Pesticides

Genetic susceptibility to toxicity of ingested pesticides

The use of pesticides is so integral in modern agriculture that residues are in everything we eat. Our body is constantly exposed to various pesticides, herbicides and fungicides that it has to deal with.

A growing number of solid and large-scale studies indicate that low-dose long-term exposure is a root cause for health related disorders such as cancer and neurodegenerative, respiratory, reproductive and developmental disorders.

Various enzymes are your front line against pesticides. These enzymes, mainly found in the liver, metabolize and detoxify various toxic chemicals.

 

Some of us are born more apt to deal with pesticides, while others are especially sensitive to its effects on health. Individuals with unfavourable combinations of gene variants are more prone to pesticides' adverse health outcomes, having less efficient enzyme activity. Others enjoy gene versions that cope better with pesticides, coding for enzymes that allow faster secretion or better detoxification rates.

 

Routes of exposure

We are inevitably exposed to pesticides in our diet. In order to limit the dose of each pesticide in our food, Maximum Residue Limits (MRL's) were set by the USDA. Some older, first generation pesticides are banned. Sporadic samples taken from fresh and processed food are tested in the lab as an additional measure to protect public health. However even if actual residue levels are within the limit, it is clear that current MRL's are a compromise that takes into account various factors and interests. 

In addition to controversy over current MRL standard, public health experts and scientists are worried over the combined effect of overall pesticide exposure. Even when each pesticide in our food is within its MRL, we ingest a cocktail of many pesticides, and exposed to various other carcinogens and toxicants. Since different chemicals are metabolized by the same detoxification enzymes, the overall burden is thought to overwhelm our capacities and lead to many chronic diseases that are common today.

 

Other than in our food, residues of pesticides and fertilizers find their way into our drinking water as well. Pesticides may contaminate the ambient air of houses that's in proximity to fields or when household insecticides are used.

Health effects

One of the most prominent effects of pesticides is induction of oxidative stress, resulting in an increase of free radicals that damage biological molecules and promoting inflammation, immune response, chronic diseases and aging.

Different pesticides are associated with various maladies. Organophosphate insecticides (OP's) are very common in the last decades, due to its relatively short half-life, relatively fast degradation rates, lower price, lower susceptibility to pest resistance and lastly, due to the ban on persistent organochlorine pesticides in the 1970s. However, as evidence accumulates, more and more health concerns are raised. The organophosphate insecticides are potent inhibitors that alter receptors' activity in the nervous system. Associated effects on human health include disruption of the endocrine system, neuropsychological disorders, developmental anomaly, hypersensitivity, non-Hodgkin’s lymphoma, lung and prostate cancer and Parkinson's disease.

Parkinson’s disease (PD) is one of the most common neurodegenerative disorders. Large scale studies have confirmed that exposure to certain insecticides, herbicides and fungicides markedly increase the risk for PD, and that individuals carrying genetic variants in relevant metabolizing genes are at much greater risk.

 

The class of insecticide called pyrethroid promotes Parkinson’s disease. Pyrethroids constitute the majority of commercial household insecticides and insect repellents. 

How to reduce risk of exposure to pesticides

​Its healthy to eat fresh fruits and vegetables, so don't stop doing so. Take the following steps to reduce exposure to pesticides from your produce:

  • Choose cleaner. Some fruits and vegetables are more contaminated than others. High levels of pesticide residues in produce sampled in the US were found in leafy greens such as spinach, lettuce, celery, cabbage,cilantro and parsley. Such crops are frequently treated and tend to absorb a lot of the chemical. Same goes with strawberries, raspberries and wolfberries. Grapes, pome fruit like apple and pear, and stone fruits like apricots, peaches, nectarines, cherries and plum tend to contain more pesticide residues. Tomatoes and bell peppers lead the list for vegetables. 

  • Consider buying organic produce, especially for fruits and vegetables that were listed here as more contaminated. Controlled trials have shown that consumption of organic food significantly decreased organophosphate pesticides levels in the blood serum of study participants.​​

  • To reduce the load of pesticides on your body, make sure you clean the produce thoroughly. Rinse fruits and vegetables under running water for at least 30 seconds, rubbing the skin with your fingers if the skin is delicate or with a brush if the skin is tougher. For produce that's difficult to scrub thoroughly with a brush because of its shape or the number of cracks and crevasses it has, like cauliflower, broccoli or lettuce, soak for one to two minutes in cold water. Wash fragile fruit like berries in a colander under running water using a kitchen faucet spray attachment.

  • Thoroughly dry the produce after washing and before eating to remove more pesticide residue. 

  • Don't use soap, detergents or bleach to wash produce to remove pesticides as they can contain substances that aren't safe to eat. Special vegetable rinses were not found any more effective than soaking in clean tap water.

  • A 15-minute baking soda rinse was most effective for getting rid of some pesticides, but not all. A concentration of about one teaspoon of baking soda per two cups of water should do the job.

  • Peeling can remove some pesticides, but many penetrate deep, or were applied via the roots. Peeling would mean missing out on the nutrient-rich skin. Did you know that potato skin is particularly rich in vitamin C?

  • Pesticide residues can be found in commodities as well, such as oil and rice, and in other processed foods. That's why it is important to support our body with varied and rich plant-based diet. Our reports recommend on a list of food, beverages, and bioactive compounds with demonstrated, or potential, clinical impact on detoxification systems.

Try to avoid or reduce the use of pesticides in your house, including your garden and on your pets. Use natural pest control methods when possible. Make pesticides your last resort when other options have failed. Make sure to use pesticide applications with precaution, as instructed by the label. 

Pesticide residues can be found in house dust or on surfaces like garden furniture and playgrounds. People living close to fields or where pesticides are used in the outdoors can reduce your exposure by cleaning such surfaces and vacuuming more often.