Nightshades: What They are and What you Need to Know

Have you noticed the term nightshades popping up more and more online and in social media?

Maybe you've heard of them, but don’t know what they are?

Hint: it’s not the shade in your room over your window that you pull down to make it darker.

Rather this is a group of vegetables that meet specific criteria and fall under the nightshade family of food.

They include things such as eggplant, coloured peppers, tomatoes, potatoes and chili peppers.

Here are my favourite:

The commonality amongst these foods is that they all produce natural pesticides known as glycoalkaloids.

The pesticides are there to defend the plant itself from pests, and are present in the leaves, flowers and unripe fruiting bodies.

It is these naturally occurring compounds however which can also present a problem to the health of certain individuals.

What’s Good About Glycoalkaloids?

Most people are fine with the nightshade family, and in fact, consuming these glycoalkaloid rich foods has many benefits:

  • Glycoalkaloids are anti-inflammatory
  • They kill bacteria and viruses, and hence help boost immunity.
  • Glycoalkaloids have been shown to have anti-cancer properties, causing cancer cells to self-destruct.

What’s Wrong With Glycoalkaloids?

For certain people, the nightshade family may pose a problem or result in unwanted health symptoms:

  • Their killing nature, applied to bacteria, viruses and cells means sometimes they can kill important cells within our body or damage the cell membrane. This has been noted in both red blood cells and mitochondrial cells.
  • Many people experience negative mental health symptoms from glycoalkaloid consumption.
  • They contain solanine, which many people claim increases inflammation, but this has not been proven scientifically. 

Who is Affected by Glycoalkaloid?

It is important to remember that much of the information currently available on nightshades, solanine and glycoalkaloids is not substantiated by scientific research in humans. Many of the studies are rat and mice studies, and require further work to give a definitive suggestion to eliminate these foods from the diet. Having said that, in some cases, individuals with inflammatory bowel disease, arthritis and autoimmune conditions find that they do better without nightshades in their diet.

Being aware of this family of food and its potential to impact the body is important if you are experiencing health symptoms and looking to learn more about improving your own health and wellness. Remember that for most people however, these foods are totally fine to consume, and given that they are vegetables and fruit, restricting them means you will be missing out on the incredible nutrient profile they can offer: eggplant is high in antioxidants, peppers offer Vitamin C and Vitamin A, tomatoes are high in lycopene, and potatoes are a great source of phosphorous and manganese. Before jumping to conclusion that nightshades are the culprit, be sure to speak to a nutritionist or do some additional research in regards to your symptoms and potential causes.

By: Laura Peill, RHN, BScH

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