Diet, Foods & Strategies for Hypothyroidism “Brain Fog”

Diet, Foods & Strategies for Hypothyroidism “Brain Fog”

Diet, Foods & Strategies for Hypothyroidism “Brain Fog”

Hypothyroidism is a hormone imbalance with strong effects in most organs of the body. “Brain fog” is not a medical condition. It’s a term used for a group of symptoms that can affect your cognition, mood, and energy. Read on to learn more about the possible link between hypothyroidism and “brain fog.”

What Is Hypothyroidism?

Hypothyroidism is a deficiency in thyroid hormone production by the thyroid gland. Its main symptoms include [1, 2]:

  • Fatigue and weakness
  • Reduced memory and concentration
  • Depression
  • Cold intolerance
  • Constipation
  • Weight gain
  • Dry skin and hair loss
  • Painful joints and muscles

Hypothyroidism can be caused by defects in the thyroid gland (primary hypothyroidism) or the hypothalamus or pituitary gland (secondary hypothyroidism) [1, 2].

What Is “Brain Fog”?

“Brain fog”, also known as ‘mental fog’, ‘clouding of consciousness’, and ‘cognitive dysfunction’, is an unofficial term used to describe a constellation of cognitive symptoms such as [3, 4]:

  • Reduced mental clarity and cognitive function
  • Difficulty focusing and multitasking
  • Loss of short- and long-term memory
  • Slow thinking
  • Confusion
  • Fatigue

Because these symptoms are generally subjective, doctors can consider them too mild or unspecific to diagnose cognitive impairment.

For more about how hypothyroidism progresses and how it may cause “brain fog” symptoms, check out this post.

Complementary Strategies that May Help “Brain Fog” Symptoms and Hypothyroidism

You may try the complementary approaches for “brain fog” associated with hypothyroidism listed below if you and your doctor determine that they could be appropriate in your case after discussing them. Remember that none of them should ever be done in place of what your doctor recommends or prescribes.

1) Physical Exercise

Always remember to speak with your physician before starting any new exercise regimen or drastic changes in diet.

Doing more exercise may improve how your thyroid gland works. In 2 small trials on 20 adults and 36 adolescents, exercise increased T3 and T4 while decreasing TSH levels [5, 6].

What’s more, exercise may be beneficial for cognitive function, especially if it combines aerobic and strength training. In 4 small trials on almost 100 people with cognitive problems, it improved learning, processing speed, attention, executive function, and movement coordination [7, 8, 9, 10, 11].

Exercise may increase cognitive function by stimulating the birth of new cells, increasing synaptic plasticity, reducing inflammation and oxidative damage, and improving blood flow in the brain [12, 13, 14, 15, 7].

However, extenuating exercise may do more harm than good. It may reduce T3 levels, increase inflammation (Th17 immune response), and cause fatigue, a typical “brain fog” trigger [16, 17, 18, 19].

Experts recommend moderate exercises such as walking, yoga, tai chi, or water aerobics.

2) Improve your Sleep

Poor sleep quality is a common cause of “brain fog” symptoms. Lack of sleep reduced attention, memory, creativity, language and numerical skills, and executive function in multiple studies [20, 21, 22, 23, 24, 25].

Sleep loss may increase free radical damage in the hypothalamus by reducing the production of the antioxidant glutathione. It also increases the production of pro-inflammatory cytokines (such as TNF-alpha, IL-6, IL-17, and CRP) [26, 27, 28, 29, 30, 31].

If you have “brain fog” from hypothyroidism, improving the quality of your sleep may help. Read this post to learn how to fix your sleep.

People with interrupted breathing during sleep (sleep apnea) are at an increased risk of “brain fog”. In addition to worsening sleep quality, apnea reduces oxygen intake. The lack of oxygen produces free radicals, which cause oxidative damage and trigger inflammation [32].

Importantly, sleep apnea increases the risk of developing Hashimoto’s hypothyroidism. The risk is especially high in women and those with severe apnea. Similarly, apnea increases thyroid antibody levels in people with Hashimoto’s, suggesting the development of the symptoms may be faster [33].

3) Reduce Stress

Stress decreases thyroid function. Repeated stress increases glucocorticoid production, which in turn reduces the levels of T3, T4, and TSH [34, 35+].

Both chronic stress and the hormones produced in these conditions may impair memory and learning. While the effects are reversible in adults, they may be permanent in young children [36, 37].

Stress may reduce the birth and branching of brain cells in the hippocampus and the function of the messenger glutamate in the prefrontal cortex [36, 38, 39].

Alternatively, the stress hormone CRH may contribute to “brain fog” by increasing inflammation. CRH increases Th1 dominance and activates the inflammatory hub NF-kB. However, it also leads to the production of the anti-inflammatory hormone cortisol [40, 41, 42, 43].

Read here how to reduce your stress response.

4) Check if You Have Gluten Intolerance

In addition to its well-known effects on the gut, celiac disease damages the brain by causing inflammation and producing antibodies that target its proteins [44].

People with celiac disease often experience “brain fog” symptoms with reduced memory, attention, executive function, and processing speed after eating. In a small trial on 11 people recently diagnosed with celiac disease, going gluten-free improved “brain fog” symptoms [45, 46].

The frequency of celiac disease is higher in people with hypothyroidism, especially in those with autoimmune types such as Hashimoto’s [47, 48, 49].

Speak with your physician to see if you suffer from gluten intolerance to determine if it could be a possible cause for your “brain fog” symptoms.

5) Prevent Insulin Resistance

Diets rich in low-glycemic sugars and fats (a combination typically found in fast food) cause obesity and insulin resistance. This means that the body’s cells don’t take up sugar from the blood in response to insulin [50, 51].

Insulin resistance causes acute fluctuations in blood sugar levels, which increases oxidative damage and inflammation. This damages the brain and may result in “brain fog” symptoms [52, 53].

Obesity triggers insulin production in the hypothalamus at lower blood sugar concentrations, resulting in higher insulin levels [54].

High blood sugar and insulin lower NAD+ levels. This reduces the ability of the mitochondria to produce the energy molecule ATP, resulting in increased fatigue [55, 56].

Reducing dietary carbohydrates may be especially beneficial in people with autoimmune hypothyroidism. In a clinical trial on almost 200 people with Hashimoto’s, a low-carbohydrate diet reduced thyroid antibody production [57].

Read here what causes insulin resistance and possible ways to combat it.

6) Reduce Goitrogenic Foods

Goitrogens are substances that reduce iodine uptake by the thyroid gland, resulting in reduced production of thyroid hormones [58, 59].

Foods rich in goitrogens include [60+]:

  • Cruciferous vegetables (cabbage, broccoli, cauliflower)
  • Root vegetables (cassava, turnip)
  • Cereals (sorghum, millet, maize)
  • Legumes (soybean, Lima bean)

People with hypothyroidism may want to reduce their intake of these foods to decrease their “brain fog” symptoms. Note, however, that most of them will only interfere with your thyroid function if you have iodine deficiency or eat high amounts (an exception being millet) and cooking these vegetables may inactivate the goitrogenic compounds [61, 62, 63].

Reduce Inflammation

Gut inflammation produces cytokines that are currently being investigated to determine if they can result in cognitive problems and behavioral changes. Although it’s important to remember the link between mental fatigue and gut inflammation remains unclear, people with chronic fatigue syndrome often have IBS as well [64, 65, 66].

Some foods may increase gut inflammation and worsen IBS symptoms, although more research is needed to confirm their potential effects on cognitive function. These include those rich in [67, 68, 69, 70, 71, 72, 73]:

  • Lectins (such as beans, peanuts, lentils, tomatoes, and eggplants)
  • Casein (dairy products)
  • FODMAPs (such as many fruits, vegetables, cereals, and dairies)
  • Salicylates (such as apricots, oranges, pineapples, dates, and raspberries)
  • Amines (such as chocolate, cheese, wine, beer, and fish)
  • Tannins (such as bananas, chocolate, tea, nuts, and whole spices)
  • Trypsin inhibitors (such as legumes, cereals, potatoes, and eggs)
  • Oxalates (such as leafy vegetables, dark chocolate, legumes, and nuts)
  • Yeast (such as gluten-free bread)
  • Food additives carrageenan and carboxymethylcellulose (such as ice cream, almond milk, candy bars, and some cheeses)
  • Caffeine (such as coffee, tea, and cocoa)

To find out if any of these food groups might be worsening your “brain fog” symptoms from hypothyroidism, you can try to follow an elementary diet for 2 weeks and then add one at a time back in. Because elementary diets can lead to deficiencies, follow your doctor’s instructions carefully.

Gut Microbiome

Some scientists believe that gut microbiota plays a role in cognitive function and behavior. The communication between these two organs is often called the ‘brain-gut axis’ [74].

In animal studies, a Western diet rich in saturated fats and added sugars reduced beneficial bacteria in the gut. These changes are associated with obesity and cognitive impairment [75+, 76, 77].

While the full link and efficacy remains unclear, recent studies have shown that probiotics improved cognitive function and the gut microbiome composition in some small clinical trials.

They improved visual memory in 22 healthy people, attention and memory in 50 people with mild cognitive impairment, and visual learning, attention, and general fatigue in 44 people with chronic fatigue syndrome [78, 79, 80].

They also improved learning and memory in mice and rats. Conversely, changes in the gut microbiota (from infections and antibiotics) were associated with cognitive problems and behavioral changes in mice [81, 82, 83, 84, 85, 86].

Interestingly, hypothyroidism is associated with bacterial overgrowth in the small bowel. It would be interesting for future research to determine if this overgrowth may worsen “brain fog” symptoms by disturbing the normal microbiome [87].


The following supplements might be of benefit in restoring normal thyroid hormone levels:

In the case of vitamin D, it’s important to combine dietary sources and supplements with sun exposure [101, 102].

Additionally, vitamin B1 increases energy by stimulating carbohydrate breakdown. Supplementation with this vitamin reduced fatigue in 3 people with Hashimoto’s hypothyroidism [103, 104], though it’s very important to remember much further work needs to be done to determine how useful vitamin B1 is in people with this disease.

Remember, it’s preferable to take certain vitamin and mineral supplements only in cases of deficiency. Some of them may be toxic at excessive doses and even worsen hypothyroidism or brain fog. Hence, remember to speak with your doctor before taking any supplements.

This is especially the case of iodine. Although it’s required to make thyroid hormones, high doses may trigger inflammation by increasing T cells (Th1 and Th17) and cytokines (such as IL-6, IL-17, and TGF-beta). This may worsen both “brain fog” symptoms and autoimmune hypothyroidism [105, 106].

Limitations and Caveats

Most studies investigating an association between hypothyroidism and brain fog symptoms were cohort studies. These studies can’t establish a cause-effect relationship.

Additional limitations to most studies included evaluating subjective symptoms, using different methods of measurement, studying heterogeneous populations, and establishing different TSH thresholds to distinguish between overt and subclinical hypothyroidism. This creates a bias that makes it difficult to compare studies.

All the studies on overt hypothyroidism and a lot of those on subclinical hypothyroidism were done on a small number of people. More studies on larger populations are required to confirm their findings.

In the case of subclinical hypothyroidism, the studies on both its association with “brain fog” and possible improvement with thyroid hormone replacement therapies showed contradictory results.

Further Reading

  • Can Hypothyroidism Cause “Brain Fog” + Mental Symptoms?


How Can You Best Cope With Your Thyroid Disease Symptoms?

Diet, Foods & Strategies for Hypothyroidism “Brain Fog”

Common symptoms associated with thyroid disease can be frustrating and impact your life in many ways. Problems such as fatigue, weight gain or loss, temperature intolerance, hair loss, and more can affect you not only physically but emotionally, interfering with your relationships and reducing your ability to enjoy daily life.

A diagnosis of thyroid disease introduces you to a lifelong need for its management. And given the relentlessness of some of its symptoms, it can be easy to accept what you're experiencing as being “just the way it is.

” But there are strategies you can employ to feel better than OK.

And knowing that symptoms associated with a thyroid condition are often confused with those related to another health concern can help you pursue other possible solutions to help you live your best life.

Managing the common (and often extremely annoying) symptoms of thyroid disease begins with finding a good thyroid doctor who will partner with you to determine your options. Then, by being proactive and persistent—but recognizing the importance of patience—you’ll be set to identify and deal with the inevitable symptoms that come your way.

No two individuals with thyroid disease experience it the same way, even if they have the same diagnosis. The most effective coping strategies may look different for you than someone else.

Believing that your symptoms are surmountable and making a conscious decision to commit to an educated plan for getting well are crucial in your overall health. Treatments for hypothyroidism or hyperthyroidism aren't magic pills or techniques. Rather, the secret to living well with thyroid disease is embracing an approach that blends both science and the art of wellness.

While there are specific strategies that can help you with some of the symptoms that can come with thyroid disease, which are discussed below, some measures are worth taking because of the widespread impact they can have on how you feel.

  • Eat a healthy diet
  • Practice good sleep hygiene: Getting not only enough sleep, but quality sleep, can reduce many of the symptoms associated with thyroid disorders.
  • Manage stress: Taking time to practice stress management is well worth it. Not only can coping with thyroid disease add stress to your life, but stress hormones such as cortisol can alter the levels of thyroid hormones in your body. (Though results are mixed, there is some evidence that suggests that stress may even play a causative role in the development of autoimmune thyroid disease, as well as pregnancy-related thyroid disease.)
  • Quit smoking: Chemicals in cigarette smoke are dangerous for anyone but are particularly detrimental to those with thyroid disease. For example, among people with Graves' disease, smoking both increases the risk of thyroid eye disease and makes treatment for the disease less effective.
  • Live a resilient life: Living is challenging enough at times without thyroid disease, but resilience can help just about anyone. Learn how to laugh even in the midst of troubles. Try carrying a positive attitude. Lean into your positive relationships and eliminate negative ones. Practice reframing, a skill that entails looking at the same situation (situations that can't be changed) in a different light.

Weight issues, either weight gain with hypothyroidism or weight loss with hyperthyroidism, are often the most distressing symptom for people coping with thyroid disease. Many people find that diet and exercise strategies that were effective in this regard before their diagnosis are now ineffective.

The first step to take whether you are coping with weight gain or weight loss is to make sure that you are on optimal thyroid treatment. Even if your TSH is “within normal limits” or in the range specified as “normal” by your clinic, optimal treatment may mean adjusting your dose so that you fall in the lower range of TSH values.

The second step is to consider any other condition you may have or change in habits that may be causing weight changes. Potential underlying causes of weight gain can range from polycystic ovaries to medication use. Unintentional weight loss should also be investigated for other causes.

Even if what you're experiencing is thyroid-related, the relationship between thyroid hormones and weight is complex.

Weight gain related to hypothyroidism is common. Even with optimal thyroid replacement, many people struggle with extra pounds that they hadn't before their diagnosis.

To help you reach your healthy weight goal:

  • Equip yourself with knowledge: Learning about insulin resistance, as well as the actions of the hormones leptin and ghrelin, can help you design a plan.
  • Stay well hydrated.
  • Exercise: If you want to lose weight, you may have to put in more than the 150 minutes of moderate exercise or 75 minutes of vigorous exercise weekly.
  • Get enough sleep: Being sleep deprived makes it more difficult to lose weight.
  • Choose foods wisely: Aside from monitoring your calories, a number of other measures, such as increasing fiber and decreasing carbohydrates, have helped some people living with thyroid disease lose weight.
  • Consider how you eat: Some people see benefit from adjusting their eating patterns through intermittent fasting. In addition, there is sometimes a connection between thyroid disease and gluten sensitivity/celiac disease, and some people have found that adopting a gluten-free diet has made the difference in their thyroid symptoms.

If you are losing weight with thyroid disease, it's important to begin looking into your thyroid function. Do you have hyperthyroidism that needs more aggressive treatment? Are you on too high a dose of replacement therapy for hypothyroidism? If your treatment is correct, talk to your doctor about options, such as increasing calorie-dense foods in your diet.

Hair loss and thinning are common with thyroid conditions, but as with other symptoms, it's important to rule out other potential causes before chalking them up to your thyroid concern. In fact, some conditions that cause hair loss are more common in people with thyroid disease.

Hair loss due to thyroid disease is, fortunately, usually temporary and treatable. Most commonly, the hair loss is diffuse (all over without bald patches), and the texture of hair may change, becoming either coarse and thick, or thin and fine.

Hair loss may occur in regions other than the head as well, especially the outer areas of the eyebrows. Most often, effective treatment of your thyroid disorder will lead to resolution of hair loss.

To promote more rapid hair re-growth, some physicians may recommend medications such as topical Rogaine (minoxidil) or the medication Propecia (finasteride).

Because these medications may have side effects (and Propecia should not be used by women who are pregnant or may become pregnant), many people find conservative measures, such as having your hair styled in a way that makes hair thinning less evident, sufficient while hair grows back.

Fatigue is another bothersome symptom that has many other potential causes besides thyroid disease. From iron-deficiency anemia, to sleep apnea, to medications, it's important to first rule out these other common causes of fatigue.

Coping with thyroid-related fatigue can be challenging in more ways than one. Not only are many people left coping with a type of fatigue that differs from ordinary tiredness, but family and friends often fail to recognize its degree, impact, and that it can be a fact of life for people with hypothyroidism or hyperthyroidism.

Optimizing your thyroid treatment alone may significantly reduce your fatigue. With hypothyroidism, this might mean having a goal TSH closer to 1.0 mU/l than 5.0 mU/l. With hyperthyroidism, more aggressive treatment may be needed.

Good sleep hygiene is essential so that you not only get an adequate amount of sleep, but quality sleep. For some people, dietary changes (such as reducing carbohydrates) are helpful.

Perhaps counterintuitively, increasing physical activity can reduce fatigue, but it's important not to overdo it—especially if your thyroid levels aren't yet stable.

Sometimes coping with fatigue due to a thyroid condition can have silver linings. For example, most people could benefit from learning to pace themselves and delegate activities they don't have to do themselves. Coping with thyroid disease just might help you face and achieve those goals.

In general, cold intolerance is a symptom of hypothyroidism and heat intolerance a sign of hyperthyroidism, but there is tremendous overlap. In addition, temperature intolerance may have nothing at all to do with your thyroid, and it's important to look for other potential causes of cold intolerance or heat intolerance.

Possible causes of cold intolerance include anemia, being overly thin, infections (even a cold virus), circulation problems, fibromyalgia, pituitary or hypothalamic problems, and more. Heat intolerance could be related to changes such as menopause, but if you are having night sweats as well, they could be a sign of something more serious.

If your temperature is elevated when you feel hot, talk to your doctor. A fever of unknown origin requires a careful workup.

Symptoms of cold intolerance often improve with optimal management of your thyroid disorder, but this can take time, especially if your thyroid dysfunction is occurring during the colder months of the year.

You may need to turn up the heat in your home, wear a hat, socks (or a few pairs if needed), long underwear, and purchase a warm comforter for the nighttime.

Getting enough sleep can make a big difference in your symptoms, as can making sure you dress for the weather.

Before you consider any drastic changes, such as a move to a warmer area, make sure you have a chance to experience life with normal thyroid function.

Heat intolerance can be every bit as annoying as cold intolerance and is sometimes more difficult to rectify.

If you hesitate to crank the air conditioning, promise yourself you'll turn it down when your thyroid test levels improve. Skip the socks, wear shorts and a sleeveless shirt. Get wet and drink cool drinks.

Even spraying yourself lightly with a water mister, or placing a wet, cold washcloth around your neck may help. Portable fans can also be priceless.

A lot (if not all) of your symptoms may very well be due to your thyroid condition, and figuring out how best to cope with them can take some worthwhile trial and error. If you're struggling, you can feel better than you do today.

Remember, however, that attributing any symptom you are experiencing to your thyroid disease may cause you to miss important clues about other conditions. You may also feel that your thyroid treatment is unsuccessful because your symptoms are still unresolved.

Being aware of the various symptoms associated with hypothyroidism and hyperthyroidism, and how they overlap with other health issues, can help guide conversations about thyroid management with your doctor and encourage you to explore strategies those mentioned here and others.

While your thyroid management and coping plan may need some fine-tuning, there's also a chance that you may need to take additional steps completely unrelated to your thyroid to reduce your symptoms.


Eating Right for Your Thyroid: Dos and Don’ts for Patients with Hypothyroidism

Diet, Foods & Strategies for Hypothyroidism “Brain Fog”

According to the American Thyroid Association, about 20 million Americans have some kind of thyroid disease. For women over the age of 50, one of the most common conditions is hypothyroidism.

Hypothyroidism is a condition in which the thyroid, a gland in the neck, does not produce enough T3 and/or T4 hormones.

This can have a wide range of debilitating side effects, including fatigue, weight gain, body aches, depression, constipation, stomach pain, and brain fog.

Hypothyroidism is typically diagnosed with a blood test, so if you think you might be suffering from this condition, you should contact a health professional to get more information. Once you have been diagnosed, there are a variety of options for treatment.

More than ever, experts are recommending an integrative approach to treating the condition that involves a variety of different management strategies, including dietary changes, that can support the health of your thyroid and get you back to feeling good again.

Nutritional Changes as an Intervention for Hypothyroidism

Clinical evidence indicates that dietary choices can either improve or exacerbate the symptoms of hypothyroidism.

Therefore, many healthcare professions include nutritional counseling as part of an integrative strategy for the treatment of hypothyroidism.

Although every individual’s situation is different, it can be helpful to have a general idea of what foods are best for people with hypothyroidism and what foods it would be better to avoid.

Top Foods for People with Hypothyroidism

If you have hypothyroidism, there are a variety of foods that can help support the health of your thyroid and/or reduce the intensity of your symptoms. Here are some foods that you may want to include in your diet:

  • Seaweed. Seaweed is one of the best natural sources of iodine, an element that is essential for proper thyroid function. You can find dried kelp, nori, or dulse at your local natural foods store and use it in soup or as a garnish on a meat dish.
  • Apples. Apples are an excellent source of pectin, a compound that can support the health of hypothyroidism patients in several ways. First, pectin helps with the removal of toxins such as mercury that interfere with iodine absorption. Research also indicates that pectin can limit the capacity of your cells to absorb fat, which can be helpful for patients who struggle with weight gain as a side effect of hypothyroidism.
  • Brazil nuts. Brazil nuts are high in selenium, an element that is involved in the conversion of the inactive form of the thyroid hormone (T4) into the active form (T3). It can also help combat inflammation (a common cause of hypothyroidism), and it contains L-Arginine, an amino acid that may help to boost energy and support weight loss.
  • Yogurt or kefir. Yogurt and kefir both contain high levels of probiotics, which help support a healthy gut. In patients with hypothyroidism, this can help improve metabolic efficiency and relieve uncomfortable abdominal symptoms constipation.
  • Salmon. Salmon is high in omega-3 fatty acids, so it can combat the inflammation that often causes or exacerbates hypothyroidism. In addition, research suggests that omega-3 fatty acids can support weight loss by signaling to liver cells to use more fat for energy rather than storing it as fatty tissue. Also, if you experience depression or brain fog as a symptom of hypothyroidism, omega-3 fatty acids can increase the activity of mood-boosting neurotransmitters.
  • Green tea. Drinking green tea is another way to help speed up the metabolic processes that are hampered by hypothyroidism. Studies show that the antioxidants in green tea, called catechins, can cause fat to be released from fat cells and converted into energy into the liver. The caffeine in green tea can also be a quick fix to fight fatigue associated with hypothyroidism.

Foods to Avoid If You Have Hypothyroidism

Although there is no evidence that certain foods cause hypothyroidism, there are some foods that have the potential to exacerbate your condition. Therefore, you may want to limit your intake of these foods:

  • Soy. Research indicates that the hormone estrogen can interfere with the body’s ability to properly respond to thyroid hormone signaling. Soy contains high amounts of phytoestrogen, so most doctors recommend that hypothyroidism patients limit their intake of this food.
  • Cruciferous vegetables. Cruciferous vegetables broccoli, cabbage, and brussel sprouts can make it harder for the body to absorb iodine. However, cooking these vegetables can help, and as long as you limit your intake to about five ounces per day, you are unly to experience any negative effects.
  • Alcohol. Consuming alcohol can make it harder for your thyroid to produce T3 and T4 hormones, and it can also interfere with your body’s ability to utilize these hormones. After you have been diagnosed with hypothyroidism, it is best to drink only in moderation.

It is important to note that these diet tips alone can’t solve the problem of an underactive thyroid. To properly address the problem, you need to develop a plan with a health care professional.

Atlanta Chiropractic and Wellness offers consultations for patients with thyroid disorders, and our expert physicians can help develop an integrated, personalized treatment plan that can help you get your life back on track.

Contact us today to schedule an appointment!



Goitrogenic Foods and Thyroid Health

Diet, Foods & Strategies for Hypothyroidism “Brain Fog”

Warnings about goitrogenic foods are popping up on alternative and conventional healthcare sites a. The truth is, goitrogens can be a problem, especially for patients with thyroid problems. Read on to learn what foods are goitrogenic, how food can be prepared to limit them, and which patients should be extra concerned about goitrogens.

The small, butterfly-shaped thyroid gland has big responsibilities. The thyroid and its hormones control metabolism throughout the body, affecting the brain, GI tract, cardiovascular system, lipid and cholesterol metabolism, hormone synthesis, gallbladder and liver function, and more.

Unfortunately, 20 million Americans suffer from some form of thyroid disease, and 60 percent of those who have it may not even be aware. One in eight women will develop a thyroid disorder in her lifetime. If something disrupts thyroid function, the health consequences can be widespread.

The term “goitrogenic” means something that causes “goiter,” or swelling of the thyroid gland. Goitrogens accomplish this by interfering with iodine uptake in the thyroid gland.

When not enough iodine is available, the thyroid cannot produce sufficient levels of thyroid hormones T4 and T3. The hypothalamus senses low T4 and releases TSH-releasing hormone, which triggers the pituitary gland to produce TSH.

The thyroid gland responds to TSH by making more hormones. If it can’t keep up with demand, it grows bigger trying.

Goitrogens, found in many vegetables, can be problematic for patients with thyroid disorders.

Goitrins, thiocyanates, and nitriles are all goitrogenic chemicals derived from natural plant pesticides called glucosinolates. During digestion, an enzyme breaks down glucosinolates into both goitrogenic and non-goitrogenic byproducts (1).

Foods that have been identified as goitrogenic include cruciferous vegetables such as bok choy, broccoli, brussels sprouts, cabbage, canola, cauliflower, Chinese cabbage, coy sum, collard greens, horseradish, kai-lan, kale, kohlrabi, mizuna, mustard greens, radishes, rapeseed, rapini, rutabagas, and turnips. The Rosaceae family of fruits, which includes almonds, apricots, cherries, peaches, pears, plums, raspberries, and strawberries, is also goitrogenic. Other examples are bamboo shoots, millet, soy, spinach, sweet potato, tapioca, and yuca (cassava or manioc).

Many chemicals from the environment and medications are also classified as goitrogenic:

  • Amiodarone (medication for irregular heart beat)
  • Antibiotics
  • Bromides (from pesticides, plastic, brominated vegetable oils, medications)
  • Dioxins (toxic industrial byproducts)
  • Heavy metals
  • NSAIDs
  • Lithium and benzodiazepines (depression and anxiety drugs)
  • Oxazolidines (from paint)
  • Perchlorates (from jet fuel, water)
  • Pesticides
  • Thiocyanate (in cigarettes)

At relatively low concentrations, goitrogens decrease the uptake of iodine by the thyroid gland. This effect can often be offset by supplementing with iodine.

However, exposure to large amounts of goitrogens impairs the incorporation of iodine into thyroid hormone itself, which means that the thyroid gland can’t properly utilize the iodine.

In this case, no amount of supplemental iodine would be able to overcome a large intake of goitrogenic substances.

Kale and Broccoli: Health Foods or Thyroid Toxins?

Goitrogens are not an outright death sentence for kale and broccoli. Fruit and vegetable consumption in general lowers the risk of chronic diseases (2). Before you stop recommending antioxidant-rich fruits and vegetables to your patients, keep reading. The goitrogen content of foods varies widely and can be modified.

Crucifers are the biggest goitrogenic offenders, with certain varieties of kale, collard greens, and brussels sprouts at the top of the list. Others have significantly lower goitrogen levels. For example, the progoitrin (one of the harmful downstream products of glucosinolates) content per dry weight of Russian kale is approximately 150 times higher than that of Chinese cabbage (1).

Fortunately, cooking lowers the goitrogenic content of foods. Steaming crucifers until fully cooked reduces goitrogens by two-thirds. Boiling crucifers for 30 minutes destroys 90 percent of the goitrogens by stimulating the production of myrosinase, an enzyme that helps deactivate goitrogenic glucosinolates (3).

On the flip side, when green vegetables are boiled and the water is discarded, some beneficial nutrients are lost as well. About 45 percent of the vitamin C, 20 percent of the thiamin, and 40 percent of the folate are lost (4).

Minerals (calcium, iron, etc.), vitamin B12, vitamin A, and others are very well retained. Steaming versus boiling will retain more nutrients. Although some nutrients leach out, cooking goitrogenic foods is generally beneficial.

In contrast to cooking, fermenting increases the goitrogen content of cabbage, but it simultaneously decreases the level of nitriles (5). Because nitriles are more harmful than goitrogens, the overall effect of fermentation is probably positive.

In a given week, if a patient is enjoying a couple of sides of steamed broccoli, a few servings of sauerkraut, and several small salads containing spinach and kale, that shouldn’t be a problem. On the other hand, if a patient is downing green smoothies every day, each with two or more cups of raw kale or spinach, then I would be worried about how that’s affecting thyroid function.

Bottom line: encourage your patients to steam or boil goitrogenic foods and not to consume them in excess.

Patients Who Are Susceptible to Goitrogenic Foods

Certain groups of patients need to take special considerations when it comes to goitrogenic foods:

Patients at Risk for Iodine Deficiency

As stated earlier, goitrogens reduce the uptake of iodine in the thyroid. If someone is already iodine-deficient, then goitrogens are more ly to cause issues. Despite iodized salt supplementation programs, iodine deficiency is on the rise. In Europe, it’s estimated that up to 44 percent of the population maybe be iodine-deficient (6).

The best food sources of iodine come from the sea: seaweeds, cod, shrimp, and tuna. Eggs and iodized salt are also options. Have your patients start with lower-iodine-containing foods and work their way up to higher levels.

Simultaneously, ensure proper selenium intake. Selenium is best obtained from foods such as Brazil nuts, cremini mushrooms, cod, shrimp, tuna, halibut, salmon, scallops, chicken, eggs, shiitake mushrooms, lamb, and turkey.

Patients with Thyroid Problems

For patients already experiencing thyroid problems, especially hypothyroidism, goitrogens will exacerbate the condition (1). These patients should be limiting their cruciferous vegetables to one cooked serving per day. And take it easy on the green smoothies!

If you suspect a patient has thyroid issues, make sure you run a full thyroid blood work panel, which should include the standard TSH and T4, but also T3, free T3, free T4, and thyroid antibodies.

Pregnant and Nursing Women

Pregnant and nursing women require 50 percent more iodine than the average adult, making them extra susceptible to iodine deficiency (7, 8, 9). Goitrogens can inhibit the transfer of iodine into a mother’s breast milk.

In a study of Boston mothers, 47 percent of breast milk samples did not have sufficient levels of iodine (10).

I recommend only three to five servings per week of cooked cruciferous vegetables and other highly goitrogenic foods for these patients.

Patients with thyroid disorders may also want to consider other dietary choices.


Oxalates protect plants from being eaten by critters and are found in most plants, nuts, and seeds. Spinach, okra, sweet potato, elderberry, figs, leeks, buckwheat, celery, other leafy greens, and dandelions are some sources. For frame of reference, ingesting 250 mg of oxalates is considered high, and one cup of raw spinach contains a whopping 656 mg (11).

Oxalic acid binds minerals calcium and potassium, making them insoluble and less bioavailable (12). Oxalate salts increase the risk of kidney stones, especially in patients with gut dysbiosis.

Gut bacteria are responsible for breaking down oxalates, but when the microbiota are compromised, oxalates can enter the blood, turn into crystals, and get stored in tissues the kidney. In one study, 65 percent of kidney stones contained calcium oxalate (13).

Unfortunately, cooking doesn’t decrease the oxalate content much.

Foods that May Trigger an Immune Response

For patients with an autoimmune thyroid disorder, eggs, nightshades, and dairy products are common offenders.

Industrial Seed Oils

Chronic inflammation can worsen thyroid disorders. The high content of omega-6 fatty acids in industrial seed oils drives inflammation.

Very-Low-Carb or Low-Protein Diets

Carbs and proteins both promote the release of insulin, which is required to convert T4 to T3. Have your patients aim their macros to at least 20 percent carbs and 10 percent protein. The increasingly popular keto diet may not be appropriate.

Other Strategies to Improve Thyroid Function

I deal with thyroid disorders often in my practice, and they can be very complex conditions. For more information, check out my articles about the thyroid’s connection with cardiovascular disease, the gut microbiome, blood sugar, and more. Beyond limiting goitrogenic foods, other strategies I recommend to improve thyroid function include the following:


9 Ways to Improve Your Memory if You Have Hypothyroidism

Diet, Foods & Strategies for Hypothyroidism “Brain Fog”

Use reminders on your phone to keep you on schedule.


Forgetting where you left your keys, having a name slip from your mind, struggling to concentrate — these can all be part of frustrating brain fog or memory issues related to hypothyroidism.

Thyroid hormone regulates metabolism in every organ of the body, including the brain. When thyroid hormone is low, it can affect your memory span and ability to concentrate.

For many people, brain fog is a fleeting symptom. When hypothyroidism is diagnosed and treated early, metabolic processes normalize and you may not have a problem with memory issues or other symptoms hypothyroidism can cause, says Joel Zonszein, MD, an endocrinologist and director of the Clinical Diabetes Center at Montefiore Medical Center in New York.

But if you don’t take medication and continue to have a very low thyroid hormone level, you could end up with severe or persistent hypothyroidism, which can cause many changes in your body. In addition to weight gain, swelling, and vascular changes, your hypothyroidism symptoms can include cognitive problems. But these are extreme cases, Dr. Zonszein adds.

The good news: It’s very easy to test your thyroid hormone, and the tests are sensitive enough for your doctor to know if you’re taking the right amount of medication, he says. So talk to your doctor about possible symptoms of hypothyroidism, get tested, and get treated if necessary. “If we replace thyroid correctly, memory problems shouldn’t be a factor,” Zonszein says.

Tips to Improve Your Memory

Hypothyroidism that’s treated properly shouldn’t cause persistent brain fog or memory concerns. But anyone can experience issues with memory or concentration from time to time. These strategies can help:

Take your medication.

 The best thing you can do for your memory is to get your thyroid hormone back to a healthy level, and that means taking your medication regularly and correctly and going back to your doctor for follow-up appointments to be sure you’re taking the right dosage, Zonszein says. The American Thyroid Association says it’s best to take your thyroid hormone on an empty stomach at the same time every day, and to not stop taking it without first talking to your doctor.

Get the house, and get moving. Staying active has an important effect on the brain, so keep up with your hobbies and social activities, along with exercise.

Physical activity is associated with a better working brain, according to the National Institute on Aging (NIA), which says that exercise has been found to stimulate your brain’s ability to maintain old network connections and make new ones.

A study published in July 2019 in the Journal of the International Neuropsychological Society found that immediately following moderate exercise, participants showed a significant increase in memory.

Get a good night’s sleep. The deep sleep you get from a good night's slumber helps keep your brain functioning well, Zonszein says. If you have trouble falling or staying asleep, try these tips:

  • Keep your bedroom dark and cool
  • Avoid alcohol, caffeine, and heavy meals too close to bedtime
  • Practice a relaxing bedtime ritual, taking a warm bath, meditating, or reading a book you enjoy
  • Stick to a schedule: Go to sleep and wake up at the same time every day, even on the weekend

Play memory games. Anything that keeps your mind working, including computer games designed to make your brain sharper, is a good idea.

Focus on one thing at a time. Set your attention on only one thing, eliminate distractions TV, and try not to let your mind drift to other things. When you focus this, you’re more ly to be able to concentrate and remember what you’re doing, notes the American Psychological Association.

Stick to a schedule. When you do something at the same time every day and in the same sequence, it will be easier to remember.

Use tools to help you remember. If brain fog has you forgetting appointments, use tools to-do lists, sticky notes, reminders on your phone, or a large wall calendar to help you stay on track, the NIA recommends.

Designate a place for your things. Keep your keys, wallet, purse, glasses, day calendar, and phone in the same place so you’re less ly to misplace them.

Repeat names and other important information. When you meet someone new or a doctor is giving you important information about your health, repeating the information back to the person or in your mind a few times can help you remember, Zonszein notes.

Thyroid problems can last a lifetime, so it means you’ll have to continue taking medication and seeing your doctor to ensure your levels stay healthy. But taking those steps to get treatment also means that memory issues related to hypothyroidism won’t last.