Toxic Superfoods

How Oxalate Overload Is Making You Sick--and How to Get Better

About the Book

An acclaimed nutrition educator reveals how the foods you’re eating to get healthy might be making you sick.
“Sally Norton’s well-researched book makes a truly important contribution to the literature in revealing just how much oxalates can damage the human body.”—Nina Teicholz, author of The Big Fat Surprise
If you’re eating a healthy diet and you’re still dealing with fatigue, inflammation, anxiety, recurrent injuries, or chronic pain, the problem could be your spinach, almonds, sweet potatoes, and other trusted plant foods. And your key to vibrant health may be quitting these so-called superfoods.

After suffering for decades from chronic health problems, nutrition educator Sally K. Norton, MPH, discovered that the culprits were the chemical toxins called oxalates lurking within her “healthy,” organic plant-heavy diet. She shines light on how our modern diets are overloaded with oxalates and offers fresh solutions including:

• A complete, research-backed program to safely reverse your oxalate load
• Comprehensive charts and resources on foods to avoid and better alternatives
• Guidance to improve your energy, optimize mood and brain performance, and find true relief from chronic pain
In this groundbreaking guide, Norton reveals that the popular dictum to “eat more plants” can be misleading. Toxic Superfoods gives health-seekers a chance for improved energy, optimum brain performance, graceful aging, and true relief from chronic pain.
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Praise for Toxic Superfoods

“Who knew that some so-called superfoods could be the opposite of healthy? The conventional advice to eat ‘mostly plants’ is seriously challenged by the reality that plants contain known toxins. Norton makes a compelling case that oxalates are the x-factor contributing to many mysterious health conditions.”—Nina Teicholz, author of The Big Fat Surprise

“What if your favorite superfood was actually a supervillain? Sally Norton masterfully pinpoints the changes in our food system and eating style that have turned a common natural occurring toxin into a potential public health crisis for people who are trying their best to eat well. Her simple and effective recommendations are grounded both in modern science and the principles of ancestral health.”—Aaron Blaisdell, PhD, UCLA Professor of Behavioral Neuroscience

“As a medical profession, we have only recently begun to realize how commonly we are seeing oxalate issues be a part of the presentation of a wide variety of chronic illnesses. I highly recommend this book to anyone who has been wrestling with poor health and not gotten the answers they need.”—Neil Nathan, MD, author of Toxic

“One conversation with Sally Norton transformed my health. Thankfully, she has shared her life’s work about the dangers of oxalates in this book. Everyone needs to hear her message.”—Dr. Bill Schindler, author of Eat Like a Human

“Sally Norton does a super job of revealing the many ways oxalates can promote the health of plants and undermine the health of people. This book is a must-read for people who eat plant-based superfoods.”—Fred Provenza, PhD, author of Nourishment

“An invaluable book that tells the story of the deleterious health effects of oxalate in our food.”—Miki Ben-Dor, PhD

“This book has the power to change the course of your health, happiness, and longevity for the better.”—James L. Oschman, PhD, author of Energy Medicine

“Juicing, raw food, and vegan trends have come and gone over my 30 years in the integrative oncology world and is currently all the rage again.  This trend has created an illusion of health, and yet, clinically, I have seen the opposite. Sally has done an excellent job confirming what I have been seeing clinically.”—Dr. Nasha Winters, ND, FABNO

“A revealing and riveting must-read.”—Kaayla T. Daniel, PhD, author of The Whole Soy Story and coauthor of Nourishing Broth

“[I]nformative. . . . The extensive charts showing the oxalate content of various foods make it easy to follow a low-oxalate diet. . . . [A] straightforward resource for potentially curbing a host of symptoms.”Publishers Weekly
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Toxic Superfoods


Health Food or Health Disaster?

The greatest obstacle to discovering the shape of the earth, the continents, and the ocean was not ignorance but the illusion of knowledge.  —Daniel J. Boorstin, The Discoverers, 1985

Actor Liam Hemsworth publicly blamed spinach smoothies for a 2019 kidney stone episode that required surgery. At age 29 he had to miss a movie premiere and an awards banquet because of it. In 2020, Men’s Health magazine quoted Mr. Hemsworth as saying: “February last year, I was feeling really low and lethargic and wasn’t feeling good generally. And then I got a kidney stone.” He added: “Every morning I was having five handfuls of spinach and then almond milk, almond butter, and also some vegan protein in a smoothie. And that was what I considered super healthy. So, I had to completely rethink what I was putting into my body.”

This book invites you to do just that: Rethink your “health” food.

Even moderate, relatively common levels of oxalate in a habitual diet can fuel the customary aches and pains of life: digestive distress, inflamed joints, chronic skin issues, brain fog or mood problems, as well as health declines associated with “normal” aging. And then there are those painful kidney stones. Eighty percent of them are formed from oxalate, much of which comes from the foods we eat.

Mr. Hemsworth was one of the lucky ones. Three weeks after completing a 10-day “green smoothie cleanse” for weight loss, a New York City woman with a history of gastric bypass surgery went to the Nassau University Medical Center on Long Island, complaining of persistent nausea, weakness, and poor appetite. She was immediately put on a low-oxalate diet, but it was too late, her kidneys did not recover, and she remained dialysis-dependent.

Similar examples of kidney failure due to consumption of “health foods” include a man, also attempting to lose weight, who juiced celery, carrots, parsley, beets with their greens, and spinach. The man’s kidneys were seriously damaged. His doctors at the Mayo Clinic prescribed dialysis and a low-oxalate diet. He stopped juicing. It took more than four months for his kidney function to improve.

And it’s not just kidney failure. Damage from dietary oxalate can hit any—or every—bodily system and cause serious chronic health problems. It’s no accident that Mr. Hemsworth’s kidney stones were preceded by malaise, depression, and lethargy. However, most medical journals reporting health crises from overzealous oxalate consumption fail to mention the non-kidney problems that likely also occurred.

Because it is so easy to overeat oxalates, chances are you may already be experiencing occasional oxalate-related aches and pains somewhere in your body. Do you tend to get a stiff neck? In those of us with dietary oxalate overload, pain, knots, or stiffness in the top of the shoulders or in the upper or lower back are typical. Some people experience chronic or intermittent joint inflammation, gout, arthritis, carpal tunnel syndrome, or a more generalized stiffness, often accompanied by a lack of pep.

Or perhaps you have long-standing injuries or chronic itching, tingling, or pain that never fully resolves. Your doctors can’t help you figure out what is going on; they seem to think you’re “just fine” and should just live with life’s little miseries. If any of this rings true for you—if you don’t feel “just fine”—this book may be your golden opportunity to turn things around.

Other seemingly small things can be indicators of oxalate overload, including itchy or dry eyes, eye floaters, excessive tartar on the teeth, tooth sensitivity, sensitive or frail skin, and odd things like pressure or pain in the loins, irritable bladder, urinary tract infections, frequent urination, or cloudy urine. Liver stress from oxalate overload can aggravate chemical sensitivity. Digestive problems like indigestion, reflux, bloating, excessive belching, constipation, and irritable bowel syndrome are especially common. Additional symptoms can include shortness of breath, sinus problems, yeast infections, and even cold hands and feet.

Do you ever feel especially clumsy or occasionally have poor coordination? Do you get muscle spasms or eye twitches, or have memory or word-finding difficulties, headaches, or anxiety and panic disorder? Being neurotoxic, oxalates can get in—and on—your nerves. Oxalic acid chemically bonds to calcium and other minerals and interferes with cell energy production. Relentless oxalate consumption can cause oxalate to build up inside the body without obvious symptoms and may culminate years later as “old-age problems” such as bad bones, chronic pain, and vision and hearing loss. Oxalate deposits are also associated with brain cell damage that leads to Parkinson’s disease and dementia disorders.

You don’t have to have symptoms to have a disease, and oxalate toxicity is no exception. But a wide spectrum of potential symptoms can occur in the wake of oxalate overload, and each of us will (eventually) suffer from our own unique subset of them if we persist with high-oxalate eating. To make it easier to consider your own situation, you can take the Risks, Symptoms, and Exposure Self-Quiz (in the Resources section, page 275) or look over Table 10.1, which lists body systems and oxalate-associated symptoms. Keep reading to get the interesting details.

There are several factors that increase the likelihood that your high-oxalate diet may be leading to oxalate overload and symptoms, including:

•A diet low in calcium and other minerals (dairy-free and vegan diets are two examples)

•Frequent use of gut-irritating foods, including beans, bran, whole grains, quinoa

•A history of repeated use of antibiotic or antifungal medications

•Long-term use of non-steroidal anti-inflammatory pain medications (NSAIDs)

•Obesity or diabetes

•Crohn’s disease, irritable bowel syndrome (IBS), leaky gut, food sensitivities, bariatric surgery, or gut dysbiosis

•Frailty or other chronic non-oxalate illness

•Poor kidney health, history of kidney stones, family history of kidney disease.

As you will see in Part 2 of the book, simply trying a low-oxalate diet for a few months is another way to assess your situation.

The Hard Road to Enlightenment

Maybe, like me, you have always considered yourself a healthy eater. It was healthy eating that led to my ill health. I was beyond exhausted—unable to read with comprehension, unable to work. A high-tech sleep study showed that I was waking up 29 times every hour. Medications did nothing to improve the situation. I was stuck, and no one could help me. I had problems with joint pain and symptoms of genital burning, but I did not connect them to my exhaustion and sleep issues. It was my genital burning that, in 2009, led me to the Vulvar Pain (VP) Foundation, and under the fog of my heavy brain fatigue I decided to try the low-oxalate diet they recommended, hoping for relief from genital pain, not understanding the potential scope of effects or the long period needed for full recovery from oxalate damage.

In my ignorance, I drifted back to my beloved sweet potatoes and celery, and in 2013, I added kiwifruit to my diet in a desperate attempt to resolve my chronic constipation. After three months of a daily kiwi (sometimes two), my arthritis and stiffness became severe (all over again). This led to the brain-twisting recognition that dietary oxalate was related to my decades of joint pain. Grudgingly, I finally got serious about maintaining a low-oxalate diet.

Once I consistently shunned my go-to high-oxalate foods (for me, mainly sweet potatoes and chard), multiple personal miracles unfolded. The debilitating sleep disorder vanished, decades of pain and joint problems receded, and I started to feel younger. I never imagined anything like that was possible. The contrast between the years of intractable problems and then dramatic, lasting, and wholly unexpected benefits in the wake of the diet change was eye-opening.

About the Author

Sally K. Norton, MPH
Sally Norton, MPH, received her bachelor's degree in nutritional science from Cornell University and her master's degree in public health from the University of North Carolina, Chapel Hill.
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