Every time a new study is published about brain health and Alzheimer’s, my ears perk up. When the research focuses on nutrition and lifestyle factors, it really gets my attention. So, when a recent study compiled evidence suggesting the mineral, selenium, is deficient in the brain tissue of those with Alzheimer’s, I made a cup of tea and put on my reading glasses.

Essential Nutrient Linked to Alzheimer’s Risk

What this study emphasizes is the crucial importance of nutrition, and subsequently micronutrients, for preventing and healing disease. It also speaks to the value of treading lightly on our bodies by avoiding “insults” like alcohol, smoking, poor diet, pollution, and toxins. The harder we are on our bodies, the more nutrients the body needs to repair damage.

This is what you need to know about selenium deficiency and how to prevent it.

This is what you need to know about selenium deficiency and how to prevent it.

1. What is selenium?

Selenium is a trace mineral found in soil that makes its way into crops and grass-eating livestock and then into our bodies when we consume these foods. This mineral is critical for thyroid function but also plays a huge role in immune function and damage prevention. Selenium works with vitamin E to prevent and reduce inflammation and recycles vitamin C to boost your immune system. Last but not least, selenium is required to create the body’s master antioxidant, glutathione, which not only protects cells from free radical damage but also helps your liver detoxify.

2. How does selenium deficiency affect the brain?

Selenium’s ability to regulate the immune system and reduce inflammation is especially important for cognitive function and the prevention of cognitive decline. Brain health is dependent upon maintaining low inflammation but also on having a strong enough immune system to handle tasks like attacking pathogens or clearing out damaged or dead cells.

This may be especially important for Alzheimer’s disease because protein structures called beta-amyloid plaques, found in the brains of Alzheimer’s patients, build up in brain tissue. This is actually a powerful immune response to damage, but if the proteins aren’t broken down and cleared out, they interrupt brain cell communication and blood flow, which leads to more dead brain cells.

Selenium doesn’t stop there; it also helps prevent damage in the first place.

Selenium reduces oxidative stress, the condition that happens when the body has more free radicals floating around than antioxidants to neutralize them.

Less free radicals mean less damage to brain cells and other tissues around the body.

This study is important, but it brings up questions. Does an inflamed brain use more selenium than a healthy brain; is that why levels are low? Or, could it be that a selenium deficiency reduces the brain’s ability to manage inflammation, which leads to damage? Either way, making sure that you’re getting essential nutrients like selenium is vital for preventing chronic diseases like Alzheimer’s. This is how to do it.

3. Boost Your Daily Selenium Intake

Essential Nutrient Linked to Alzheimer’s Risk

Eating more selenium-rich foods is a great way to increase your levels. People 14 and older should eat about 55-400mcg per day, a pretty large range. Eating 2 brazil nuts per day contains an average daily serving of selenium around 150mcg in total. It’s important not to overdo it because too much selenium can lead to side effects like nausea, neurological problems, hair loss, and brittle nails.

The highest food sources of selenium include:

  1. Brazil nuts
  2. Sunflower seeds
  3. Pinto beans
  4. Halibut
  5. Sardines
  6. Grass-fed beef
  7. Wild-caught salmon
  8. Beef liver
  9. Oats
  10. Navy beans
  11. Chicken
  12. Turkey
  13. Eggs
  14. Spinach
  15. Lentils


Selenium is an important micronutrient that supports optimal health and disease prevention, but it’s definitely not the only one. It’s important to know that each body has unique requirements for nutrition based on genetics, environment, and health history. That’s why I utilize comprehensive and advanced testing to identify every patient’s specific risk factors for cognitive health and chronic disease. This individualized approach underpins the foundation of the functional medicine mission to find the distinct root causes of imbalance in each patient so that we can support the body’s innate healing from the inside out.

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