Sally Norton always had an interest in doing right by her health. Even as a kindergartner, after being taught how much milk she was supposed to drink each day, she remembers running home and schooling her mother on the subject.
"I was the one kid who would geek out with my mom and eat pickled herring and yogurt," she says. "I was a great food adventurer. I ate anything and everything, and in rather large doses. I was the kid who ate three servings of goulash and then skipped ice cream to go play."
Although she was raised in a family that liked cooking from scratch and had the ethic of eating lots of fresh vegetables and salads, the modern world of food encroached when her mother began working several evenings a week as an optician. Sally's job was to heat up the new-fangled TV dinners when her mother wasn't there. But with her growing focus on healthy eating, she was concerned that TV dinners didn't have enough vegetables.
By age nine, she had learned how to grow vegetables and was enjoying the delights of having lots of fresh beet greens and Swiss chard available from the family's garden. By the time she was 12, however, she started to experience back and joint pain. She also started having some cognitive struggles with homework and concentration. But never in a million years did she think her problems could be related to food.
"I thought, if you just ate right, you could fix anything," she says. "In the seventh grade, I saw a filmstrip where the science teacher showed us pictures of hot dogs and junk food as cancer promoting and broccoli and other vegetables as anti-cancer, and that captivated me." Eventually she enrolled in Cornell University in Ithaca, New York, and majored in nutrition, disease prevention and wellness education.
And after reading Diet for a Small Planet, a 1971 bestselling book by Frances Moore Lappé about the individual and global benefits of going vegetarian, Sally adopted a vegetarian lifestyle, buying things like soy flour and putting it in muffins and breads. She even stopped drinking milk.
Because she lived off campus her freshman year, she cooked all her own meals, scanning grocery store ads to find out what produce she could afford.
But her health was not fabulous. Trying to get in better shape, she started exercising on the cement floor in her basement and ended up with acute foot pain. The doctor ignored her complaints, saying she was too young to have anything wrong. He refused to do an X-ray and handed her a prescription painkiller instead.
By the end of Sally's first semester, she was limping, and by the end of her second semester she could hardly walk. Finally, an orthopedist did an X-ray and discovered that her sesamoid bone—one of two, pea-shaped bones located in the ball of the foot, beneath the big toe joint—was broken.
A surgeon with the Cincinnati Ballet Company carried out surgery on her foot, but Sally did not receive appropriate physical therapy afterward and ended up even more crippled. Furthermore, she had pain in both feet, not just the one with the broken bone. Ultimately, she was forced to take several years' sabbatical from college, using crutches and a wheelchair to get around.
Hoping to help matters, she upped her health food regime and went vegan. When she got married at 23, she did so in sneakers with orthopedic inserts. Upon her return to Cornell, she was a "broke, married college student, basically living on the Swiss chard I planted in my yard."
A steady decline
As time passed, her body-wide stiffness, painful joints and arthritis-like symptoms increased. Then she developed a large blood blister on her vulva. Eventually the blister went away, but her aches and stiffness increased, and she developed bleeding uterine fibroids.
By 2009, Sally had undergone a complete hysterectomy to remove the fibroids, discovering in the process that she had endometriosis enveloping her ovaries, fallopian tubes and the tissue lining the pelvis.
"I had such an extreme case of vulvar pain that I had an outburst in the house, basically screaming, 'Somebody cut these off! I can't live like this anymore!'"
With that, Sally's husband jumped on the internet and discovered The Vulvar Pain Foundation, which advocated an unheard-of nutritional approach focused on eating a low-oxalate diet to relieve vulva pain and other pelvic disorders.
Oxalates are a toxic acid found in many plant foods. Despite a lack of proof and her own skepticism, Sally was so desperate that she tried the diet, dropping high-oxalate foods like her beloved Swiss chard from her meals and reintroducing meat.
The vulva pain quickly went away. But she didn't think its disappearance was necessarily related to her change in diet. Although she continued to avoid the massive amounts of Swiss chard she had been ingesting for years, she unknowingly continued to eat a lot of other high-oxalate foods like sweet potatoes.
After graduating and getting a master's degree, Sally had landed a job writing research grant proposals for a government health education project, but her chronic back pain had grown so severe she was only able to work part-time. "It was so bad I couldn't sit in a chair all day, so I would spend an hour or so on my knees and then sit in a chair for half an hour and then back and forth."
Connecting the dots
Eventually the pain became so acute, she had to quit her job. She also suffered from irritable bowel syndrome and increasing levels of fatigue and cognitive impairment. "I didn't have the mental energy to even read my own mail."
In the meantime, she had seen by her count at least 17 different chiropractors, plus acupuncturists, herbalists, homeopaths and a huge network of alternative healers. Nothing worked.
She was then diagnosed with a sleep disorder, and her personal research on that pointed toward brain toxicity as the culprit. So she tried the Kiwi Diet to flush her system of toxins, which entailed adding in more high-oxalate foods like kiwi fruit and celery.
"And by October 2013, I was so stiff and arthritic I found myself lying in bed having another conversation with God, asking, 'Why am I turning to stone? Why am I in pain again? Why do I feel like I'm 95 years old?'"
It was the same pain she had experienced back when she was a college student and a vegan with constantly swollen, painful joints and feet.
"Then it dawned on me: now that I was eating high levels of oxalate again every day, I was getting stiffer—and I suddenly realized all this started back when I was 12 years old eating all that Swiss chard!"
She cut out the kiwi and celery, and within 10 days she was reading the mail, alert and mentally more functional. She started a low-oxalate diet for the second time just before Thanksgiving 2013.
Pain and stiffness bothered her less and less. The belching and bloating she had been experiencing went away. One by one all the other problems got much better, including her feet.
By July 2014 she was wearing high heels—the highest she'd ever worn in her life—for over seven hours at a nephew's wedding. She could hardly believe it, but it seemed her 30-year health ordeal was finally over.
Poisonous plant protection
Oxalic acid is an organic compound with the formula C2H2O4. Its name comes from the wood sorrel pant (Oxalis) from which the compound was first scientifically isolated, and it's a colorless crystalline solid that dissolves in water.
Free-form oxalate ions, soluble oxalate salts, insoluble oxalates and mineralized calcium oxalate crystals are found in varying concentrations in many plants, including healthy foods such as leafy greens, vegetables, fruits, cocoa, nuts and seeds.
When we ingest foods with oxalates, tiny oxalate crystals attach to healthy cells as well as to damaged cells or cellular debris in our body.
When the cells can't contain, dissolve or discard the attached crystal, it attracts other available oxalate particles, and the crystal structure grows. This type of pathological crystal formation in the body is especially common in the kidneys but also occurs elsewhere in the body.
Oxalate is also produced by the human body as a metabolic byproduct of breaking down ascorbic acid (better known as vitamin C). The breakdown of 60 mg of ascorbic acid can potentially result in the formation of up to 30 mg of oxalate per day. About 10 to 25 mg of oxalate is naturally created in the human body by the liver every day.1
A hidden hazard lurking in our superfoods
A toxic organic compound, oxalic acid is commonly used in cleaning products such as toilet bowl cleaners, metal cleaners, rust removers and laundry detergent. According to the US National Library of Medicine's Toxicology Data Network, oxalic acid is a poison. Ingesting as little as 5 grams of this strong acid on its own can be fatal.1
And while it's unlikely that anyone will ingest the pure acid in any amount, it's all too easy for the oxalates in healthy leafy greens such as spinach and Swiss chard to add up to an unhealthy dose when large amounts are used in smoothies, green drinks and salads—which many people ingest on a regular basis, even several times a day.
Heavy consumption of oxalate-rich juice is a potential cause of oxalate nephropathy (kidney disease) and acute renal failure (a condition that occurs when the kidneys suddenly are unable to filter waste products from the blood).2
Oxalate can also alter the function of the heart and nervous system by reducing the level of calcium ions in body fluids.3
"Oxalic acid itself is a very small molecule, but when you put a lot of it together you can amass crystals, particularly calcium oxalate crystals," says Dr George Diggs, an evolutionary biologist and professor of biology at Austin College in Texas.
"Some oxalate crystals called raphides literally look like a sewing needle. Some plants accumulate a large amount of these crystals that provide very effective protection. And if you eat plants like this, you can really be messed up."
The agave is one such plant, and over 80 percent of workers in tequila factories who regularly handle agave develop a characteristic skin irritation from coming into contact with the crystals.4
The build-up of calcium oxalate crystals is responsible for approximately 80 percent of the half-million cases of kidney stones in the US every year, and there's some evidence to suggest that the amount of oxalate in the diet can increase the risk of this painful condition.
In one analysis, people who consumed the most dietary oxalate (with an average intake of 328 mg/day for men, 287 mg/day for older women and 293 mg/day for younger women) were up to 20 percent more likely to develop kidney stones than people with the lowest oxalate intake.5
CASE STUDY: Cindy H., Philadelphia, PA, age 52
For 13 years, Cindy experienced chronic pelvic pain, including vulvar pain and burning. She had been diagnosed with vulvodynia—chronic pain of the vulva with (officially) "no known cause."
Initially, she was prescribed a number of drugs including an antidepressant that she says numbed her and masked the pain. She also underwent injections of a homeopathic remedy into the vulva and pelvic floor muscles to relieve the pain, which helped temporarily. Physical therapy also helped but did not get to the root cause.
Cindy learned about Sally Norton through the Trying Low Oxalates Facebook group. "I would be utterly disabled, depressed, probably suicidal or dead by now, seriously, if I did not know about the role oxalate plays in my health," she says.
"I had done the low-oxalate diet for 13 years and it really helped, but I took it to another level once working with Sally this year."
Today she is about 85 percent improved in her pain levels. As a natural health practitioner with her own practice, Cindy says, "From my experience both as a sufferer and as a practitioner who sees a lot of suffering, I have no doubt oxalate is the root cause of a very, very high percentage of health problems."
CASE STUDY: Nevada G., Boston, MA, age 42
Nevada suffered from asthma, allergies and eczema from birth. In her early teens, she was diagnosed with polycystic ovary syndrome (PCOS), a hormonal disorder triggering prolonged menstrual periods or excess male hormone (androgen) levels.
She experienced back pain, irritable bladder, joint pain, swelling and stiffness, headaches, mental fog and unexplained skin rashes. She was also diagnosed with cauda equina syndrome, a condition where the bundle of nerves below the end of the spinal cord known as the cauda equina is damaged, triggering low back pain that radiates down the leg.
Nevada underwent surgery for the back condition and went on a Paleo diet, but was still ingesting a lot of high-oxalate foods. Fortunately, she ran across one of Sally Norton's podcasts about oxalates and immediately began gradually detoxing and eliminating all the culprit fruits and vegetables from her diet.
It's important, she says, to realize that detoxification of oxalate can take years. "While a gradual elimination diet works wonders in weeding out the foods that are inflaming you and providing relief in symptoms, it is vitally important to understand that you must reduce oxalates gradually to avoid or minimize the effects of 'oxalate dumping.'"
Today, she has made a complete recovery from cauda equina syndrome, put her PCOS and prediabetes into remission, eliminated all her allergy and asthma symptoms, lost over 90 pounds and proudly proclaims, "I am in the best health of my life!"
It might sound like a lot, but 300 mg of oxalates a day is actually quite a modest amount considering that a half-cup of cooked spinach contains 750 mg of oxalate, and the average green smoothie might easily contain well over 1,000 mg (1 gram) once high-oxalate foods like nut milks, nut butters, turmeric, blackberries and raspberries are thrown in.
"Researchers assume people are eating about 150 mg of oxalates a day. But there could be eight times what's considered normal just in one smoothie alone," says Sally. "And if you have a whole bag of spinach and cook it down to make a spinach omelet later in the day, that's another gram of oxalate right there."
Considering the increased focus on dark leafy greens, berries and nuts as healthy eating "superfoods," it isn't surprising that the prevalence of kidney stones is increasing globally. Incidence has doubled in the US since 1972.6
In addition to kidney stones, calcium oxalate is thought to be a contributor to gout, a form of inflammatory arthritis most often affecting the big toe.7
Beyond the kidneys, oxalates are also known to accumulate in the bones,8 the breast tissue, where oxalate deposits have been associated with benign lesions 9 and the synovial fluid in the joints, where deposits of calcium oxalate crystal can cause a form of arthritis called oxalate arthropathy.10
Sally, now a full-time vitality coach and health consultant informing the public about the dangers of oxalates, says, "Eighty-five percent of people over age 50 have detectable oxalate crystals in their thyroid gland. It used to be 58 percent of people over age 60. So, it seems to be getting worse."
Calcium oxalate has been associated with sarcoidosis, an inflammatory disease that affects multiple organs in the body, especially the lungs and lymph glands, with symptoms including swollen, painful joints, inflammation of the pericardium (the lining around the heart), seizures and psychiatric issues such as depression and psychosis.11
Oxalate toxicity has even been linked to autism in children.12
Another aspect to the oxalate issue is reduced nutrition. "Part of the problem is that if you're ingesting a lot of oxalic acid, your body is not able to utilize a lot of minerals," says Diggs.
"Oxalate binds with potassium, magnesium and other minerals in addition to calcium, so it decreases the bioavailability of these minerals."
Additionally, oxalic acid is potentially corrosive to the digestive tract and may contribute to gastrointestinal diseases. The needle-sharp raphide crystals are known to perforate mucus membrane cells, which hints that they might contribute to leaky gut, although no studies have evaluated this possibility.
Lab studies have shown, however, that elevated oxalate levels can induce mitochondrial dysfunction in cells.13 According to Sally, this can lead to dysfunction of organs and glands, as well as create nerve cell damage, pain and functional problems associated with the brain and nerves.
A new way of eating
Sally is now a leading voice in the US in the field of oxalate toxicity, with her first book forthcoming.
Besides the year-round availability of seasonal vegetables like spinach, many high-oxalate food products are widespread today that barely had a presence on the grocery store shelves decades ago—exotic foods like pomegranates, kiwi fruit, greens and turmeric, plus nuts, nut butters, potato chips and chocolates that now come in dozens of styles and flavors, taking up whole sections of the grocery store shelves.
"Nobody is saying, 'Hey, these are high oxalate,' even though the fact that you shouldn't eat high-oxalate vegetables as a staple has been in the medical literature ever since the 1940s," she says.
Hopefully, with experienced, research-savvy advocates like Sally coming into the global health arena, the ignorance around oxalates won't last much longer.
CASE STUDY: Linda K., Tustin, CA, age 69
For years, Linda suffered with chronic Candida, including urinary tract infections. She felt generally unwell, and normal everyday tasks took most of her energy. Over the course of some 10 years, she consulted several physicians, but all test results were normal, and physical exams showed no evidence of inflammation.
Linda then sought treatment from two naturopaths, a chiropractor and an acupuncturist. "I tried different diets, supplements and exercise. I juiced, sprouted, fermented, journaled, meditated and prayed. I tried to remove every toxic chemical and found the most nontoxic skin care products." Her blood test for food allergies showed a few mild intolerances. She was given numerous antifungal herbs and supplements and placed on a food elimination diet and a strict Candida diet.
"This worsened my symptoms until I was so thin and weak, I could barely walk," she says. "Although I managed to keep working and doing daily tasks, I didn't ever feel well."
She found Sally Norton on the internet. "All my symptoms seemed to be related to oxalate toxicity," she says. "When I removed the high-oxalate foods, relief came within days. And when I added back high-oxalate foods, I felt the pain come back very quickly." She made gradual changes reducing high-oxalate foods and now feels better than ever.
"Oxalate wastes and destroys minerals and uses up B vitamins," she says. "I was always really hungry, and now I don't ever really feel like overeating or eating junk food."
How to get diagnosed
According to Sally Norton, nutritional expert, vitality coach and health consultant, there really isn't an effective test to reliably determine whether your load of oxalates is high.
Hip bone testing (which involves taking a chip out of the hip bone and analyzing the oxalate content) is highly invasive, and both it and urine tests are not especially accurate.
Instead, Sally uses an inventory approach to determine how much oxalate you have been eating. This history is then combined with a detailed questionnaire on symptoms to determine whether oxalates are responsible for your condition.