I am somewhat embarrassed to tell you that until a few years ago, after I began my life as a health coach, I knew nothing about nightshades. I had never heard of them.
Now, working with some of my clients who have various digestive or leaky gut issues, I’ve learned from them, and from additional research enough to say a few things about them. It turns out that the more we learn about food with all it’s benefits and concerning issues, the more there is to learn. In truth, with the standard American diet (SAD) as it is, we’ll be hearing lots more about this interesting group of foods -nightshades- moving forward.
By way of introduction, nightshades are members of the family Solanaceae. Common edible nightshades include white (but not sweet) potatoes, eggplant, tomatoes, and peppers, both sweet and eye-watering hot. Some spices made from peppers, such as paprika, red pepper flakes, and cayenne are also included on the list of nightshades. (Black pepper is from another plant.)
There is a longer list of inedible nightshades, most of which are toxic to humans. Think belladonna poisoning in Macbeth, for example.
Historically there has been some concern that if a family of foods can be so toxic even to the point of deadly in some cases, the apparently harmless tomato must be up to no good, as well. Some farmers through time have avoided growing some basically harmless nightshades for fear that they were unhealthy by association with their poisonous relatives.
Truly, there is no evidence that nightshades are dangerous in any way to most healthy people.
What makes nightshades problem foods?
All nightshades produce a combination of alkaloids in small amounts. One of them, for example, is solanine, found in potatoes, especially green ones. Another is nicotine. Nightshades are not addictive like cigarettes. Another, capsaicin gives peppers their heat.
While the plant is alive, these alkaloids act as a pesticide/herbicide from inside the plant. They protect the plant from pests and molds that would otherwise kill it. They are designed to be toxic. In the poisonous members of the nightshade family these chemicals are so concentrated that they can be deadly, but they are present in much smaller amounts in the edible plants, and mostly in the leaves and stems, which, in many cases, are not eaten anyway. It’s like trying to taste a single grain of sand in a huge bowl of soup. It’s not a good idea to eat sand, as a general rule, but such a tiny amount will not make a difference to your health in the majority of people.
People with healthy guts can do just fine with the amount of chemicals in nightshades and can even benefit from them. Consider capsaicin, for one. It serves as an anti-inflammatory when we eat hot peppers. The alkaloid causes a minor irritation which triggers a strong anti-inflammatory response, that the overall result is anti-inflammatory and beneficial.
So what’s the problem?
Alkaloids present in nightshades may cause too much irritation to a gut which is already inflamed, so that it becomes a “leaky gut.” The intestinal lining becomes more permeable, so various proteins sneak through into the bloodstream, causing an auto-immune response.
Those who already are compromised by an autoimmune disease may have some trouble. If there is already an auto-immune response in play, the alkaloids in the nightshades may increase the power of its response, which would not be helpful in efforts to heal it.
These dangers are only relevant to people who are nightshade-sensitive. Even if you have some “gut distress” of one sort or another, there are other measures to take before blaming nightshades. Click here for some ideas about that.
Should you avoid nightshades?
The fact is that the same compounds that are problematic in nightshade-sensitive people can bring benefits to people with healthy digestive systems. If you are trying to heal from an autoimmune disease, (especially rheumatoid arthritis or anything else that causes joint pain and inflammation), eliminating nightshades for 30 days may give you some very valuable clues about what’s aggravating your system.While total elimination is one option, people who may only be slightly sensitive may find relief by just reducing the nightshades in their diets.
This can be done by
- Peeling all potatoes (most of their alkaloids are in the skin)
- Avoiding green tomatoes and green and/or sprouting potatoes (unripe nightshades are higher in alkaloids.
- Cooking nightshade vegetables whenever you eat them, (as this will further reduce the alkaloid content.)
It certainly doesn’t hurt to experiment, but if you don’t have an auto-immune disease or a chronic pain issue, there may be very little or no benefit to eliminating nightshades from your diet. Continue to enjoy tomatoes, eggplant, and hot peppers as you like, and receive the benefits from those same alkaloids.