Does Roundup Cause Cancer?

There is ongoing debate between researchers and regulatory agencies as to whether Roundup increases your cancer risk. Bayer, the manufacturer of Roundup, insists that its herbicide is safe when people follow the directions on the label.

However, the International Agency for Research on Cancer classified glyphosate, Roundup’s active ingredient, a “probable human carcinogen” in 2015. The U.S. Environmental Protection Agency disagrees and maintains that glyphosate doesn’t cause cancer in humans. Even so, mounting scientific research and legal pressures have pushed the EPA to re-evaluate glyphosate’s cancer risks and it intends to revisit its evaluation.

Outside studies have also revealed concerning findings. A 2019 study by the University of Washington, for example, found an over 40% increased risk in some cancers with high glyphosate exposure — a finding not disclosed anywhere on Roundup labels.

“All of the meta-analyses conducted to date, including our own, consistently report the same key finding: exposure to GBHs (glyphosate-based herbicides) are associated with an increased risk of non-Hodgkin lymphoma,” the authors of the study wrote.

Non-Hodgkin lymphoma is a form of blood cancer that targets a type of white blood cell called lymphocytes. It is referred to as a cancer of the lymphatic system and typically originates in lymph nodes or other areas of the lymphatic system.

“It is uncommon that a singular cause for cancers such as lymphoma is identified. The development of cancer is thought to be a complex process that requires a lot of exposures, damage to stem cells and time to develop,” Dr. Daniel Landau, board-certified oncologist and hematologist, told Drugwatch. “We can’t control everything that leads to cancer developing. However, there are exposures we can limit.”

“Limiting Roundup exposure may be important. While studies with Roundup have found differing results, many do accept that the toxic chemicals in Roundup can increase cancer risks. Limiting use and using only as prescribed is recommended,” Landau said.

Case Study: Kathy Spreadbury’s Battle With Cancer

Kathy Spreadbury was an enthusiastic gardener from Florida with a prized collection of over 100 plumerias. She routinely used Roundup to control weeds in her garden.

She developed B-cell lymphoma — something she and her husband attributed to long-term exposure to the herbicide. Throughout her decline, Kathy’s husband, Paul Spreadbury, witnessed her suffering and lamented the lack of warning about Roundup’s potential dangers.

“Her first battle with B-cell lymphoma required months of chemo and other treatments. Kathy lost her hair, a ton of weight, became weak, fell and had to have a hip replaced,” Paul told Drugwatch. “The cancer went into remission, but it returned in the summer of 2020 with a vengeance.”

Despite undergoing intensive treatments, her condition worsened. She entered hospice care in early December 2020, eventually dying on Christmas Eve.

“Those who gave the go-ahead to sell Roundup without warning people of its dangers need to pray to heaven that no hell exists,” Spreadbury said. “I would like Monsanto and Bayer to know that my wife was not a weed. I’ve got 37 years of memories, a beautiful daughter and two wonderful grandchildren to prove it. She has dozens of friends and a sister to prove it.”

A Centers for Disease Control and Prevention study found that over 80% of urine samples taken from Americans contained glyphosate. This is concerning, as exposure to glyphosate has increased by 500% between the introduction of Roundup Ready crops in 1996 and the study’s publication in 2017, and non-Hodgkin lymphoma is not the only potential risk unveiled by medical research.

Roundup Associations With Multiple Myeloma and Leukemia

Leukemia, multiple myeloma and acute myeloid leukemia are different types of cancer affecting blood and bone marrow cells. Glyphosate’s link to these cancers is inconclusive, according to researchers.

The long-term Agricultural Health Study found that those with the highest exposure to glyphosate had an increased risk of acute myeloid leukemia. Meanwhile, a 2021 study contradicted this, suggesting that only non-Hodgkin lymphoma is linked to glyphosate.

In 2019, the U.S. Agency for Toxic Substances and Disease Registry (ATSDR) reported that glyphosate exposure may increase the risk of multiple myeloma. While several studies have found a connection between glyphosate exposure and non-Hodgkin lymphoma or multiple myeloma, the link is statistically insignificant in some of these studies.

Roundup and Parkinson’s Disease

Parkinson’s disease is a progressive disorder that affects body movements, thinking and speech. Glyphosate exposure can lead to neurodegeneration through various mechanisms, including affecting the gut microbiome, oxidative stress, neuroinflammation and mitochondrial dysfunction.

These are all processes implicated in Parkinson’s disease, according to a 2023 article in The Lancet. Of interest in the article is that farmers have an increased risk of developing Parkinson’s disease.

While there have been no formally established links between glyphosate and Parkison’s, some animal studies suggest that glyphosate exposure can damage the nervous system, especially when combined with other chemicals that are harmful to the brain in ways commonly found in neurodegenerative diseases.

Roundup and Autism

Autism disorder impacts how someone communicates and socializes with others. While there is no conclusive link between Roundup exposure and autism in humans, a 2022 animal study published in the journal PNAS looked at pregnant mice exposed to large amounts of glyphosate.

Maternal exposure to high levels of glyphosate in the study led to autism-like behaviors and altered gut microbiota in offspring mice. Researchers observed an increased presence of a key enzyme in the brain, suggesting a potential mechanism. However, they wrote that such high exposures are improbable in human pregnancies. Further research linking animal and human data is needed.

There are several tips to help prevent exposing you or your family to Roundup. Most importantly, if someone uses Roundup nearby, be careful not to breathe in the product or let it contact your skin.

Consider Roundup alternatives that do not contain glyphosate. These products sometimes contain natural herbicides or pesticide ingredients, such as vinegar, salt and soap. Natural products can be very effective and safer for you and the environment.

What To Do If You’ve Been Exposed to Roundup

Most dangerous Roundup exposure incidents happen through ingestion, but inhalation poisoning has occurred. Short-term symptoms of Roundup poisoning include skin and throat irritation, stomach upset, difficulty breathing, changes to mental state and kidney failure.

If you suspect Roundup poisoning, seek medical help immediately. Do not induce vomiting unless advised by a healthcare professional. Short-term poisoning requires a visit to the ER, while long-term exposure may increase the risk of certain cancers. Local poison control centers can be reached by calling 1(800) 222-1222 from anywhere in the United States.

Roundup Lawsuits Claim Exposure Caused Cancer

If you were exposed to Roundup and later diagnosed with cancer, contact a lawyer experienced in Roundup litigation to discuss your options for filing a lawsuit. You may be entitled to compensation for medical expenses and lost wages.

Roundup settled 100,000 lawsuits for nearly $11 billion in 2020. Verdicts in Roundup lawsuits have been as much as a $2.25 billion jury award to a Pennsylvania man in 2024.