The Flaming Vegan

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Know Your Nightshades: They Can All Be  Deadly!
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Know Your Nightshades: They Can All Be Deadly!

I love the name “nightshade”, and apparently these plants are so called because they are grown in the shade of night. I imagine that the one most people will be most familiar with is the poisonous plant deadly nightshade, or belladonna. But did you know a lot of the relatives of this plant are common in our diets?

Nightshades (Latin name Solanaceae) are an extremely diverse family of flowering plants, which include some of our favourite and most common vegetables, i.e. potatoes, peppers, tomatoes and aubergines. Although these are important agricultural crops and usually feature strongly in the diets of vegetarians and vegans, a lot of them are toxic. Nightshade is a generic name which describes over 2,800 species! Throughout history they have actually been more famous and widely-used as drugs and poisons rather than food, especially mandrake and belladonna (deadly nightshade).

The family includes Jimson weed (datura), mandrake (mandragora), deadly nightshade (atropa belladonna), wolfberry, tomatillo, Cape gooseberry flower, chilli pepper and bell peppers (Capsicum), potatoes, tomatoes and aubergines/eggplants (Solanum), petunia, and tobacco (Nicotiana). Most parts of the plants, especially the green parts and unripe fruits, are poisonous to humans (although not necessarily to other animals), but some of the species bear edible parts, such as tubers and fruit, and several are cultivated and are of global importance, e.g. potatoes, tomatoes and aubergines. Potatoes and tomatoes contain small amounts of nicotine, not surprising since they are related to the tobacco plant.

A certain group of substances in these foods called alkaloids can have an adverse effect on digestive and nerve muscle function in both humans and animals, and they may also impact on joint function, as they have inflammatory properties. The plants produce these toxic alkaloids to protect themselves against attack by insects, but they can also adversely affect humans (some people, it appears, have a certain sensitivity to them). Anyone suffering from arthritis or other inflammatory diseases should consider excluding these vegetables from their diet, and research suggests that the rest of us would do well to eat them in moderation. The alkaloid content in the food plants, however, is very low compared to that in other nightshade plants, which can be highly toxic and dangerous. Cooking the vegetables lowers the alkaloid content by about 40-50%, so bear this in mind when eating them. If you find green and/or sprouted spots on potatoes, this usually indicates a high alkaloid content, so remove these spots before eating, or do not use the potatoes.

It is not just the vegetables you have to be careful of, but certain condiments and seasonings as well. The seasoning paprika is also derived from Capsicum annum, the common red pepper, and the seasoning cayenne comes from another nightshade, Capsicum frutenscens. Hot sauces that contain hot peppers should also be considered as a nightshade food, a prime example of this being tabasco sauce. It may be helpful to note here that black pepper, which belongs to the Piperaceae family, is not a member of this group. However the nightshade influence can even be found in some popular drinks, and other household products: chilli pepper and paprika are found in cola drinks (hence the name Dr Pepper), and a lot of pesticides are based on nicotine.

So although certain members of this plant family are highly nutritious, delicious and a food staple, they can also have certain potentially harmful effects which it is wise to be aware of.

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  1. evalovesbend
    Great info! Voted.
  2. pftsusan
    This is very good. Voted. I will come back later, when I have more time to comment more on this.
    1. pftsusan
      I have arthritis. I don't have potatoes anyway. What else should I avoid from the toxic group of vegetables? i like tomatoes once in a while and jalapeno peppers. I also think that washing them really good would get some of these preservatives out of them. Black pepper, I'm allergic too. BTW, green and red peppers are on the dirty dozen lists.
      1. Veganara
        Sorry to hear you have arthritis Susan. Try eliminating all of them, tomatoes, peppers, aubergines, everything that I have mentioned above, including the sauces and seasonings, and see if it improves at all. Whilst I was researching this article I found a lot of reports of people with arthritis and other inflammatory diseases who eliminated the nightshade foods and products, and their conditions either disappeared or improved a lot. There are other people who don't have arthritis but have a kind of allergic reaction after eating any of these foods. They never seem to affect me, but I don't go overboard on them anyway! Thank you to you and Eva for the votes and comments.
        1. pftsusan
          The last time, I got organic tomatoes. So that should be ok. Or Jersey tomatoes. No one has them like we do this time of the year in Jersey. But this blog did give me a few things to think about.
  3. Carolyn
    Oh wow such an information packed article! Sorry missed voting due to working third shift the past several days. Congrats for making Top Posts! Will be watching for future articles!
  4. BobbieSue
    Wow, would have never guessed there was nicotene in potatoes and tomatoes...or even eggplant! I love ALL those! Now, I really do not eat them all the time, but tomatoes more than the others...oh, and bell peppers I eat more than twice a week, I grow them. I do have carpal tunnel in my hands and wrists...will it help that to slack on these "nightshades?"
    1. Veganara
      It could well help it BobbieSue: I suggest you try cutting the tomatoes and peppers out of your diet for a while, and see if the carpal tunnel improves. I know that it helps some people, if they have inflammatory conditions. I never seem to have any problems with eating the nightshade vegetables, but some people do seem to have a certain sensitivity to them. Thanks for commenting, I always enjoy having a dialogue with people!
  5. moregreensplease
    This is an interesting and very informative article. For quite a while I've known the alkaloids in potatoes. The chili pepper in cola. 10th vote.


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