Category: Cancer

Benzene in the London Times

Benzene RingUK paper the Times today picked up on the benzene in soft drinks problem I mentioned in sciencebase on February 22.

The paper reports how the Food Standards Agency has found levels of benzene (“six parts carbon, six parts hydrogen”) at eight times the level permitted in drinking water in samples from some 230 drinks on sale in Britain and France.

What’s more interesting than this finding, eight times a miniscule amount remains a miniscule amount, is that the paper lists several sources of benzene to which we might be exposed. It is, says reporter Rajeev Syal, It is produced during incomplete combustion of carbon-rich substances: “produced from petrochemicals, but occurs naturally in volcanoes, forest fires and in cigarette smoke. Volcanologists, forestry firefighters, and smokers should be listed among those banned from worrying about their being too much benzene in their cola, bottled water, or ‘fruit’ drink.

Regardless of the actual hazards involved, what’s the betting that benzene in soft drinks will displace fears of bird flu, in the UK, for at least a couple of weeks. It might just be long enough to keep the media fed until all those ducks have flown the coop, as it were…

You can read The Times’ article (here).

Benzene Soda

Sodium benzoate (E211) is a public health issue that has been bubbling for fifteen years and could soon come to a head and have the fizzy drinks industry frothing at the mouth.

Sodium benzoate is a preservative added to carbonated beverages, but those drinks that also have added citric or ascorbic acid (vitamin C, E300) can be susceptible to the formation of benzene as a degradation product. At least that’s the theory.

The US Food & Drugs Administration (FDA) was aware of this issue in the 1990s and alerted manufacturers who were then meant to introduce a “quick fix” to prevent this carcinogenic degradant from forming in amounts above safety levels. However, there have been hundreds of new susceptible beverages brought to market the world over since by smaller manufacturers as well as the well-known ones and seemingly the benzene message has been lost in the intervening time.

Germany’s food watchdog, BfR, and the UK’s Food Standards Agency are currently testing drinks to see whether benzene levels are above WHO recommendations. Other countries are also on the alert. The renewed concern follows the FDA’s re-opening of an investigation, closed for 15 years, into benzene in soft drinks.

You can read more details of this at industry newsletter Beverage Daily

Some studies have shown that levels of benzene are present at five times the WHO’s limit for drinking water contamination and can occur in bottled soft drinks exposed to heat and light especially.

In acid conditions, benzoate is converted to benzoic acid (the active antimicrobial form, benzoate is added as a preservative for a reason after all) and it is thought that it interacts with hydroxyl radicals released by the ascorbic acid (better known as vitamin C) reaction with iron or copper ions in the water. These hydroxyl can decarboxylate benzoic acid, releasing carbon dioxide and leaving benzene behind. But, at what rates this occurs is not clear.

Moreover, leaving out the ascorbic or citric acid from soft drinks would be the simple solution and avoiding benzoate as a preservative in foods that contain these acids naturally would offer an end to the “problem”.

However, the issue brings to the fore once again the issue of acceptable risk. Sodium benzoate is present in soft drinks only in very small amounts and even if degradation were complete, the risk to someone drinking it is tiny. To have the same exposure as lab animals used to demonstrate carcinogenicity would mean a person having to drink 10,000 bottles of benzoate-containing soda.

Still, such minor details will not stop the media from jumping on this as the next big scare story despite the fact that it’s been around for years as public chemophobia.

Combat Breakthrough in Cancer Fight

The first entirely new approach to DNA recognition since the year of my birth has been developed by Mike Hannon and colleagues at the University of Birmingham and Miquel Coll at the Spanish Research Council in Barcelona. The team has discovered a new route through which drug molecules can attach themselves to DNA. The researchers say this is a crucial step forward in drug discovery, the first in four decades.

The scientists have developed a synthetic agent that targets and binds to the centre of a three-way junction in DNA. Such junctions are formed where three double-helical regions join together and are particularly exciting as they have been found to be present in diseases, such as some Huntington’s disease and myotonic dystrophy, in viruses and are present during cancerous cell replication.

The Birmingham team created a nanosize synthetic drug shaped like a twisted cylinder. Together with colleagues in the UK, Spain and Norway they previously demonstrated its unprecedented effect on DNA. Now, structures revealed by the Barcelona team show that it binds to DNA in an entirely novel way – fixing itself to the centre of a 3-way junction. The resulting complex is held electrostatically. The researchers explain that the drug fits like a round peg in a round hole.

According to Hannon, “This is a significant step in drug design for DNA recognition and it is an absolutely crucial step forward for medical science researchers worldwide who are working on new drug targets for cancer and other diseases. This discovery will revolutionise the way that we think about how to design molecules to interact with DNA. It will send chemical drug research off on a new tangent. By targeting specific structures in the DNA scientists may finally start to achieve control over the way our genetic information is processed and apply that to fight disease.”

Let’s just hope that quote from Birmingham University’s press release on this research bears fruit, I’d hate to think that a discovery that’s waited my whole life to be made will be anything less than a breakthrough of unprecedented scale.

The work appears in the February 8 issue of Angewandte Chemie.

No Cellphone Cancer Link

It’s almost been as if the chattering classes were hoping to find that cellphones give you brain cancer. It would give them something else to chatter about, after all. But, the BBC reports that a study of almost 3000 people in the UK effectively debunks this myth – The amount of mobile phone use does not correlate with glioma, the most common form of brain tumour.

If you want to talk about this give me a call.

Dogs Sniff out Cancer

Can dogs detect cancer? There have been numerous popular science stories doing the rounds over the last two years and anecdotal evidence is mounting. But, in a world where lung and breast cancers are among the leading causes of cancer death, it seems that any early detection method is highly desirable, however canine it might be.

Now, a study published in the March 2006 issue of the journal Integrative Cancer Therapies presents astonishing evidence that man’s best friend, the dog, may indeed be able to sniff out cancer.

Apparently, the dog’s extraordinary sense of smell can distinguish between healthy people and those with both early and late stage lung and breast cancers from healthy controls.

Cancer therapy side effects

There’s an interesting tale of a novel side-effect causing problems for young cancer sufferers in the UK. Nightclub bouncers it seems have been turning away cancer patients who have been rendered hairless by their treatment on the basis that they must be “skinhead thugs”. According to the Times – http://www.timesonline.co.uk/article/0,,2-2319293.html – half the young cancer patients from Manchester’s Christie Hospital have been turned away from a pub or club door. The solution was to issue the patients with a photo identity card to stop them being turned away.

Red meat linked to increased risk of bowel cancer

The UK media today reported that red meat increases the risk of bowel cancer: e.g. Telegraph

35% increased risk screamed the headlines. But, as fascinating as the finding is none of the reports I saw mentioned the incidence rate and how low that actually is compared to, say, deaths from road accidents or obesity-related heart disease. No absolute risk was mentioned. If it’s 100 in a ten-thousand, then a 35% increase would then be 135 in 10000…

So, a 35% increased risk of something not very risky is not necessarily as significant as the cancer research organisations are claiming. Moreover, just one portion of any fish once a week can reduce the risk by 30%. So, presumably you can eat bacon, burgers and bangers 5 days a week and fish at weekends to almost cancel the positive effect with a negative.

Artemisinin Could Kill Selectively

Artemisinin could selectively kill cancer cells while leaving normal cells unharmed. Many moons ago I wrote about pioneering medicinal chemistry into this ancient Chinese fever remedy that was showing promise in fighting malaria. Now, in the spirit of modern drug-multitasking it turns out the twisted little tricyclic can also kill cancer cells!

Cancer mismatch

UK scientists believe a map of how cancer research funding is distributed might help streamline the R&D process and spot underfunding in particular areas. The National Cancer Research Institute has produced the first map of its kind to analyze the distribution of some $390m of cancer research funding from charities and government in the UK. The map revealed that most of the money is spent on the biggest cancers but some rare disorders are being funded disproportionately. (Brit Med Journal)