In a new study, one of the first to look at fast-food consumption and exposure to these chemicals, those who consumed the most fast food had phthalate levels up to 40% higher than those who ate the least fast food.

Commenting on the study which appears in the journal Environmental Health Perspectives lead author Ami Zota, ScD, MS, an assistant professor of environmental and occupational health at Milken Institute School of Public Health (Milken Institute SPH) at the George Washington University said: “Our findings raise concerns because phthalates have been linked to a number of serious health problems in children and adults.”

Phthalates belong to a class of industrial chemicals used to make food packaging materials, tubing for dairy products, and other items used in the production of fast food. Other research suggests these chemicals can leach out of plastic food packaging and can contaminate highly processed food.

Grains and meats are the most contaminated

The scientists looked at the diets of 8,877 people who answered detailed questions about their food consumption over the previous 24 hours. These people also provided  a urine sample that could be tested for the breakdown products of two specific phthalates – DEHP and DiNP.

Results showed that people in the study with the highest consumption of fast food also had 23.8% higher levels of the breakdown product for DEHP in their urine sample. Those same fast food lovers had nearly 40% higher levels of DiNP metabolites in their urine compared to people who reported no fast food in the 24 hours prior to the testing.

The researchers also determined that grain and meat items were the most significant contributors to phthalate exposure. Foods in the grain category included bread, cake, pizza, burritos, rice dishes and noodles. Other studies have also identified grains as an important source of exposure to these potentially harmful chemicals.

The likely source of exposure is food packaging, however phthalates are also present in some pesticide formulations.

BPA – also present in meat products

In addition, the researchers also looked for exposure to another chemical found in plastic food packaging – bisphenol A or BPA. Researchers also believe exposure to BPA can lead to health and behaviour problems, especially for young children. This study found no general association between total fast food intake and BPA. However, it did find that people who ate fast food meat products had higher levels of BPA than those who reported no fast food consumption.

No safe substitute

This study fits into a bigger field of ongoing research showing that phthalates are in a wide variety of personal products, toys, perfume and even food. In 2008 US Congress banned the use of phthalates in the production of children’s toys because of concerns about the health impact of these chemicals.

Both DEHP and DiNP are still in use in the US despite concerns that they leach out of products and get into the human body. Studies of the health impact of exposure to these chemicals have suggested they can damage the reproductive system and they may lead to infertility.

DEHP, the original chemical used as a plasticiser, was banned in 2004 in Europe after researchers elsewhere found a link between exposure to the plasticiser and detrimental effects on human health. Many manufacturers began replacing it with DiNP – though there are questions about how ‘safe’ this is.

The authors sensibly note that frequent consumption of fast food is not recommended because these foods contain higher amounts of fat, salt and calories. “People concerned about this issue can’t go wrong by eating more fruits and vegetables and less fast food,” Zota suggests.

A diet filled with whole foods – especially if they are organic – offers a variety of proven health benefits that go far beyond the question of phthalates and their potential health risks

New evidence shows that drinking strong coffee three hours before bed-time can turn the body clock back nearly an hour.

Caffeine resets the clock by delaying a rise in the level of melatonin, the body’s chief sleep hormone. Resetting our internal body clock affects many aspects of human health and disease, such as when we feel sleepy, how we metabolise food, and even when in the day we observe the best athletic and cognitive performance.

Your body clock rules…everything

This circadian rhythm (a 24 hour cycle) operates in every single cell of the body, turning different genes on and off at different times of day to allow us to best anticipate the external cycle of night and day.

Disruption of this daily internal rhythm, during shift work or through repeated jet lag, significantly increases the risk of various cancers as well as cardiovascular disease, type-2 diabetes and neurodegenerative disorders such as Alzheimer’s disease.

It is known that caffeine counteracts some of the effects of sleepiness and makes it easier to stay awake, but until now no one had looked at whether there is also an effect on the internal circadian body clock.

Jet lag

For the study, published in Translational Medicine, researchers monitored 5 volunteers in laboratory conditions so that their internal body clock could be observed.

Each person lived in the laboratory for 49 days (without a clock, or any knowledge of external night and day). They were given caffeine or a placebo, and dim or bright light (the bright light was a control, since bright light at night also delays the human circadian clock).

Melatonin is the main sleep hormone and is released from the pineal gland at night to make you feel sleepy. By observing the timing of the evening melatonin surge they showed that in those who were given caffeine equivalent to a double espresso, melatonin levels rose on average 40 minutes later than those given the placebo. In some people it was delayed for one hour 45 minutes – essentially the same effect as being jet lagged by an hour.

To understand more about how caffeine ‘jet lags’ the body the researchers added caffeine to human cells in the lab and found that it also delayed their built-in circadian clock.

They found that caffeine affects adenosine receptors which are found in all cells, and by reducing the levels of this protein on the cell surface it minimised the delay that caffeine would normally produce.

Side effects but also benefits

Caffeine is the world’s most widely consumed psychoactive drug, being the main drug in drinks such as coffee, tea energy drinks and colas.

Caffeine’s ability to keep us away is well established and the finding that caffeine influences human circadian physiology may have implications for treating sleep-wake disorders. Simply avoiding evening caffeine may help to treat problematic delayed sleep timing through circadian as well as established wakefulness-sleep mechanisms.

The study results highlight problems of the abuse of caffeine but, say the researchers it also points to potential benefits.

Properly timed caffeine use may also be of benefit with respect to shifting circadian timing, potentially assisting with circadian adaptation to large phase delays required when flying across many time zones westward, as well as sustaining wakefulness until bedtime in the new time zone.

Global experts in this field, announcing the findings, concluded that infertility and male reproductive dysfunctions, birth defects, obesity, diabetes, cardiovascular disease, and neurobehavioral and learning disorders were among the conditions that can be attributed in part to exposure to endocrine-disrupting chemicals (EDCs).

The €157 billion estimate is conservative, and represents 1.23% of Europe’s gross domestic product (GDP). These costs may actually be as high as €270 billion ($359 / £236 billion), or 2% of GDP.

A staggering cost

“The analysis demonstrates just how staggering the cost of widespread endocrine-disrupting chemical exposure is to society,” said Leonardo Trasande, MD, MPP, Associate Professor of Pediatrics, Environmental Medicine & Population Health at NYU Langone Medical Center, who led a team of eighteen researchers across eight countries in this landmark initiative. “This research crystalises more than three decades of lab and population-based studies of endocrine-disrupting chemicals in the EU.”

EDCs mimic, block or interfere with the body’s hormones. EDCs include bisphenol A (BPA) found in water bottles and can linings, certain phthalates found in plastic products and cosmetics, flame retardants and pesticides such as chlorpyrifos.

Nearly 100% of people have detectable amounts of EDCs in their bodies, according to the Introductory Guide to EDCs published by the Endocrine Society and IPEN.

Based on the body of established literature,  a panel of global EDC experts evaluated the likelihood that EDCs contributed to various medical conditions and dysfunctions but limited the analysis to the disorders with the strongest scientific evidence.

The analysis included direct costs of hospital stays, physician services, nursing home care and other medical costs. The researchers also calculated estimates of indirect costs such as lost worker productivity, early death and disability.

“Although this analysis was limited to the European Union, the disease and cost burden of exposure is likely to be on the same order of magnitude in the United States and elsewhere in the world,” Trasande said.

Losing our minds, gaining weight

In the EU, researchers found the biggest cost driver was loss of IQ and intellectual disabilities caused by prenatal exposure to pesticides containing organophosphates. The study estimated the harm done to unborn children costs society between €46.8 billion ($51 / £33 billion) and €195 billion ($214 / £140 billion) a year. About 13 million lost IQ points and 59,300 additional cases of intellectual disability per year can be attributed to organophosphate exposure.

Adult obesity linked to phthalate exposure generated the second-highest total, with estimated costs of €15.6 billion a year.

“Our findings show that limiting exposure to the most common and hazardous endocrine-disrupting chemicals is likely to yield significant economic benefits,” said one of the study’s authors, Philippe Grandjean, MD, PhD, Professor of Environmental Medicine at the University of Southern Denmark and Adjunct Professor at the Harvard T.H. Chan School of Public Health.

“This approach has the potential to inform decision-making in the environmental health arena. We are hoping to bring the latest endocrine science to the attention of policymakers as they weigh how to regulate these toxic chemicals.”

The findings are published in a series of studies published in the Endocrine Society’s Journal of Clinical Endocrinology and Metabolism.

• The study Estimating Burden and Disease Costs of Exposure to Endocrine-Disrupting Chemicals in the European Union can be found here
• The study Obesity, Diabetes, and Associated Costs of Exposure to Endocrine-Disrupting Chemicals in the European Union can be found here
• The study Neurobehavioral Deficits, Diseases and Associated Costs of Exposure to Endocrine Disrupting Chemicals in the European Union can be found here
• The study Male Reproductive Disorders, Diseases, and Costs of Exposure to Endocrine-Disrupting Chemicals in the European Union can be found here