http://www.westonaprice.org/food-features/1897-nightshades.html
The nightshades are members of an enormous family of plants called Solanaceae, represent a huge family of plants. The ones that concern us in the Western diet mainly include tomatoes, potatoes (not sweet potatoes or yams), eggplant and peppers—this means all peppers including chili peppers, habenero, cayenne pepper and paprika (not peppercorns, see sidebar). Paprika is a sneaky one, showing up in lots of flavoring mixes and often under “spices” on ingredient labels. Other nightshades include goji berries (the new darling of the antioxidant crowd), ashwagandha (an adaptogenic herb from Ayurvedic medicine), Cape gooseberries (not normal gooseberries), ground cherries and garden huckleberries (not blueberries). [...]
The nightshades are considered a “calcinogenic” plant; that is, they cause calcinosis, which is a toxic calcification of soft tissues when eaten by animals. This happens because they contain calcitriol (1,25-dihydroxy vitamin D), the most active form of vitamin D. Please note that calcitriol is not vitamin D3 (cholecalciferol). This is an extremely important distinction, as you will see.
In humans, calcitriol is normally the end product of vitamin D metabolism, so let me start at the beginning. Cholecalciferol, or vitamin D3, is produced in the skin by the action of sunlight or can be consumed in food or supplements. In the liver, vitamin D3 is transformed into calcidiol (25-hydroxycholecalciferol, the compound that we test in the blood as a measure of vitamin D status); then the kidneys transform calcidiol into calcitriol (1,25-dihydroxy vitamin D).
Calcitriol is an extremely potent hormone, thousands of times more potent than vitamin D3. [...]
Overconsumption of calcitriol from nightshade foods can circumvent the kidney’s control and over time lead to calcium deposits in the soft tissues such as the tendons, ligaments, cartilage, cardiovascular tissues, kidneys and skin. Osteoarthritis is basically calcium deposits in the soft tissues of joints. Chronic hypercalcemia can lead to generalized vascular (blood vessel) calcification, which is coronary artery disease. Nephrocalcinosis is calcification of the kidneys.
We are not supposed to bypass the body’s control mechanisms for calcitriol. Nightshades do this to our detriment. Many of us do not notice because it happens so slowly and gradually. [...]
SOLANINE
Solanine is a glycoalkaloid, that is, a non-protein compound containing nitrogen. It is a potent poison found in species of the nightshade family, especially potatoes and eggplant. [...]
Solanine poisoning is primarily displayed by gastrointestinal and neurological disorders. Symptoms include nausea, diarrhea, vomiting, stomach cramps, burning of the throat, cardiac dysrhythmia, headache and dizziness. Hallucinations, loss of sensation, paralysis, fever, jaundice, dilated pupils and hypothermia have been reported in more severe cases.5
Potatoes naturally produce solanine and chaconine, a related glycoalkaloid, as a defense mechanism against insects, disease and predators (humans included). Potato leaves, stems and shoots are naturally high in these glycoalkaloids. When potato tubers are exposed to light, they turn green and increase glycoalkaloid production. This is a natural defense to help prevent the uncovered tuber from being eaten.
In potato tubers, 30–80 percent of the solanine develops in and close to the skin. If the potato looks green under the skin, throw it away; likewise if it has begun to sprout, just discard it.
How toxic are these compounds? The World Health Organization sets an upper limit of 20 mg per 100 grams of solanine per fresh weight of potato. Above that limit, they cannot be sold in stores, as they are considered too toxic for human consumption.6
Solanine and related glycoalkaloids are poisonous because they are acetylcholinesterase inhibitors—they inhibit the breakdown of acetylcholine, resulting in increased level and duration of action of this neurotransmitter. What does this mean? They cause prolonged muscle contractions. This is why people who are sensitive to nightshades or eat a lot of them often feel stiff when they wake up in the morning or sit for extended periods.
Studies with animals indicate that solanine causes cell membrane disruption in the digestive tract—exacerbated irritable bowel disorder in mice,7 gastrointestinal tissue destroyed in Syrian hamsters.8 It affects the gene expression of the human intestinal cell linings and also inhibits proteolytic enzyme activity.9 Solanines also destroy human liver cells in vitro.10
I have found fourteen research reviews linking potato blight in Ireland with birth defects in the following years.11 Potato blight involves a particular fungus growing on potatoes, causing them to kick in their defense mechanisms and make high levels of solanine. In my opinion, it would be wise for pregnant women to avoid the nightshades.
WHAT ABOUT PEPPER?
Peppercorns are not the same as peppers; they are not members of the nightshade family. Peppercorns do not contain poisonous alkaloids. Fresh ground pepper is the best; pre-ground pepper is not good for you. It doesn’t taste very good and you’ll notice you have to use a lot more of it. Once the peppercorns are cracked open, the protective and flavorful essential oils begin to evaporate. This allows a type of aspergillus mold to grow, which then produces aflatoxin. You may be familiar with aflatoxin already, as it is very toxic to the liver and is the same toxin that occurs with peanuts. If you don’t eat peanuts for this reason, you would not want to use pre-ground pepper either. Freshly ground pepper helps with digestion—pre-ground pepper does not.
TOMATOES
Tomatoes contain lycopene, which is one of the first things people mention when I suggest avoiding nightshades. Lycopene is a carotenoid found in almost any red, orange or pink fruit or vegetable; it’s simply highest in tomatoes. As with all of the fat-soluble carotenoids, to maximize absorption you’ll need to eat it with fat. We hear a lot about lycopene supposedly preventing cancer. However, in a study on prostate cancer in rats, when rats were given lycopene by itself, there was no observed decrease in cancer mortality when compared to the controls.20 However, when given tomato powder, there was a significant decrease in mortality rates from the induced prostate cancer. So there’s something in the whole tomato that protects against cancer and it’s not lycopene by itself.
The new theory in this reductionist way of thinking is that the anti-cancer substance in tomatoes is another glycoalkaloid called tomatine. While tomatine has been shown to inhibit and destroy cancer cells, it has also been shown to do the same to normal cells!21 This is the likely reason why many people get heartburn after eating tomatoes, not only because they are acidic (they are), but because the cells that line the stomach and esophagus are being destroyed. Can you really blame the stomach for sending you a signal that it isn’t very happy?
By the way, epithelial cells are what line the urethra as it passes through the prostate. Eating tomatoes in the hopes of reducing prostate cancer is similar to friendly fire—it destroys the cancerous cells and normal cells at the same time. Does destroying your normal and healthy cells sound like a good idea? Not to me. Actually, it sounds very similar to chemotherapy and radiation—trying to kill cancer cells while hoping that the normal cells survive the process. While there is a time and place for that type of approach, I don’t think I’d want to be eating such a potentially cell-destructive substance every day in my food.
Scientists are currently studying tomatine to use as an adjuvant in vaccines, in order to make the vaccine more effective by stimulating a massive immune reaction. The immune reaction happens because the body is reacting to the cell destruction that occurs when tomatine comes in contact with human cells.
Tomatoes also contain tomato lectin (another well-known lectin is gluten) which has been shown to agglutinate human, mouse and sheep erythrocytes—it can cause red blood cells to clump together. Combined together with tomatine, these compounds can cause leaky gut syndrome and potentially be a major issue in autoimmune diseases of all sorts.
For those of you have gone off gluten and you’re wondering why you still have digestive problems, it may be because of tomatoes. Potatoes can be another culprit, as many gluten-free products are filled with potato starch.
