Should You Eliminate Nightshades from Your Diet?

The Internet and popular health books would have you believe peppers, tomatoes, eggplant, and other nightshades cause inflammation, autoimmune diseases, and gastrointestinal diseases.  As I am often asked about nightshades, this article explores the research behind the misinformation and myths about nightshades.  And when it comes to health books, it is important to remember the following quote from Mark Twain:

Be careful about reading health books.  You may die of a misprint.

What are nightshades?

Nightshades are the edible parts of the flowering plants in the Solanaceae family (pronounced sō-lə-ˈnā-sē-ē).  In fact, there are thousands of plants in the Solanaceae family.  While many are inedible, humans have eaten the edible nightshades like peppers, tomatoes, eggplant and potatoes for thousands of years without any problems.

Why are nightshades called nightshades?

It is unclear why nightshades are called nightshades.  While there are many theories, my best guess is that it is because many of these plants prefer to grow in shady areas or they flower at night.

What Are You Giving Up by Avoiding Nightshades?

If you are going to follow the popular Internet and "health" book advice and avoid nightshades, you need to know what you are giving up.  If you do choose to give up these foods, you will have to work hard to make sure you pick up these key nutrients and disease fighting abilities from other foods.

1. Tomatoes

Tomatoes are one of the best sources of the powerful anti-oxidant, lycopene.  Tomatoes are also high in vitamins A, C, and fiber.

Tomatoes have been shown in medical studies to help prevent heart disease and cancer.  These two conditions alone account for approximately 80% of all deaths in the US.

2. Peppers

Peppers are another nutritional powerhouse food.  If you give up peppers you will need to make up for the lost vitamins A, C and B6 as well as folate and fiber from other food sources.

In addition to giving up these key nutrients, studies show you will also lose the weight loss benefits, metabolism boost, pain reduction, and heart disease protective effects of peppers.

3. Eggplant

While eggplant may not be as flashy as tomatoes and peppers when it comes to nutritional qualities, they can still hold their own.  Eggplant is a high fiber food which is also high in anthocyanin.

Anthocyanin is that same purple color that is in blueberries.  Many studies show that anthocyanin improves brain function and protects you from many brain diseases including dementia.

4. Potatoes

Potatoes have a bad reputation.  This is probably because more than 90% of potatoes are eaten as french fries or potato chips in the US.  However, if you bake a real potato, and eat it with the skin, you will get a heathy dose of vitamins B6 and C, potassium, and fiber.

For those with diabetes or blood sugar issues, potatoes can be eaten as a resistant starch.  Merely the process of baking a potato, putting it in the fridge overnight, and then reheating it the next day changes it into a resistant starch with no significant blood sugar spike for most people.  To learn more about resistant starches, please read blog number 164, How to Eat Pasta Without Gaining Weight.

Do Nightshades Cause Autoimmune Diseases

One widely propagated belief on the Internet and in "health" books is that nightshades causes autoimmune diseases.  This belief arises from the alkaloids which are in nightshades.

Anecdotally, many people claim that eliminating nightshades helped their autoimmune diseases.  And for those people who report an improvement in their autoimmune disease by cutting out nightshades, they should continue to avoid these foods  However, despite these anecdotal reports,