American Association for the Advancement of Science

Overeating and obesity to blame for medical disorders, NOT plastics chemical found in body

Modern Western diet could be factor in health problems associated with an increase in exposure to bisphenol A


Overeating and obesity can explain many of the medical disorders that have been blamed on a plastics chemical found at low levels in the human body, scientists said today.

A number of studies have suggested a link between bisphenol A (BPA), which is widely used in the plastic packaging, and illnesses ranging from diabetes to infertility, but the association does not mean that the chemical actually causes these disorders, they said.

A more likely explanation is that obese people who overeat - and who develop chronic illnesses as a result - are also more likely to have raised levels of BPA in their bloodstream from plastic food packaging, said Professor Richard Sharpe of the Medical Research Council’s Centre for Reproductive Health in Edinburgh.

“Studies consistently show an association between higher BPA exposure and Western disorders such as obesity, type-2 diabetes, liver and cardiovascular diseases,” Professor Sharpe said.

“There are numerous such studies, so numerous that we have to accept that the associations are real but this does not mean they represent cause and effect,” he told the American Association for the Advancement of Science meeting in Boston.

“None of these studies actually shows that bisphenol A exposures causes the disorders, the exposure is simply associated with occurrence of the disorders,” he said.

“If this association was due to cause and effect, it would mean that bisphenol A was incredibly potent and toxic, and this does not agree with published studies. This possibility therefore seems illogical,” he added.

An alternative explanation is that there is a third element that is actually responsible for the health problems and that it is associated with an increase in exposure to bisphenol A, Professor Sharpe told the meeting.

“I will suggest that this third factor is diet, or more accurately a modern Western diet, because we know that such as diet is associated with all the disorders [linked with BPA],” he said.

Studies have shown that diet accounts for about 95 per cent of the BPA levels in the body but these can be lowered by two thirds if people eat food that is freshly sourced rather than wrapped in plastic packaging, he said.

“My hypothesis is that a modern Western diet determines the level of BPA exposure – the more of it you eat, the more BPA you're exposed to – with the result that over-eating causes obesity etc, but also causes higher BPA exposure,” Professor Sharpe said.

“If this interpretation is correct, it means that a Western, poor diet is responsible on the one hand for causing the disorders and on the other hand for causing increased exposure to bisphenol A, [which is] innocently associated with the disorders as a result,” he said.

“The attraction of this hypothesis is that it fits the available facts whereas the possibility of bisphenol A causing the disorders does not fit the facts - it fails because of our exceedingly low exposure level,” he added.

Some scientists have suggested that BPA has an effect on the human body by mimicking the effect of female oestrogens, which could account for increase in infertility and other reproductive problems in men, they have argued.

However a review of 150 published studies on BPA has concluded that the concentrations of the chemical found in the human body are far too low for them to mimic oestrogens, said Justin Teeguarden of the Pacific Northwest National Laboratory in Richland, Washington.

“At these exposure levels, exposure to BPA can’t be compared to giving a baby the massive dose of oestrogens found in a birth control pill, a comparison made by others,” Dr Teeguarden said.

“Human internal exposures to BPA are below levels we would expect to cause toxicity in the general population and children,” he said.

Start your day with The Independent, sign up for daily news emails
ebooksAn unforgettable anthology of contemporary reportage
Latest stories from i100
Have you tried new the Independent Digital Edition apps?
Independent Dating

By clicking 'Search' you
are agreeing to our
Terms of Use.

iJobs Job Widget
iJobs General

Recruitment Genius: Business Development Executive / Digital Marketing Executive

£26000 - £35000 per annum: Recruitment Genius: A luxury beauty house with a nu...

Recruitment Genius: Housekeepers - Immediate Start

£8 per hour: Recruitment Genius: This company are currently recruiting new exp...

Recruitment Genius: Head Concierge

£25000 - £28000 per annum: Recruitment Genius: This award winning Property Man...

Recruitment Genius: Content, SEO and PPC Executive

£20000 - £25000 per annum: Recruitment Genius: A fantastic opportunity has ari...

Day In a Page

On your feet! Spending at least two hours a day standing reduces the risk of heart attacks, cancer and diabetes, according to new research

On your feet!

Spending half the day standing 'reduces risk of heart attacks and cancer'
Liverpool close in on Milner signing

Liverpool close in on Milner signing

Reds baulk at Christian Benteke £32.5m release clause
With scores of surgeries closing, what hope is there for the David Cameron's promise of 5,000 more GPs and a 24/7 NHS?

The big NHS question

Why are there so few new GPs when so many want to study medicine?
Big knickers are back: Thongs ain't what they used to be

Thongs ain't what they used to be

Big knickers are back
Thurston Moore interview

Thurston Moore interview

On living in London, Sonic Youth and musical memoirs
In full bloom

In full bloom

Floral print womenswear
From leading man to Elephant Man, Bradley Cooper is terrific

From leading man to Elephant Man

Bradley Cooper is terrific
In this the person to restore our trust in the banks?

In this the person to restore our trust in the banks?

Dame Colette Bowe - interview
When do the creative juices dry up?

When do the creative juices dry up?

David Lodge thinks he knows
The 'Cher moment' happening across fashion just now

Fashion's Cher moment

Ageing beauty will always be more classy than all that booty
Thousands of teenage girls enduring debilitating illnesses after routine school cancer vaccination

Health fears over school cancer jab

Shock new Freedom of Information figures show how thousands of girls have suffered serious symptoms after routine HPV injection
Fifa President Sepp Blatter warns his opponents: 'I forgive everyone, but I don't forget'

'I forgive everyone, but I don't forget'

Fifa president Sepp Blatter issues defiant warning to opponents
Extreme summer temperatures will soon cause deaths of up to 1,700 more Britons a year, says government report

Weather warning

Extreme summer temperatures will soon cause deaths of up to 1,700 more Britons a year, says government report
LSD: Speaking to volunteer users of the drug as trials get underway to see if it cures depression and addiction

High hopes for LSD

Meet the volunteer users helping to see if it cures depression and addiction
German soldier who died fighting for UK in Battle of Waterloo should be removed from museum display and given dignified funeral, say historians

Saving Private Brandt

A Belgian museum's display of the skeleton of a soldier killed at Waterloo prompts calls for him to be given a dignified funeral