You Feel Tired and Stupid. Do You Have Oprah's Thyroid Trouble?

My cat had it. My sister-in-law had it. Now I have it: a thyroid disorder. And so did Oprah. Bless her little butterfly-shaped neck gland; she has once again changed the way middle-aged American women go about their business. Now, in addition to wearing waist-cinching belts and wielding a pneumatic staple gun, Oprah’s viewers are running in droves to get their thyroids tested.

It’s a good thing, too, because thyroid disorders are the second most common endocrine problem after diabetes. What’s weird, though, is how stealthy these ailments are. You walk around feeling a little tired and stupid, just assuming that’s life, especially after Labor Day, and then you find out there are actual tiny hormonal signals to blame.

Some 13 million Americans have a thyroid-related health problem, and 80 percent of them are women. Most are over age 35. Another 13 million Americans are probably walking around with undiagnosed thyroid conditions, according to estimates from the American Association of Clinical Endocrinologists. By age 60, one in five women will have thyroid trouble.

While Oprah was surfing through the high end of the weight scale a couple of years ago, she went for a walk with her exercise guru, Bob Greene. She recounts the day: He said to her, "I think something's wrong. You're listless. Your movements are slower, even when you're just doing normal stuff. Twice I've told you something and you don't remember it. There's no sparkle in your eyes. I think you're in some sort of depression."

At my last annual check-up, my doctor asked the standard assortment of stuff, including if I felt tired.

“No more than usual,” I said. I’ve been tired for eight years, since the day my first child was born and I had to learn a whole new definition of the word juggle. I got my annual scrip for Ambien, the Valium of the new millennium, and stopped in the lab for some blood tests on the way out.

Two days later, the nurse called me. “You have Hashimoto’s thyroiditis,” she burbled. Cool syllables aside, this turns out to be the most common of the glandular disorders, in which the body makes antibodies that are slowly menacing to the thyroid. It often happens after pregnancy, possibly because the immune system surges after being tamped down for nine months. As a consequence, my gland was not quite producing enough of the thyroid hormones that do mission-critical things like regulate metabolism, reproduction, growth, and mood.

For an obscure chunk of tissue below the Adam’s apple, the thyroid is surprisingly important. “The thyroid is a master gland,” explained the nurse. “When it goes wrong, it impacts the entire body.” Intricately tied in to the rest of the body’s endocrine system, the thyroid takes orders from the midbrain’s hypothalamus and the pituitary gland in the brain’s underbelly. The gland’s job is to mix dietary iodine with an amino acid called tyrosine and pulse out T3 and T4. These hormones are released to every cell in the body to regulate cellular metabolism. It is, in short, the body’s fuel refinery. But the thyroid is easily buffeted by our steroidal hormones, estrogen and progesterone, and it appears to be sensitive to environmental assaults such as smoking, radiation, industrial chemicals, and diet.

I scanned the description of symptoms: Tired? Check. Weight gain? A wee bit around the belly, I admit. Brain fog? Check—I love it that there’s a clinical term for this symptom. I started getting excited. I often can’t think of the word for something. And I’m a writer. My husband will say something like, “Have you seen the grilling tongs?" And I’ll say, “They’re in the washing machine, I mean the fridge, I mean the, the whatsit-thing, the dishwasher!” Last month after one such exchange, he said, “For someone so smart, you sure are dumb.” What if I could take a cheap pill that makes all of this go away?

I was curious to know how a brain so coddled with a classical education could just, pfffft, forget stuff. So I called Mary Shomon, an Internet thyroid presence extraordinaire [2] and best-selling author of The Thyroid Diet [3]. When thyroid function is low, she explained, so is cellular oxygen, because respiratory enzymes in the cells require that magic fuel from the thyroid. “One of the first things to go is the brain,” she said reassuringly. “You could have very low, very subtle hypoxia, causing poor memory among other things. In fact, a lot of women were sure they had Alzheimer's before they were diagnosed.” The good news? Historically, people who entered hypothyroid-induced comas emerged right back out of them with the simple administration of some supplemental hormone. Clever Chinese doctors were actually handing out desiccated deer thyroids to patients as early as 3000 B.C.

I’m on a synthetic version, but it’s the same idea. It takes a while to kick in. I’m told I’ll feel a “clean windshield effect” soon.

So what about the cat?

Well, sadly, mine died. He had hyperthyroidism, which is, believe it or not, the leading cause of death in older cats. Hyperthyroidism occurs when the thyroid makes too much thyroid hormone—the opposite of my problem. This often happens because of small growths on the gland. A 2007 study by the U.S. Environmental Protection Agency linked the rising incidence of this problem in cats to household dust, which contains indoor pollutants such as flame retardants that shed off of carpets, furniture, fabrics, and electronics. Before 1980, when flame retardants became widely used, hyperthyroidism in cats was virtually unknown. The study found that blood levels of the flame retardant PBDE were three times higher in hyperthyroid cats than in healthy ones (and their levels were 20 to 100 times higher than found in the average human adult). Cats, the theory goes, loll around on carpets and in the dust, then lick themselves silly, ingesting the pollutants.

Which naturally raises the question: Could pollutants be affecting our thyroids as well? Scientists are trying to find out. Rats, fish, and birds are known to suffer from thyroid disorders when exposed to organochlorines and brominated pollutants, such as pesticides. Human studies are rare and largely inconclusive. Sometimes the same chemical appears to cause the gland to both over- and under-produce hormones. One study found that pregnant women who eat fish contaminated with PCBs (now banned but once heavily used by industry and still persistent in some places) give birth to children with lower IQs, an effect that may be mediated through the thyroid. Another study found elevated T4 levels in adult men who ate fish from the Great Lakes contaminated with flame retardants. These elevated levels weren’t generally high enough to cause a disorder, but such studies point to a plausible association; many chemicals are known to have endocrine-disrupting effects, and the thyroid is a reasonable target.

In addition, thyroid cancer is on the rise. It hits women of childbearing age the hardest. Diagnoses of thyroid cancer are increasing about six percent a year, faster than any other cancer, according to the National Cancer Institute. The increase cannot be fully explained by better tools of diagnosis. Currently, the only known environmental agent is radiation. After the Chernobyl nuclear accident in 1986, thyroid cancer rates quadrupled. But many scientists suspect other environmental causes as well. One study found an association between thyroid cancer incidence among women in Shanghai and workplace exposure to benzene and formaldehyde.

The biggest environmental cause of thyroid trouble is far less exotic. It’s salt, says Mt. Sinai’s Dr. Yaron Tomer. Iodine deficiency causes all sorts of trouble. In pregnant women, insufficient iodine is the number one preventable cause of mental retardation in infants worldwide (the fetal brain needs T3 and T4 to develop). The United States used to have what was called the “goiter belt” in salt-starved regions around the Great Lakes and Rocky Mountains; goiters develop when the thyroid gland swells in the neck to compensate for not making enough hormones.

Our recent cultural infatuation with designer salt (read: not enriched) means that some of us may not be getting enough iodine. (And this is doubly true for those of us eating less iodine-rich seafood because of the mercury).

I was sure this wasn’t my problem because I cook with plain old Morton’s salt, albeit the coarse version. It had to be enriched, right? But when I checked the box, and rechecked the company’s Web site, I learned that it wasn’t.

Switching salts isn’t the answer to my problems, however. Both Dr. Tomer and Mary Shomon cautioned me that once you have a thyroid problem, rapidly increasing your iodine intake can make it worse. So I’ll stick with the standard meds for now and wait eagerly for the fog to lift.