Paracetamol use may raise asthma risk in children

HONG KONG (Reuters) - Infants who have been given the common pain reliever paracetamol may have a higher risk of developing asthma and eczema by the time they are 6 or 7, a large study covering children in 31 countries has found.

The findings were published in the journal Lancet together with two other studies, which found that runny noses and wheezing early on in life may be strong predictors of asthma.

In the first study, researchers pored through data provided by parents of more than 205,000 children and found paracetamol use in the first year of life was associated with a 46 percent higher risk of asthma by the time the children were 6 or 7 compared to those never exposed to the drug.

Known as acetaminophen in the United States, where it is widely sold under the brand Tylenol, it is used to relieve fever, minor aches and pain, and is used in a liquid suspension for children.

Medium use of paracetamol in the past 12 months increased asthma risk by 61 percent, while high dosages of once a month or more in the past year raised the risk by over three times.

Medium use was defined as once per year or more, but less than once a month.

Suspicions of a possible link between paracetamol and asthma emerged in recent years when experts observed an increased use of the drug to a simultaneous rise in asthma prevalence worldwide.

One theory is that paracetamol reduces antioxidants in the body. Some experts think antioxidants, which stop unstable molecules known as free radicals from doing too much damage, can lower the risk of cancer, heart disease and other ailments.

"Paracetamol can reduce antioxidant levels and ... that can give oxidative stress in the lungs and cause asthma," one of the researchers, Richard Beasley at the Medical Research Institute of New Zealand, told Reuters in a telephone interview.

As with asthma, monthly use of paracetamol doubled the risk of eczema and trebled that of rhinoconjunctivitis -- repetitive sneezing, rhinorrhea, nasal congestion and hay fever -- by the time children were 6 or 7, the study found.

PARACETAMOL REMAINS DRUG OF CHOICE

However, the researchers stressed paracetamol should remain the preferred drug to relieve pain and fever in children because its alternative, aspirin, was linked to the risk of Reye's syndrome, a rare but serious complication in children.

"The findings do lend support to the current guidelines of the World Health Organization, which recommend that paracetamol should not be used routinely, but should be reserved for children with a high fever (38.5 Celsius or above)," they wrote.

Another study in The Lancet found that rhinitis, or hay fever and other allergic reactions causing a runny nose, was a strong predictor of asthma that develops in adulthood.

Researchers monitored 6,461 people in 14 countries who were free of asthma at the start of study for more than 8 years.

Those who suffered rhinitis and were allergic to an assortment of agents like house dust mites, cat, grass and birch were 3.5 times more likely to develop asthma later on compared to those who suffered no allergies nor rhinitis.

The third study in Arizona in the United States found wheezing early in life may be an ominous sign of asthma developing in adulthood.

Researchers pored through data on 849 people going back 22 years to the time they were babies. Of 181 cases of active asthma, 49 were newly diagnosed, of which 35 were women.

"In over 70 percent of people with current asthma and 63 percent of those with newly diagnosed asthma at age 22 years, episodes of wheezing had happened in the first three years of life or were reported by parents at age six years," wrote the researchers at the Arizona Respiratory Center.

In an accompanying comment, Suzanne Lau of Charite University Medicine in Germany, wrote: "These findings identify a population at risk of chronic obstructive airway disease in early adulthood, and they already showed a predisposition during preschool years." Lau was not involved in the study.

(Reporting by Tan Ee Lyn; Editing by Jerry Norton)

By Tan Ee Lyn

Which plastic water bottles don't leach chemicals?

Choose your water bottles very carefully in order to prevent chemicals in the plastic from leaching into your water.
Plastic water bottles are very convenient for carting water around when we are on the go, as they don't break if we drop them. However, it is worth paying attention to the type of plastic your water bottle is made of, to ensure that the chemicals in the plastic do not leach into the water. If you taste plastic, you are drinking it, so get yourself another bottle.

To be certain that you are choosing a bottle that does not leach, check the recycling symbol on your bottle. If it is a #2 HDPE (high density polyethylene), or a #4 LDPE (low density polyethylene), or a #5 PP (polypropylene), your bottle is fine. The type of plastic bottle in which water is usually sold is usually a #1, and is only recommended for one time use. Do not refill it. Better to use a reusable water bottle, and fill it with your own filtered water from home and keep these single-use bottles out of the landfill.

Unfortunately, those fabulous colourful hard plastic lexan bottles made with polycarbonate plastics and identified by the #7 recycling symbol, may leach BPA. Bisphenol A is a xenoestrogen, a known endocrine disruptor, meaning it disturbs the hormonal messaging in our bodies. Synthetic xenoestrogens are linked to breast cancer and uterine cancer in women, decreased testosterone levels in men, and are particularly devastating to babies and young children. BPA has even been linked to insulin resistance and Type 2 Diabetes. For more of the science on the effects of BPA on our endocrine system etc. see these studies: Environmental Health Perspectives Journal. Nalgene, the company that manufactures the lexan water bottles also makes #2 HDPE bottles in the same sizes and shapes, so we have a viable alternative. Order one at Nalgene.

Unfortunately, most plastic baby bottles and drinking cups are made with plastics containing Bisphenol A. In 2006 Europe banned all products made for children under age 3 containing BPA, and as of Dec. 2006 the city of San Franscisco followed suit. In March 2007 a billion-dollar class action suit was commenced against Gerber, Playtex, Evenflo, Avent, and Dr. Brown's in Los Angeles superior court for harm done to babies caused by drinking out of baby bottles and sippy cups containing BPA. So, to be certain that your baby is not exposed, use glass bottles.

Check the recycling numbers on all your plastic food containers as well, and gradually move to storing all food in glass or ceramic.

Store water in glass or brass if possible, and out of direct sunlight.

by Vreni Gurd | Thu, 03/29/2007 - 10:23pm

Plastic Bottles Release Potentially Harmful Chemicals (Bisphenol A) After Contact With Hot Liquids

ScienceDaily (Feb. 4, 2008) — When it comes to Bisphenol A (BPA) exposure from polycarbonate plastic bottles, it's not whether the container is new or old but the liquid's temperature that has the most impact on how much BPA is released, according to University of Cincinnati (UC) scientists.

Scott Belcher, PhD, and his team found when the same new and used polycarbonate drinking bottles were exposed to boiling hot water, BPA, an environmental estrogen, was released 55 times more rapidly than before exposure to hot water.

"Previous studies have shown that if you repeatedly scrub, dish-wash and boil polycarbonate baby bottles, they release BPA. That tells us that BPA can migrate from various polycarbonate plastics," explains Belcher, UC associate professor of pharmacology and cell biophysics and corresponding study author. "But we wanted to know if 'normal' use caused increased release from something that we all use, and to identify what was the most important factor that impacts release."

"Inspired by questions from the climbing community, we went directly to tests based on how consumers use these plastic water bottles and showed that the only big difference in exposure levels revolved around liquid temperature: Bottles used for up to nine years released the same amount of BPA as new bottles."

BPA is one of many man-made chemicals classified as endocrine disruptors, which alter the function of the endocrine system by mimicking the role of the body's natural hormones. Hormones are secreted through endocrine glands and serve different functions throughout the body.

The chemical--which is widely used in products such as reusable water bottles, food can linings, water pipes and dental sealants--has been shown to affect reproduction and brain development in animal studies.

"There is a large body of scientific evidence demonstrating the harmful effects of very small amounts of BPA in laboratory and animal studies, but little clinical evidence related to humans," explains Belcher. "There is a very strong suspicion in the scientific community, however, that this chemical has harmful effects on humans."

Belcher's team analyzed used polycarbonate water bottles from a local climbing gym and purchased new bottles of the same brand from an outdoor retail supplier.

All bottles were subjected to seven days of testing designed to simulate normal usage during backpacking, mountaineering and other outdoor adventure activities.

The UC researchers found that the amount of BPA released from new and used polycarbonate drinking bottles was the same -- both in quantity and speed of release -- into cool or temperate water.

However, drastically higher levels of BPA were released once the bottles were briefly exposed to boiling water.

"Compared to the rate of release from the same bottle, the speed of release was 15 to 55 times faster," explains Belcher.

Prior to boiling water exposure, the rate of release from individual bottles ranged from 0.2 to 0.8 nanograms per hour. After exposure, rates increased to 8 to 32 nanograms per hour.

Belcher stresses that it is still unclear what level of BPA is harmful to humans. He urges consumers to think about how cumulative environmental exposures might harm their health.

"BPA is just one of many estrogen-like chemicals people are exposed to, and scientists are still trying to figure out how these endocrine disruptors--including natural phyto-estrogens from soy which are often considered healthy--collectively impact human health," he says. "But a growing body of scientific evidence suggests it might be at the cost of your health."

The UC team reports its findings in the Jan. 30, 2008 issue of the journal Toxicology Letters. UC graduate student Hoa Le and summer undergraduate research fellows Emily Carlson and Jason Chua also participated in this study, which was funded by a National Institute of Environmental Health Sciences grant.

Water bottles made with the controversial carbonate plastic bisphenol A, or BPA

Q&A: How Am I Affected?
Where is BPA found?

The National Toxicology Program says the main source of human exposure to bisphenol A, or BPA, is the tiny amounts that leach from Nalgene-type polycarbonate water bottles and from metal cans — that could include canned vegetables and fruits — lined with an epoxy resin that contains BPA. The chemical is also found in baby bottles, tableware and food storage containers.

Does BPA cause health problems?

Studies about the effects of BPA have been conflicting. Some animal studies have suggested a link between BPA and effects on the brain, behavior and the prostate gland — and raised concerns about the effects of exposure on the developing fetus and young children. But there are no conclusive studies linking BPA to human health problems.
It's also unclear what determines how much leaching occurs. It may depend on the temperature of the liquid or bottle or how the plastic is reused.

What should I avoid?

To minimize exposure to BPA, the National Toxicology Program recommends that people avoid microwaving plastic food containers or washing them in the dishwasher with harsh detergents. Repeated exposure to high temperatures and harsh cleaning agents can deteriorate the plastic and release BPA.

Additionally, some sources, such as NTP, have advised consumers to avoid hard, clear plastic containers with the No. 7 on the bottom. While the chemical industry maintains that plastic bottles contain little BPA and leach trace amounts too low to be harmful to humans, some companies have voluntarily elected to sell BPA-free products. Nalgene sells BPA-free water bottles, and retailers such as Toys R Us and Wal-Mart offer baby bottles and other children's products that are BPA-free.

— Kathleen Masterson

Study Finds Link Between Plastics Chemical, Disease

Day to Day, September 16, 2008 · A new study could change the debate over the safety of bisphenol A, a compound found in many plastics.

It suggests that there is an association between higher exposures to BPA and the development of heart disease and diabetes.

The study, appearing in this week's Journal of the American Medical Association, finds that adults with the highest levels of BPA in their urine were more than twice as likely to report having diabetes or heart disease — compared with adults with the lowest levels of the chemical in their urine.

Though it brings up new possible human health risks, the study, which is being discussed today at a meeting of the Food and Drug Administration's science advisory board, offers no conclusive answers. It does not prove a cause and effect between use of plastic food containers and the development of diabetes or heart disease.

"We don't have a lot of evidence in people about the effects of BPA. This is one of the first studies, and it finds something disturbing. It's suggesting there may be harm in adults, which we didn't really believe based on the animal studies," says David Schardt, a staff scientist with the Center for Science in the Public Interest.

The study uses data drawn from the National Health and Nutrition Examination Survey — a survey conducted by the federal government — isolating a group of adults between the ages of 18 and 74 who are representative of the U.S. population at large. The survey asked a series of health-related questions, and participants provided a urine sample. Researchers then tested the urine samples for a range of compounds, including bisphenol A.

"We were interested in diseases of the 50 and older age group and that's originally what we looked at. And then we realized that these associations went into the larger adult populations. And it just turned out that these signals were exceptionally strong and exceptionally robust," says David Melzer, the study's director and professor of epidemiology and public health at Peninsula Medical School in England.

The researchers adjusted for things like weight and smoking, but the association between high BPA urine levels and likelihood of having the diseases held.

"If you could take two individuals with same sex, race, age, ethnicity, body build, cigarette smoking status, and had one individual that [had] low levels of BPA and one individual that had high levels of BPA, the individual with high levels of BPA would be more likely to also report being a diabetic or having cardiovascular disease history," says Ken Portier, a statistician with the American Cancer Society and an expert at interpreting these kinds of snapshot-in-time studies.

Portier says the findings are certainly strong enough to merit follow-up, and the next step might be to look at another group of the survey participants and see if the associations hold up.

Melzer is scheduled to discuss his findings today at a Food and Drug Administration meeting where the agency has issued a draft proposal on bisphenol A.

At this time, the FDA finds the current level of exposure to BPA through food containers safe.

by Allison Aubrey

FDA Defends Plastic Linked To Health Risks

Morning Edition, September 17, 2008 · The Food and Drug Administration defended Tuesday a controversial compound found in plastic baby bottles and in food packaging. A major study has linked bisphenol A to possible risks of heart disease and diabetes.

by Allison Aubrey