As you (our gracious company of Apples) know, we unequivocally love our vegetables. Powerhouses of nutrients and antioxidant action, they’re the backbone of a good Primal Blueprint diet . But the issue of nightshades has come up a few times recently. Nightshades, those vegetables that find their roots in the Solanaceae family of plants, include a host of reputable veggies and spices: eggplant, potatoes (yes, we know, not so reputable), peppers, tomatoes, tomatillos, pimentos, paprika, cayenne pepper, Tabasco sauce, et al. (Black pepper isn’t included in this list.)
Nightshade, you might exclaim? Isn’t nightshade those plants (many with alluring little berries) our camp counselors told us never, ever, to so much as put our grubby hands on? Quite possibly. The kinds of nightshade plants growing wild in the woods can be highly toxic. Some can cause death if ingested. Some actually have psychotropic properties. Inherent in this power is pharmaceutical potential. Very minute amounts of some nightshade components are prescribed to successfully treat a few kinds of allergic reactions or chemical poisoning as well as nausea related to certain conditions.
These potent little components are alkaloids, chemical substances that have one or more circular structures containing nitrogen. Essentially, they act as natural pesticides. (Evolution wasn’t just our gig after all. A plant’s gotta protect itself!) Four kinds of alkaloids in the Solanaceae family include the steroid alkaloids (the alkaloid found in most nightshade foods), tropane, pyrrolizidine and indole alkaloids. Steroid alkaloids have been shown to block certain nerve activity that can, at high levels, cause muscle shaking, paralysis and respiratory difficulty. They have also been associated with inflammation , particularly in the joints. Finally, some nightshade foods like eggplant and tomato contain trace amounts of nicotine.
But what does this mean for the tomato salad I always serve at our 4th of July barbeque? Should I give up eggplant parmigiana? No peppers or Tabasco? I thought hot food was good for me!
Before you raid your kitchen and gardens, let’s stop and take a closer look here. First off, nightshade foods contain a very small fraction of the alkaloid levels found in other “toxic” nightshade plants. If nightshades presented a major health threat to humans, we would’ve stopped eating them a long time ago or died off from the inability to learn from our neighbor’s experience. Even when nightshade foods are common ingredients in certain ethnic diets (peppers in parts of Latin America or tomatoes in Italy, to give some basic examples), the population as a whole in those parts doesn’t seem to suffer ill effects.
So, what gives? Are they bad, or are they O.K.? Our simple answer: eat them (and enjoy them) in moderation if you don’t feel any ill effects. While research hasn’t yet turned up any definitive evidence that the alkaloid-containing foods in question harm the human system, it’s generally accepted that some people are much more sensitive to them than others. Nightshades, in those with this sensitivity, have been associated with symptoms like stomach discomfort, digestive difficulties, joint pain, and muscle tremors. These reports have been enough to influence medical care professionals and some organizations to advise those with certain conditions like GERD, gout, or arthritis to avoid nightshades. If you don’t have these conditions but are concerned, it’s a good idea to take a full 2-4 weeks off from nightshade foods and see if you feel any differently. Some of us have mild enough reactions that we may not feel the difference until we set our own “control” scenario for comparison.
Finally, if sensitivity doesn’t seem to be a problem but you’d like to take some reasonable precautions, know that cooking nightshade foods (steaming, boiling, baking) can reduce the alkaloid levels to nearly half. And yet another reason to avoid potatoes: sprouted potatoes (and their associated green parts) have higher levels of alkaloids than other foods.
And, finally, we’d like to put in a plug for a widely varied diet. As much as we love our tomatoes, eggplants, and peppers, we wouldn’t recommend making them the sole or primary vegetables in your diet. Variety offers the best in nutrient-rich and low-risk nourishment.
What are your thoughts on nightshades? Do you choose to embrace or avoid them? What influences your decision?
willsfca  Flickr Photo (CC)
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