Heavy Metals Found In Popular Health Foods – And How To Avoid 

Heavy metals are like many toxins we talk about in the food supply – microplastics, PFAS, pesticides – you can’t see or taste them and might not even know they are there.

However, small amounts of toxins in food, throughout days and weeks, and eventually over a lifetime, impact health in tragic ways that we continue to uncover. 

Often, we think we are doing the right thing by choosing healthy foods but are unaware of the contamination.

In today’s article, we are going to take a closer look at heavy metals and hidden sources in food. 

Read on to learn more about:

  • Heavy metals
  • How heavy metals get into food
  • Specific concerns with arsenic, lead, cadmium and mercury
  • Surprising places you might find heavy metals in your diet
  • Tips for reducing these metals and finding more information

Heavy Metals

Metals exist in the environment in rocks, soil, air and water. Some metals, known as minerals, are essential for health.

These include:

  • Calcium
  • Iron
  • Copper
  • Zinc
  • Selenium
  • Sodium
  • Potassium 
  • Manganese
  • Molybdenum
  • Iodine
  • Other trace minerals

Other metals, known as heavy metals, are not natural components of the human body.

While small levels naturally exist in the environment, the high levels of heavy metals we find as contaminants are due to human activity, and especially industry.

Once these metals are displaced, they persist and pose risks to the environment and human health. 

Examples of heavy metals include:

  • Aluminum
  • Antimony
  • Arsenic
  • Barium
  • Beryllium
  • Cadmium
  • Lead
  • Mercury
  • Silver
  • Strontium
  • Nickel
  • Rubidium
  • Thallium
  • Uranium
  • Vanadium

Heavy Metals In Food 

How do heavy metals get into our food?

Heavy metals that contaminate the environment make their way into food via:

  • Uptake from the soil into plants
  • Agricultural practices
  • Manufacturing processes
  • Water use in agriculture and food production  

Geographical areas and past or current local contamination may make some food or food products higher than others.

In addition, we now know that heavy metals are also transported in the environment bound to microplastics. 

This is another way that water use in agriculture and food processing may raise the heavy metal levels in certain foods. 

The U.S. Food and Drug Administration sets levels for some heavy metals in some food products, but in some cases, the levels are set too high, or no guidance is provided at all. 

Let’s look at some of the specific heavy metals that make their way into the food supply.

Arsenic 

Arsenic contaminates the environment from mining, fracking, coal power plants, arsenic-treated wood and arsenic-based pesticides. Inorganic arsenic is the most toxic form and is carcinogenic.

It has been linked to an increased risk of cardiovascular disease, skin lesions, skin cancer and bladder cancer. In utero and childhood, exposure impacts cognitive development and memory. 

Lead

Lead is found in soil as a result to industry and contamination of lead-containing products such as paint.

Lead is absorbed by plants and may be concentrated in certain plant-based food products and supplements.

Water contaminated with lead, from lead pipes for example, used in the manufacturing of food products also contributes. 

Lead is toxic and damages the brain and nervous system, which is particularly detrimental to children. It slows growth and development, contributes to behavioral problems and decreases IQ levels. 

Cadmium

Cadmium is another heavy metal that makes its way into water, air and soil from industry, including mining and the burning of fossil fuels.

Cadmium is also used in agriculture as a component of certain pesticides, fertilizers and sewage sludge. Some plants absorb more cadmium from the soil than others.

Cadmium is also a component of cigarette smoke and paint.

Cadmium is carcinogenic and may be related to many common cancers including breast, lung, prostate, pancreatic and renal cancers. Cadmium exposure also increases the risk for osteoporosis. 

Mercury

Mercury is another global heavy metal pollutant. It enters the environment from its use in metal refining, electric appliances, light bulbs, batteries, thermometers, dental amalgams and other human goods.

It’s also produced from fossil fuel production and used in agricultural and chemical applications. Mercury circulates globally, accumulating through the food chain. 

Once in the body, mercury may be hard to detoxify, especially for those with methylation issues.

Mercury exposure has been linked to reproductive harm and negatively impacts fertility, pregnancy outcomes and development. For these reasons, it is considered an endocrine disruptor. Mercury is a neurotoxin and immunotoxin. 

Most of us are aware that mercury levels in seafood are an issue, but if not, read Is Seafood Good For You?  There may be other, often surprising, foods that contain heavy metals. 

Hidden Sources Of Heavy Metals In Your Food

Here are some food and food products to be aware of:

Rice 

Rice is a staple around the world, but also one of the leading dietary sources of arsenic. This is because rice may absorb up to 10 times more heavy metals from the soil than other grains and soils conducive to rice farming are more likely to be contaminated with arsenic. 

In the United States, fortified rice cereals are recommended as baby’s first food, so arsenic contamination is of particular concern. 2020 FDA testing of 149 rice cereals found an average of 85 ppb (parts per billion) of inorganic arsenic, with a range of 22 to 142ppb.

A 2021 U.S. House of Representatives report found high levels of arsenic, lead and cadmium in baby food, including many popular brands, some of which are organic. You can read the report here. 

The FDA has set a target of arsenic under 100ppb, although ideally there would be no detectible levels in food, since no amount is safe, especially for children. 

Tips for reducing arsenic and other heavy metals in rice:

  • Consider alternative first foods for baby such as egg yolks, meat, avocados and sweet potatoes. 
  • A Paleo diet excludes grains, and therefore often decreases heavy metals in the diet. 
  • Reduce arsenic in rice by soaking (and discarding the water) or rinsing rice before cooking. Cook rice like pasta with a higher ratio of water to rice. Consider Jasmin or Basmati rice as they typically have lower arsenic content.

Chocolate

Poor-quality chocolate carries social and environmental issues such as rainforest deforestation and slave labor.

In the Functional Medicine community, we turn to high-quality, dark, fair-trade chocolate for Paleo treats and antioxidant benefits. However, even high-quality chocolate may contain cadmium and lead. 

U.S. chocolate products tested contained cadmium at levels from 0.004 to 3.15 mg/kg and lead from undetectable levels up to 0.38mg/kg.

The U.S. government has not set a target level for heavy metals in chocolate, but the World Health Organization (WHO) has set a level of 0.3mcg of lead per gram of cacao.

California Prop 65 requires chocolate to contain a warning label if cadmium levels are higher than 4.1mg for a daily serving. 

Higher levels of these metals correlate with the source of chocolate, the percent cocoa used in the chocolate as well as the type of cacao bean used.

And while soil contributes, chocolate is more likely to be contaminated through processing and shipping. 

Tips for enjoying chocolate without heavy metals: 

  • Check your favorite chocolate bar using these independent test results from As You Sow. 
  • Choose chocolate brands that test their source ingredients and final products for heavy metals and other contaminants and who are transparent with their results. 

Protein Powder

Protein powders are a staple in many health-conscious kitchens and provide a convenient way to meet our daily protein needs, especially for smoothie lovers.

However, protein powders are another source of heavy metals, including lead and cadmium, as well as other contaminants such BPA. 

The Clean Label Project conducted a study of 134 top-selling protein powders in 2018. What they found might shock you. The study found:

  • 70 percent of protein powders contained lead, 74 percent contained cadmium and 55 percent contained BPA. 
  • Organic protein powders contained up to 4.8 times more cadmium and up to 1.5 times more of both lead and arsenic than non-organic protein powders. 
  • Plant-based protein powders tested worse than powders from an animal source, with 75 percent positive for lead. 

Tips for heavy-metal free protein:

  • Check the Clean Label Project study for results on your favorite powder here. 
  • Choose animal proteins from food, or animal protein powders, such as egg protein more often. 
  • Choose protein powders that have been tested for contaminants, with transparent results and that have been vetted by your Functional Medicine provider. You can find Dr. Shippy’s picks here. 

Mushrooms

Edible and medicinal mushrooms may be another food source of heavy metals. Mushrooms absorb metals from the environment in which they grow.

Lead and cadmium accumulate in the caps of the mushrooms and correlate with soil levels. 

Mushroom-related tips: 

  • Diversify the mushrooms you eat. Choose mushrooms from a known source, such as wild foraged local mushrooms. 
  • Be aware of mushrooms in supplements  and mushroom extracts in food products. Ask for testing and transparency from manufacturers. 

Turmeric

Turmeric is one of the most beloved spices for its contribution to delicious cuisine and medicinal, anti-inflammatory properties.

Just as we care about the source of our vegetables or meats, spices deserve some attention as well. 

One study of turmeric samples purchased in Boston in 2011 and 2012 revealed an average lead concentration of 0.11 parts per million (ppm), with 99.5ppm being the highest.

The FDA does not have guidelines regarding lead in spices but allows 0.1 ppm in candy. Sixteen of the 32 samples were above this level.

The study authors hypothesize that in some cases lead is intentionally added to spices to improve weight and color, and this is of great concern especially considering some lead poisoning cases that may be linked to consumption.

Turmeric is often a spice involved in product recalls. 

Again, it is very important to know your source and purchase from companies knowledgeable about these issues and who are taking action to provide you with spices of the best quality and purity. 

Heavy metals show up in some surprising places.

When we know where heavy metals are hiding, we can take specific actions to limit exposure.

It may also be helpful to have heavy metal testing, from time to time, and work with your Functional Medicine provider for detoxification guidance. 

References

  1. https://www.fda.gov/food/chemicals-metals-pesticides-food/metals-and-your-food 
  2. https://www.fda.gov/food/metals-and-your-food/arsenic-food-and-dietary-supplements 
  3. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7745115/ 
  4. https://annalsofglobalhealth.org/articles/abstract/10.1016/j.aogh.2014.09.005/ 
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  9. https://www.fda.gov/media/135552/download 
  10. https://www.consumerreports.org/arsenic-in-food/fda-sets-limits-for-arsenic-in-baby-rice-cereal/ 
  11. https://oversight.house.gov/sites/democrats.oversight.house.gov/files/ECP%20Second%20Baby%20Food%20Report%209.29.21%20FINAL.pdf
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