Is buying organic worth the extra cost?
There isn’t a one-size-fits-all answer to that question.
Pesticides sprayed on conventionally grown foods affect people differently. Some people carry genetic variants that decrease their ability to detoxify specific pesticides, others may be more resilient.
This is Part Two in a series on pesticides.
What are organophosphates?
Organophosphates are a class of chemicals used in some pesticides. When insects are exposed to organophosphates, their acetylcholinesterase enzyme is blocked.
Acetylcholine is a neurotransmitter that sends a signal from one nerve to the next. Acetylcholinesterase is the enzyme that turns off that signal. Both are needed — and need at the right time — for your nerves to work.
By blocking acetylcholinesterase, organophosphates cause insect nerves not to stop firing, which eventually kills the insect.
Where are organophosphates used?
Organophosphates are commonly used as insecticides on conventionally grown crops:
- Parathion (banned in most countries)
Organophosphates were also used as a nerve gas during WWI and WWII. Examples of nerve gas include sarin, VX, and Novick.[ref]
Chlorpyrifos use commonly controls termites, mosquitoes, and roundworms and now prohibited for indoor home use. On crops, it is used on grapes/fruits, soybeans, and corn.
The map from the USGS below shows the usage of chlorpyrifos in the US. (2016).
Chlorpyrifos is one of the most commonly used organophosphates in the US. It is used on corn, soybeans, wheat, grapes, and more. Hawaii and NY have recently banned the use of chlorpyrifos in those states due to concerns over health impacts.
Let’s take a look at some of the impacts of different organophosphates on human health…
Organophosphate exposure has links to impaired attention, memory problems, and other cognitive problems. Also links to chronic health problems such as Gulf War Syndrome, Alzheimer’s, and Parkinson’s exist.[ref]
Acute exposure to organophosphates negatively impacts the central nervous system, cardiovascular system, respiratory system, and gastrointestinal system.[ref]
If you are thinking ‘that is pretty much everything in the body’, you are right. And acute exposure at a certain level is lethal – either through not being able to breathe or your heart shutting down… But most of us will never be exposed to acute levels of organophosphates (hopefully).
Avoiding all organophosphates is difficult, perhaps almost impossible. A study of Canadian children found organophosphate metabolites in the urine of 91% of children.[ref] Another study found organophosphate metabolites in the urine of 100% of the participants (adults, Atlanta, GA).[ref]
Long-term, low dose exposure to organophosphates has links to:
- psychiatric problems or impaired neurobehavioural functioning[ref]
- motor neuron problems (Parkinson’s like symptoms)
- developmental neurotoxicity[ref]
- general exposure from living in agricultural areas is linked to Parkinson’s[ref]
- prenatal exposure affects cognitive development in kids, depending in part on the mom’s genotype (more below)[ref]
- another prenatal study in agricultural workers found that higher maternal OP pesticide exposure decreased their children’s IQ. The top quartile of mom’s exposure had a 7 point lower IQ in the kids.[ref]
- farmworkers generally show neurological effects from organophosphate exposure such as problems with executive function, verbal, memory, or processing speed[ref]
- a study in India found that OP exposure was linked to HbA1c levels and diabetes risk — but not through acetylcholine esterase but via the gut microbiome[ref]
- increased risk of obesity[ref]
- disrupts thyroid function (study of pregnant women)[ref]
- muscle weakness and numbness (rice farm workers)[ref]
There are numerous animal studies using the various organophosphate pesticides at low and high doses. Here are results from just a few of the recent studies:
- organophosphates modify expression in genes regulating the cell cycle and apoptosis in the brain (baby rat study)[ref]
- organophosphate exposure in early life exacerbates the risk of obesity, especially in high-fat diets (rat studies)[ref]
- chlorpyrifos has shown to decrease intestinal integrity, which increases LPS and low-grade inflammation (in mice). This leads to obesity.[ref]
- chlorpyrifos damages sperm and decreases sperm count in rats. A high-fat diet decreased the effects.[ref]
- chlorpyrifos messes with rats’ brains — decreased neurocognitive performance and increased anxiety-like behavior.[ref]
Genetic variants that interact with organophosphates
Your genetic variants play a role in how well you detoxify and get rid of pesticides from your body. Some people are champs at getting rid of organophosphates, and others of us are more at risk from the negative effects.
BChE Gene Variants:
Butyrylcholinesterase (BChE), also known as pseudocholinesterase, breaks down organophosphates from pesticides and nerve gas.
Check your genetic data for rs1803274 (23andMe v4, v5):
- T/T: K variant, ~14% reduction in BChE, increased risk of Parkinson’s due to organophosphate exposure[ref]
- C/T: carrier of one copy of the K variant, reduced BChE, increased risk of Parkinson’s due to organophosphate exposure[ref]
- C/C: typical
Members: Your genotype for rs1803274 is —.
PON1 Gene Variants:
Paraoxonase 1 (PON1) is an enzyme that hydrolyzes organophosphate pesticides, allowing them to be excreted by the body. This is actually the second step in the process that the body goes through to break down and excrete organophosphates. The first phase of the process creates a toxic molecule, so this second phase, which uses PON1, is extremely important for getting rid of the organophosphates.[ref]
Check your genetic results for rs662 (23andMe v4, v5; AncestryDNA):
- T/T: typical – but possible effects on kids exposed in utero.
- C/T: (most common genotype in most populations)
- C/C: increased risk of thyroid problems from organophosphate exposure[ref] prenatal organophosphate exposure increases BMI in children[ref] generally poorer outcome for exposure to organophosphate pesticides[ref][ref][ref]
Members: Your genotype for rs662 is —.
In general, higher exposure to organophosphates and decreased cognitive development are linked. A study that looked at maternal genotype, exposure of the child while in utero, and then later cognitive development found that when mom carried the rs662 TT genotype and had higher exposure to organophosphates, their kids were more likely to have decreased intelligence exam scores at ages 6 – 9. The mothers in this study were Hispanic and African American women, exposed to normal amounts of organophosphates in New York City. The study didn’t show the kids’ PON1 genotypes.[ref]
Chromosome 8q24 Variant:
Check your genetic data for rs4242382 (23andMe v4, v5; AncestryDNA):
- A/A: Exposure to permethrin increases the risk of prostate cancer[ref]
- A/G: Exposure to permethrin increases the risk of prostate cancer
- G/G: typical
Members: Your genotype for rs4242382 is —.
CYP2B6 Genetic Variants:
While PON1 takes care of the second phase of detoxifying organophosphates, there are several genes that code for the enzymes responsible for the first phase of detoxification. The CYP2B6 enzyme metabolizes organophosphates at lower concentrations, such as from normal exposure from pesticide residue. Another enzyme (CYP3A4) is utilized at high concentrations, such as from pesticide poisoning.[ref]
Check your genetic variants for rs3745274 (23andMe v.4):
- T/T: CYP2B6*6, increased activity, less toxicity from chlorpyrifos[ref][ref]
- G/T: somewhat increased clearance of organophosphates
- G/G: typical
Members: Your genotype for rs3745274 is —.
Check your genetic data for rs2279343 (23andMe v4, v5):
- G/G CYP2B6*6, increased activity, less toxicity from chlorpyrifos[ref][ref]
- A/G: somewhat increased clearance of organophosphates
- A/A: typical
Members: Your genotype for rs2279343 is —.
Organic foods have low (or no) organophosphate pesticide residue. You can check the FDA data on pesticide residue for your favorite fruits and vegetables here.
Meat, fish, and dairy usually have low amounts of organophosphates.
While fruits and vegetables are generally considered to be good for you, it may be a trade-off with the pesticide exposure in conventionally grown foods. A study on kids in Atlanta showed that switching out conventional fruits, vegetables, and grains for organic ones substantially reduced the number of organophosphate metabolites in their urine to almost undetectable levels.[ref]
Put your gut bacteria to work:
An animal study shows the bacteria Lactobacillus rhamnosus (commonly found in probiotics) helps reduce the toxicity of organophosphate exposure. It does this by binding to the organophosphates.[ref] In humans, L. rhamnosus shows reductions in the bioaccumulation of mercury and arsenic.[ref] Lactobacillus plantarum has also shown in cell studies to degrade organophosphates.[ref]
Quite a few probiotics have L. plantarum included in them. If you are looking for L. rhamnosus, Culturelle is a brand that is available at most stores and online.
A rat study found that chlorpyrifos caused altered cognitive and neurological behavior in animals (backing up many other studies). Adding a quercetin supplement along with the chlorpyrifos mitigated some of the negative effects.[ref]
N-Acetyl Cysteine (NAC):
Similar to the above study, adding NAC protected rats against the sperm altering effects of chlorpyrifos.[ref]
Overall, your best bet if you carry any of the susceptibility variants for problems from organophosphates is to eat organic (fruit, veggies, grains) whenever possible and avoid spraying them in agricultural settings.
The studies on the impact on kids when exposed in utero make me think that all pregnant women should avoid organophosphates.
Related Genes and Topics:
Glyphosate: interaction with genetics
The active ingredient in RoundUp is glyphosate, and people with certain genetic variants may be more prone to problems with glyphosate.
BPA: Genetics and Detoxification
Ubiquitous in our environment, BPA is an endocrine-disrupting chemical. Some people are genetically at a disadvantage for detoxifying BPA.