So Are Certain Vegetables Actually Bad For You? - 24Seven Wellness & Living

If you are concerned about inflammation you may have read at one time or another that certain vegetables in the nightshade family can cause inflammation. Obviously, if you are trying to reduce inflammation in your body then eliminating these vegetables would make sense wouldn’t it? But should you be saying goodby to all tomato products  forever? Are nightshades actually bad for you? Should you eliminate them all?

Well, here’s the lowdown on nightshades.

Firstly, what are nightshades?

Nightshades are members of the Solanaceae family which includes both edible and non-edible plants. Edible nightshades include:

  • Potatoes (not sweet potatoes or yams)
  • Tomatoes
  • Eggplant
  • All peppers (not peppercorn), including hot peppers, chili peppers, sweet peppers and paprika
  • Ashwaganda
  • Gogi berries
  • Cape gooseberries (not normal gooseberries)
  • Ground cherries

I can literally hear many of you groan when reading the above list. After all anyone eating a varied healthy diet is going to be including at least two thirds of that list every week. In fact it would seem that nightshades are fundamental to our modern day diet. It’s not just the actual tomatoes we are eating but consider pizza, marinara sauce (in fact most pizza sauces) ketchup, barbecue sauce ……. The list could go on and on! Potatoes are also another household staple in the form of baked potatoes, French fries, chips, mashed and roasted potatoes. I think we all eat peppers at least once a week these days in salads or roasted.

So we know we like them, we know we consume them often and we probably thought they were good whole foods we should be including in our diet.  So what are the potentially problematic aspects of nightshades?


Nightshades contain substances called alkaloids, which can cause inflammation and stress. One type of alkaloid in nightshades, Solanine, has been studied for its ability to block cholintesterase, an important enzyme in nerve cells. The ability of this alkaloid to inhibit cholintesterase often results in joint stiffness and joint pain.


Another harmful substance in nightshades is calcitriol, a hormone that signals the body to update calcium from the diet. Although adequate dietary calcium supports hormones, excess calcitriol causes too much calcium in the blood. This results in calcium deposits in soft tissues, such as tendons and ligaments.


Nightshades are high in lectins, a substance produced in all plants as a natural pesticide. Lectins are “sticky” molecules that tend to attach to the walls of the intestine. The action of lectins on the small intestine lining can cause or exacerbate leaky gut. Leaky gut occurs when things like undigested carbohydrates or lectins create little gaps between the cells of the small intestine, allowing undigested food particles to escape into the blood stream.

So should you be eating nightshades at all?

Unfortunately, as with most things in life there is not one definitive answer, it really depends on the individual. However, there are a few medical issues that eating nightshades could exacerbate:

  • Autoimmune diseases
  • Arthritis
  • Gout
  • Osteoporosis
  • Ongoing inflammation

Also some of us are more sensitive to the lectin and alkaloid content of nightshades.

Often the only way to find out if you do have a sensitivity to nightshades is to eliminate them for approximately 30 days and introduce them back one by one and monitor your response. Or maybe contact your health care provider or nutritionist and arrange a food sensitivity test.

If you are not suffering with one of the above listed medical issues and feel that you do not have a severe sensitivity to nightshades then there are some tips to help you keep it that way.

How to eat nightshades

  • Choose ripe nightshades, since solanine levels are highest in unripe ones. For example, choose red tomatoes over green tomatoes and red peppers over green peppers.
  • Cook nightshades, cooking them reduces the alkaloid content up to 50%. Lectins are also degraded, to varying levels, with cooking.
  • Use moderation and variety. Ensure you are not eating them every day and reduce the how many you eat. Remember it is just not the whole food variety but the sauces and condiments you may be using.