Autism Dietitian


Autism Dietitian Blog

Heavy Metal and Essential Trace Element Levels in Hair and Autism Severity

A recent study has found a significant and positive correlation between hair metal burden (lead, aluminum, arsenic, and cadmium levels) and severity of autism symptoms including social communication deficits and repetitive, restrictive behaviors [1].

Heavy metals are dense metals that are typically toxic at low concentrations, while trace elements (or micronutrients) are elements that are essential in a living organism, but in very small amounts (less than 0.1 percent by volume).

Heavy Metals

  • Aluminum

  • Arsenic

  • Lead

  • Mercury

  • Nickel

  • Lithium

  • Beryllium

  • Cadmium

  • Uranium

Trace Elements

  • Chromium

  • Cobalt

  • Manganese

  • Zinc

  • Copper

  • Selenium

  • Iron

  • Magnesium

  • Molybdenum

Heavy Metals Graphic.png

Results of the Study

This study [1] found a positive correlation between the severity of autistic symptoms (social communication deficits and repetitive, restrictive behaviors) and hair metal amounts of lead, aluminum, arsenic, and cadmium. They also found that hair zinc levels were inversely related to age and also found that the severity of autism and zinc levels had a negative, significant association. Individuals who had lower amounts of zinc also tended to have a higher severity of autistic symptoms, such as defective functional play and creativity and an increase of stereotyped behavior. Lead, molybdenum, and manganese hair levels were found to be inversely correlated with cognitive level.

In summary:

  • ↑ Lead, Aluminum, & Cadmium = ↑ ASD Behaviors (↓ social communication + ↑ repetitive, restrictive behaviors)

  • ↑ Age = ↓ Zinc Levels

  • ↓ Zinc = ↑ ASD Symptoms (↓ functional play and creativity + ↑ stereotyped behavior)

  • ↑ Lead, Molybdenum, & Manganese = ↓ Cognitive Level

Testing for Heavy Metals + Trace Elements

There are many ways to test for heavy metals - through hair, urine, or other body tissues (blood, fingernails, and other body tissues). There are some heavy metals that don’t stay in the bloodstream for very long, so testing through hair is one of the better ways to measure long-term exposure since it can capture previous exposure. I often order this panel for my clients, and it’s an easy at-home hair collection. This at-home test will capture levels of 17 toxic metals and 22 essential elements:

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Interested in testing for heavy metals?



Treating Heavy Metal Toxicity

If high levels of heavy metals are detected, there are a few ways we can help the body detox. Finding the source of exposure is always the first step. For example, children can be exposed to high levels of lead from lead-based paints (found in older houses, as lead-based paint was banned in 1978), water pipes, imported canned goods, contaminated soil, certain imported toys, and household dust. Eliminating the source of the lead would be our first step to stopping the lead toxicity, and from there we can move on to other ways to help the body detox.

Our bodies naturally detox, and it is the primary function of our liver and kidneys. Many times, our own bodies will be able to excrete these levels of heavy metals after the source is removed. Other ways to help our bodies detox can be nutrition supplements (like activated charcoal - talk to your doctor before starting), certain binding drugs, or in severe cases, chelation.

Preventing Heavy Metal Toxicity

  1. Test your water supply for heavy metals. The EWG has a great resource: Tap Water Database to help give you the typical status of water in your area. You can also do an at-home test

  2. Wash your hands and child’s toys often. Wash their hands after outdoor play, eating, and bedtime

  3. Remove shoes before entering the house to decrease tracking in contaminants from the soil and ground

  4. When boiling water, always start with cold tap water. Hot tap water increases the risk of heavy metals and other elements leeching into your water

  5. Use a water filter - this water filter is my favorite

  6. Keep your home well maintained. Analyze your home’s paint, pipes, and keep up with maintenance and codes.




[1] Blaurock-busch E, Amin OR, Dessoki HH, Rabah T. Toxic Metals and Essential Elements in Hair and Severity of Symptoms among Children with Autism. Maedica (Buchar). 2012;7(1):38-48. LINK