ON SOCIAL MEDIA, certain influencers love to throw around the word “toxic.” Seed oils are toxic. Oatmeal is toxic. Kale is toxic. But these claims are often false or misleading.
Toxins are a real concern. But anything (even water) can be toxic if you’re exposed to too much of it. So you need nuance to fully understand whether something is potentially toxic and could actually harm you, says Ryan Marino, MD, a medical toxicologist, emergency physician, and associate professor at the Case Western Reserve University School of Medicine in Cleveland, Ohio.
“Anyone using the word “toxin” right off the bat—people should be careful about where it’s going because there’s a ton of misinformation out there,” he says.
Here’s what toxicologists want you to know about toxins, including how they’re measured and how to parse through the misinformation about them.
What exactly is a toxin?
TRADITIONALLY, THE TERM “toxin” refers to a chemical produced by a “living organism,” such as a plant, animal, bacteria, or virus, that’s poisonous, explains Ziad Kazzi, MD, president of the American College of Medical Toxicology’s board of directors. That could include snake venom or certain kinds of mushrooms, for example.
On the other hand, a “toxicant” typically refers to manmade substances, such as forever chemicals or other synthetics, that may be poisonous, he says.
However, regular people (that is, not doctors or scientists) often use “toxin” to encompass both categories, and Dr. Kazzi says that’s usually OK for general discussions.
How toxins are measured
IT’S IMPORTANT TO note that anything can be toxic in a certain amount, says Jack Kain, PharmD, director of medical affairs and medical science liaison of drug monitoring and toxicology at Quest Diagnostics. Toxicologists measure toxic amounts in a few different ways.
LD50
“There’s an old saying in toxicology, ‘the dose makes the poison,’ which implies, if you take too much of almost anything, even something as simple as water, it can be toxic,” Dr. Kain says. A high dose of some toxins is necessary to be harmful, while small doses of other toxins can be dangerous.
The LD50, or the median dose of a substance that would be lethal to 50 percent of a population, is one way the effects of an amount of a toxin can be measured, Dr. Kazzi says.
However, Dr. Marino explains that most LD50 studies have been done on animals, so doctors don’t always know a substance’s LD50 for humans. “You can’t readily test poisoning people,” he says.
He uses the example of fentanyl. It’s a commonly prescribed medication that’s safe in the right dose, but it’s deadly when someone takes too much, and the drug has been responsible for many overdose deaths. But Dr. Marino says experts haven’t studied fentanyl’s specific LD50 for humans.
Long-term exposure
Toxins can also be something you’re exposed to in low levels over a long period of time, which could affect your health down the road, Dr. Kain says.
For example, forever chemicals, like PFAS, are found in many different products that you may come in contact with every day. However, research is ongoing to fully understand their long-term health impacts.
Lead is another example. Dr. Marino says the body can store lead over time, potentially leading to health consequences.
Doctors can test your blood or urine levels for some toxins to determine how much is in your body, including whether it’s from a large or small dose—but not always, Dr. Kazzi says.
Is exposure to toxins always dangerous?
EVERY DAY, YOU come into contact with toxins. But being exposed to a toxin doesn’t necessarily mean it will harm your health, Dr. Kazzi says.
Everyone responds to these substances differently, Dr. Kain says. Someone’s age, weight, genetics, and overall health can determine how a toxin affects them. Dr. Kazzi says children, older people, pregnant and breastfeeding women, and people with chronic health conditions may be more likely to be affected by toxins, even small amounts.
For most healthy people, the body “has adapted very well to dealing with some amount of exposure to these potentially toxic things,” Dr. Marino says. Your liver and kidneys are your body’s primary detoxifiers and can help excrete these substances. Your lungs and digestive system also play a role, Dr. Kain says.
When to worry about toxins
IF YOU KNOW you’ve been exposed to something potentially toxic, seek emergency medical care. Some signs that this may have happened include headache, dizziness, weakness, trouble breathing, slow heartbeat, skin changes, sweating, nausea, or vomiting, according to the American Red Cross.
If you’re generally worried about long-term exposure to various toxins, talk to your primary care doctor, Dr. Kazzi says. They can address your concerns and potentially do a blood or urine test.
When you see people on social media mentioning that various foods, products, or substances are toxic, Dr. Marino suggests taking the information with a “grain of salt.”
Toxins are real and can be harmful to your health, Dr. Marino emphasizes. But, he says, people often misunderstand toxins, and some information about them on social media is misleading.
Information about toxins is also often oversimplified and ignores the nuances of the impact of toxic substances, Dr. Kain says, which can lead to “fear-based mongering.” He suggests doing your own research, including talking to your doctor, if you’re worried about something you see online being toxic.
Erica Sweeney is a writer who mostly covers health, wellness and careers. She has written for The New York Times, HuffPost, Teen Vogue, Parade, Money, Business Insider and many more.
