Are Plastic Containers Raising Your Blood Pressure?
Research suggests even “safer” plastics may be harming our health
One word: plastics. They’re oh-so-convenient in wraps for leftovers, containers for carry out and bottles for water, but researchers have long been concerned about their effects on human health.
Products that contain phthalates, used to make plastics softer, are suspected of causing cancer and disrupting the endocrine system when they migrate into our food and water. Manufacturers in the United States began phasing out some of these years ago, replacing them with other, allegedly safer phthalates. But new studies suggest these chemicals, too, may be harmful, possibly raising the risk of high blood pressure and diabetes.
The “old” phthalate, DEHP (di-2-ethylhexylphthalate), was banned by European regulators in 2004. Since that time, manufacturers in the United States have been voluntarily replacing it with DINP (di-isononyl phthalate) and DIDP (di-isodecyl phthalate).
Research just out from NYU Langone Medical Center is the first to examine potential health risks from these “replacement” compounds. A study published this month in the journal Hypertension found a “significant association” between high blood pressure and levels of DINP and DIDP in the participants.
The researchers examined blood and urine samples collected over several years from children and adolescents who are participants in the National Health and Nutrition Examination Survey, an ongoing annual survey of 5,000 people in the United States. They found that for every 10-fold increase in the amount of DINP or DIDP consumed, there was a 1.1 millimeters of mercury (mm Hg) increase in systolic blood pressure (the top number of a blood pressure reading).
“Rates of childhood hypertension have reached almost epidemic proportions, and the evidence suggesting links between phthalates and adverse health effects is rapidly increasing,” the study authors concluded. They explained that phthalates can change heart cells and other "targets" and cause an imbalance in the body’s antioxidant defense system.
“One thing that’s important is that what we found in our study was an association, not a cause and effect relationship,” said Teresa M. Attina, MD, PhD, a research scientist at NYU Langone Medical Center and a senior investigator on the studies. “However, there is definitely a cause for concern because exposure to these chemicals is widespread. They are in food containers, plastic bottles — they are pretty much in anything.”
In a separate study published in May 2015 in The Journal of Clinical Endocrinology & Metabolism, the same researchers found adolescents with the highest concentrations of DINP and DIDP in their blood and urine were more likely to have insulin resistance, a precursor to diabetes, than those with the lowest levels.
How to reduce your exposure
The researchers suggest several simple ways to lower your risk:
- When microwaving, don’t use plastic containers or cover the dish with plastic wrap.
- Use alternatives to plastic wrap, such as aluminum foil and wax paper, for wrapping sandwiches and other foods.
- Avoid buying packaged fresh fruits and vegetables.
- Wash plastic food containers by hand rather than in the dishwasher.
- Avoid using plastic containers with the numbers 3, 6 or 7 inside the recycle symbol.
The researchers plan to look at the long-term effects of exposure to such chemicals, particularly during pregnancy and early childhood. They say their studies point up the need to test chemicals for toxicity before introducing them into the market for widespread use.
“The problem is that under U.S. regulation chemicals are innocent until proven guilty,” says Attina. “They enter the market and then, if they are found to be toxic, they are removed. That’s the general approach. That’s why we need these types of studies to build a body of evidence to suggest these chemicals are not that safe.”