In nutrition, it is not uncommon to hear everything and its opposite. So how do you find your way around when one day you hear that you have to eliminate a certain food from your diet, and then the next day it’s the one that you absolutely have to have on your plate? You may have heard that nightshades, also known as “solanaceae”, are dangerous to your health because they contain toxic compounds and it would be better to avoid them. Therefore, should nightshades be eliminated from your diet? And if so, why?
The solanaceae family includes nearly 100 genera and more than 2,700 species of plants. There are fruits and vegetables industrial plants (tobacco) and many ornamental plants.
Among the fruits and vegetables, many are commonly consumed such as: tomatoes, eggplants, potatoes, peppers, chilis, and goji berries. Many herbs and spices are also derived from these vegetables, including cayenne pepper, chili powder and paprika.
Solanaceae contain certain compounds which are considered toxic, such as lectins and alkaloids, if they are ingested in large quantities. These compounds are present in the plant because they play a protective role against pathogenic bacteria, viruses, and fungi as well as certain predatory insects.
To learn more about lectins, I invite you to read our article on the subject.
The types of alkaloids differ depending on the type of fruit and vegetable and some are more toxic than others. For example, those present in potatoes are more toxic to the human than those in tomatoes.
Consumed in large quantities, alkaloids can cause symptoms such as sweating, nausea, diarrhea, abdominal cramps, headaches, bronchospasms, drowsiness, agitation, tremors, confusion, or vision disturbances.
Several factors can significantly increase the alkaloid content of fruit and vegetables such as: genetics, storage conditions, exposure to light, or bruising during harvesting. It should be noted that these substances are mainly found in the flowers, leaves, sprouts, and skin of fruits and vegetables.
When a food contains high levels of alkaloids, it can have a pronounced bitter taste in the mouth and cause burning sensations.
However, rest assured, solanaceae are regularly consumed by millions of people around the world and poisonings are rare, which suggests that the low concentrations contained in food do not raise concerns.
Studies in mice suggest that alkaloids in potatoes have a cytotoxic effect on the cell membrane that can affect intestinal permeability and increase intestinal inflammation in individuals predisposed to inflammatory bowel disease (IBD).
Some blame them for being pro-inflammatory and for being able to worsen the symptoms of people with autoimmune diseases (such as celiac disease, multiple sclerosis and rheumatoid arthritis). This is why some people choose to exclude them from their diet.
However, current scientific knowledge does not allow recommendations to be made in this regard.
Indeed, before nutritional recommendations can be made, more research is needed to know if these conclusions can be transposed to humans and if this can be extended to all solanaceae.
Fruits and vegetables are excellent sources of vitamins, minerals, antioxidants and fibers, which have many health benefits. It is not for nothing that we recommend filling half of our plate with vegetables and fruits of various colors at each meal and snack.
Here are some good reasons to consume nightshades:
Note that cooking does not decrease the alkaloid content of food.
In conclusion, excluding nightshades from your diet is not an optimal solution because these foods also contain many nutrients that are essential for health.
If you experience symptoms, digestive or otherwise, that you think might be related to the foods that you consume, or if you suffer from an autoimmune disease, one of your best options is to talk to a dietitian. They will help review your diet with you and can offer modifications aimed at alleviating your symptoms by maximizing food diversity.
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