Flavor of the month diets seems to come and go, with social media trending specific foods to eat, or avoid altogether. Lately claims have been doing the rounds that vegetables in the nightshade family, such as tomatoes, eggplant, peppers, and potatoes, are bad for you and should be avoided. From gluten free, to diary free, to all-meat, to no meat, it is not easy to decide which foods to put on your personal watch list. Should nightshades be added to your watch list?
What are nightshades?
Both edible and non-edible nightshade plants are part of the Solanaceae botanical family with more than 2 000 different species. The main edible members of the nightshade family are:
- Tomatoes.
- Potatoes (but not sweet potatoes).
- Eggplant.
- Peppers.
Although tomatoes, eggplant, and peppers are technically classified as fruit, they are regarded as vegetables in terms of nutritional sources.
There are a large variety of nightshade plants that are inedible and some of them are potentially toxic such as tobacco plants, or even deadly, such as Atropa belladonna and mandrake plants. The nightshade family of plants also includes flowers, such as morning glories.
Edible nightshade plants contain heathy substances such as antioxidants that protect cells in the body from damage due to stress. Nightshades are also rich in vitamins and minerals that contribute to good health. No wonder nightshades form part of the Mediterranean diet, which has repeatedly received accolades as the best diet overall.
Are nightshades bad for you?
One of the main characteristics of nightshade plants is that they make potentially toxic chemicals called glycoalkaloids, which protect these plants by repelling insects and herbivores. Glycoalkaloids are mostly concentrated in the green parts of the plant, such as the stem and leaves.
The nightshades found in grocery stores only have negligibly small trace amounts of glycoalkaloids, with the exception of green or sprouting potatoes, which have higher concentrations of glycoalkaloids, and it is best to throw them out. The same applies to green tomatoes.
In spite of claims that nightshades contribute to certain health conditions such as arthritis or other inflammatory diseases, there is no hard evidence that potatoes, tomatoes, peppers, or eggplant may cause these diseases.
In some instances, however, nightshade vegetables may have harmful effects on humans. Just like some people are intolerant to gluten, dairy products, or other foods, some people may have an intolerance to nightshades. An inclination to struggle with food sensitivities or allergies, or having any type of inflammatory or autoimmune disease, may result in nightshades worsening the condition, for some people. Alternatively, if you develop inexplicable gastrointestinal symptoms after eating nightshades, it may indicate a sensitivity (food intolerance) to them.
Nightshades probably won’t cause inflammation directly, but for some people they may increase inflammation that is already there, if you have a sensitivity to nightshades.
How to determine an intolerance to nightshades:
Should you suspect that you may be sensitive to nightshades, delete them from your diet for at least two weeks. Then slowly introduce them into your diet, one by one with at least three days between introducing the different nightshades, to see if any one or more of them contribute to your symptoms. Should one or more of them increase your symptoms, it is best to avoid them, like you do with other foods you are intolerant to.
Conclusion:
While social media and the internet may abound with claims that nightshades trigger an inflammatory response, it is not supported by medical research and as a matter of fact, nightshades form part of one of the world’s healthiest diets, the Mediterranean diet. However, people can be sensitive to certain foods. Some people may be sensitive to one or more, or all of the nightshade vegetables, in which case it is best to eliminate them from your diet, allow your body time to recover, and get key nutrients from other sources.
References:
The problem with tomatoes (there’s good and bad.) Published 22 January 2024. The Nutrient Watchdog. (www.thenutrientwatchdog.com)
Nightshade vegetables: How to find out if they’re bad for you. Published 9 January 2023. Blog by Dr. Josh Axe. (www.draxe.com)
Ask a doctor: Are nightshade foods bad for you? Published 19 June 2023. Washington Post. (www.washingtonpost.com)
What to know about nightshade vegetables. Published 2 May 2023. WebMD. (www.webmd.com)
What’s the deal with nightshade vegetables? Published 19 September 2019. Cleveland Clinic. USA. (A nonprofit multi-specialty medical centre that integrates clinical and hospital care with research and education.) (www.clevelandclinic.org)
The idea that nightshade vegetables are “bad” for us is a complete falsehood, says a functional medicine doctor and a RD. Published 20 March 2023. Well & Good. (www.wellandgood.com)
HEALTH INSIGHT