Spring is in the air—and so are the annual testing lab reports on everything from cars to washers and dryers and even lead in fruit juices. That report reminded me of how fortunate I am that I understand where our food comes from. With my background in Food and Nutrition Sciences, I was not shocked to know that low levels of metals—such as lead, cadmium and arsenic—are present in our day-to-day meals.
As a typical science nerd, I’ve memorized every element on the classic periodic table and learned that most elements are found naturally on the earth. Elements can be solid or liquid and metals are typically seen in their solid forms.
Elements Are Essential for Life
My nutrition training has helped me understand how natural elements can promote good health and are critical to sustaining life.
We interact with some elements more than others. Some elements help us build strong bodies and others help us build the structures and technologies that make our lives easier. In addition to commonly known elements, like oxygen, carbon, and hydrogen, there are dozens of others on the periodic table that are particularly necessary and beneficial to our health and well-being. For example,
- Zinc supports a healthy immune system and growth.
- Calcium promotes strong bones and muscles.
- Magnesium keeps the biochemical functions in our bodies regulated.
It All Starts in the Soil
Plant-based foods and beverages all start in the soil. Plant life depends on the elements that are naturally present in the earth to grow. When fully grown, these plants are harvested, cleaned and sometimes processed to become the familiar foods we enjoy every day.
Our bodies don’t produce every nutrient we need. We rely on our food to receive many of them. As part of their own growth process, plants take up all-natural forms of elements from the soil, air and water using their roots and stomata. Along the way, trace levels of natural metals in the soil make their way into the plant and, like the elements that promote good health, are detectable in our food supply. Metals such as lead, arsenic and cadmium can be detected at very low levels in our food.
Human exposure to these metals is much lower than everyday exposure from the environment where we live, work, and play. Most homes built prior to 1978 used lead-based paint and can still be present under layers of new paint—potentially causing their residents to be exposed every day.*
*It is important to note that the U.S. federal government banned the use of lead-based paints in 1978. Source: U.S. Environmental Protection Agency, 2019
All Elements Are Not Essential
Although most elements have similar Earth-bound origins, their impact to public health is very different. Some elements—like zinc, magnesium and calcium—are essential to life. However, other metals metals—such as arsenic, cadmium and lead—can result in adverse health effects if a person is exposed to extremely high doses for extended periods of time. Lead is especially harmful to vulnerable populations and can negatively impact a child’s brain health and development. Excessive exposure to any element can be toxic, and monitoring programs are in place globally to ensure that dietary exposure is minimized. CODEX, an internationally recognized body of standards, codes of practice and guidelines for safe food and animal feed, also sets accepted maximum levels for cadmium, lead and arsenic in food.
- Cadmium, a “heavy metal” like lead, arsenic, cobalt, mercury and nickel, is detected at very low levels in food as well as in lipsticks and cosmetics. Overall these amounts do not pose a public health risk.
- Lead, like other heavy metals, does not biodegrade or disappear from the environment over time. Low levels of lead continue to be detected in some foods due to the continued presence of lead in the environment.
- Arsenic levels in the environment are generally low but can vary depending on the natural geological makeup of local areas. Contamination from mining, fracking, coal-fired power plants, arsenic-treated lumber, and arsenic-containing pesticides also contributes to increased levels of arsenic in certain locations.
Source: The Food and Drug Administration: Metals
Getting the Lead Out of Food
It’s not as easy as you might think. The levels of metals in our food supply are extremely low. Plants can’t distinguish arsenic from calcium, which makes it nearly impossible to eliminate one without the other. Plus, the benefits of the whole food often do better for public health than harm from exposure to metals.
Since metals can’t be completely taken out of your favorite foods, there are ways to reduce its uptake—starting in the soil. According to the Food and Drug Administration’s Toxic Metals Strategy, researchers are working to understand the role of weather conditions, agriculture practices and water sources as ways to reduce metal exposure in the soil.
In addition, much effort is underway to reduce workplace exposure to these metals. The Centers for Disease Control and Prevention provides recommendations to reduce exposure in occupational settings and to reduce “take-home exposure” for those who work as miners, construction workers and artists.
Metals Are Not Added to Food
While most elements are naturally found on Earth, some are residues from stars and others are naturally made, which is the closest to nature itself. Even though metals can be detected at trace levels in food, they are extremely low given the global monitoring systems that are in place.
The Moral of My Story
Don’t be shocked to hear about trace levels of metals in your food. They are quite low given a balanced diet and are not a major threat to your health, unlike some other environmental sources. After all, elements are essential for life. And isn’t daily life enough of a shocker without having to think about metals in your food?
This blog post was written by Cassandra Maya, PCQI.