I drink water out of my glass (protected by a silicone outer sleeve) or stainless steel water bottle and buy foods such as spaghetti sauce in glass jars rather than cans, as I wrote about in a 2012 Think Pink, Live Green column. That’s because I’m trying to avoid bisphenol A, called BPA for short. BPA is a chemical used in hard plastics, the resins that line food cans, and cash register receipts.
BPA can act like a weak form of the hormone estrogen and turn on breast cell growth and trigger other unhealthy activities in your body. Significant BPA exposure has been linked to many illnesses, including heart disease, diabetes, immune- and nervous-system disorders, and brain, prostate, and breast cancer.
BPA also may affect fertility. Studies have shown that BPA may play a role in infertility in both men and women and may even affect the course and outcome of a pregnancy. Even worse, BPA’s unhealthy effects can extend beyond people directly exposed to BPA, potentially including their children and grandchildren. (Some of these issues were covered in a prior column.)
In response to the growing number of studies linking diseases to BPA, manufacturers have started using alternatives. You may have seen these products in stores — they’re labeled “BPA-free.” Unfortunately, these alternatives — bisphenol S (BPS), bisphenol F (BPF), bisphenol B (BPB), and others — are chemically similar to BPA, have limited safety profiles, and may share similar unhealthy effects on the body.
Does this BPA make me look fat?
We’re reporting again on BPA to cover new studies linking BPA and weight gain. Researchers now believe that BPA may be contributing to the rise of abdominal obesity (excess fat around the waist), diabetes, and metabolic syndrome — a group of conditions including increased blood pressure, high blood sugar, and high cholesterol levels that together increase risk of heart disease, stroke, and diabetes. BPA’s role in weight gain is an extra concern because many studies have demonstrated that being overweight is a risk factor for developing breast cancer or experiencing a recurrence.
How can BPA make us fatter? BPA itself has weak estrogenic activity. But it seems to have other hormonal effects that lead to weight gain. And since extra fat can make extra hormones, there are additional unhealthy effects that can follow. A new study suggests that higher levels of a BPA-related chemical may tell our bodies to turn flexible cells in our body into new fat cells. (Our body has a bunch of extra cells that are ready to help out and take on a new job description, if recruited.)
Recent studies link higher BPA levels to:
- heavier weight and higher body mass index (weight-to-height ratio)
- higher percentage of body fat
- bigger waist size
A recent review of 16 studies found a link between higher BPA levels in people’s bodies, measured in their urine, and the risk of being obese. The risk of obesity was almost 50% higher in people with higher BPA levels in their bodies.
A Korean study of 560 elderly people found a significant association between BPA in urine and overweight women, but not men. However, the finding that women are more likely than men to gain weight when exposed to BPA is not consistent in other studies.
Because BPA can cross the placenta, children are exposed to it before they’re born. Babies can also be exposed to BPA via breast milk. Researchers found that some babies exposed to BPA during the third trimester had a higher percentage of body fat and a bigger waist size at age 7.
A genetic study using human fat cells from non-obese children found that BPA can turn on genes that help build fat and turn off a gene that produces insulin, promoting metabolic disorders.
Still, not all studies found a link between BPA exposure and fat gain — whether exposed in the womb or as a child. Researchers think that the timing and amount of BPA exposure might affect whether or not a child becomes obese. More research is needed to fully understand the relationship.
How are we exposed to BPA?
Food and drink packaging is the main way people are exposed to BPA. But BPA is also on thermal receipts — paper coated with a shiny film used in modern cash registers — at levels 250 to 1,000 times greater than the amount found in food containers or hard plastic water bottles. Because BPA can enter the body through the skin, people who work with these receipts — cashiers, waiters — tend to have higher BPA levels in their bodies.
Many companies have removed BPA from baby bottles, though some plastic baby bottles still contain traces of BPA that can get into milk or formula. The chemical also may still be in children’s toys, spoons, pacifiers, and teething rings. Because babies suck and chew on just about anything they touch, they may be exposed to BPA in ways that adults are not.
The alternative chemical BPF is also used in lacquers, varnishes, glues, water pipes, and dental sealants. So besides food cans or water bottles, you or your children might be exposed to bisphenol chemicals via dental materials, indoor dust, and soil.
Steps you can take to limit your exposure
The U.S. Food and Drug Administration has not banned BPA, but many researchers and several other government agencies are worried about it. Recently, California’s Office of Environmental Health Hazard Assessment required a written warning on products containing BPA.
I believe in the precautionary principle: if there is evidence that something can cause harm — even if not everyone agrees or its use is still legal — I try to avoid it. Basically, it’s better to be safe than sorry. To reduce your exposure to BPA and similar chemicals, I recommend that you:
- Use glass or stainless steel containers for foods and drinks.
- Never put plastic containers in the microwave.
- Choose foods that are fresh, frozen, or sold in glass containers. Avoid canned food and plastic packaging. (Hello, farmers’ market!)
- Reuse glass jars for food storage and carrying drinks.
- Remove household dust by wet mopping, wiping with microfiber cloths, and vacuuming with a machine that has strong suction and a multilayered bag.
- Avoid touching receipts. Refuse them if offered and do not give them to children. But if you need to collect them for your records, just wash your hands afterward.
- If you handle receipts for your job, wear protective gloves or wash your hands afterward.
- When you visit the dentist, ask for composite fillings that are free of all bisphenols and phthalates. Phthalates are used to hold color and are also a component of many personal care and cleaning product fragrances. Phthalates are also a hormone disruptor.
If all this sounds scary, there is one good thing to know: BPA and similar chemicals don’t last long in your body. So efforts you make to reduce your exposure will help you right away.