Solanine toxicity or benefits; fibromyalgia and the Nightshade family.

Peruvian Ground Cherries are in the nightshade family & tomatoes, peppers, eggplant and potatoes. Unripe ground cherries are red and inedible due to the solanine content. The yellow ones have less.

The Golden Berries are a colorful name for a plant that seems more like a tomato it turns out. Which helps explain the significant vitamin A content - it is like a tomato.

A helpful reply to my last post from jon archer mentioned the solanine content that may be present in Peruvian Ground Cherries/ Golden Berries, thanks! And I am sensitive to white potatoes. Eating potato products causes the fibromyalgia like pain for me too - so it may be a combination of factors adding to my discomfort.

Excess of solanine and solanidine alkaloids can be deadly but more typically causes digestive pain, nausea and diarrhea. In higher amounts it may affect the Central Nervous System (seen in horses where ground cherry plants are in the field). The plant was native to Peru and Chile and has since been found elsewhere including Africa, Australia, and India. Removing it from grazing pastures sounds like a need if the plant is present where animals might graze.

“Ground Cherry is in the same family as deadly nightshade and belladonna. Although it contains many of the same compounds, they are at somewhat lower concentrations.”

“Physalis peruviana, more commonly known as Ground Cherry or Cape Gooseberry, is a fruit-bearing plant that protects each of its fruits with inflated paper-like calyx.” [The ‘cherry’ forms inside of a little papery-balloon husk.]

“Each part of this plant contains the glycoalkaloid solanine which, when eaten, will irritate the gastrointestinal system and may also attack the central nervous system in sufficient doses. This plant originates in Peru and Chile and is now found in many places around the world including Africa, Australia, and India.”

- Ground Cherry Poisoning in Horses (wagwalking.com)

Solanine has been found to cause increased pain, inflammation and worse joint pain in ~ 50% of patients with fibromyalgia (a study).

“Green peppers, eggplant, tomatoes and white potatoes contain solanine, a substance that interferes with enzymes in muscles and may cause pain…” - from a good overview article which mentions the Epstein-Barr/mononucleosis infection connection but does not include the Retinoid Toxicity gene change that may have occurred due to the viral infection - leaving an ongoing excess of active retinoids which directly cause flu-like inflammation symptoms. It is a good overview of what is going wrong in the body and has a list of mitochondrial support supplements that may indeed be helpful.

• Fibromyalgia - A Difficult Diagnosis, (theholistichealthapproach.com)

I knew eggplant was a problem for me a long time ago and then white potatoes too, but I was only beginning to suspect that even mild Bell peppers are a problem food for me.

Why is my detox ability so bad? Genetic differences do seem to be involved in fibromyalgia risk as it is seen more often in families than unrelated adults. (theholistichealthapproach.com)

If I deep-fried the ground cherries? (Not for me, they would still be a vitamin A source). Dehydration does not decrease the solanine content but high heat cooking might decrease it up to 40%.

“Alkaloids like solanine have been shown to start decomposing and degrading at approximately 170 °C (338 °F), and deep-frying potatoes at 210 °C (410 °F) for 10 minutes causes a loss of ∼40% of the solanine. Freeze-drying and dehydrating potatoes has a very minimal effect on solanine content.” (Wikipedia)

How much might be too much for most anyone? “0.25 and 0.3 mg of solanine per gram* of potato” or “0.43 mg” or “0.5 mg” in potatoes have been recorded for mass sickenings in a few historical events related to potatoes served in school or military type group settings, or for a large family. Fatalities are less common than food poisoning type digestive symptoms. Removing the peel would tend to reduce solanine content as the chemical is produced by the plant to ward-off insects or other pests from eating the fruit. (Wikipedia) *The ___mg/gram may be an error, more typically phytonutrient content is listed as ___ mg/ 100 grams of the food.

Solanine itself is colorless, but I had learned to associate with potatoes that are still green under the peel - throw away those potatoes is what I had learned. The content of solanine is higher in unripe produce so that may be the connection. Greenish potatoes may be less ripe? I don’t know. Yes, green tomato dishes are prepared - green tomatillo salsa or fried green tomatoes, but those would have an increased risk for glycoalkaloid toxicity. (Kurek, 2018)

New potatoes, still on the plant. Photo by Aarón Blanco Tejedor on Unsplash

Sprouted potatoes also have an increase in solanine and likely should be discarded rather than trimmed and used. And do not eat potato flowers - almost doubled in content from the sprout content. The older leaves of an eggplant plant are also VERY high in solanine content. Drought during the growing season increases solanine content and very wet conditions may also - any additional stress or wounding of the plant tissue will generate an increased amount. (Kurek, 2018)

“It is important for human safety to keep steroidal GA levels as low as possible in edible organs of these crops [16]. Some of the toxic effects of [glycoalkaloids] GAs are attributed to direct inhibition of cholinesterase activity and more general cell membrane disruption mediated via interactions between membrane sterols and the steroidal moiety of the steroidal GAs [40–42]. Furthermore, interactions between membrane budding and increased permeability may result in a loss of ion conductivity of the cells [43,44]. Excessive consumption induces gastroenteritis, gastrointestinal discomfort, diarrhea, vomiting, fever, low blood pressure, fast pulse rate along with neurological and occasional death in human and farm animals [45].”

“The toxicity of solanine depends on the species and route of administration. Parenteral administration is much more toxic than oral administration.”

[*Parenteral administration: Intravenous injection of a supplemental food mixture containing glycoalkaloids versus a tube feeding or normal food consumption by mouth would be a much greater risk of adverse effects.]

“Gastrointestinal effects may occur at relatively low levels of exposure such as lower than 2 mg total GA/kg body weight." (Kurek, 2018)

Other symptoms observed in mice given α-solanine included “the animals were quiet and appeared to be sleepy and apathetic, exhibiting more rapid breathing, hind leg paralysis, and dyspnea [48].” (Kurek, 2018) *Dyspnea = shortness of breath.

Other symptoms seen in human poisoning from eating Jamaican susumber berries (Solanum torvum- Solanaceae) that were found to have alkaloids not present in non-toxic berries included:

“varying degrees of gastrointestinal distress, dizziness, slurred speech, cranial nerve deficits, and ataxia. The most seriously afflicted patient developed hypertension, confusion, proximal upper extremity weakness, and hypercapnic respiratory failure requiring prolonged mechanical ventilation.” (Smith, et al., 2008)

Another group who consumed unripe susumber berries developed symptoms 14 hours after ingesting “with varying degrees of diarrhea, weakness, facial paralysis, slurred speech, ataxia, early hypertension, and proximal weakness. Two patients had ventilatory decompensation; one required intubation. Poisonous berries appeared indistinguishable from non-toxic varieties. We isolated solasonine, larger amounts of solamargine, and other steroidal glycoalkaloids in the toxic berry strains.” (Smith, et al., 2008)

The glycoalkaloids cause membrane breakdown of red blood cells. The chemical half-life of alpha-solanine is ~ 21 hours (Kurek, 2018) - and I am feeling much more myself today than yesterday when I was just really exhausted and with body aches everywhere. Another glycoalkaloid may be present and the combination can worsen symptoms as the alpha-chaconine has a half-life of 44 hours. (Kurek, 2018)

“The biological half-life of α-solanine is about 21 hrs; it disrupts the membrane of red blood cells and other cellular membranes and exhibits poor absorption in the gastrointestinal tract, its highest distribution is in spleen, but levels in blood become greatest after about 5 h [46,47].” (Kurek, 2018)

The LD50 (lethal dose for half a population) for mice has been reported to be 27.5 mg/kg body weight and for rabbits, 50 mg/kg. “[49]” (Kurek, 2018)

For people who are not at increased sensitivity - glycoalkaloids have healing properties and foods in the nightshade family are popular and in common use around the world. Solanine and other glycoalkaloids also have shown anti-cancer properties including inhibition of metastasis, invasion, migration and angiogenesis. Inhibition of vascular endothelial growth factor (VEGF) and matrix metalloproteinases (MMPs) has been observed, “[76]”, and activation of the p38 MAPK pathway was seen in a study on prostate cancer cells. “[78]” (Kurek, 2018)

“Since these compounds also possess biological properties such as anti-inflammatory, antimicrobial, and anticarcinogenic activities, it could be a useful strategy to use novel extraction techniques to maintaining bioactivities after extraction and simultaneously to reduce toxicity in the source plants.”

“Shiu et al. demonstrated solamargine had a greater cytotoxic effect than cisplatin, methotrexate, 5-fluorouracil, epirubicin, and cyclophosphamide against human breast cancer cell lines. … [92]” (Kurek, 2018)

Glycoalkaloids have also shown to have anti-fungal, anti-parasitic and antibiotic effects. Solamargine has shown effectiveness against Trypanosoma cruzi. “[128, 129]” (Kurek, 2018)

“In addition to the activities reported above, some GAs have been reported to possess antibiotic, antiallergenic, antipyretic, anti-inflammatory, and anti-hyperglycemic activities at certain doses and conditions. Choi and Koo studied the analgesic and anti-inflammatory effect of a potato extract. They reported that an ethanolic extract of potato resulted in a significant effect in three types of pain induction suggesting that its analgesic effect may in part be related to its anti-inflammatory neurogenic and narcotic properties [130]. The antinociceptive effect of the potato extract may be related to the reduction in Ca2+influx at the axon terminal of the afferent nerve inducing a decrease in adenylyl cyclase activity, which results in decreased levels of cyclic AMP and efflux of K+ ions.” (Kurek, 2018)

As with many things in the plant kingdom - dose makes the medicine or the poison.

If any readers are working in food industry, the chapter includes exhaustive detail on food preparation or storage issues that can increase, or help reduce, the glycoalkaloid content in foods that are naturally rich sources. The sections on cancer studies using GAs is also very extensive in addition to a lengthy section on anti-fungal and anti-parasitic applications. The ‘other benefits’ section is shorter but also a detailed review of research on the topic. (Kurek, 2018) An excellent work, I give it 5 stars.

Disclaimer: This information is being provided for educational purposes within the guidelines of Fair Use and is not intended to provide individual health guidance.

Reference List

(Kurek, 2018) Abu Bakar Siddique M and Brunton N (2019) Food Glycoalkaloids: Distribution, Structure, Cytotoxicity, Extraction, and Biological Activity. Alkaloids - Their Importance in Nature and Human Life. IntechOpen. DOI: 10.5772/intechopen.82780. https://www.intechopen.com/chapters/65187 *Open Access Chapter if you register for the download. (pdf in my Dropbox)

(Smith, et al., 2008) Smith SW, Giesbrecht E, Thompson M, Nelson LS, Hoffman RS. Solanaceous steroidal glycoalkaloids and poisoning by Solanum torvum, the normally edible susumber berry. Toxicon. 2008 Nov;52(6):667-76. doi: 10.1016/j.toxicon.2008.07.016. Epub 2008 Aug 7. PMID: 18725244. https://pubmed.ncbi.nlm.nih.gov/18725244/