Health, Nutrition

The Science Behind Nightshade Vegetables

There is a lot of conflicting information out there when it comes to Nightshade Vegetables. Many claim that they cause inflammation while others claim that they are beneficial against inflammation. But who is right? Well, let’s check the science and see for ourselves. 

What are Nightshade Vegetables?

Nightshade Vegetables are a group of vegetables also known as Solanaceae. This group is highly diverse and includes white potatoes, bell peppers, tomatoes, eggplant, okra, and even spices like paprika and cayenne pepper.

But it goes far beyond vegetables as well and includes common plants such as the black nightshade. But we are not going to talk about those, and simply refer to members of the Solanaceae family that are currently in our food supply.

These vegetables are commonly used in a wide variety of recipes and many diets advise against eating them. These include the Paleo diet and the Macrobiotic diet. The reasons why includes a lot of claims that this group of vegetables causes harm. But do they? 

Do Nightshade Vegetables cause inflammation?

One of the biggest claims when it comes to these vegetables is that they cause inflammation in your body. Particularly in those with autoimmune diseases and inflammatory bowel disease, among other medical ailments. It is believed that for many, eating tomatoes and eggplant will make their arthritis flare up.

However, there really isn’t any evidence for this at all. I have looked through many scientific studies and could not find any evidence that nightshade vegetables cause any form of inflammation. There is conflicting evidence when it comes to certain vegetables, like tomatoes. Some studies claim it causes inflammation, while others claim that it fights inflammation.

However, one thing is sure. All vegetables contain antioxidants, which have anti-inflammatory properties. So if you are consuming a food or beverage that makes you feel bad for any reason, it is recommended that you stop consuming that product, vegetables included. 



Do Nightshade Vegetables contain a toxic compound?

There are many things that are believed to be in nightshade vegetables that can cause harm. Three of these are the alkaloids solanine, capsaicin, and nicotine. The first two are found fairly higher quantities in nightshade vegetables.

Solanine, for example, can be a toxin if ingested high enough doses. For instance, potatoes that are exposed to sunlight as they are growing can contain very high amounts, as can potato sprouts. You can tell if a potato is high in this if they are green on the inside. However, solanine overdose is highly unlikely, even if you eat a potato that is a little green. Although when it doubt, toss it out. 

Capsaicin is often found in hotter peppers, like cayenne peppers and paprika. While these peppers have anti-inflammatory properties, it is best to eat them in moderation, as they can flare up GERD pretty brutally, and can even give you ulcers if eaten often enough. But unless you are eating a ton of it, you are not going to see any significantly bad effects.

Nicotine is something that you may find odd to find in an article about vegetables, but this is because tobacco, which is also a nightshade, has this chemical in high amounts. All nightshades have this chemical in them, but it would be wrong of me to claim that this makes tomatoes and eggplant unhealthy. Let me explain. 

1 typical cigarette has 18mg of nicotine in it.  In comparison, tomatoes, which has the highest amount of nicotine in it, only has 1µg nicotine in 233 grams of tomatoes, or 0.001mg per cup of tomatoes. It’s in so small a quantity that it has no discernible effect on the human body. The other nights have an even lower amount, and the amount absorbed into the body is far lower.

That said, there is evidence that suggest that consuming these plants can lower your risk of having Parkinson’s disease. 

Do Nightshade Vegetables harm the liver?

I have seen it often claimed that nightshade vegetables harm the liver. However, there does not seem to be any evidence to show that this is the case, as the American Liver Foundation mentions a lot of food to eat and avoid when it comes to the health of your liver. They seem to have missed mentioning nightshades. 

The only studies that I could find that mentions certain nightshades and their effects on the liver actually shows them to be beneficial to it. One study on rats mentioned how tomatoes can benefit those with hyperlipidemia and can benefit the liver. Another study showed that tomato juice can be beneficial for those suffering from non-alcoholic Fatty Liver Disease. 

So there does not seem to be any evidence to show that your liver will be harmed by consuming nightshade vegetables. But always check with your doctor before gorging on tomatoes. 

Stuffed Eggplant

Stuffed Eggplant

So, is there any reason to avoid Nightshade Vegetables?

In terms of worrying about side effects of eating these foods? Not really. There is no evidence to date that suggests that these foods are bad for you or that you should avoid them for any reasons. Nightshade vegetables are chock full of vitamins and minerals and many even have anti-inflammatory properties. 

However, each person is different, and foods can affect people in different ways. For instance, if eating these foods causes you inflammation, then it is best to avoid eating them. If you are going to take these foods off the menu, make sure that you replace them with foods that provide a similar nutrition profile, that way you do not have to worry about losing out on some vital nutrients as a result of avoiding some foods.

Another issue is with foods like tomatoes, which can affect people suffering from acid reflux. So use some common sense to find out which foods are best for you. Always check with a doctor and a registered dietitian when it comes to consuming certain foods in regards to medical conditions. 


What is your experience with Nightshade Vegetables? We would love to gather your feedback and thoughts on these delicious, yet perhaps inflammatory foods!