Does Roundup cause cancer?

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Roundup's products, herbicides that contain the chemical glyphosate , have drawn attention to its potential role in human cancer. There is evidence from laboratory cell studies, animal studies, and population studies linking Roundup exposure to non-Hodgkin lymphoma in humans. The combination of these factors led the International Agency for Research on Cancer (IARC) to classify glyphosate as a Group 2A carcinogen (probable).

Since association does not mean causation, we will look at the research available for Roundup, as well as alternatives for both agriculture and home gardening.

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boonchai wedmakawand / Getty Images

What is a raid?

Roundup is a very popular herbicide or herbicide that is most often used in agriculture. The key ingredient in Roundup is glyphosate, a compound with a molecular structure similar to the amino acid glycine.

Background on Roundup (glyphosate)

Glyphosate, the active ingredient in Roundup products, was first marketed as a herbicide in 1974. Since then, it has become the most widely used herbicide in the United States. Although it has been in use since 1974, it is estimated that as of 2016, two-thirds of the amount of glyphosate applied to crops was fumigated in the previous decade alone.

How does it work

Glyphosate works by inhibiting an enzyme in plants that is required for the production of various amino acids (the building blocks of proteins). Since this enzyme and metabolic pathway is only present in plants (not humans or other animals), it was thought to be relatively non-toxic. Glyphosate also binds (chelates) certain minerals (such as calcium, magnesium, manganese, and iron) that are important for plant growth.

Applications

In the United States, Roundup is used for weed control and can also be used as a desiccant, a hygroscopic substance that is used as a desiccant. In the U.S. It is used in conjunction with genetically modified crops (GMOs). Under these conditions, transgenic crops are resistant to enzyme inhibition, while nearby weeds are not. These Roundup Ready crops include:

  • Soy
  • Corn
  • A little cotton
  • Alfalfa
  • Sugar beet

In Europe, GM crops are not approved, so they are used in a slightly different way.

Human exposure

Human exposure to glyphosate has increased significantly since its first use. Levels (measured from urine samples) in people over the age of 50 increased by 500% between 1993 and 1996, and subsequent measurements were taken between 2014 and 2015 .

Role in cancer

When considering whether Roundup might play a role in cancer, it is important to look at the evidence differently. After all, it would be unethical to expose one group of people to a large amount of Roundup and another to none (control group) to see if the exposed group developed more cancers. There are several different types of evidence that scientists use to reduce cancer risk.

Certificate

Here is some evidence that may support the role of the chemical in cancer:

  • Mechanism: Does a chemical cause damage to the DNA of cells that can lead to cancer?
  • In vitro cell research (in the lab): What effect does Roundup have on cells, including cancer cells, grown in a dish in the lab?
  • Animal research : does this substance cause cancer in laboratory animals?
  • Human studies: Since it would be unethical to include one group of people in Roundup and not another, the studies look at population studies. For example, do people who live in regions where Roundup is used most often have a higher incidence of some type of cancer? Is there a correlation between Roundup use and cancer incidence over time? Is the incidence of one type of cancer correlated with glyphosate residue measurements in humans, for example, in urine samples?
  • How Roundup Affects Plants: Can Roundup modify plants so that they are more or less likely to cause disease when ingested later?
  • Correlation of cancer incidence and glyphosate use over time: Is there any cancer that started to increase when glyphosate use began in the United States or in other regions of the world?

The reason research is needed from different angles is because correlation does not necessarily mean causation. For example, the incidence of cancer may increase as Roundup use increases, but there are other reasons that may also be causing this.

Epidemiologists often cite examples of ice cream and drowning. People tend to eat more ice cream in the summer and there are more cases of drowning in the summer, but that does not mean that ice cream causes drowning.

Carcinogenic status

In 2015, the International Agency for Investigation (IARC) classified glyphosate as a probable human carcinogen (group 2A).

In vitro cell studies and carcinogenicity mechanisms.

Scientists studied the effect of glyphosate on lymphocytes (a type of white blood cell) grown in a dish in a laboratory ( in vitro ) to assess potential DNA damage, as well as the type of damage if found.

Exposure to glyphosate was found to cause DNA damage (and other changes) similar to those seen with the conventional chemotherapy drug Vepesid (etoposide). This was a dramatic change, but the authors posited that chronic exposure could lead to cumulative damage over time. Other studies have also shown evidence of DNA damage, as well as chromosomal damage in human cell lines, as well as the ability of glyphosate to induce oxidative stress .

In an in vitro study using human breast cancer cells, low glyphosate concentrations (similar to those found in the average adult) resulted in faster growth (proliferative effects) of tumors that were hormone-dependent ( estrogen / progesterone receptor ). -positive cancer cells ). However, faster growth in non-hormone-dependent breast cancer cells was not seen, suggesting that glyphosate has estrogen-like activity, at least under these conditions. (Glyphosate also altered the expression of estrogen receptors.)

Although the research has so far only been conducted in vitro, this requires further evaluation. Estrogen receptor positive breast cancer is the most common type of breast cancer. Also, it is a type of breast cancer that can recur many years or decades after initial treatment for early stage cancer ( late recurrence ), and it is largely unknown why some tumors recur and others do not. It is unknown whether the anti-estrogen therapy that many women use after their initial treatment will counteract the potential effects of glyphosate.

Impact of the raid on animals

According to IARC, Roundup (glyphosate) has "sufficient evidence" of carcinogenicity (carcinogenicity) in animals .

In a 2020 review of several studies in rats and mice (examining chronic exposure and carcinogenicity), there was relatively strong evidence that glyphosate can cause hemangiosarcomas (tumors of the blood vessels), kidney tumors, and lymphomas. Other tumors that increased in size included basal cell carcinomas of the skin, adrenal tumors, and liver tumors .

By looking at the underlying mechanism (at least with lymphomas), another study has shown that glyphosate is capable of causing B-cell mutations that may play a role in both B-cell non-Hodgkin's lymphoma and multiple myeloma .

Population studies (humans)

Several epidemiological (population) studies have shown a link between Roundup and non-Hodgkin lymphoma (NHL). Non- Hodgkin lymphoma is cancer of a type of white blood cell called lymphocytes (T lymphocytes or B cells) and is quite common. About 2.1% of people are expected to develop NHL in their lifetime, with a slightly higher incidence in men than women.

Although the correlation does not imply causation, the incidence of NHL has been observed to double between 1975 and 2006. Additionally, the incidence of NHL is higher in people who have been occupationally exposed to glyphosate-containing herbicides or who live near agricultural land that they are generally treated with herbicides.

Other potential impacts with increased NHL have been considered, including exposure to radon in the home , as regions with high levels of radon in the soil also tend to have high levels of NHL.

There have been several studies on NHL and glucophate in the United States and Europe since 2001. In 2008, a Swedish study involving people between the ages of 18 and 74 found: strong the association between herbicides in general, especially glyphosate, and non-Hodgkin's lymphoma (those exposed to glyphosate were twice as likely to develop NHL).

A meta-analysis of six studies from 2019 reaffirms this association. Overall, people who were exposed to the highest levels of glyphosate were 41% more likely to develop NHL. The authors note that, in addition to the epidemiological association, the evidence for the role of NHL is supported by links between glyphosate exposure and immunosuppression, endocrine disruption, and the type of genetic change often seen in NHL.

Relative risk versus absolute risk

When considering cancer risk, it is important to describe what the highest risk statistic actually means. Relative risk indicates the likelihood that a person will develop cancer than a person who is not exposed to carcinogens. In this case, the relative risk was 41%. However, the absolute risk means how likely you are to develop NHL. In this case, the absolute risk is 0.8%. If your lifetime risk of developing NHL (on average, because there are other risk factors) is 2%, it could increase to 2.8% with exposure to glyphosate.

However, not all studies have shown a link between Roundup (glyphosate) and NHL. A large 2018 study published in the Journal of the National Cancer Institute found no clear link between glyphosate exposure and any solid tumors or blood cancers in general. There was some evidence of an increased risk of acute myeloid leukemia in the most exposed, but this required confirmation. This study was conducted using questionnaires and, due to the high failure rate of the study, no definitive conclusions could be drawn .

These results, in which some but not all studies suggest a link between exposure and cancer, are very common when looking for causes of cancer. Here it is very useful to look at not only population studies, but also animal studies, cell studies, and possible mechanisms to determine if positive results are significant.

Glyphosate and plant nutrients

Another aspect to consider when studying the effects of glyphosate and cancer risk is not related to the effects of glyphosate, but rather how glyphosate can affect the nutrients in cultivated food or its toxicity.

Some researchers are concerned that glyphosate, by binding to minerals in the soil (chelation), could make plants more toxic or reduce the absorption of nutrients from the soil. In turn, foods that people eat that are processed with glyphosate have the potential to be toxic or lack nutrients (some of which may be associated with a reduction in cancer) found in plants grown without glyphosate. It is currently unknown if this is of concern to people, but it should be considered whether glyphosate use continues to rise in the United States.

Other medical problems

In addition to the risk of cancer, the use of Roundup has raised concerns about other medical problems. Some of these include:

  • Fatty liver disease: Mice given a glyphosate dose estimated to be 100 times lower than the average human developed liver dysfunction similar to nonalcoholic fatty liver disease. Of course, it is important to note that rodent exposure to a chemical does not necessarily translate into human exposure.
  • Birth defects: A study in Argentina found that regions with a high concentration of glyphosate in the soil had twice the rate of birth defects and three times the rate of spontaneous abortions, compared to regions with a lower concentration of glyphosate. chemical substance. Again, this was a correlation and did not necessarily imply causality. Birth defects have also been observed in young pigs fed soy containing residual glyphosate, and similar birth defects have been observed in people living near farmland where Roundup is used.
  • Effects on Pregnancy: In rats, exposure to glyphosate during pregnancy has been found to alter the expression of several genes associated with oxidative protection, inflammation, and fat metabolism. In theory, it's possible that exposure to Roundup in utero could cause long-term neurological effects (but again, this study was only done in rodents).

There are also reports suggesting the potential effects of Roundup on the liver, kidneys, general metabolic processes, and the composition of the gut microbiome.

Additional rules and problems

In addition to medical concerns, the increasing use of Roundup, especially due to the need for large volumes as resistance develops, raises other concerns, including environmental and environmental concerns. This may be due to glyphosate, a product of AMP metabolism, to both, or to an effect in combination with genetically modified proteins.

Research has shown that Roundup can alter normal levels of bacteria in the soil, as well as organisms such as earthworms, monarch butterflies, and honey bees.

In terms of human health, the Environmental Protection Agency (EPA) has established a chronic daily reference dose for glyphosate (cRfD) of 1.75 milligrams (mg) / kilogram (kg) of body weight per day. The European Union (EU) also has a cRfD, although the threshold is lower than the United States at 0.5 mg / kg / day. In the EU, scientists have recommended a cut-off level for operators of 0.1 mg / kg / day.

Despite these numbers, it can be difficult to know what level of exposure might be related to cancer. According to the EPA, a carcinogen has an "acceptable risk" if it is believed to "only" cause cancer in 1 in 10,000 to 1 million people in their lifetime. At the same time, an increased risk is generally allowed in the workplace (up to 1: 1000).

Alternatives to Roundup

There are potential alternatives to using Roundup products in both agriculture and home gardens.

A house and a garden

There are several alternatives to using herbicides in your home garden. They may include:

  • Hand pulling out weeds
  • Use very hot water (but be careful not to burn yourself).
  • Depending on the weeds, your local gardening association can probably offer you non-toxic weed removal ideas, from vinegar to other solutions.

farming

Researchers have studied a number of agricultural-scale Roundup alternatives, especially in some countries that prohibit or restrict the use of glyphosate (such as Austria, France, Germany, and Vietnam).

Even in cases where Roundup is fully allowed, it is recommended that contingency plans be made from now on. Even without limitation, increasing resistance of weeds to glyphosate is likely to lead to the need for alternative methods of weed control in the near future.

Physico-mechanical methods (eg, tillage and cut) are an option. Cultivation methods such as protecting crops, changing planting dates, and replanting can also reduce the need for chemical control.

Protect me

If you use products like Roundup at home or at work, or if you live near a farm where Roundup is applied, there are a number of steps you can take to reduce your exposure.

Application security:

  • Wear protective clothing when applying Roundup (our skin is not an impenetrable barrier, as evidenced by the many medications now available in patch form). Take care when removing the clothes you are wearing so as not to expose family members who may wash your clothes.
  • Some people like gloves, but whether you wear them or not, always wash your hands thoroughly (at least 20 seconds with soap and water) after you are done.
  • Consider wearing eye protection, especially if you are using pressurized herbicides.
  • Avoid walking barefoot for at least 24 hours and it is advisable to wait for rain (or water) after applying Roundup. Keep pets away.
  • Do not eat, drink, or smoke while applying any type of herbicide or pesticide.
  • Consider your method of application – high-pressure sprays can have more of an impact.
  • Review the material safety data sheets for any chemicals you work with and follow the protection recommendations.

General exposure control measures:

  • Wash all food before eating.
  • Avoid indoor herbicides if possible, especially for indoor plants.
  • Keep children and pets away from Roundup-treated fields (this may require some awareness in places like parks and playgrounds). Keep in mind that Roundup is just a chemical in the environment, and often a combination of factors, rather than a single cause, that leads to cancer. There are many potential problems in the environment (for example, Roundup), but there are also well-known problems. Make sure to focus on the main risk factors (such as quitting smoking, excessive sun exposure, and eating a wide variety of fruits and vegetables).

Get the word of drug information

While the potential risks and reduced efficiency can be concerning, it is also an opportunity for researchers to develop alternative weed control methods that are not only sturdier and safer, but also healthier for the environment. You don't have to postpone the action yourself. While the agricultural industry is considering alternatives, people can begin to practice practices that minimize glyphosate use and exposure in their gardens today.

One final note: don't limit your vegetable intake due to concerns about rodeo residue in your food. When it comes to your daily routine, increasing your intake of vegetables (to at least 600 grams per day) is an easy way to reduce your risk of cancer later in life .

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