Treat Your Thyroid To Heal Your Brain

Let me run some symptoms past you…

Are you experiencing brain fog, anxiety, nervousness, irritability, mood swings, memory loss, fatigue, depression, lack of motivation, or reduced libido?

Conventional doctors will probably tell you these symptoms are all either part of the “natural aging process,” or you might even be told you have mental health problems.

They couldn’t be more wrong.

The likelihood is that they have absolutely nothing to do with your age or mental health.

Instead, the real problem could be one of America’s most misdiagnosed and misunderstood conditions. I’m talking about an overactive thyroid gland.

You see, the small, butterfly-shaped organ that sits just below your voice box has now been directly linked to brain damage.

This condition is also known as thyrotoxicosis or hyperthyroidism, an autoimmune condition in which your antibodies attack and stimulate the gland to produce an excess of thyroid hormone. And it now affects around 1 in 100 Americans over the age of 12.1

You see, in the past 40 to 50 years, huge quantities of environmental toxins and hormone-disrupting chemicals have contaminated your food supply, the water you drink, and the air you breathe.

As these pollutants build up in your body, your thyroid is one of the first organs to malfunction and become diseased, as irritants and toxins, like fluoride and chlorine, as well as chemical additives, attach themselves to receptors on your thyroid.

Mainstream medicine rarely pays attention to your thyroid – until it goes haywire. And then the more common diagnosis is hypothyroidism or an underactive thyroid.

But most doctors are unaware that a growing body of scientific evidence links an overactive thyroid to physical changes in your brain.

I’ve been observing the mental effects of high thyroid hormone levels for many years, and recent studies now prove the physiological and psychological


Researchers at the University of Gothenburg, in Sweden, studied the MRI brain scans of 62 people with Graves’ disease – the most common form of hyperthyroidism. And they were amazed to discover that high levels of thyroid hormones caused the amygdala and hippocampus in the brain to shrink.2

Both the amygdala and hippocampus sit together deep in your brain and are involved in your emotions, memory, appetite, motivation, pleasure, and stress responses.

So, it’s no surprise that high levels of TSH might be mistaken for mental health problems.3

The good news is that the Swedish study also revealed that shrinkage of the amygdala and hippocampus could be reversed by restoring thyroid hormones to their normal levels.

The first best way to test thyroid function is to measure your levels of thyroid-stimulating hormone (TSH) in a blood sample.

Conventional doctors will almost always prescribe methimazole for an overactive thyroid. But this Big Pharma drug doesn’t maintain thyroid health. Instead, it merely treats the symptoms of a disorder caused by our toxic environment.

Here at the Sears Institute for Anti-Aging Medicine, I tell my patients that eating a low-iodine diet is key to treating an overactive thyroid gland.

The mineral iodine plays a key role in making thyroid hormones. Therefore, a low-iodine diet helps to reduce thyroid hormones. I recommend adding these foods to your daily diet:

  • Non-iodized salt
  • Coffee or tea
  • Egg whites
  • Unsalted nuts
  • Nut butters
  • Oats
  • Raw honey
  • Bamboo shoots
  • Bok choy
  • Broccoli
  • Brussels sprouts
  • Cauliflower
  • Collard greens
  • Kale

Treat your thyroid to heal your brain

Here at the Sears Institute for Anti-Aging Medicine, I recommend a number of natural supplements to my patients to help reverse hyperthyroidism. Here are three of them:

    1. Iron: Low levels of iron and anemia are extremely common, with an overactive thyroid gland. You see, hyperthyroidism produces high amounts of ferritin, a protein that helps your body store iron. While it may seem logical that increasing iron storage would prevent anemia, the opposite is often true. High ferritin can trigger an inflammatory response that prevents the body from using iron normally. To support thyroid function, I recommend foods that are rich in iron. You can get plenty of iron from foods like dried beans, leafy vegetables, lentils, poultry, and grass-fed red meat.
    2. Magnesium: Deficiencies in magnesium have been linked to hyperthyroidism and goiter (an enlarged thyroid gland). Certain nuts, such as almonds, and green leafy vegetables like spinach and chard, are rich in magnesium, but it’s hard to get enough of this important nutrient from your diet. I recommend Magnesium Citrate at a dose of 600 mg a day to support your thyroid.
    3. Acetyl L-Carnitine: L-Carnitine is an amino acid shown to reduce or prevent hyperthyroid symptoms. A clinical trial found that L-carnitine positively affected weakness and fatigue, shortness of breath, anxiety, heart rate, insomnia, bone mineral density, and palpitations.4 The best source of L-carnitine is grass-fed red meat. But you can also supplement. I suggest taking at least 500 mg of acetyl-l-carnitine daily on an empty stomach. Look for a formula with only L-carnitine and not D, L-carnitine. D-carnitine is synthetic.

To Your Good Health,

Al Sears, MD, CNS


1. De Leo S, et al. “Hyperthyroidism.” Lancet. 2016;388(10047):906–918.
2. Mats Holmberg, et al. “A Longitudinal Study of Medial Temporal Lobe Volumes in Graves Disease.” J Clin Endocrinol Met. 2022 Mar 24;107(4):1040-1052.
3. Bremner JD, et al.  “Hippocampal volume reduction in major depression.” Am J Psychiatry. 2000 Jan; 157(1):115-8.
4. Benvenga S, et al. “Usefulness of L-carnitine, a naturally occurring peripheral antagonist of thyroid hormone action, in iatrogenic hyperthyroidism: a randomized, double-blind, placebo-controlled clinical trial.”  J Clin Endocrinol Metab. 2001 Aug;86(8):3579-94.