Earlier this month, I talked about foods that came from the “New World” in the Americas, including potatoes and peppers. And these plants have another surprising connection—they both belong to the nightshade family of plants, known botanically as Solanaceae.
The “deadly” nightshade family also includes:
- goji berries
Now, I know many “natural-know-it-alls” have issued a blanket indictment against eating all nightshade vegetables. And they blame nightshades for just about every health problem you can dream of.
But as usual—their advice is more about superstition than it is about science.
For one, these foods have been safely consumed in many cultures for thousands of years. They also contain important nutrients that science shows can reduce inflammation and protect you against chronic disease.
So, today, let’s set the record straight about nightshades and go over everything you need to know about these often misunderstood plants…
Nightshades produce natural pesticides
Nightshades are flowering plants that include annual and perennial food crops, herbs, medicinal plants, vines, shrubs, and trees. They also produce fruits, which attach to the plants’ stems with green tendrils. And, of course, it is the fruit that we consume, except in the case of potatoes and tobacco. (The tuber of the potato and the leaf of the tobacco are consumed.)
All nightshades also produce natural pesticides called glycoalkaloids to protect themselves against predators, such as insects, and other dangers, such as bacteria, fungi, and viruses. (Apples, beets, and cherries also contain small amounts of these same natural pesticides, although they are not nightshades.)
These glycoalkaloids are concentrated in the plants’ flowers and leaves…as well as in the plants’ unripe “fruit.” (Which is why you should stay away from the flowers, leaves, and unripe fruit of nightshade plants.)
The deadly nightshade, also called belladonna (which means “beautiful lady” in Italian), is perhaps the most toxic of all the nightshades, as it contains very high amounts of alkaloids. (Interestingly, during the Renaissance, women used eyedrops made with belladonna to dilate their pupils and create a seemingly seductive look.)
Nightshades cause problems for some, but not all
We know that ingesting high amounts of glycoalkaloids can cause some very serious problems, including…
1.) Digestive issues
Modern studies show high doses of glycoalkaloids can cause the membranes of red blood cells and mitochondria (your cells’ energy factories) to split open. Leaving some scientists to wonder whether they may contribute to irritable bowel problems, such as acute diarrhea and gas, as well as chronic problems, such as “leaky gut” syndrome.
2.) Neurotoxic effects
Glycoalkaloids can also act as neurotoxins, blocking the enzyme cholinesterase, which normally breaks down the neurotransmitter acetylcholine (this effect caused the belladonna look in women’s eyes). When this happens, it can cause a tonic spasm of muscle cells, which can lead to convulsions, cardiorespiratory arrest, paralysis, and even death. For some perspective, military nerve gases and the pharmaceutical agent atropine both work in this same way.
3.) Mental health effects
Nightshade plants also have somewhat of a bad reputation when it comes to their effect on mental health. For example, centuries ago, eggplant was referred to as the “mad apple.” More modern studies seem to suggest that nightshades can actually cause toxicity to the central nervous system, which can lead to apathy, confusion, dizziness, drowsiness, incoherence, hallucinations, rambling, stumbling, stupor, trembling, and visual disturbances.
Anecdotal reports also suggest that nightshade vegetables and fruits can aggravate arthritis, fibromyalgia, heartburn, insomnia, migraines, and chronic pain as well.
On the flip side, glycoalkaloids are also thought to have some positive health benefits…
Clear benefits of constituents in nightshades
In lower amounts, glycoalkaloids have been shown to have some impressive health benefits. In fact, in lab studies, they appear to manifest a steroidal-like effect, reducing inflammation.
They also seem to possess natural anti-bacterial and anti-viral properties. And they even show anti-cancer properties, causing cancer cells to self-destruct. (We call this mechanism “apoptosis.” And big pharma seeks to simulate this mechanism in their experimental cancer treatments.)
Of course, nightshades also contain loads of vitamin C and other important nutrients. For example, tomatoes are a good source of lycopene (which I helped discover in the mid-1980s). It’s a carotenoid with potent health benefits—especially for the prostate. (You can learn more about the many effective, natural approaches to supporting healthy prostate function in my comprehensive, science-backed Insider’s Guide to Ultimate Prostate Health. To sign up or to learn more about this innovative learning protocol, click here now!)
The truth is, people around the world have been enjoying nightshade vegetables without incident for thousands of years. So, if you’ve been enjoying potatoes, eggplants, tomatoes, and peppers without any ill effects, you can probably continue eating them in moderation.
However, if you’ve noticed gastrointestinal (GI) upset, headaches, joint pain, heartburn, or sleeplessness after eating these foods, you may have some sensitivity to them.
The only real way to know if nightshades are a problem for you is to eliminate them completely from your diet for a few weeks and see how you feel. Then, you can reintroduce them one at a time. If the symptoms return, you’ve got your answer.
Fortunately, as I mentioned earlier, ripened fruit (which is the part of the plant you consume) contains a much lower concentration of glycoalkaloids. Plus, cooking also reduces the concentration.
So, when you do eat nightshade vegetables, make sure they’re fully ripe. For potatoes, that means avoid eating unripe tubers that are green, have “eyes,” and seem to be sprouting. And if you’re not sure about the difference between ripe and unripe nightshade vegetables, don’t hesitate to ask your local farmer or grocer.
Now, you know all about the science of nightshade vegetables. And you can leave the superstition to the witches (and internet trolls).
P.S. I recently launched a groundbreaking new protocol for restoring healthy lung function. And now, enrollment for my Breathe Better Lung Health Protocol just reopened! In it, you’ll learn all of the natural ways to strengthen your lungs and protect yourself from lung disease—America’s third most lethal killer. To learn more, or to enroll today, click here now.
“How Deadly are Nightshades?” Diagnosis Diet, 5/1/19 (diagnosisdiet.com/nightshades/)