Science

Not a big risk

This is ridiculous (from The Guardian):

Processed meats rank alongside smoking as cancer causes – WHO

UN health body says bacon, sausages and ham among most carcinogenic substances along with cigarettes, alcohol, asbestos and arsenic

Bacon, ham and sausages rank alongside cigarettes as a major cause of cancer, the World Health Organisation has said, placing cured and processed meats in the same category as asbestos, alcohol, arsenic and tobacco.

The report from the WHO’s International Agency for Research on Cancer said there was enough evidence to rank processed meats as group 1 carcinogens because of a causal link with bowel cancer.

It places red meat in group 2A, as “probably carcinogenic to humans”. Eating red meat is also linked to pancreatic and prostate cancer, the IARC says.

The IARC’s experts concluded that each 50-gram (1.8-ounce) portion of processed meat eaten daily increased the risk of colorectal cancer by 18%.

Really - they found “a causal link with bowel cancer”?  I don’t think so.  What they found was that people who eat more processed meat have a higher incidence of cancer.  It’s easy to play around with the data and identify some correlation between two items, but if you want to go on to establish a causal link you need to do a much better study that eliminates most of the other variables. 

And “Bacon, ham and sausages rank alongside cigarettes as a major cause of cancer”.  Well, not really.  The Q&A (issued with the press release) says that:

this does NOT mean that they are all equally dangerous.  The IARC classifications describe the strength of the scientific evidence about an agent being a cause of cancer, rather than assessing the level of risk.

I think it’s that weasel word “alongside” (used by The Guardian in their headline as well as the body of the article), with its implication that they are somehow equivalent.  Which they aren’t

We know beyond all reasonable doubt that smoking causes cancer, we certainly don’t know that about sausages, ham and bacon.  Plus, all they are saying is that your risk of these cancers might go up from 5% to 6%.

Other journalists have added their own speculation.  There was a cover story in Time magazine that included the suggestion that it could be the nitrates / nitrites (probably not, as the body produces nitrites) or the process of cooking (grilling, frying, BBQ) - but I’m sure that theory was debunked.   

I can think of two simple explanations.  People who eat a lot of sausages and bacon might have a generally unhealthy lifestyle and could well be overweight, or could it just be the quality of the meat that is used in cheap sausages and ham?  But neither of those would really be news. 


Plain packs

I’m a bit late with this, but good to see that Australia is doing something constructive to dissuade people from smoking:

Ignore big tobaccos absurd fight against plain packs

New Scientist 02 May 2011 by Simon Chapman

Australia's bold plan to remove all branding from cigarettes and their packaging is a triumph for public health

EARLIER this month the Australian government released draft legislation that promises to be a landmark in the global fight against tobacco. If passed, from January 2012 cigarettes and hand-rolling tobacco will have to be sold in plain, unappealing olive-brown packs plastered with large, graphic health warnings. The only thing distinguishing one brand from another will be the name written in a standard font on the top, bottom and front of the pack, below the health warning. This is a world first.

The legislation also proposes that cigarettes themselves should be completely plain. That means no branding, no coloured or flavoured papers, no gold-banded filters and no different gauges like slimline and mini cigarettes.

With this bill, the Australian government is sending out an unambiguous message that cigarettes are exceptionally dangerous. Future generations will grow up never having seen the finely crafted elegance of a cigarette box sitting alongside confectionary and groceries in their local shop.


Eat more, eat less

A recent study showed that being "overweight" can be good for you (Study: Overweight People Live Longer):

There is more evidence that people who are overweight tend to live longer than people who are underweight, normal weight, or obese.  In a newly published study, people who were underweight and those who were extremely obese died the earliest.

People who were overweight, but not obese, actually lived longer than people whose weight was considered normal, based on body mass index (BMI).

This seems counter-intuitive because we are always told that we should be losing weight.  But wait - monkeys who are given 30% less food appear to stay healthier and live longer

Over 20 years, monkeys whose diets were not restricted were nearly three times more likely to have died than those whose calories were counted.

Writing in Science, the US researchers hailed the "major effect" of the diet.

It involved reducing calorie intake by 30% while maintaining nutrition and appeared to impact upon many forms of age-related disease seen in monkeys, including cancer, diabetes, cardiovascular disease and brain atrophy.

It seems as if there is a study somewhere out there that will support almost any theory.


Eat, drink and be merry

Two recent studies say that drinking moderately is good for you (and that exercise helps a lot).

The first survey also concludes that it's OK to be overweight as long as you eat your sprouts:

People who adopt four principles for a healthy lifestyle can add as much as 14 years to their lives, a study revealed today.

Researchers found that not smoking, taking exercise, drinking in moderation and eating five servings of fruit and vegetables a day can have a huge impact on life expectancy.

Academics at Cambridge University monitored the health of 20,000 men and women aged between 45 and 79 from Norfolk between 1993 and 2006.

The study concluded: "The results strongly suggest that these four achievable lifestyle changes could have a marked improvement on the health of middle-aged and older people, which is particularly important given the ageing population in the UK and other European countries."

The research showed that a person's social class or body mass index (BMI) had no role to play in life expectancy.

Moderate drinkers are at 30% lower risk of heart disease than teetotallers, according to a study of nearly 12,000 people. And those who combine a mild tipple with regular exercise are even less likely to die of the disease. Their risk is between 44% and 50% lower than couch potatoes who abstain from alcohol.

The second survey is specifically about heart disease.

The team behind the 20-year study said that previous research has shown that moderate drinking and exercise both lower the risk of heart disease. But this is the first time scientists have quantified the benefits of both together.

"We've known for years that physical activity is good for you and it prevents heart disease. And the same for alcohol - a small amount of alcohol is good for the heart," said Morten Grønbæk, a professor at the University of Southern Denmark in Copenhagen.

"The new thing about our study is that we look at the combined effects of drinking alcohol and being physically active compared to, for instance, only being physically active and not drinking or drinking but not being physically active ... it's the only study on this issue," Grønbæk said.

His team used data from 11,914 people in Copenhagen. Participants were recruited between 1976 and 1978 and were asked questions about alcohol intake, physical activity and other factors that might influence the results, such as whether they smoked, their education and marital status. Over the next two decades 5,901 of the participants died of a variety of causes and 1,242 developed heart disease.


Bad Science

I highly recommend Ben Goldacre's website Bad Science and his column in The Guardian.  He is a (medical) doctor, and has taken it upon himself to expose quackery and the appallingly sloppy way that science is reported in newspapers and on TV.  He does it effectively and entertainingly.  A good place to start is his Self-indulgent retrospective - 2007:

Nobody listens to a word I say: I’ve been saying it for so long now that I think I’d be sorry if they did. Scaremongering season kicked off with the Panorama WiFi special. Among its many crimes against sense, this program featured “independent testing” by - oh, hang on - a campaigner against WiFi, who also sells his own brand of special protective equipment to those frightened about WiFi. The BBC have since upheld complaints. Immediately after the show was broadcast, the Independent were promoting elaborate quack devices to protect against WiFi: these will take off in 2008.

The media’s MMR hoax – as it will come to be known – was kept alive on the Observer’s front page; the Independent cried “suppressed cancer report shows GM link to potatoes” about a research paper which didn’t mention the word “cancer” (not once!); and the scattergun scaremongering of the Daily Mail peaked when they demanded the banning of a chemical which had, rather brilliantly, already been banned.

Combatants in the drug war continued to chip away at their own credibility. The Independent on Sunday repeatedly announced that cannabis is 25 times stronger than before (in fact average potency has doubled). That was followed with “cannabis doubles the risk of psychosis”. Then the MHRA pushed a scare about “nitrous oxide” claiming that “the ‘rush’ users experience is caused by starving the brain of oxygen” (it’s a drug which acts on the opioid and NMDA neuroreceptor systems).

I've enjoyed his pieces on homeopathy and of course he has had fun at the expense of "Dr" Gillian McKeith:

In the face of all this, the homeopaths’ melodramatic whining about some kind of special vendetta against them looks pretty weak. Of course this year marked the rebranding of Dr Gillian McKeith PhD as a pantomime figure rather than an academic expert, but the wider project of deliberately overcomplicating diet in order to create a new profession called “nutritionists” – and thus paradoxically disempower us all - went so far that by christmas, the media were cheerfully pushing chocolate and booze as health foods, on account of their antioxidant content.

Worth reading.


It's not true

I like to think of myself as rational and logical.  Sadly, the world is full of people who believe that all sorts of stupid things are true, and usually these untruths are not only repeated but they are reinforced by doctors, and other people we tend to believe.

Is it really dangerous to use your mobile phone in a hospital, on a plane, or at a petrol station?  No, no, and no. 

Can you catch a cold just because you are out in the cold?  No.  Will antibiotics help with that cold?  No. 

The Guardian reports on some more of these (Heard the one about reading in dim light being bad for your eyes? It's just a myth):

They are the universal pearls of wisdom that explain some of the more puzzling things about the human body and help people live healthy lives: don't read in dim light, drink eight glasses of water a day and don't use mobile phones in hospitals.

The problem is: there is no evidence to suggest that these gems of advice are actually true. In a study out today researchers have scoured through leading databases of medical research to test whether any of the most commonly held beliefs among doctors and patients bear any links to reality.

The two doctors behind the research wanted to remind their colleagues that anyone could get things wrong and suggested that doctors should think twice about commonly held ideas that might not be based on evidence.

"We got fired up about this because we knew that physicians accepted these beliefs and were passing this information along to their patients. And these beliefs are frequently cited in the popular media. We didn't set out to become myth busters," said Aaron Carroll of the Regenstrief Institute in Indianapolis.


Honey and Lemon really does work

As a child, I was always taught that lemon and honey was a good remedy for coughs, sore throats and colds (or URTI as they now seem to be known).

Big drug companies spend fortunes trying to persuade us to buy their various concoctions, and yet it seems that honey is as good, if not better, than the stuff they want to sell us:

The study, published Monday in the Archives of Pediatrics and Adolescent Medicine, found that children who received a small dose of buckwheat honey before bedtime slept better and coughed less than those who received either a common over-the-counter cough suppressant (dextromethorphan) or nothing at all.

"This is the first time honey has been actually proven as a treatment," says lead study author Dr. Ian Paul, a researcher at Penn State College of Medicine. He adds that honey has been recommended for ages by grandparents in certain cultures.

Paul says that the type of honey plays a role in the treatment.

"Darker honeys have more antioxidants than lighter honeys, and we wanted the best chance to see improvements," he says, noting that lighter honeys would probably also benefit kids. "At least locally [buckwheat honey] is available. I can get it here at the local supermarket."

Honey is also generally less expensive than over-the-counter medications, he says, and bring none of the side effects like dizziness or sleepiness.

The current study was inspired by an earlier investigation by Paul and his group. In 2004, they showed that the two most common active ingredients in cough syrup, dextromethorphan and diphenhydramine, had the same effectiveness in treating cough symptoms as a placebo ingredient.

I can't quite believe that this is the first time that honey has been proved to have beneficial effects.


Cheap fuel, expensive food

I see that today's SCMP has a longish piece about biofuel on the mainland (Enormous potential in laggard biofuel - subscription required):

Ethanol – produced by fermenting crops such as corn, soybean, rapeseed and sugarcane, or other plants such as cane-like sweet sorghum, sweet potato and cassava – has figured in the plans of many biofuel producers in the mainland. Beijing hopes to raise the nation’s annual bioethanol output 10-fold to 10 million tonnes by 2020, and that of biodiesel by 20 times to two million tonnes.

But these targets were thrown into doubt in June after Beijing indicated it will ban biofuel projects that use staple food crops as a fuel source, amid rising food prices and food security concerns.

Well, yes indeed.  There was an interesting article in The Guardian (The looming food crisis) about the unintended consequences of developing alternative energy sources:

Land that was once used to grow food is increasingly being turned over to biofuels. This may help us to fight global warming - but it is driving up food prices throughout the world and making life increasingly hard in developing countries. Add in water shortages, natural disasters and an ever-rising population, and what you have is a recipe for disaster.

The mile upon mile of tall maize waving to the horizon around the small Nebraskan town of Carleton looks perfect to farmers such as Mark Jagels. He and his father farm 2,500 acres (10m sq km), the price of maize - what the Americans call corn - has never been higher, and the future has seldom seemed rosier. Carleton (town motto: "The center of it all") is booming, with $200m of Californian money put up for a new biofuel factory and, after years in the doldrums, there is new full-time, well-paid work for 50 people.

But there is a catch. The same fields that surround Jagels' house on the great plains may be bringing new money to rural America, but they are also helping to push up the price of bread in Manchester, tortillas in Mexico City and beer in Madrid. As a direct result of what is happening in places like Nebraska, Kansas, Indiana and Oklahoma, food aid for the poorest people in southern Africa, pork in China and beef in Britain are all more expensive.

Challenged by President George Bush to produce 35bn gallons of non-fossil transport fuels by 2017 to reduce US dependency on imported oil, the Jagels family and thousands of farmers like them are patriotically turning the corn belt of America from the bread basket of the world into an enormous fuel tank. Only a year ago, their maize mostly went to cattle feed or was exported as food aid. Come harvest time in September, almost all will end up at the new plant at Carleton, where it will be fermented to make ethanol, a clear, colourless alcohol consumed, not by people, but by cars.

I think it's generally accepted that this is a somewhat crazy policy.  I seem to have read several articles recently about the concerns that scientists have, such as this one (Corn biofuel 'dangerously oversold' as green energy):

Ethanol fuel made from corn may be being "dangerously oversold" as a green energy solution according to a new review of biofuels.

The report concludes that the rapidly growing and heavily subsidised corn ethanol industry in the US will cause significant environmental damage without significantly reducing the country's dependence on fossil fuels.

"There are smarter solutions than rushing straight to corn-based ethanol," says Scott Cullen of the Network for New Energy Choices (NNEC) and a co-author of the study. "It's just one piece of a more complex puzzle."

The report analyses hundreds of previous studies, and was compiled by the environmental advocacy groups Food and Water Watch, NNEC and the Vermont Law School Institute for Energy and the Environment. The study was released as the US Congress debates key agriculture and energy laws that will determine biofuel policy for years to come.

The Guardian article suggests that the problem may only be temporary:

Others say that the food price rises now being seen are temporary and will fall back within a year as the market responds. Technologists pin their faith on GM crops, or drought- resistant crops, or trust that biofuel producers will develop technologies that require less raw material or use non-edible parts of food. The immediate best bet is that countries such as Argentina, Poland, Ukraine and Kazakhstan will grow more food for export as US output declines.

I think that is correct.  It was widely assumed that growing population would lead to major global food shortages by the end of the 20th century, but in fact that hasn't happened.   


More useful advice

Simon got there first with some useful advice from today's SCMP:

Couples have been warned not to rush into sex because the hormones released during orgasm can blind people to the true value of their relationship. Patricia Love, a counsellor on love and marriage, said the effects of the hormones could make an "alcoholic with seven kids seem like a good catch".

I sometimes wonder if these people just think up daft things to say so that they can get their names in the newspaper.

Meanwhile, on a similar theme, yesterday's Guardian mentions another interesting theory:

Alan Riley, professor of sexual medicine at the University of Central Lancashire has discovered that, while men appear to be on a five-day cycle when it comes to wanting sex, women are on a 10-day cycle. In other words, for a bloke the alarm goes off five days after they last had sex, and they want it again, whereas for women the clock is still ticking away and would do so happily for another five days.

Oh, sorry, it's a discovery not a theory.


Go to hospital, get sick

Did anyone else watch that documentary on TVB Pearl three weeks ago about antibiotics? Unfortunately, having a good subject doesn't guarantee a good documentary.

Their concept was to send a presenter off around Europe within a hidden camera in his bag. This is a favourite technique of documentary makers, but for it to work you need a bad guy who can be confronted later when you have gathered the shocking evidence. Sadly for them, in this case there was no villain but rather a number of misguided but well-meaning doctors and pharmacists trying to give people what they wanted. Worse than that, the evidence was neither surprising nor shocking.

Nevertheless, we were treated to several trips to pharmacies around Europe. In each case, the reporter tried to get antibiotics for his imaginary cold. In Belgium, Spain and the UK he was successful. In the Netherlands he was not successful. Unfortunately we were not give any information about how many pharmacies in each country would have refused to sell antibiotics without a prescription (I am quite sure that many in the UK would have sent the reporter on his way empty-handed) nor whether any action is taken to prevent this abuse.

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