Rachel asks: I hear that it’s not great to eat vegetables in the nightshade family? Why is this? Should I be avoiding eating nightshades on a raw food diet?
Great question! Let’s start from the beginning….
What are nightshades?
Nightshades are a term commonly used for the group of plants in the Solanaceae family.
What vegetables are in the nightshades family?
You will find quite a wide range of edibles in this family, as well as several poisonous inedibles. Tasty and familiar edibles such as tomatoes, potatoes, eggplants, red, green and chili peppers as well as paprika and tomatillos and the tobacco plant are all nightshades. Even the popular and celebrated superfood, goji berries are in this family.
Understanding how plants protect themselves
To understand where this fear of nightshades comes from, you need to understand how plants protect themselves. Nature is very intelligent, and so are plants. All plants come with a built-in defense mechanism to defend themselves against predators, because unlike animals, plants can’t run away. No kidding! I think it’s only fair, porcupines get big spikes, cheetahs can run fast, bears are big and scary, and plants needed a defense mechanism too – they got phytochemicals. Phytochemicals are naturally occurring, chemical compounds found in plants and there is a huge range of them, with alkaloids being only one category of phytochemicals. Plants want to keep their plant species alive, just like animals do. So when they are in danger of being completely irradiated (the whole plant species being wiped out due to an animals over-consumption), they create these plant chemicals or alkaloids, in small amounts to protect themselves. The plant starts to taste more bitter, and the ‘predator’ (whether animal, human or insect) stops eating it. Plants are so intelligent that when one plant starts to get eaten, it increases the production of alkaloids and that chemical actually signals the other plants nearby to start making this same chemical as well, to protect itself from the danger of being completely eaten – pretty amazing, wouldn’t you say?
There is also a very wide range of alkaloids. Some alkaloids are more toxic than others, including nicotine and caffeine, and some are not toxic at all, think flavonoids.
Why would nightshades be bad for you?
The primary kind of alkaloid found in nightshades is called solanine. This is the main alkaloid that this particular plant family uses to defend itself from being eaten before they are ripe (which essentially means before their seeds are ready to spread and make new plants). Some research suggests that solanine may interfere with the production of enzymes in muscle tissues, increasing pain, inflammation and stiffness associated with rheumatoid arthritis.
Why might they be good for you?
In small doses, alkaloids are actually thought to be protective, and we get very small doses when we eat nightshades. You would have to eat quite a large amount to experience toxic effects from solanine. That’s one of the reasons why variety in your plant-based diet is helpful; so that we will have exposure to a wide variety of protective alkaloids without overdoing it on a concentration of just a few. (Check out my article about keeping your greens on rotation).
Other research shows that edible nightshades do have benefits to eating them. They are usually high in potassium, which is known to help balance sodium intake. And tomatoes, in particular, contain the alkaloid lycopene, which has been shown to help prevent osteoporosis and cancer.
It’s a matter of Dosage
In my opinion, it’s really a matter of dosage. In very large doses, this could have detrimental effects and could be toxic to the body to a certain degree. In small doses however, the alkaloid I personally don’t think they can hurt you and some say that they actually have beneficial effects to the immune system. The theory is that the plants defense mechanism can enhance our defense mechanism (being our immune system). I think it’s pretty standard, even in western medicine to acknowledge that small doses can be beneficial, but larger doses of medication can be quite harmful and even toxic to the body. If you have a predisposition to reacting against nightshades this is a different story. If you have arthritis and your joints swell up when you eat nightshades, your body is clearly communicating to you. Try reducing consumption and see what happens. After about 30 days of no nightshades, try a small amount of just one and see how it affects you.
And a Matter of Ripeness
As I alluded to earlier, one of the key factors to keep in mind here is ripeness. The solanine levels are highest in unripe vegetables and drop as the vegetable ripens. So eating an organic heirloom tomato fresh out of your backyard is very different from eating a GMO, pesticide-laden tomato that was picked green pre-maturely and gassed with a ripening chemical, all so it can have a long shelf life. Which one would you choose? The same goes for bell peppers. Not that many people know that green peppers are like green tomatoes; they are not ripe yet. If you wait long enough, for them to actually ripen on the plant, you will see them start to change color. If anything, I do recommend avoiding green peppers, and I highly recommend eat nightshades from local organic farmers, picked fresh that day, or ideally from your own backyard garden.
Your Body Is Your Best Guide
I find this question about nightshades very interesting because everyone is different, and everyone, even the scientists are still trying to figure it all out…not just about nightshades, but about how all foods actually affect us. And I think as a culture, we’ve all become extremely reliant on seeking the answers outsides of ourselves. I can give you all this information about nightshades, but at the end of the day, your body is going to know better than I do about how it reacts to this plant family. You’d be amazed at what your body is communicating to you, if you listen and pay attention to it.
My mom, every single time she eats peppers, of any color can’t stop burping, a key sign of indigestion. It’s uncomfortable for her and it upsets her stomach so she doesn’t eat them, but she absolutely loves tomatoes, and likens eggplant to candy.
I have no problems with colored bell peppers but I do notice green peppers very hard on my system, so I avoid them, but love the rest of the nightshade group as well. Some people are more prone to allergic reactions with tomatoes, but do fine with the rest of the nightshades.
Let’s not forget to keep in mind that there are a wide range of people who show sensitivities and allergies to all sorts of different kinds of foods. Of course there will be people out there with a sensitivity to solanine in the nightshade family, doesn’t this make sense? However, if I had to bet, I would guess that there’s a lot more people out there with a food intolerance to peanuts than to nightshades…but that’s just a guess!
I also question how much our food beliefs play a role in how we experience food. I’ve talked with people who diligently avoid all nightshades (with a slight degree of panic and fear) only to see them eating a bag of goji berries and not have any degree of alarm about the huge handfuls their eating, because they’re not aware that goji berries are also a nightshade. I love the way Michael Pollan puts it:
“Indeed, no people on earth worry more about the health consequences of their food choices than we Americans-and no people suffer from as many diet-related problems. We are becoming a nation of orthorexics: people with an unhealthy obsession with healthy eating.”
The unpleasant physical symptoms to this particular sensitivity may come in the form of arthritic and joint pain, headaches or sore muscles. Experiment with this, do you get these symptoms after you eat these foods? If you do, time after time, then consider avoiding them, or at least seeking out the best source of them (GM tomatoes are way more common than most of us would like to believe) and see if this makes any difference.
And like everything else, consume nightshades in moderation, as local and organic and as fresh as possible!
Aloha from the Big Island of Hawaii