Nightshades are plants in the solanaceae family. Within that family are some common foods in almost everyone’s diet. These include: potatoes, tomatoes, eggplant, and all types of pepper (except black pepper). According to Michael Lebowitz, DC, goji berries and ashwaganda (“Indian Ginseng”) contain the same potential toxin as nightshades. And the National Toxicology Program reports that apples, cherries, and sugar beets contain the chemical as well. Bilberry (huckleberry) is also in that list. Obviously, don’t forget about condiments and products that contain these foods. Lastly, tobacco is a nightshade.
OK, so now for the reasons these nightshades can cause a problem! These foods have a specific chemical in them known as solanine. First, according to one researcher, solanine may directly irritate the gastrointestinal (GI) tract. And additionally, when it is absorbed into the bloodstream, it can cause destruction of the oxygen-carrying red blood cells. I could not find the mechanism related to that effect.
Second, solanine is known as an aceytlcholinesterase inhibitor. That means it acts to prevent the breakdown of the neurotransmitter acetylcholine (ACh), leading to an excessive build-up of ACh in the nerve receptor sites. Therefore, it will allow for a constant (over)stimulation of ACh receptors. Acetylcholine has many functions in the nervous system. Generally, it is responsible for stimulating the parasympathetic nervous system. To avoid boring you, I won’t go into all of the effects of ACh.
Instead, I’ll simply discuss the potential symptoms of nightshades as it pertains to their neurological effects. Don’t forget, as stated above, direct GI tract irritation can occur. And some researchers found that solanine can cause vomiting and enteritis (GI tract inflammation). In addition, nausea, diarrhea, and stomach cramps were reported. According to research by Michael Lebowitz, DC, solanine has the following potential attributes: “1- act as an endocrine disruptor especially to the thyroid; 2- cause chronic joint pain, arthritis (all forms), joint inflammation- this is due to solanine’s ability to remove calcium from the bones and deposit it in any weak or genetically predisposed area of the body; 3- for the same reason it can be a major contributor to osteoporosis (since it removes calcium from the bones) and arteriosclerosis (it can deposit the calcium in the blood vessels); 4- “leaky gut” as well as IBS; 5- appendicitis; 6- birth defects including spina bifida; 7- depression; 8- migraines; 9- can greatly interfere with calcium and vitamin D absorption, despite supplementation.” There may be more symptoms associated, but that’s a good start.
And for your information, “nerve gas” and certain pesticides act as acetylcholinesterase inhibitors as well. Strange to think of those foods acting like such toxic chemicals. Drugs that act as acetylcholinesterase inhibitors are used to treat Alzheimer’s disease and dementia.
Please be aware that not everyone will be affected by nightshades in the same way. However, if you are, you’ll want to know so you can avoid them. Some of my colleagues find solanine to be causing a problem in about one-third of their patients. You know I always ask the question: “Why?”, so let me address that. There can be many reasons why they affect an individual, and they are similar to why other potential toxins cause symptoms. They are: genetics, the ability to clear the chemical from the system (most likely liver and kidney metabolism), and the amount of exposure. These are some of the main reasons affecting the body’s response to solanine. Additionally, it is unclear how long one will need to avoid ingesting solanine before their symptoms abate. It may be quite “difficult” to avoid eating nightshades, however, it will be well worth your while if something so simple can stop debilitating or annoying symptoms.
When I find this problem with patients, I also use supplement(s) to help clear the solanine from the system, to provide faster symptom relief. And with the in-office procedures I use, it is simple to tell “on the spot” if solanine may be causing you problems. My patients appreciate this because it prevents them from unnecessarily avoiding some of their favorite foods. This problem can be both a blessing and a curse. See you soon.
Dr. Robert D’Aquila – NYC Chiropractor – Applied Kinesiology