Nicolás Olea, professor: ‘Plastic coffee capsules contribute to exposure to endocrine disruptors’

Until recently, endocrine disruptors — found in many everyday products — were largely absent from public discussion, but that term is now heard more and more. Nicolás Olea, emeritus professor of Radiology and Physical Medicine at the University of Granada in Spain, has played a key role in this shift. “I began to study them in 1988 in the United States, and it was a big surprise.”

In 1992, he focused on one in particular, bisphenol A, and since then has participated in dozens of studies on these substances, which he detailed in the popular science book Libérate de tóxicos (Free Yourself from Toxins). Six years later, he has recently published 80 recomendaciones para evitar los tóxicos (80 recommendations for avoiding toxins), a book offering advice for living a healthier life.

Question. What are endocrine disruptors?

Answer. They are chemical substances which, once inside the body, modify its hormonal balance. Hormones are the messengers that communicate between, for example, the ovary and the breast, as does estradiol, which is an estrogen. Disruptors can mimic estradiol and compete with that message, distorting it. They are hackers that alter hormonal messaging.

Q. Do they have immediate effects?

A. The effect is certainly immediate, because the alteration is instantaneous, but the repercussions of adverse effects can be very long-term: early exposure to a hormone can condition your adult life. The consequences are not visible until adulthood, so it is difficult to establish causality. In our study on poor semen quality, the prevailing hypothesis is that it was defined in the first 40 days after the child’s fertilization.

Q. What other effects do they cause?

A. Thyroid disorders — there are a huge number of people taking thyroid hormone for hypothyroidism — weight gain and diabetes, infertility. This summer, a scientific article noted that declining fertility in Europe is linked to women’s empowerment and economic conditions, but also to poor semen quality, decreased ovarian reserve, and diseases such as endometriosis and polycystic ovary syndrome, all of which are associated with endocrine disruptors.

Q. Are women more affected by endocrine disruptors?

A. Yes, because hormonal variability plays a major role in female physiology. Between the development of puberty, the first period, mammary development, monthly ovarian cycle and pregnancies, they are much more susceptible to hormonal changes. Hypothyroidism affects 17 times as many women as men, and chemical sensitivity also multiplies in women.

Q. If endocrine disruptors are so harmful, why are they allowed?

A. There has been an enormous delay in incorporating the legislation that a compound is hormonally active into chemical regulations. If the compound is CMR [carcinogenic, mutagenic or reprotoxic], it is banned, but hormonal toxicity is not included in those rules. When the European Chemicals Agency [ECHA] wants to legislate on endocrine disrupters, it considers whether they are reprotoxic [toxic to reproduction]; the regulations are stricter in that area. The first time that endocrine disruptors might be regulated is in upcoming European toy regulation.

Q. In your book, you give advice on avoiding toxins. One of the tips is to avoid using coffee capsules.

A. Coffee prepared under pressure and at a high temperature in a cheap plastic capsule liberates microplastics that contribute to exposure to endocrine disruptors. The plastic is usually polyethylene and often contains an epoxy resin that acts as glue between the two pieces, as well as other additives. The alternative is the traditional coffee maker.

Q. What about plastic cups?

A. The same thing happens when you put a hot beverage in them.

Q. What about plastic bottles?

A. Six years ago, we were talking about how there were 3,000 microplastics per bottle. A year ago a paper was published in the PNAS journal looking at microplastics, and it raised that figure to 300,000 per liter of water. The more they are reused and the older they are, the more microplastics are released. It’s also very bad to leave a bottle of water in the car in the summer, it can reach 50ºC [122ºF]. In Spain, it is much better to drink water from the tap. At home, 1,000 liters cost around €2 [$2.33], while in the street you could get one liter for that price.

Q. Does the food we eat at home have pesticides?

A. Around 38% of all food has some kind of residue, and 2% is above the legal limit. But the key is how much is in conventional food: enough that biomonitoring studies show that Spanish children urinate a cocktail of pesticides. Current regulations satisfy officials, but they do not protect human health. The French have measured pesticides in breakfast, lunch, snacks and dinner through the country’s Générations Futures project and found 87 substances — though most are legal, regulations do not take into account the cocktail effect when they combine. This combined effect does not appear in legislation. Pesticides, cosmetics, and plastics converging in the same system can alter hormones.

Q. What kinds of fish contain mercury, and how does it affect us?

A. The small ones, like anchovies, sardines, squid and blue whiting, are clean. On the other hand, large predators have high mercury levels: tuna, shark, dogfish, emperor fish and swordfish. Since 2019, the Association of Southeast Asian Nations has recommended not eating much of that kind of fish, and not sucking the heads of shrimps because they contain cadmium.

Q. What about food packaging?

A. Canned food containers used to have epoxy resins derived from bisphenol A, but since last year, that has been regulated [by the European Union — the FDA continues to classify the substance as safe for use in food packaging], and now they’ll have to look for another material for packaging. That is why we have always recommended glass jars.

Q. Where are perfluorinated compounds (PFAs) found?

A. They are found in non-stick frying pans, stain-resistant clothing, fire extinguishers, many cosmetics… they have many applications, because they improve the qualities of products, but they are very persistent. The ECHA has declared war on perfluorinated compounds and has already regulated 12, but there are 12,000 on the market. In 2017, it was reported that the levels of perfluorinated compounds in the blood of Spanish people were very high. History repeats itself: first, organochlorines [PCBs, DDT] were banned, then organobromides, and now we are dealing with perfluorinated compounds. They are obesogenic, and their main effect as endocrine disruptors is to promote obesity. They are found in all living beings and are not eliminated through urine.

Q. What is the issue with tea bags?

A. Before, they were made from vegetable cellulose, but now they are made of polyamide or polyester, which means that every time they are put in boiling water, millions of microplastics and nanoplastics are released. The alternative is to use traditional metal tea infusers.

Q. What about microwave popcorn?

A. The inside of the bag usually contains perfluorinated compounds, which heat up along with the food and are very toxic, because they pass into the food and contribute to exposure to endocrine disruptors.

Q. Should food be heated in plastic containers?

A. No. They release phthalates and chemical contaminants, and microplastics wear down and release components when heated, which end up in the body. The same is true for silicone containers. The alternative is glass containers and metal or glass ovenware.

Q. What about cosmetics?

A. A lot of them have benzophenones, parabens. In Spain, a woman uses an average of 14 products, each containing an average of 38 ingredients, which amounts to 400 chemical compounds that can produce a cocktail effect. They say that the concentrations are low and absorption is minimal, but then you see that many remain in the urine. Exposure has been proven. In girls, early use may be linked to the onset of early puberty that pediatricians are seeing.

Q. Sunscreen?

A. They usually contain benzophenones. The ECHA has a list of substances that it will restrict next year, which includes benzophenones, camphen, and a salicylate.

Q. What happens if a dog or cat wearing a flea collar sleeps in a kid’s bed?

A. The Spanish Medicines Agency says that flea collars contain pyrethrin and other pesticides that are not designed to be in your child’s bed, and can affect them.

Q. What are the health risks linked to clothing?

A. They often have perfluorinated compounds, although they are not usually indicated on the label. They prevent clothes from staining and eliminate the need for ironing, but they are endocrine disruptors.

Q. You say not to put a newborn baby in a new car. Why?

A. The interior of a car is made of plastic, even in electric cars. And the newer the car, the worse the exposure, because they release more chemicals like phthalates, phosphates, bisphenols — a volatile mixture. If you have a new car, ventilate it thoroughly and never get in with your child if the vehicle has been left in the sun and is very hot.

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