What Are Nightshade Vegetables and Why Are They Bad?

Nightshade vegetables are a group of vegetables that belong to the family “Solanaceae.” Tomatoes, potatoes, eggplant and peppers are nightshade vegetables. Nightshades reportedly worsen arthritis and other health conditions, although there is no solid scientific evidence to validate the claim.

We live in the era of fad diets. Today, you hear something is good for you and tomorrow you hear the opposite. Sometimes, a piece of half-baked information spreads to the extent that most people start believing it. There have been several concerns related to the “nightshade vegetables” as well. Even the name sounds ominous, isn’t it? However, the truth often differs from reality.

Nightshade vegetables are a group of vegetables that belong to the family “Solanaceae.” The term “nightshade” is typically associated with poisonous plants. The nightshade family, however, also contains several important food crops, such as tomatoes, potatoes (not sweet potatoes), peppers (hot and bell peppers) and eggplant. The reason for naming these plants “nightshades” is not definitively known. One theory suggests that they were called that because most of them grow in shade and bloom at night.

The plant generally called nightshade in North America and the United Kingdom is a woody nightshade or bittersweet (scientific name: Solanum dulcamara). The leaves and egg-shaped red berries of this plant are poisonous. They contain a substance called solanine that can cause seizures and death when consumed in large doses. Another plant, the black nightshade (scientific name: Solanum nigrum) is also generally considered poisonous. However, fully ripened fruit, leaves and stems of the black nightshade are cooked and eaten in some areas.

Because of the presence of certain compounds, such as alkaloids (certain nitrogen-containing compounds of plant origin, such as solanine) and lectins (carbohydrate-binding proteins), most plants of the nightshade family have earned disrepute. Various diets urge people to avoid eating them. It is claimed that these compounds can aggravate inflammation in the body, thereby worsening chronic health conditions, particularly arthritis. There is no scientific evidence to support these claims and they continue to be merely anecdotal. Researchers suggest that if you feel that these vegetables worsen your symptoms you may remove them from your diet for a few days. Then, reintroduce them slowly to check whether they were responsible for your symptoms. Exclude them from your diet if you are absolutely sure that they worsen your symptoms. If you are not sure, follow your doctor’s advice.

Nightshade vegetables are loaded with nutrients. There seems to be no logical reason to eliminate them from your diet. One of the healthiest diet plans, the Mediterranean diet, advises you to eat lots of vegetables, including nightshade vegetables. The benefits of some of the nightshade vegetables are

• Tomatoes: These are rich in anti-inflammatory and anti-aging compounds, including lycopene and vitamin C.
• Bell peppers: A single bell pepper contains even more vitamin C than what you need every day (the recommended daily amount). They are also rich in other nutrients, including minerals and fiber.
• Potatoes: These are rich in antioxidants (such as flavonoids, carotenoids and phenolic acids), potassium and fiber. They help keep you fuller for longer and maintain overall health.
• Eggplant: This dark-colored vegetable is packed with nutrients, including vitamin K, potassium and magnesium. It helps keep your heart, bones, muscles and nerves healthy.

Thus, there seems to be no proven association between nightshade vegetables and health conditions, such as arthritis, migraines, osteoporosis and autoimmune diseases. If you are sure that these vegetables make your symptoms worse, discuss the situation with your doctor because you could be sensitive to them. For most people, including nightshade vegetables in the diet can help them stay fit and healthy.