Three reasons you should never drink out of plastic water bottles

Though water is the healthiest thing anyone can drink , science suggests that drinking from plastic water bottles might not be the best thing for you or the environment .

Here are reasons you should avoid drinking from plastic water bottles as much as you can :

• They can release potentially harmful chemicals into your water. When you expose plastic bottles to heat ( such as in a hot car , dishwasher , ultraviolet radiation from the sun or microwaves) , the outer layers can break down. In response , plastics marked with recycle codes 3 or 7 can release a chemical called bisphenol A ( BPA) , while BPA-free plastics can release bisphenol S ( BPS) . These can contaminate your water , says Dr. Cheryl Watson , a biochemist at the University of Texas Medical Branch in Galveston , who ’ s done extensive research on human exposure to BPA and BPS.

The problem : When you ingest even small amounts , they mimic oestrogen , which can change the way your endocrine system functions . In humans , exposure has been linked to chronic diseases, including diabetes , asthma , and cancer . Animal studies suggest in utero exposure can ultimately impair development of the brain and immune system of a growing baby , with effects that could be passed down to future generations .

• Plastic chemicals might make it harder for you to have a baby . Researchers found that men and women undergoing in- vitro fertilization who had high levels of BPA in their blood , urine , and work environment were less likely to have a successful pregnancy , according to a 2013 review of 91 studies published in

Reproductive Toxicology .

The problem : Although more research is needed , the results suggest that when BPA imitates oestrogen , it interferes with different stages of pregnancy , such as fertilization and implantation , says Dr. Sheela Sathyanarayana , adjunct associate professor of environmental and occupational health sciences at the University of Washington .

• Plastic chemicals could raise your risk of heart disease and other circulatory issues . Humans exposed to the highest levels of BPA have an increased risk of heart disease , according to a 2012 study published in Circulation . Researchers think this could be due to BPA’s link to high blood pressure , a risk factor for heart disease .

 After all , the blood pressure of adults who drank from cans containing BPA rose almost immediately in a small but thorough 2015 study published in Hypertension .

The problem : Since BPA and BPS can mimic oestrogen once they get into your system , and high levels of the hormone increase the production of the blood plasma protein , according to Dr. Sathyanarayana , exposure to these chemicals could also lead to blood clotting and related complications like heart events and stroke .