Endocrine-disruptive chemicals can end up in our food and drinks since they are used in food processing packaging and equipment. Endocrine disruptors are chemicals that can interfere with thyroid hormone, estrogen, testosterone, insulin, or other hormones. Even at very low levels these disruptors can turn on, off, or alter the signals that the hormones send throughout our bodies.

BISPHENOL A (BPA) is an endocrine disruptor that’s used to make polycarbonate, a hard plastic, and to protect the insides of bottle caps, jars and lids. It’s not clear how BPA is harmful to adults, but this is the latest research:

Obesity: Researchers monitored the weight of nearly 1K nurses for over 10 years, the women who entered the study with the highest BPA levels gained an average of 5 lbs more than those with the lowest levels.

Cancer: BPA can act as an estrogenic compound, therefore it may promote the growth of any tumors that are driven by estrogens, such as breast cancers. Studies with mice showed that exposing them to BPA in the womb lead to an increase in breast tumors. However, there is limited research on exposure in humans and its impact on cancer susceptibility or growth.

Type 2 diabetes: Insulin allows blood sugar to enter cells. If your cells become resistant to insulin, you have an increased risk of type 2 diabetes and heart disease. Some animal studies show a greater insulin resistance to animals given BPA. In humans, based on the nurse’s study, those with the highest levels of BPA were 50% more likely to later be diagnosed with type 2 diabetes than nurses with the lowest BPA levels. However, that wasn’t true for nurses in their middle-aged. It is believed that the younger women, who have not experienced menopause, may be more vulnerable to endocrine disruptors than older, postmenopausal women.

HOW TO DECREASE EXPOSURE

Avoid foods and beverages in cans and plastic. Some researchers suspect that BPA substitutes labeled as “BPA-free” may not be safe either.

Check the recycling number on the bottom of plastic bottles and containers. Avoid:

No. 3 [V]—Vinyl or Polyvinyl chloride (PVC), it can contain phthalates.

No. 6 [PS]—Polystyrene foam. It contains styrene, a chemical that the International Agency for Research on Cancer calls a possible human carcinogen.

No. 7—Other. It’s mostly polycarbonate, which contains BPA.

If it’s convenient, wash plastic containers by hand, to avoid high heat of the dishwasher. If you run them through the dishwasher, put them on the top shelf.

Use fewer canned foods. The insides of most metal cans are coated with an epoxy resin that contains BPA. The resins used in most “BPA-free” cans may be no safer.

When possible, microwave in glass or ceramic. If you microwave in plastic, try to avoid using polycarbonate (recycling number 7). And cover the food with a paper towel or a plate.

Try not to put very hot liquids or foods into plastic containers.

If you keep food in plastic, you’re better off with:

References:

NeuroToxicology 49: 174, 2015.

Int. J. Obes. 38: 1532, 2014.

PLoS One 7: e33814, 2012.

Environ. Health Perspect. 122: 616, 2014.

Circulation 125: 1482, 2012.

Biol. Reprod. 85: 490, 2011.

Toxicol. Sci. 140: 190, 2014.