Nightshades and Arthritis

I've been enjoying a bowl full of my friend's garden fresh tomatoes over the past few days, which lead me to thinking about nightshades. Many sources will tell you not to eat nightshades as part of an anti-inflammatory diet, but what are nightshades and should I avoid them?

Tomatoes, white potatoes, eggplant, and peppers (including cayenne and paprika, but not black pepper) are all part of the Solanaceae family, commonly referred to as nightshades. With the exception of those I just mentioned, most nightshades are poisonous, like belladonna, or the deadly nightshade made famous in MacBeth. Most people have no problem digesting edible nightshades. I rather enjoy cayenne, paprika, and tomatoes, but a case has been made that nightshades can cause problems for people with autoimmune diseases, like rheumatoid arthritis.

The evidence for health risks associated with rheumatoid arthritis in humans is largely based on personal reports. Although, loads of evidence exists that edible nightshades cause joint and bone problems in cows and horses because of the way that their bodies process the potent form of vitamin D3 specific to nightshades. In cows and horses, nightshades prevent the metabolization of calcium, leaving calcium deposits in the soft tissue, instead of in the bones that need it. This leads to painful arthritis and inflammation in cows and horses.

Humans aren't cows and horses. Our bodies don't process vitamin D3 the same way, but the alkaloids and lectins in nightshades do cause some people to complain of discomfort.

The term 'alkaloid' refers to any nitrogenous organic compound that has a pronounced physiological reaction in humans, including everything from morphine to strychnine. A lectin is a protein that binds certain sugars. Lectins are also thought to play a role in immune function and body fat regulation.

"Because we don’t digest lectins, we often produce antibodies to them. Almost everyone has antibodies to some dietary lectins in their body. This means our responses vary. Certain foods can even become intolerable to someone after an immune system change or the gut is injured from another source. The presence of particular lectins can stimulate an immune system response. There are some lectins that no one should consume. 

Ever wonder why you don’t see sprouted red kidney beans?" - Source.

Alkaloids developed in plants as a defence mechanism against bugs. Humans use them as medicines, addictive drugs, and as insect repellants.

'While the plant is alive, these compounds work as its home-grown “bug spray,” defending it from pests and molds that would otherwise kill it. In other words, they’re designed to be toxic. In the poisonous members of the nightshade family, these chemicals are so concentrated that they have deadly effects on humans, but in the edible nightshades, they’re present in much smaller amounts, and mostly in the leaves and stems (which we don’t eat anyway).' - Source.

Being so much larger than a caterpillar, and because we don't eat kidney bean sprouts or tomato leaves, most people experience no reaction to alkaloids. I imagine it is like eating a non-organic carrot, or anything at most restaurants. The trace amounts in the foods we eat are fairly insignificant to healthy people. But what about me? What about people with autoimmune disorders, like rheumatoid arthritis?

"Healthy guts can deal with these chemicals just fine, but people whose digestive system is already compromised by an autoimmune disease have trouble with them. For example, some kinds of alkaloids increase the power of the immune response – exactly what you don’t want when you’re dealing with an autoimmune disorder." - Source.

This can be especially problematic for people dealing with autoimmune disorders that directly effect their digestive system because the cells lining the intestinal tract are often the first victims of alkaloids. Lectins cause the same reaction for some people, but again... the evidence is based solely on personal reports. And this evidence is not as strong as what we've learned from animals, but it's harder to keep us in such a controlled setting as... say... lab mice.

The Arthritis Foundation maintains:

"They also contain solanine, a chemical that has been branded the culprit in arthritis pain. There’s no scientific evidence to suggest that nightshades trigger arthritis flares. In fact, some experts believe these vegetables contain a potent nutrient mix that helps inhibit arthritis pain." - Source.

Certain nightshades have great health benefits. Cayenne pepper, for example (also one of my favourites), is also high in capsaicin, which works as an anti inflammatory in healthy bodies. Tomatoes are considered highly antioxidant, and are believed to help fight cancer (which runs in my family).

Nightshades are like gluten, only people who have a genuine sensitivity to them need to avoid them. For people, like me, with rheumatoid arthritis, it may be worthwhile to eliminate nightshades from your diet for 30 days to see if you notice any improvement. I'd say it can't hurt, but I really love cayenne and still have a bowl of tomatoes in my kitchen.

Rather than wasting my food for something that has yet to be proven, the alkaloid content in the nightshades I east can be reduced by preparing them properly. Peel your potatoes and don't eat them when they are sprouting, or unripe. Cook everything thoroughly. Cooking your food is a good idea most of the time anyway, as cooked foods are generally easier to digest than raw foods.

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