Heavy metals in food 101 (And does LMNT contain heavy metals?)

Assuming you have eaten real food this week, you’ve almost certainly consumed heavy metals.

The truth is, it’s practically impossible to avoid heavy metals in food. Spinach has them. Cauliflower has them. Nuts have them. Even wine has them.

This isn’t meant to scare you. Consuming trace amounts of heavy metals in food is inevitable and generally safe. If it were unsafe, everyone eating whole foods would be getting sick–and across scientific literature, consuming more fruits, vegetables, and other whole foods correlates with better health.

My point is, the human body can typically handle (and excrete) the minuscule amounts of heavy metals found in real foods. But that doesn’t mean we should never concern ourselves about heavy metals.

For instance, I wouldn't recommend people (especially pregnant women) consume tuna or swordfish regularly. Both these species of fish are high in mercury, a heavy metal that is toxic to multiple organ systems. Also, some packaged foods are contaminated with harmful levels of lead during the manufacturing process. Candy is the infamous example.

Regulators have drawn up a handful of laws to protect consumers from toxic exposure. Proposition 65, for example, requires that products sold to anyone living in California bear a warning label if they contain unacceptable levels of heavy metals.

I’ll talk more about Prop 65 later. I’ll also talk about the steps we take at LMNT to ensure our electrolyte drink mix is safe for everyone who consumes our product—including your family and mine. First though, let’s take a minute to discuss the basics of heavy metals.

What are Heavy Metals?

The term “heavy metals” refers to a group of elements with a high molecular weight compared to water. Metals are not innately bad. Some of these elements play essential roles in the human body, while others do not.

Iron, for instance, is required to produce hemoglobin (the component of blood which carries oxygen), synthesize DNA, and produce energy as ATP. Zinc, copper, and manganese are also heavy metals with crucial biological functions.

Other heavy metals—including arsenic, lead, cadmium, and mercury—serve no biological role. When talking about heavy metals, these are the minerals most people mean.

All heavy metals (including the undesirable ones) are ubiquitous in nature. Because of this, they’re found in much of the food supply. For context, I’ve listed the heavy metal concentrations in four common consumables below.

Note: this data comes from the US FDA Total Diet Study, an ongoing program that tests common foods for nutrients and contaminants. The levels in the study are listed as mg/kg, but we converted them to micrograms (mcg) per 3 ounces so we can more easily compare to Prop 65 limits later.

Heavy Metals in 4 Common Foods per 3-ounce Serving:

#1: Spinach

Lead: 0.34 mcg

Mercury: 0.03 mcg

Arsenic: 0.03 mcg

Cadmium: 15.6 mcg

#2: Cauliflower

Lead: 0.04 mcg

Mercury: 0 mcg

Arsenic: 0 mcg

Cadmium: 0.77 mcg

#3: Peanuts

Lead: 0 mcg

Mercury: N/A

Arsenic: 0.43 mcg

Cadmium 3.74 mcg

#4: Red or white table wine

Lead: 0.60 mcg

Mercury: N/A

Arsenic: 0.68 mcg

Cadmium: 0.09 mcg

As you can see, even healthy foods like spinach contain heavy metals. Is this a cause for concern?

Health Impact of Heavy Metals

All heavy metals (even the essential ones) become toxic at high enough concentrations. Iron overload can cause serious organ damage, excess arsenic can increase cancer risk, excess lead can damage brain cells, and so on.

Let’s zoom in on lead for a moment. Compared to adults, children absorb lead at higher rates. Because of this—and because children tend to have more lead exposure (e.g., via fake jewelry, vinyl or plastic products like bibs, car seats, backpacks, and lunch boxes, or artificial turf athletic fields made of nylon)—children are at higher risk of cognitive impairment, kidney damage, anemia, hypertension, and other medical problems stemming from lead toxicity.

Products that use lead paint (like some toys) and contaminated tap water, air, and food are historical sources of lead exposure. And the FDA has paid special attention to lead in candy because candy often becomes contaminated in the production process.

Are heavy metal concentrations found in less-refined foods dangerous? With a few exceptions—large fish (mercury), some lower-quality dark chocolate (cadmium), and rice in large amounts (arsenic)—usually they’re not.

In general, a whole foods diet isn’t a troubling source of heavy metals. If it were, you’d see health problems linked to ancestral eating. But instead, you see the opposite. Also, understand that the human body has mechanisms for disposing of heavy metals. You excrete them through sweat, urine, and feces.

Since heavy metals are ubiquitous, you’re guaranteed to consume some of them. The trick is to avoid substantial exposure. That’s why regulators have set standards for food, water, and consumer products. For example, the U.S. Environmental Protection Agency will take action if public drinking water is found to contain over 15 mcg of lead per liter (much higher than the levels in the aforementioned whole foods). And at the state level, perhaps the most famous regulation is Proposition 65.

Prop 65 Explained

A few decades ago, Californians voted to pass the Safe Drinking Water and Toxic Enforcement Act of 1986. These days, the law is known as Proposition 65, or Prop 65 for short.

Prop 65 requires that:

  • Businesses inform Californians if their product contains any chemicals linked to cancer, birth defects, or other reproductive problems. The product can be anything that consumers use: food, clothing, Christmas lights, fertilizer, and more.
  • California businesses don’t knowingly contaminate drinking water sources with these chemicals.
  • California publishes the list of chemicals annually. (There are about 900.)

Essentially, Prop 65 is a labeling requirement. Let’s take lead as an example.

Prop 65 requires businesses to include a warning label if their product contains over 0.5 micrograms of lead per maximum daily usage. This limit was set by the California Office of Environmental Health and Hazard Assessment (OEHHA).

How did OEHHA come up with this and other Prop 65 limits? By taking the level of contamination with “no observable effect” for causing reproductive toxicity, then dividing by 1000. In other words, they took quite a safe limit and then divided it by 1000.

As you’ll recall, spinach contains about 0.34 mcg of lead per 3 oz serving. So if you have two servings of spinach, you’re over the limit set by Prop 65.

The FDA has published a more reasonable limit for lead, an “interim reference level” of 12.5 mcg per day for women of childbearing age. This limit (and the corresponding blood levels) haven’t been linked to any adverse effects.

And in case you were wondering, LMNT’s test results for all heavy metals are below not just the FDA guidance, but also the super conservative Prop 65 limits.

Does LMNT Contain Heavy Metals?

LMNT is an electrolyte drink mix that contains minerals mined from the natural world. Because of this, it does contain extremely trace amounts of heavy metals.

Remember, heavy metals are part of planet Earth. If you eat foods from planet Earth—fruits, vegetables, nuts, dairy, chocolate, potatoes, etc.—you’re consuming tiny (generally safe) amounts of lead, cadmium, arsenic, and mercury.

To completely avoid heavy metals in food, you’d need to curate your diet in a sterile lab. Test-tube meat, anyone?

One more time: LMNT comes from natural sources and therefore contains traces of heavy metals. So, how do we ensure these levels are safe? Glad you asked.

It starts with our sourcing practices and ends with our meticulous testing protocol. Let me tell you more about both.

Our mineral sourcing

We source our salt from traditional non-blast salt mines. No salt will be 100% free of impurities, but this method is the closest you can get.

Consider the problems with other types of salt:

  • Table salt is refined with chemicals like chlorine and sulfuric acid (though these, like heavy metals, also exist in nature), fortified with iodine (which people don’t always need more of), and contain anti-caking agents like sodium aluminosilicate and calcium aluminosilicate.
  • Sea salt is widely contaminated with microplastics. In animals, these tiny particles have been found in multiple organ systems.
  • Some forms of Himalayan pink salt contain unacceptable levels of lead per governmental standards.

For more on choosing a pure and healthy salt, check out this comprehensive blog.

What about the other ingredients in LMNT?

Testing protocols

At LMNT, we test all our products for mineral content, bacterial contamination, heavy metals, and other impurities. And we don’t just test once, but at every point along the production process.

We test:

  • The raw materials when we receive them
  • The bulk mix of the blended raw materials
  • The LMNT stick packs themselves (at multiple time points from the production run)

Why do we test so rigorously? To ensure that every stick of LMNT has the purity, quality, and consistency our customers and their families have come to expect.

Staying Safe With Heavy Metals

If you eat food, drink water, or breathe air, you’re taking in heavy metals. Heavy metal exposure comes with being human on this green planet.

The key is to avoid too much lead, arsenic, mercury, thallium, and cadmium in your life. And a variety of laws exist to help you do so by making informed decisions. The most stringent of these laws is the California directive, Prop 65. As a reminder: Prop 65 takes a level that’s known to be safe for a given chemical, then divides it by 1000.

Many whole foods wouldn’t pass Prop 65 standards. But LMNT does.

Thanks to our responsible sourcing practices—and our diligent testing and retesting of every batch—we can confidently say our heavy metal content is well below any recognized standards for risk established by any governing body on the planet.

We wouldn’t have it any other way. Professional athletes use LMNT. Young athletes use LMNT. We use LMNT. Our kids use LMNT.

People—including our own families—don’t just count on us to provide a tasty electrolyte drink mix to help them stay healthy, hydrated, and energized. They count on us to provide a product that’s 100% safe to consume. And that’s exactly what we’re providing.