Nightshades on the Banting Diet


The term “nightshade” does seem like it should belong in a horror story, but are nightshades as deadly as they are made out to be?

What’s in a name?

Nightshades belong to the family of plants called Solanaceae and include tomatoes, tomatillos, white potatoes (not sweet potatoes), all types of peppers (chilli, paprika, cayenne pepper, sweet bell peppers) and eggplants (aubergines).

Other nightshades include goji berries and Cape gooseberries.

The above, fairly innocent fruit and vegetables, are in no way comparable to the deadliest of nightshades: belladonna. This one can really kill you. The one thing the deadly, and the not so deadly, nightshades have in common is that they each sprout the same type of flower, and that is why they’ve all been lumped into the same category. In ancient times tomatoes and eggplants were only grown as ornamental plants and not eaten. The lethal plants in this family were used as sleeping pills, and the Romans were even thought to poison their enemies with them during wartime.

Antinutrients, the kung fu of the plant world.

Every living thing on the planet has some sort of defense mechanism to protect it from predators and infection. Plants can’t get up and fight or run away, so many, like the nightshades, contain antinutrients. These either prevent the nutrients in the plant food from being absorbed, or act as toxins against predators. The antinutrients, or alkaloids, in the nightshade family are mainly concentrated in the leaves, flowers, and unripe fruits. (So don’t be tempted to eat any of those!)
Generally, nightshades do not pose a problem for healthy individuals, because a healthy digestive tract prevents absorption of most of the alkaloids.

Who should not eat nightshades?

Excessive consumption can cause a build-up of alkaloids, which can take some time to be cleared (and during times of stress they can have a detrimental effect on the body).  For those with already compromised guts and immune systems, and those with an existing autoimmune disease – eating nightshades can spell a whole world of pain. A diet high in sugar and refined carbs, especially gluten, seems to exacerbate the problem, as this alters the gut biome, and is thought to prevent the gut bugs from being able to protect the gut against these toxins.

Eating potatoes as part of a diet high in gluten, sugar and omega 6 can have a massive inflammatory effect. People with severe insulin resistance, those with diabetes, who are overweight, or have any other metabolic illness should avoid potatoes.

What are the symptoms of nightshade sensitivity?

Anecdotal evidence shows symptoms of nightshade sensitivity include muscle pain and tightness, morning stiffness, poor healing, sensitivity to the weather, arthritis, insomnia, gall-bladder problems, heartburn.

Other symptoms of nightshade intolerance are constipation, anxiety, headaches, nausea, bloating, flatulence, IBS, poor food absorption, joint pain, fibromyalgia, and osteoporosis.

“There is simply nothing else that anyone can do to help somebody in pain when nightshade sensitivity is the cause—because once they eat some nightshades again, their pain will return as it was before,” says Naturopathic physician, Garrett Smith.

Ironically, the same chemical compounds that cause so many problems in nightshade-sensitive people can bring benefits to people with healthy digestive systems.

Unfortunately, due to the heavy consumption of processed carbs and sugars, most of our digestive systems will probably be compromised in some way – particularly those with insulin resistance. If you show any of the above symptoms, you may be intolerant to nightshades. Consider eliminating them from your diet, whether you’re Banting or not.

The alkaloids in potatoes, tomatoes, eggplant, and peppers:

  • Most of the alkaloids are found in the skin of the potato, but peeling removes most of them. Unripe, green and sprouting potatoes have the highest concentration of alkaloids and should be avoided (For an in-depth look at potatoes, please read here)
  • Deep frying seems to increase the levels of alkaloids in potatoes
  • As with potatoes, green tomatoes have higher levels of toxic alkaloids, although ripe tomatoes are 20 times less toxic than the alkaloids found in potatoes
  • The alkaloids in eggplants are mainly in the seeds and the flesh, but are considered less toxic than potato alkaloids. Ripe eggplant seems to have fewer toxins than underripe ones
  • Red and green bell peppers have the least amount of alkaloids, so if you react to them, it could be an indication of your high sensitivity to nightshades.

In conclusion: If you see a tomato plant hiding behind a corner or lurking in a garden, don’t run the other way – most people do not have an adverse reaction to nightshades. If you do have poor gut health, leaky gut, IBS, or any of the other symptoms mentioned above, it may be an idea to eliminate them from your diet for at least a month to three months depending on your health.

Here are some tips to follow when it comes to nightshades:

  • Avoid potatoes if you are severely insulin resistant, overweight, have diabetes or any other metabolic illness
  • Avoid nightshades if your gut is compromised or if you have an auto-immune disease*
  • Avoid nightshades if you are intolerant to gluten or dairy, as they could make the symptoms worse
  • Do not eat green or sprouting potatoes or green tomatoes
  • Do not eat the leaves, flowers or stems of nightshades
  • Peel your potatoes before use
  • Cook your nightshades well
  • Eat your nightshades with fat, especially butter, to better absorb the nutrients
  • Only eat very ripe eggplants, and soak the slices in salty water for a couple of hours to remove the toxins
  • Avoid all processed nightshades especially those that are deep fried in seed oils
  • Eat nightshades in moderation
  • Focus on healing your gut by following a Banting lifestyle. Avoid sugar and processed carbs, incorporate probiotic-rich foods such as fermented foods and drinks, prebiotic-rich foods such as fibrous vegetables, and drink homemade bone broth to help repair the gut lining

* If you have an auto-immune disease, it might also be beneficial to eliminate eggs, dairy, nuts, seeds and legumes from your diet for at least a month to see how you react to them.

For those about to embark on our new Banting 2.0 journey, nightshades can be eaten during all phases, except potatoes, which should be avoided during Transformation (remember to factor in the carb-count). This is unless you suffer from any of the symptoms mentioned above. If you find that you are not making progress during any of the phases, try cutting out the nightshades.


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