Besides the fat and calories in fast food – now we need to think about phthalates

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May 11, 2016

A few weeks ago, there was an article in the Washington Post about consumption of fast foods that I thought would get more press. It reported on a study published in Environmental Health Perspectives that looked at phthalate levels and how they relate to fast foods.

First, to explain, phthalates are used to improve flexibility in plastics. They are ubiquitous, as they are used in food packaging, some shampoos and lotions, as an inactive ingredient in some dietary supplements and medications (UpToDate), in flooring, and in medical devices. They can leach into foods from plastics like tubing used in the milking process, plastic wrap, lid gaskets, gloves used for food preparation, conveyor belts, etc.

Since fast foods (FF) are highly processed, packaged and handled, and may be transported in bulk and reheated and handled again, they are likely to be a source of more phthalates than other foods. These chemicals can enter the body by being eaten, breathed in, or absorbed through the skin. In fact, the two phthalates that were measured in this study are so commonly consumed that they are detectable in the urine of 98% of the population.

Most prior studies regarding phthalates have been in animals, not humans, and some have shown that they can be “endocrine-disruptors” and act as anti-male hormones.

A few months ago, an article in National Geographic reported that a majority of male smallmouth bass had eggs in their testes in a Northeastern US refuge area.  Although some fish can naturally be hermaphrodites, having both male and female characteristics, they are labeled ‘intersex’ when found in fish species like the smallmouth bass, in which it is not a natural state.

This phenomenon was first discovered accidentally in 2006 in the Chesapeake Bay when fish were being examined for a major die-off. My concern is that these intersex fish may be the ‘canary in the coalmine’ for us. We are exposed to the same water that the fish are.  Are we seeing behavioral effects, hormone-related cancers and other health effects from exposure to these and the many other chemicals we are exposed to on a daily basis?  The water of the Chesapeake may have pollutants from many sources; the Northeast refuge, on the other hand, is only near dairy farms. The endocrine disruptions seen there seem to suggest that chemicals that interfere with hormones are everywhere – human waste from birth control pills, animal waste, cosmetic products, etc.

The National Geographic article goes on to say that, “Exposures to endocrine disrupting chemicals in drinking water, food, and household products have been linked to health problems in people too, including reduced fertility, developmental delays in children, and some cancers. But it’s too soon to say whether feminized fish are indicative of health effects for humans too.”

Getting back to the recent phthalate article – as I’ve mentioned in other articles, dietary studies are very difficult to do. People can’t recall accurately what they ate, their foods are difficult to control, ingredients and amounts may vary, etc. This particular study is the largest one to date about fast food consumption and markers in the blood of environmental chemical exposure. They defined FF as food obtained from a restaurant without waitstaff, a pizza restaurant with or without waitstaff, and all carryout and delivery.

The authors looked at data on almost 9000 people in the National Health and Nutrition Examination Survey (NHANES 2003 – 2010), a population study conducted by the CDC that has examined many other issues. This particular part of the study required recall of the person’s food intake over the past 24 hours. They looked at total calorie intake, and how much of the fat component came from fast food.

They found that the greater the % of total calories that came from FF, the higher the phthalate levels. This “dose response” usually suggests that the levels are truly related to the fast food intake and not just a random finding. They also looked at bisphenol A, which we reviewed in 2013. You may recall that at that time, there was so much in the news about BPA that cans and reusable bottles were changed so they could be labeled as “BPA-free”. Understandably, the current study did NOT find any increase in it with fast food, since BPA is predominantly found in food and beverage cans and thermal receipts, not in plastic containers.

The authors reviewed problems regarding their own study. Clearly, a longer and more detailed study is needed, but these preliminary findings are helpful. Scientific groups, including the US Environmental Protection Agency have advised limiting exposure to phthalates due to concern about health effects, but until now few sources of significant exposure have been identified.

For now, this study adds one more reason to avoid fast food – in addition to its harmful effect on weight and subsequently on blood pressure, insulin resistance and high cholesterol, we now should be concerned about potential hormone-disruption.

Since less phthalate exposure is better, take any opportunity to have a simple meal at home rather than indulge in fast food. Some basic precautions I take to avoid excess phthalates, which at this point are my personal preferences not necessarily substantiated by science, are to avoid getting soup-to-go (potentially eating melted plastic just seems like a bad idea), and to avoid reheating foods in single-use plastic containers, and mostly avoiding coffee brewed through plastic containers. In fact, at home, I only use glass containers – one large set from Costco serves all my needs!

The Pediatric Environmental Health Specialty Units website states that most information on phthalates and BPA is from animal research, as noted above, but for those who wish to be precautionary, the following lifestyle choices would apply:

●Buy low fat dairy products such as skim milk and low fat cheeses and avoid high fat foods such as cream, whole milk, and fatty meats as much as possible.
●Buy fresh or frozen fruits and vegetables when possible and avoid canned and processed foods.
●Purchase items that are phthalate-free or BPA-free, when possible.
●Minimize use of personal care products.
●Use glass, stainless steel, ceramic, or wood to hold and store foods instead of plastics.
●Do not microwave food/beverages in plastic or use hard polycarbonate plastics (some water bottles/baby bottles/sippy cups) for hot liquids.
●Particularly avoid plastics marked 3 (PVC or vinyl), 6 (polystyrene foam), or 7 (other, can contain BPA) on the bottom, which are most likely to contain these chemicals.
●Wash hands frequently.
●Minimize handling of receipts.
●Remove shoes at home to avoid tracking in dust that may contain these chemicals.
●Keep carpets and windowsills clean to minimize dust that may contain these chemicals.


Prior LadyDocs articles written by interns at George Washington University on plastics and kitchen appliances

Recent Fast Food Consumption and Bisphenol A and Phthalate Exposures Among the U.S. Population in NHANES, 2003-2010
National Geographic article about intersex fish