Trouble Absorbing Iron Could Be Causing a Sluggish Thyroid

Picture a spigot releasing a flow of water to your garden. Your plants lap up the liquid and use it to thrive. Block off the spigot, though, and the foliage shrivels up, starved for the nourishing water that’s pulsing through the pipes.

Now imagine those plants are your thyroid, and a blocked spigot is preventing it from getting essential nourishment. Research shows that’s the case for 55 percent of women. Scientists have discovered that internal inflammation prevents the body from optimally metabolizing iron — a nutrient that plays a key role in the production of thyroid hormones. As Lisa Tussing-Humphreys, PhD, a researcher as the University of Illinois at Chicago, explains, “The iron-regulating hormone hepcidin is like the knob that controls the spigot so iron can flow into the thyroid and activate metabolism-revving hormones. When the body has the iron it needs, the faucet is turned off and excess iron is stored for future use. but inflammation hinders this process — it keeps hepcidin elevated, trapping iron in cells so the body can’t metabolize it.

Women battling excess pounds are most at risk for faulty iron metabolism. What’s more, Tussing-Humphreys found that inflammatory markers and hepcidin levels are up to eight times higher in overweight women than in leaner women. Part of the problem is that women are storing iron, but the body can’t access it. There’s plenty stored away, though, so iron levels can check out fine on conventional blood tests. And increasing iron intake alone isn’t the answer — when hepcidin levels are elevated, the body decreases its absorption of iron from food.

Impaired iron absorption sets up a vicious cycle: The thyroid, starved of iron, becomes sluggish and metabolism slows. And since iron is also needed to produce hemoglobin, a protein that helps deliver oxygen throughout the body, this imbalance can manifest as fatigue. “Patients who have a problem with low iron and hypothyroidism sometimes can’t manage to make the lifestyle changes they need to feel good,” says Sara Gottfried, a Harvard- and MIT-trained weight loss specialist. And addressing these issues with standard thyroid treatments may prove ineffective, she says. “Many women who are on a thyroid healing plan might not see the results they deserve because they’re not taking iron into account.”

Is a lack of iron causing your sluggish thyroid?

Symptoms like fatigue and weight gain can be so general that faulty iron metabolism and sluggish thyroid can be tricky to diagnose. Here are a few more telltale signs:

• Thinning hair
• Puffy wrists and ankles
• Constipation
• Frequent blue moods
• Painful joints or muscle tenderness

The Fast, Natural Fix

Improving the body’s ability to metabolize iron will revitalize your sluggish thyroid — and that’s going to restore energy, fire up fat burn, and ensure that lost pounds stay off for good. To get the benefits, consider taking the following steps:

Get the Right Dose

According to the US Food and Drug Administration, premenopausal women need 18 mg. of iron a day. But women who are postmenopausal shouldn’t get more than 8 mg. per day because they’re no longer losing iron stores every month during menstruation.

While you can supplement with a daily multivitamin that contains the right amount of iron for you, eating iron-rich plant foods like beans and greens is the best approach, especially after menopause. That’s because plant foods deliver non-heme iron, a form that’s more readily absorbed when the body’s iron stores are low and less readily absorbed when stores are high. This helps prevent iron overload. “I actually tell all my patients to get greens twice a day,” says Dr. Gottfried. Leafy greens contain 6 mg. of iron per cup. Other top plant sources of iron include lentils (6 mg. per cup), beans (5 mg. per cup), pumpkin seeds (5 mg. per 1/4 cup), and mushrooms (4 mg. per 1/2 cup).

Fight Inflammation

An easy way to increase iron intake and turn down thyroid-suppressing inflammation: Enjoy omega-3-rich seafood like salmon or shellfish and wild game like buffalo. “You want to make sure you stick with a 3- to 4-oz. serving,” says Dr. Gottfried, who also advises supplementing with 2,000 mg. of omega-3 fatty acids a day.

Increasing the flavor of your meals with anti-inflammatory herbs and spices can deliver big perks as well. Try adding 2 tsp. of turmeric to sauces or salad dressings each day — researchers found that the spice’s curcumin significantly lowers levels of three key inflammatory markers in as little as eight weeks. Other anti-inflammatory flavor boosters include ginger, rosemary, thyme, parsley, and peppermint.

Add Iron Boosters

You can improve iron absorption by enjoying your iron-rich foods alongside fruit and vegetables rich in vitamin C (like citrus fruits, bell peppers, and broccoli). Or simply take a 1,000-mg. vitamin C supplement, like Nature’s Bounty Vitamin C ($9.31, Amazon) with an iron-rich meal or snack. (Do this up to three times a day, not exceeding 3,000 mg. of C daily.)

Also smart: Drink a glass of water mixed with 1 Tbsp. of apple cider vinegar before iron-rich meals, or dress your salads with a mixture of 1 part apple cider vinegar to 3 parts olive oil. Vinegar’s acid helps release iron from food, so more of the mineral is available for absorption in the gut.

Limit Iron Depleters

Harvard scientists have identified two plant compounds that block iron absorption by up to 64 percent: tannins in coffee and tea, and phytates in grains. It’s best to enjoy these foods and beverages 45 minutes before or one hour after eating iron-rich fare.

But what about iron overload?

Getting too much iron can be just as harmful as getting too little. Experts caution that postmenopausal women and women who have irregular periods are most at risk of developing iron overload. If you experience increased fatigue, heart palpitations, or unexplained abdominal pain after increasing your iron intake from whole-food sources, visit your health-care provider — she can administer a standard blood test to rule out iron overload.

This article originally appeared in our print magazine, Heal Your Thyroid.