Tomatoes are high in potassium and limited as potassium restriction becomes an issue. I have heard that peeling tomatoes, soaking in ice water for an extended time, diminishes their potassium content. Tomatoes contain tiny seeds. These seeds can cause difficulties with diverticula, a common side symptom from those with PKD. Solanine is a glycoalkaloid poison found in species of the nightshade family (Solanaceae). 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.
There is something I have noticed in a very few sensitive individuals; eating tomatoes can intensify any existing craziness. There is a simple solution. Withdraw tomatoes and see if the mood diminishes. In others tomatoes can aggravate health issues by causing numbness, paralysis, arthritic flare ups and more. Best to avoid tomatoes altogether. If not possible then avoid any greenish tomatoes and eat them only very ripe and in the peak season. Garden grown are especially nice.
Another nightshade, Potato
The steroid alkaloids in potato - primarily solanine and chaonine - have been studied for their health effects in two areas. First is their ability to block activity of an enzyme in nerve cells called cholintesterase. Many of the alkaloids found in nightshades possess this kind of activity, called cholinesterase inhibition. If the activity of cholinesterase is too strongly blocked, the nervous system control of muscle movement becomes disrupted, and muscle twitching, trembling, paralyzed breathing, or convulsions can result. The steroid alkaloids found in potato have clearly been shown to block cholinesterase activity, but this block does not usually appear strong enough to produce nerve-muscle disruptions like twitching or trembling.
Effect of steroid alkaloids on joint health: A second type of problem potentially related to the potato alkaloids involves damage to the joints caused by inflammation and altered mineral status. Whether alkaloids can contribute to joint damage of this kind is not clear from current levels of research. Some researchers have speculated that nightshade alkaloids can contribute to excessive loss of calcium from bone and excessive depositing of calcium in soft tissue. For this reason, these researchers have recommended elimination of nightshade foods from the meal plans of all individuals with osteoarthritis, rheumatoid arthritis, or other joint problems like gout.
Effect of nicotine alkaloid on health: Just as there is no firm research evidence for the impact of the steroid alkaloids in nightshade foods on the nervous system or joints, there is also no solid research evidence for impact of the more drug-like alkaloids in nightshade foods on body systems. But to the surprise of many people, nightshade foods do contain very small amounts of drug-like alkaloids that have long been fascinating to medical and drug researchers. Consider, for example, the most famous of the one-ring type alkaloids (monocyclic alkaloids) found in the highest concentrations in tobacco (Nicotiana tabacum): nicotine. This alkaloid is found not only in non-food nightshades like tobacco, but also in the food nightshades including eggplant and tomato.
But there is one important difference here: while alkaloids like nicotine are definitely found in nightshade foods, the amount involved is dramatically less. Even in the case of eggplant, which is the food nightshade that appears to have the highest nicotine content after tobacco, the amount of nicotine is far lower than the amount found in tobacco. In the case of green tomatoes, which also contain nicotine, the amount is even less. The levels of nicotine in all nightshade foods are so low that most health care practitioners have simply ignored the presence of nicotine in these foods as a potential compromising factor in our health. At the World's Healthiest Foods, we both agree and disagree with this conclusion. While we agree that the amount of nicotine in nightshade foods is very, very small, it still seems possible to us that some individuals might be particularly sensitive to the alkaloids found in nightshades, and that even very small amounts might compromise function in the bodies of these individuals.
Increased alkaloid content of green and sprouting potatoes: It's important to point out that green spots on potatoes, or sprouting on potatoes, usually correspond to an increased alkaloid content, and this increased alkaloid content is one of the main reasons for avoiding consumption of green or sprouted potatoes. (The green color itself is chlorophyll, and helpful to our health, but unfortunately, it's also accompanied by the increased alkaloids that we can't see). Interestingly, in one study conducted with hamsters who were fed the sprouted portions of potatoes, increased alkaloid content did not seem to impact the nerves or joints nearly as much as the digestive system itself. The researchers focused on damage to the stomach and intestines when trying to understand the problems caused by ingestion of potato sprout material, and concluded that there were reasons to avoid this material based on digestive system evidence alone. A bitter taste in potatoes after the potatoes have been cooked is usually a good indication that excessive amounts of alkaloids are present.
The effect of cooking on the alkaloid content in nightshade foods: Steaming, boiling, and baking all help reduce the alkaloid content of nightshades. Alkaloids are only reduced, however, by about 40-50% from cooking. For non-sensitive individuals, the cooking of nightshade foods will often be sufficient to make the alkaloid risk from nightshade intake insignificant. However, for sensitive individuals, the remaining alkaloid concentration may be enough to cause problems. |
