Surface of a kidney stone
Iron Oxalate Crystals
Raphides, needle-shaped calcium oxalate crystals, were collected from kiwifruit homogenate through heavy media separation using a dense CsCl solution. (A) The SEM image of purified raphides (x400). (B) Further magnification of the left part of the image (A) (x1,500).
The white bars in photos indicate 100 μm (or 0.1 mm). Raphides purified from kiwifruit had sharp needle-like shapes with smooth surfaces, and did not have grooves and barb-like shapes observed in raphides of Araceae plants.
Thirteen sources were identified, and 8 sources (6 Web sites and 2 applications) were used to construct figures for comparison of commonly listed foods. Oxalate content was extremely variable between various sources. Fruits with the widest observed range of oxalate included oranges (2.07-10.64 mg/100 g) and bananas (0-9.9 mg/100 g). Among vegetables, the oxalate contents of spinach (364.44-1145 mg/100 g), rhubarb (511-983.61 mg/100 g), and beets (36.9-794.12 mg/100 g) were most variable. Among nuts, the oxalate content of peanuts ranged from 64.57 to 348.58 mg/100 g, and pecans ranged from 4.08 to 404.08 mg/100 g.
Since oxalate is only found in plant foods, all the meats and fish are safe.
Mammals make oxalate as a metabolic waste product, but it has no known function. Higher amounts are generated when:
The mediation of calcium oxalate size on cell death mode in Vero cells. Nano-sized COM and COD crystals primarily caused apoptotic cell death owing to their small size effect and uniform and moderate injuries. Micron-sized crystals primary caused necrotic cell death due to their large size and local acute injuries.
Can lead to a wide range of problems throughout the body
Science is studying these questions, because we don’t know enough yet. It is hard to study oxalate handling, distribution, and oxalate crystal deposition in the body.
There is no single pattern of symptoms that identifies oxalate toxicity, everyone has their own unique set of reactions to over-exposure to oxalates. But If you have ever had kidney stones, or if you have three or more of the following problems, you may benefit from lowering your oxalate consumption:
(3)Inaccuracy about the contribution of endogenous production to total oxalate load.
Lodi states that 80-90% of oxalates in the body are endogenously produced. Unfortunately, the best scientific study refutes his assertion. According to Holmes et al3, who did extremely well-controlled studies on every aspect of oxalate metabolism and has publishedforty-one scientific articles on oxalates in the peer reviewed literature, the mean dietary oxalate contribution to total oxalate in the diet is 52.6 % on a high oxalate diet which was defined as a diet of 250 mg oxalate per day. The person drinking a green smoothie with 2 cups of raw spinach ingests 1312 mg of oxalates or over five times the level of what Holmes considers a high-oxalate diet, just in the spinach consumption alone and over 26 times the amount of oxalates in a low oxalate diet (50 mg per day)4. The estimated human production of oxalates is 40 mg per day3. On a green smoothie diet with two cups of spinach, the diet in normal humans contains 33 times the endogenous human production of oxalates just based on the spinach alone.
All of Lodi’s assertions about the benefits of a vegetarian diet are meaningless since there is no single vegetarian diet; there are as many vegetarian diets as there are vegetarians.
(4)Inaccuracy about the availability of calcium and magnesium in spinach. Lodi states that “every plant, green and otherwise (including spinach) has abundant magnesium and calcium and potassium”. Unfortunately, none of the calcium and magnesium in spinach or other high oxalate plants is bioavailable since it is strongly bound to oxalates. Furthermore, the average oxalate value of spinach is 7.5 times its calcium content, making spinach a very poor choice for someone to maintain adequate calcium stores5. According to Kohmani, who added a good deal of spinach, similar to the diet of a person ingesting a daily green smoothie or a large daily spinach salad, to the diet of rats to determine its effects5:
“If to a diet of meat, peas, carrots and sweet potatoes, relatively low in calcium but permitting good though not maximum growth and bone formation, spinach is added to the extent of about 8% to supply 60% of the calcium, a high percentage of deaths occurs among rats fed between the age of 21 and 90 days. Reproduction is impossible. The bones are extremely low in calcium, tooth structure is disorganized and dentine poorly calcified. Spinach not only supplies no available calcium but renders unavailable considerable of that of the other foods. Considerable of the oxalate appears in the urine, much more in the feces.”
(5)Lodi argues that his patients haven’t complained about kidney stones while drinking a lot of green smoothies so oxalates must not be problematic.
Lodi’s contention that his patients on a high oxalate diet don’t have kidney stones is anecdotal. He presents no data from active chart review of his patients to determine if questions about kidney stones were ever asked. Furthermore, it is doubtful that his patients would have even have connected their diet with their kidney stones. I have had numerous seminars on the connection between oxalates and kidney stones and it is common to get feedback from the audience members that they had kidney stones shortly after starting either a diet including a spinach green smoothie or a large spinach salad on a regular basis. Since these comments were not even solicited, it is likely that even a larger number of individuals may have experienced kidney stones but were shy to voice their experiences. A neurologist friend attributes his recent severely-disabling stroke to the dietary changes encouraged by his wife that placed him on a daily green spinach smoothie for a considerable time.
Furthermore, Lodi seems to think that a lack of kidney stones indicates a lack of oxalate problems. However, oxalates may form in virtually every organ of the body including the eyes, vulva, lymph nodes, liver, testes, skin, bones, gums, thyroid gland, heart, arteries, and muscles6-7. Oxalates may occur in these other organs without appearing in the urinary tract at all and in individuals without genetic hyperoxalurias7. Oxalates have been implicated in heart disease7, stroke, vulvodynia, and autism8-10. Women of child-bearing age need to be especially careful of the spinach green smoothie diet because of the autism oxalate connection and the negative effects of spinach containing oxalates on fertility5. Prisoners in the state prisons in Illinois were encouraged by the Weston-Price Nutrition Foundation to file a lawsuit against the state because of their deteriorating health due to a high amount of soy protein in the prison diet11. Soy protein is tied with spinach as the highest oxalate foods4. Oxalates are especially toxic to the endothelial cells of the arteries, leading to atherosclerosis12. Oxalate crystals are concentrated in the atherosclerotic lesions7. Such lesions have commonly been overlooked by the use of stains of atherosclerotic lesions that make the oxalate crystals difficult to visualize. The relatives of people consuming the green smoothie diet would only know of their loved ones’ oxalate deposits throughout their organs on the day of their autopsies which employed pathological examinations that can detect oxalates.
Primary genetic hyperoxaluria is not the major cause of kidney stones in adults since 80% of individuals died of this disorder before age 20 and it is so rare that it could not possibly be the cause of most cases of oxalate kidney stones13. However, a genetic polymorphism present in up to 20% of Caucasian groups called P11L codes for a protein with three times less activity of alanine: glyoxylate aminotransferase (AGT) than the predominant normal activity polymorphism, leading to excessive endogenous production of oxalates14. This substantial group of individuals would be even more susceptible to the harm of a high oxalate diet. Kidney stones were rampant in the United Kingdom during the World Wars when rhubarb, another high oxalate food, was recommended as a substitute for other low oxalate but unavailable vegetables13.
In summary, those who do not care for their health can eat or drink whatever they want. But they should realize that their diets are fad-based and/or based on quasi-religious (“feasts” as part of the “awakening” according to Lodi) reasons, not based on hard scientific evidence. Furthermore, they should be aware that their diet may kill them. The green smoothie fad will go down in medical history with the AMA journal allowing cigarette advertising with physician endorsements and the use of mercury-containing teething powder for babies as one of the greatest health follies in a considerable time.
2’ He began to make violent efforts to vomit, which were frequently repeated, till
12’, when they ceased; and the breathing became full and frequent; sensibility unimpaired; great restlessness,
16’ 30”. Breathing short, and at times suspended for a few seconds; he then hung the head in a peculiar manner, looked very dull, lay down on the side, and would not rise when stirred; at last, when he was set on his legs, he walked easily across the room; suddenly the breathing became very quick and short, and then ceased, although the chest was quite relaxed ; he staggered a few paces, and sank down on the side at
20’, motionless and senseless; the body was now spasmodically extended for a second or two, after which he made a few convulsive gasps; no pulsation could be felt in the region of the heart after the 20th minute.
21’. Death being complete, the body was opened without delay. The heart was distended in its pulmonary cavities, and not contractile; the blood in those cavities was dark, in the aortal florid, in both fluid, and coagulated almost immediately in loose clots.
Abstract In many plants, oxalate crystals are present. These relatively large microcrystals have the potential to inflict mechanical injury. On the other hand, ionic, soluble, and nano-crystal forms of oxalate are readily absorbed. Bioaccumulation in humans is well documented. Crystals and ionic oxalate are associated with pain and both functional and chronic disorders.
Today’s many health challenges have led people to select foods purported to be healthier, many of which are high in oxalate. Modern dietary approaches have placed great emphasis on the health benefits of vegetables, nuts, and spices. Many of these are high oxalate foods that are now distributed through a global food system in which seasons have been erased, making harm from dietary oxalate more likely now than ever before. Lack of awareness of this potential creates fertile ground for continued increases in human suffering and public health problems.
Keywords: Amaranthaceae, bariatric surgery, bioaccumulation, biological availability, biomineralization, calcium, calcium oxalate, chronic disease, citrates, crystals, deficiency, Dieffenbachia, diet, fatal outcome, food poisoning, food science, foodborne diseases, fruits and vegetables, humans, hyperoxaluria, inflammation, inflammasome, intestinal inflammation, low oxalate diet, legume, microbiota, microbiome, nuts, oxalate, oxalic acid, oxalosis, pain, plant foods, Polygonaceae, raphides, toxicity, kidney failure acute, kidney calculi, renal, renal insufficiency, renal stone, thyroid, toxicology
Oxalic acid and its salts occur as end products of metabolism in a number of plant tissues. When these plants are eaten they may have an adverse effect because oxalates bind calcium and other minerals. While oxalic acid is a normal end product of mammalian metabolism, the consumption of additional oxalic acid may cause stone formation in the urinary tract when the acid is excreted in the urine. Soaking and cooking of foodstuffs high in oxalate will reduce the oxalate content by leaching. The mean daily intake of oxalate in English diets has been calculated to be 70-150 mg, with tea appearing to contribute the greatest proportion of oxalate in these diets; rhubarb, spinach and beet are other common high oxalate-content foods. Vegetarians who consume greater amounts of vegetables will have a higher intake of oxalates, which may reduce calcium availability. This may be an increased risk factor for women, who require greater amounts of calcium in the diet. In humans, diets low in calcium and high in oxalates are not recommended but the occasional consumption of high oxalate foods as part of a nutritious diet does not pose any particular problem.
Internet news this past fall indicated the conviction of an oncologist who attempted to kill her boyfriend who was involved with another woman. The weapon of choice was ethylene glycol, popularly known as antifreeze, which had been placed in his coffee. Although emergency measures saved his life, extensive deposits of oxalate crystals, the main toxic metabolite of ethylene glycol, had caused extensive kidney and liver damage, reducing the man’s lifespan by about half.
Similar results in sabotaging your own health can occur through the regular consumption of a popular concoction called a “green smoothie.” A recent Google search for “green smoothie” yielded 609,000 hits. In addition, a recent “improving your diet” seminar that I attended promoted this same idea. Interestingly, on the same day, I reviewed test results of a urine organic acid test of a woman with oxalate values 3 times the upper limit of normal. A conversation with the patient indicated that she had recently turned to consuming daily “green smoothies” to “clean up her diet.” The most common “green” components of the most popular green smoothies are spinach, kale, Swiss chard, and arugula. Each of these greens is loaded with oxalates. A typical Internet recipe advises that 2 cups of packed raw spinach leaves is a good starting point for a smoothie. In addition to the high oxalate greens added to the blender, green smoothie proponents frequently recommend adding a variety of berries or almonds, also containing high oxalate amounts. Similar high urine oxalate results were found in organic acid tests of a number of patients with kidney stones who had decided to eat large spinach salads daily as a “move to clean up my unhealthy diet.” Unfortunately, kidney stones are not the only health problems that people who regularly consume green smoothies and large spinach salads will experience with their new “clean” diet.
Calcium oxalate (CaOx) crystals are distributed among all taxonomic levels of photosynthetic organisms from small algae to angiosperms and giant gymnosperms. Accumulation of crystals by these organisms can be substantial. Major functions of CaOx crystal formation in plants include high-capacity calcium (Ca) regulation and protection against herbivory. Ultrastructural and developmental analyses have demonstrated that this biomineralization process is not a simple random physicalchemical precipitation of endogenously synthesized oxalic acid and environmentally derived Ca. Instead, crystals are formed in specific shapes and sizes. Genetic regulation of CaOx formation is indicated by constancy of crystal morphology within species, cell specialization, and the remarkable coordination of crystal growth and cell expansion. Using a variety of approaches, researchers have begun to unravel the exquisite control mechanisms exerted by cells specialized for CaOx formation that include the machinery for uptake and accumulation of Ca, oxalic acid biosynthetic pathways, and regulation of crystal growth.
Background: Although autistic spectrum disorders (ASD) are a strongly genetic condition certain metabolic disturbances may contribute to clinical features. Metabolism of oxalate in children with ASD has not yet been studied.
Aim: The objective was to determine oxalate levels in plasma and urine in autistic children in relation to other urinary parameters.
Method: In this cross-sectional study, plasma oxalate (using enzymatic method with oxalate oxidase) and spontaneous urinary calcium oxalate (CaOx) crystallization (based on the Bonn-Risk-Index, BRI) were determined in 36 children and adolescents with ASD (26 boys, 10 girls) aged 2e18 years and compared with 60 healthy non-autistic children matched by age, gender and anthropometric traits.
Results: Children with ASD demonstrated 3-fold greater plasma oxalate levels [5.60 (5the95th percentile: 3.47e7.51)] compared with reference [(1.84 (5the95th percentile: 0.50e4.70) mmol/L ( p < 0.05)] and 2.5-fold greater urinary oxalate concentrations ( p < 0.05).
No differences between the two groups were found in urinary pH, citraturia, calciuria or adjusted CaOx crystallization rates based on BRI. Despite significant hyperoxaluria no evidence of kidney stone disease or lithogenic risk was observed in these individuals.
Conclusions: Hyperoxalemia and hyperoxaluria may be involved in the pathogenesis of ASD in children. Whether this is a result of impaired renal excretion or an extensive intestinal absorption, or both, or whether Ox may cross the blood brain barrier and disturb CNS function in the autistic children remains unclear. This appears to be the first report of plasma and urinary oxalate in childhood autism. ª 2011 European Paediatric Neurology Society.
Primary oxalosis or primary hyperoxaluria is an inborn error of glyoxylate metabolism, characterised by high and continuous urinary excretion of calcium oxalate, recurrent calcium oxalate nephrolithiasis and nephrocalcinosis. The disease was only recognised as a separate entity at the end of the fifties , and Franceschetti was the first to describe the retinopathy. Depending on the age of appearance and probably of the severity of the mutation, different forms can be distinguished: infantile, juvenile and in young adults. In the stage of advanced kidney insufficiency, the insoluble calcium oxalate crystals accumulate in various tissues including the eyes, bones, joints, skin and cardiac conduction system. There are two major forms: primary hyperoxaluria type I, which is the most severe, usually starts in childhood and is associated with all its complications including depots in the eyes, and hyperoxaluria type II which is far more benign and provokes recurrent nephrolithiasis but not an accumulation of oxalate crystals in the tissues.
The VP (Vulvar Pain) Foundation was incorporated in North Carolina (USA) as a nonprofit organization in October 1992. It was started to end the isolation of women suffering from a syndrome that includes genital (vulvar) pain, and to help them get out of pain safely through scientific research.
For nearly fifteen years (1992-2006) the VPF worked with a renowned biomedical research scientist, Clive C. Solomons, Ph.D., director of Scientific Connections laboratory in Colorado. While conducting a research study known as The Pain Project, he discovered the connection between periodic hyperoxaluria (more than normal amounts of oxalate in urine), connective tissue instability, and widespread pain, including genital, urological, muscular, and intestinal pain and discomfort.
By working closely with over 3,000 study participants from 1986-2006, Dr. Solomons developed an effective, reliable treatment protocol that includes a low oxalate diet, calcium citrate without vitamin D; NAG (N-Acetyl-Glucosamine) and CMO (cetyl myristoleate). These therapies reduce oxalate in the body, and stabilize a component of connective tissue known as hyaluronic acid, respectively.
From 1992 to 2004, the VPF sponsored 31 Research Seminars throughout the United States, and one in Canada. Dr. Solomons, along with several nationally recognized clinicians and therapists, met with 1,787 women, men (spouses, partners), and health care professionals, resulting in recovery for the majority of sufferers.
Shortly after organizing, the Foundation instituted a membership program for women, their families, friends, and interested health care professionals. Through membership, the VPF has continuously offered a network of support to sufferers. It is led by experienced volunteers who have recovered through the Pain Project research.
In recent years men with parallel symptoms have joined the VPF, along with other patient groups who are experimenting with a low oxalate diet, including oxalate kidney stone formers.
Conclusion: UA and CaOx SF have similar amounts of plaque, whereas UA SF have more endoscopic but not histologic collecting duct plugs. These data suggest an overlap between the pathogenesis of UA and CaOx stones. The anchoring site for UA stones remains uncertain.
Only a few plants contain sufficient amounts of sodium and potassium oxalate to be considered toxic. Moreover, ruminants that consume these plants develop increasing amounts of tolerance to oxalate. An oxalate degrading anaerobe microorganism has been isolated from pure culture of rumen bacteria. This organism, Oxalobacter formigens, uses oxalate as a sole energy source and produces carbon dioxide and formate as end products. This ability is extremely rare among anaerobic bacteria and therefore this organism occupies an unique niche in the rumen’s microflora. The ability of the ruminant to adapt and tolerate high oxalate diets directly depends on the selection of oxalate- degrading microorganisms.
In the context of a global food system and 24-hour retail groceries offering every imaginable food 365 days a year, the dictum to “eat more plants” may be dangerous to human health due to unaware excessive consumption of oxalates. Dramatic increases in calcium-oxalate kidney stones, and functional problems with digestive health, neurotoxicity (sleep, brain function), inflammation (pain, autoimmunity, cellular stress, fatigue), and connective tissue instability (osteoporosis, arthritis, vulnerability to injury) are all consistent with increased oxalate toxicity. Learn how modern food choices and meal patterns create the conditions for accumulation of oxalate in the body, and how oxalates create metabolic havoc. This session explains how modern foods and medicines increase susceptibility to oxalates; makes the case for careful attention to oxalate consumption; dispels the notion that all vegetables and seeds are healthy and safe to eat on a regular basis; and introduces the therapeutic benefits of a low-oxalate diet.