Are Nightshade Vegetables Bad for Your Health?

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Nightshade vegetables in your diet could cause arthritis, autoimmune problems and other health conditions. Learn which vegetables can cause you health problems.

It has long been thought that vegetables or fruits in the nightshade family are bad for our health. Even though nightshades are some of the most popular foods around the world and nightshade vegetables are considered healthy, can they actually be bad for our health?

It seems there are always different schools of thought when it comes to what foods are healthy or unhealthy for us. Since not everyone is alike, some foods can cause health problems for one person and be healthy for another. I have wondered about nightshades since I first learned about macrobiotics, because macrobiotics teaches us not to eat any nightshades. I also like to grow my own food, and where I live, some years, nightshades like peppers and tomatoes are the only foods that want to grow in my garden.

List of Nightshade Vegetables

The list of nightshade vegetables is a long list of popular foods that include:

  • Peppers (Except black pepper or peppercorn, they are not nightshades).
  • Tomatoes
  • Potatoes (Sweet potatoes and yams are not considered nightshades).
  • Eggplant
  • Tomatillos
  • Garden huckleberry
  • Pimentos
  • Tobacco
  • Tabasco sauce
  • Paprika
  • Cayenne
  • Goji berries

The History of Nightshades

Nightshades are considered New World plants since they weren’t discovered until the Americas were discovered, so they are fairly new to humans as a food. Nightshades were first found and introduced to humans in the 16th century and at that time, most of them were only grown for ornamental purposes and most thought they were all poisonous to eat.

Nightshade vegetables were considered a poison and tobacco was once used as a pesticide. Most if not all of the leaves of nightshade plants are poisonous. Jimsonweed, a very poisonous plant to both animals and humans is also part of the nightshade family.

Before the 1600s, nightshades like belladonna, mandrake, henbane and thorn apple were restricted to medical purposes only as a sedative, anesthetic and some used them for witchcraft. Armies and warriors used them as poison against their enemies.

Why Nightshade Vegetables Could be Bad for Our Health

Nightshades contain alkaloids. Alkaloids in plants are a part of the plants defense system that protects the plants from insects eating them. Though, when I think of all the bugs on my tomato plants some summers, I wonder about this.

Macrobiotics has long taught that all nightshades should be avoided for good health. Most of the reasoning I have read for this is that nightshades contain oxalic acid, which inhibits our body’s ability to properly absorb calcium. But when looking at the USDA list of vegetables and the amount of oxalic acid in them, nightshades have very little oxalic acid in them [1].

There are health problems that have been associated with nightshades, especially in people who are sensitive to nightshade vegetables and fruits. The list of health problems includes:

  • Arthritis is by far the most common health problem talked about in relation to nightshade foods.
  • Rheumatoid arthritis and osteoarthritis.
  • Aches, pains and joints popping.
  • Chronic pain
  • Acne
  • IBS (irritable bowel syndrome)
  • Headaches and migraines
  • Gout
  • Acid reflux
  • GERD (Gastro Esophogal Reflux disease) can especially be caused by tomatoes.
  • Crohn’s disease
  • Autoimmune diseases
  • Eczema, especially in children can be cleared up by avoiding nightshades.
  • Psoriasis, cyctitis and lupus symptoms can be relieved by avoiding nightshades.
  • Chronic fatigue
  • Delayed healing of muscle, tissue and bone healing.

Doctors report that one in three people with arthritis have arthritic pain or inflammation when they eat nightshade foods. The most likely reason for the arthritic reaction is sensitivity to the solanine in the nightshades. I read stories from people with arthritis, aches and pains, joint popping and arthritis say that they have felt better after eliminating all nightshades from their diet for 6-12 weeks. Most doctors say it can take up to six months of complete avoidance of nightshade foods.

It does appear that potatoes (not yams or sweet potatoes) seem to be the worst of the nightshade foods when it comes to health problems. When you think about how popular the white potato is in our diets with all kinds of potato side dishes, potato chips and French fries with ketchup, maybe there is something to this.

When avoiding nightshades foods completely, you also have to be aware of the nightshades as ingredients in foods, like mustard and some foods that list “spices” since that could mean paprika.

Survey of Nightshades and Arthritis

A book was published that included the “No Nightshade Diet” in it. The book included a post card so a survey could be done with 434 volunteers returning the survey card. The volunteers, age 20-80 had been diagnosed with some form of arthritis. Of those who responded, 52% of them said they had rigidly followed the no nightshade diet. Of those who rigidly followed the diet, 94% had complete or substantial relief from the arthritis pain [2].

Nightshades and Quitting Smoking

Some doctors who advise people on how to stop smoking tell them they should not eat nightshade vegetables because all nightshades have some amount of nicotine in them [3].

Food Alternatives to Nightshades

Nightshades are such a huge part of our daily diets and taste good, so they are not easy to give up. If you do suffer from any of the above health conditions, it could be well worth giving them up for at least three months to find out if your health problems go away.

  • Alternatives to potatoes can be sweet potatoes. Sweet potato French fries are very good as are mashed sweet potatoes. Mashed cauliflower is healthy and tastes good.
  • Giving up tomatoes is not easy. There is a product called Nomato that contains no tomatoes in their products. They make alternatives to ketchup, barbeque sauce and marinara sauce.

Conclusion of Nightshades

There are not many studies about nightshades and our health, but there seems to be enough real-life stories concerning nightshades and certain health problems. It could be the alkaloids in nightshades or it could be that some people have a bad reaction to nightshade vegetables and fruits much like some people have intolerances to wheat and gluten. If you do have any of the above health conditions, it could be worth it to avoid all nightshades for several months and see if your conditions improve.

Copyright © February 2012 Sam Montana


[1] USDA Oxalic List

[2] An Apparent Relation of Nightshades (Solanaceae) to Arthritis by N.F. Childers, Ph.D., and M.S. Margoles, M.D. Journal of Neurological and Orthopedic Medical Surgery (1993) 12:227-231

[3] American Chemical Society (ACS) – Nicotine Amounts in Nightshade Foods

Photo by Treimann/Flickr



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