foods. They are best avoided by anyone who is aiming for optimum health.