A new study published Tuesday found that after switching to an organic diet for just a few days, people could cut the levels of a pesticide linked to cancer found in their urine by more than 70 percent.

The researchers collected a total of 158 urine samples from four families –seven adults and nine children – and examined the samples for the presence of the weed killer glyphosate, which is the active ingredient in Roundup and other popular herbicides. The participants spent five days on a completely non-organic diet and five days on a completely organic diet.

“This study demonstrates that shifting to an organic diet is an effective way to reduce body burden of glyphosate… This research adds to a growing body of literature indicating that an organic diet may reduce exposure to a range of pesticides in children and adults,” states the study, which was published in the journal Environmental Research.

Notably, the researchers found that the children in the study had much higher levels of glyphosate in their urine than did the adults. Both adults and children saw large drops in the presence of the pesticide following the diet change. The mean urinary glyphosate levels for all subjects dropped 70.93 percent.

Despite its small size, the study is an important one because it shows people can markedly reduce their exposures to pesticides in food even without regulatory action, said Bruce Lanphear, Professor of Health Sciences at Simon Fraser University.

Lanphear noted that the study showed children appear to be more heavily exposed than adults, though the reason is unclear. “If the food is contaminated with pesticides, they will have a higher body burden,” Lanphear said.

Roundup and other glyphosate herbicides are commonly sprayed directly over the top of growing fields of corn, soybeans, sugar beets, canola, wheat, oats and many other crops used to make food, leaving traces in finished food products consumed by people and animals.

The Food and Drug Administration has found glyphosate even in oatmeal and honey, among other products. And consumer groups have documents glyphosate residues in an array of snacks and cereals.

But glyphosate and glyphosate-based herbicides such as Roundup have been linked to cancer and other illness and disease in several studies over the years and growing awareness of the research has led to growing fears about exposure to the pesticide through the diet.

Many groups have documented the presence of glyphosate in human urine in recent years. But there have been few studies comparing glyphosate levels in people eating a conventional diet versus a diet made up only of foods grown organically, without the use of pesticides such as glyphosate.

“The outcomes of this research validate the previous research in which organic diets could minimize the intakes of agrochemicals, such as glyphosate,” said Chensheng Lu, adjunct professor of the University of Washington School of Public Health and honorary professor, Southwest University, Chongqing China.

“In my opinion, the underlying message of this paper is to encourage producing more organic foods for people who want to protect themselves from the exposure of agrochemicals. This paper has proven again this absolute right pathway for prevention and protection,” Lu said.

The study was authored by John Fagan and Larry Bohlen, both of the Health Research Institute in Iowa, along with Sharyle Patton, director of the Commonweal Biomonitoring Resource Center in California and Kendra Klein, a staff scientist at Friends of the Earth, a consumer advocacy group.

The families participating in the study live in Oakland, California, Minneapolis, Minnesota, Baltimore, Maryland and Atlanta, Georgia.

The study is the second of a two-part research project. In the first, levels of 14 different pesticides were measured in the urine of participants.

Glyphosate is of particular concern because it is the most widely used herbicide in the world and is sprayed on so many food crops. The International Agency for Research on Cancer, part of the World Health Organization, said in 2015 that researched showed glyphosate to be a probable human carcinogen.

Tens of thousands of people have sued Monsanto claiming exposure to Roundup caused them to develop non-Hodgkin lymphoma, and many countries and localities around the world have recently limited or banned glyphosate herbicides or are considering doing so.

Bayer, which bought Monsanto in 2018, is attempting to settle more than 100,000 such claims brought in the United States. The plaintiffs in the nationwide litigation also claim Monsanto has long sought to hide the risks of its herbicides.

A California appeals court ruled last month that there was “abundant” evidence that glyphosate, together with the other ingredients in Roundup products, caused cancer.