Perhaps you have heard that certain vegetables in the nightshade family cause inflammation. But it is worthwhile to say goodbye to tomato products forever? Are nightshades bad for you? Here’s the lowdown on nightshades.
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)
- All peppers (not peppercorn), including hot peppers, chili peppers, sweet peppers and paprika
- Gogi berries
- Cape gooseberries (not normal gooseberries)
- Ground cherries
Nightshades seem fundamental to our modern diet. I never really considered how tomatoes permeated my meals until a few years ago when naturopath told me to reduce nightshade consumption (and I currently avoid all nightshades to help heal my gut). Ketchup, pizza, marinara sauce, barbecue sauce… the list goes on! Potatoes are also a staple: french fries, baked potatoes, mashed potatoes and roasted potatoes. Peppers are another popular ingredient, since paprika and chili powder are in many spice blends and mexican dishes.
(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 described as “sticky” molecules because they tend to attach to the walls of the intestine. This is exactly the reason that the Autoimmune Paleo Protocol calls for eliminating high-lectin foods like nightshades, since 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.
Should I eat nightshades?
There is not a one-size-fits all answer to this question, but there are a few issues that are widely exacerbated by nightshades. Additionally, some people are more sensitive to the lectin and alkaloid content of nightshades.
If you have one of the following issues, I would recommend eliminating nightshades (or at least strictly limiting them):
- Autoimmune diseases
- Ongoing inflammation
One easy method to determine if nightshades are bad for you is a simple Food Sensitivities Test. This allows your body to communicate to you if nightshades cause a stress reaction.
How to eat nightshades
If nightshades are not a sensitivity for you and they do not cause unpleasant symptoms for you, here are some tips to enjoy nightshades in your diet:
- Choose ripe nightshades, since solanine levels are highest in unripe ones. For example, choose juicy red tomatoes over green tomatoes and red peppers over green peppers.
- Cook nightshades if practical, since cooking reduces alkaloid content up to 50%. Lectins are also degraded, to varying levels, with cooking.
- Use moderation and variety. I don’t think that anything should be eaten everyday, because that can cause the body to develop a sensitivity. So it isn’t a great choice to use tomato sauce and ketchup as a daily condiment. Enjoy variety in your meals and that will help you eat nightshades in moderation.