“Consuming too many oxalates can cause pain and inflammation throughout the body,” says Ken Berry, MD, who experienced oxalate sensitivity after adopting a seemingly healthy diet. The sneaky condition is often referred to as “the great pretender” because it can mimic everything from arthritis pain to skin rashes, irritable bowel syndrome (IBS), and anxiety. In reality, everyone reacts differently to these plant chemicals that can become toxic when consumed in amounts beyond our individual ability to process them. That’s why Dr. Berry: “Most people who are highly sensitive to oxalate ingestion have no idea it’s causing their symptoms.” Indeed, Cornell University-trained nutritionist Sally K. Norton, MPH, author of Toxic superfoodsclaims that many women in the US over the age of 50 may have an oxalate overload.
Understand the theories of oxalate accumulation
Once oxalate crystals enter the bloodstream, they can hide anywhere, even in our most important metabolic gland: the thyroid gland. Sally K. Norton, MPH, refers to a 1993 study of 182 deceased women (whose calcium oxalate crystals were measured within five hours of death): “Older women have an 85 percent chance of having oxalate crystals in their thyroid gland, thyroid function, and body weight regulation. ” (Note that the 85 percent statistic refers to women age 70 or older.) Based on this study, it is theorized that the cells closest to these oxalates lose their ability to produce weight-regulating thyroid hormone even at women without a diagnosed thyroid condition.”These crystals can destroy the machinery of life: cell membranes,” says Norton.But there’s also good news: “When oxalates leave the body, it’s possible to heal tissues and reverse chronic conditions.”
Decades of ill health led Norton to search libraries at medical schools and the National Institutes of Health. She found studies showing that oxalate crystals can accumulate anywhere, including our fat-burning liver, thyroid and adrenal glands. Animal studies show that oxalate ions can damage any cells they come near, shortening cell lifespan, impairing organ function and putting a metabolic strain on the body. Norton says, “Oxalates can make a mess of our metabolism.”
Oxalate buildup and poor gut health
Oxalates can also steal minerals from the foods we eat, causing nutrient deficiencies and cravings. In addition, women with poor gut health are the most vulnerable to overexertion. That’s a big group, as experts say most of us struggle with some degree of “leaky gut,” a condition linked to an increase in belly fat. Healthy intestinal cells limit the absorption of oxalate, but when the intestinal lining is damaged, from things like pesticides or NSAIDs (nonsteroidal anti-inflammatory drugs like ibuprofen), toxins leak through the cell barrier and into the bloodstream, leaving damage behind.
Dietary trends such as plant-based eating, which include healthy foods high in oxalates, have made oxalate overload more common in recent years. Norton adds, “When we pulverize our food and turn it into nut milks or spinach smoothies, we break up hard-to-digest plant structures that might otherwise limit the effects of oxalate.” Her advice? “If conventional wisdom about healthy eating isn’t working for you, look to oxalates.”
How to reduce your oxalate intake
The good news: By limiting oxalate intake, our kidneys, which remove oxalates from the body, may be able to recover from the toxic backlog. To do that, Norton suggests replacing the highest oxalate foods in your diet with nearly identical swaps for a month to see how your body responds. “This is the easiest elimination diet in the world,” promises Norton.
With fewer oxalates in the body, cells can function better and gut health can improve — a factor that can accelerate fat loss. Women also report improvements in brain fog, cravings and digestion. Dr. Berry, who follows his own zero-oxalate plan, adds, “While lowering your oxalates, you naturally lower your carbohydrate intake to promote fat loss.”
And potential weight-loss benefits may be just the beginning. Within 10 days of exchanging high-oxalate foods, Norton felt relief from arthritis pain, restless sleep, and bloating. She says: “For the first time in my life I felt good. As the improvements continued, I felt like I was getting younger.”
“There is no downside to a low-oxalate diet,” adds David Perlmutter, MD, Weight Loss Expert. “It can be a health miracle.”
Note: Additional research shows that a diet low in oxalate has no weight loss benefits and is only beneficial for people trying to reduce their risk of kidney stones. Talk to your doctor before switching to a low-oxalate diet.
Norton’s approach to excluding high oxalate foods
Not all healthy foods are healthy for every body, according to Norton. “I was floored to think that foods in my healthy diet like spinach, Swiss chard, and sweet potatoes had made me sick,” she says. Now she’s spreading the word about oxalate overload, especially among older women, as cells weakened by age or chronic inflammation are most at risk for oxalate accumulation — and hold the most potential for a cure. Dr. Adds Berry, “Lowering your oxalates will give you massive relief from inflammation fast.”
In Norton’s four-week plan, you practice oxalate-conscious eating by limiting foods high in oxalate and choosing lower-oxalate alternatives. In general, meat, eggs, cheese and cabbage are low in oxalate, while some seeds, nuts and beans are higher in oxalate. But this approach is not about perfection. To see weight-loss results, follow this gentle step-down approach…
Week 1: Reduce oxalate consumption to less than 200 milligrams (mg) per day (approximately 60 mg per meal). Start by cutting out the biggest offenders, such as spinach, beets, and dark chocolate.
Week 2 to 4: Reduce oxalates to 100 milligrams or less per day, aiming to get below 60 milligrams daily (about 20 milligrams per meal).
Week 5 and beyond: Once you’ve reached your goal, experiment with adding some food during maintenance mode. But know that healing can take time depending on your sensitivity level. If symptoms return or weight returns, reduce oxalates by repeating the previous step.
Additional tips for success with a low-oxalate regimen
While a low-oxalate diet hasn’t been proven to help you lose weight, it may be helpful if you suffer from kidney stones. Check out these tips to reduce the amount of oxalates that build up in your kidneys.
Squeeze a lemon. Start each day by consuming citric acid in the form of ½ cup of undiluted (full strength) lemon juice. Norton says, “It helps break down oxalate crystals.”
Get calcium this one way. This mineral binds to oxalates, mopping up the excess and protecting the kidneys from stones. Aim for a daily dose of 800 to 1,400 mg, depending on your dairy intake. Find a product without vitamin D to improve oxalate excretion.
Cook your broccoli. To lower the oxalate content in raw broccoli, boil it for 10 minutes and discard the water. Norton explains, “This breaks down the cell structures so that some of the oxalates can leach into the cooking water.”
Enjoy a healing bath. Some temporary detoxification symptoms, such as headaches or fatigue, can occur when oxalates are flushed from the body. Soaking in mineral-rich water can help, says Norton. To do this, add ½ cup of Epsom salt in a tub of warm water and soak feet for 15 minutes every other day or add two cups to a bath twice a week.
How to know if you have oxalate overload
Home tests are available to test for oxalate stores, but Norton says most of us don’t need them. Instead, consider these signs: joint pain, gastrointestinal problems, skin rashes, brain fog, slow recovery from injury, or low bone density. But the most common sign is cloudy or grainy urine. “If there is no urinary tract infection, urine with a cloudy, misty white appearance is likely filled with oxalates.” If you experience these symptoms, try the tips above.
Note: These symptoms could instead be signs of other conditions.
This content is not a substitute for professional medical advice or diagnosis. Always consult your doctor before following any treatment plan.
A version of this article originally appeared in our print magazine, First for women.