I am concerned about the high rate of low sperm count (one out of six young men) and the research that is being done to try to find the cause. Plastics may be to blame, but it’s not a simple issue.
Plastics play a vital role in our daily lives. Our modern world would not be as functional without their thousands of uses. Many of these are not readily apparent to us. Plastics are used in many everyday products, including toys for children, insulation around electrical wires, food containers and wraps, and medical products such as blood bags, gloves, syringes, and tablets.
Are there any hidden risks of plastics for human health and fertility, particularly in men? It is difficult to answer this question, especially because we are all exposed to plastic-derived chemicals. We don’t have a group of people who are not exposed to chemicals (the “control” group) against which we can compare.
The majority of people don’t know how plastics expose us to chemicals. We don’t chew on the electrical wiring or eat plastic wraps that surround food. Plasticizers (chemicals) are used to bend and strengthen plastic, which is normally hard and brittle. The more flexible the plastic is, the higher the amount of plasticisers it contains. The most commonly used plasticizers, phthalates are available in different forms and have different purposes.
Plasticizers will leach from the plastic with time, contaminating any food or drink that comes into contact. It was for this reason that phthalate plasticizers in water bottles were banned many years ago. They were replaced with polyethylene terephthalate which has different properties. Our main exposure to the most common phthalate still comes from in our diets and food, even though we don’t fully understand how it occurs.
Studies in laboratory rats sparked concern about the effects of phthalates on fertility. The studies showed that certain phthalates were responsible for reproductive problems in male offspring. This included reduced fertility and sperm count. Could the exposure of pregnant women to phthalates (and the male fetuses within their wombs) cause reproductive disorders in men’s offspring?
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Evidence that contradicts each other
This question can be answered directly by measuring phthalate exposure in pregnant women and if this is linked to reproductive disorders among their sons. These studies show that some, but not all of them, have found an association between male reproduction disorders and maternal phthalate exposure. This approach is flawed because it can’t prove that exposure led to the disease. Other Evidence Points in the Completely Opposite Direction.
The fetal testes of male rats are less likely to produce testosterone, the male hormone. This effect can only be achieved by exposing pregnant rats to phthalate levels that are 50,000 times greater than those of pregnant women. The testosterone levels of human fetal tests (obtained ethically from legal terminations of pregnancy) are not affected by the same high phthalate concentrations as rats. Male monkeys also do not develop reproductive disorders after being exposed to high levels of phthalate during pregnancy.
It is not uncommon to encounter problems like this in research when different types of data do not agree. What should we do when faced with this uncertainty? The first reaction would be to assume the worst and accept all studies that support the association. The next step is to restrict or ban phthalate usage, which will result in many changes to modern society. Some people argue that this is the safest route.
Although I am 100% for safety, I also know that one cannot ignore scientific evidence when it does not support a certain point of view. This is especially true if the evidence is robust. This is not a science-based approach, and it isn’t very smart by any standard.
It does not mean I am convinced that plastics can be 100% safe. But neither does the evidence available convince me that they play a significant role in male reproductive disorders. I’m convinced that our lifestyles or environment are the cause of low sperm count. I wish I could tell you what it was.