Exposure to BPA

Bisphenol A (BPA) has been used since the 1950s, in food packaging, industrial materials, dental sealants, and personal hygiene products.

Everyone is exposed to BPA through skin, inhalation, and digestive system.

BPA disrupts endocrine pathways, because it has weak estrogenic, antiandrogenic, and antithyroid activities.

What is BPA?

BPA is a common chemical, also known as 4,4’-dihydroxy-2,2-diphenylpropane. BPA is used in the production of polycarbonate, a high-performance transparent, rigid plastic. Polycarbonate is used to make food containers, such as some beverage bottles, infant feeding (baby) bottles, tableware (plates and mugs) and storage containers.

Residues of BPA are also present in epoxy resins, used to make protective coatings and linings for food and beverage cans and vats. BPA can migrate in small amounts into food and beverages stored in materials containing the substance. As it is such a common chemical that has been in use for several decades, it can be found in small quantities in the urine of most adults.

How Does BPA Enter the Body

Everyone is exposed to BPA through skin, inhalation, and digestive system. High temperatures cause the release of free BPA. Epoxy resins containing BPA are used to line water pipes, as coatings on the inside of many food and beverage cans and in making thermal paper, such as that used in sales receipts.

BPA absorbed by humans is metabolized by the liver, with half-life of 6 h, and excreted with the urine in 24 h.

There is increasing evidence that BPA has impact on human fertility and is responsible for the reproductive pathologies, e.g., testicular dysgenesis syndrome, cryptorchidism, cancers, and decreased fertility in male and follicle loss in female.

Impact on Female Fertility

BPA is a xenoestrogen, exhibiting oestrogen-mimicking, hormone-like properties. BPA also affect the oocyte and granulosa cells, essential for oocyte survival and nourishment. In women who undergo IVF, a higher level of BPA in the urine negatively correlated with oocytes maturation and peak concentrations of oestradiol.

In women undergoing ICSI, a higher concentration of BPA in the serum was connected with a decreased probability of mature oocytes. But in women with polycystic ovary syndrome (PCOS) there is a significant association between BPA and elevated androgen concentrations.

BPA can affect the hypothalamic-pituitary-ovarian axis which controls the ability to ovulate and prepare the reproductive organs to support potential pregnancy. Maternal or paternal exposure to BPA can affect the birth weight of newborns.

BPA levels (total or unconjugated BPA) were inversely associated with peak oestradiol levels, number of oocytes retrieved, oocyte maturation, fertilization rates, and embryo quality. BPA levels were associated with increased implantation failure.

Impact on Male Fertility

BPA disrupts spermatogenesis.Among couples in need of treatment of infertility, in 98% of patients, BPA was found in the urine samples, and its level negatively correlated with sperm count and motility.
In vitro BPA has also been linked to reduction of sperm reserves, shorter transit time of sperm, and lower mitochondrial activity.
BPA exposure is related to a decrease in the activity of the antioxidant system, resulting in oxidative stress, the most common cause of damage to the sperm

How to Reduce Exposure to BPA?

• Avoid plastic food containers or choose containers labelled “BPA free”. You can also opt for glass containers instead.
• Eat fresh organic food that doesn’t come in metal cans, plastic containers or packaging.
• Buy frozen fruit and veggies if you can’t get them fresh.
Cut down on canned food. Use dried beans instead of canned. The coatings used in canned goods to protect against bacteria and spoilage (known as epoxy resins) often contain BPA too.
• Cook from scratch. This way you are avoiding lots of unnecessary processed foods and waste.
• Keep your plastics cool and avoid heating them in the microwave. BPA and other chemicals have been known to leach into foods when heated.
• When purchasing water bottles, use a glass water bottle or stainless steel. Same goes for reusable coffee and tea mugs.
• Choose a glass coffee maker. Automatic coffeemakers may have BPA in their plastic containers and tubing
• Avoid plastic tableware like plates, cups, bottles.