ADVERTISEMENT
  About the SA Blog Network













Guest Blog

Guest Blog


Commentary invited by editors of Scientific American
Guest Blog HomeAboutContact

Lindau Nobel Meeting–Beef Bug to Blame for Bowel Cancer?

The views expressed are those of the author and are not necessarily those of Scientific American.


Email   PrintPrint



Even if you adore red meat, you’ll put off your big juicy steak by hearing what Harald zur Hausen has to say about it. At the 61st Lindau meeting, the Nobel laureate spoke about his current hypothesis about why beef causes colorectal cancer. He thinks it might contain a nasty pathogen that infects us that then causes the disease but the source hasn’t been discovered yet.

Colorectal cancer has a high incidence among men and women worldwide, and cases are increasing. Researchers blame this on the ‘Westernisation’ of lifestyles, including eating more red meat, in economically transitioning countries, such as China. 

Right: Harald zur Hausen at Lindau, photo: Christine Ottery

Zur Hausen reached this hypothesis by eliminating possible carcinogenic factors and searching for correlations. First, he looking at the way that food was cooked, and found that it seems implausible to blame the cooking processes for beef-related cancer when eating white meat or fish cooked the same way is safe. He also looked at countries that have high and low incidences of bowel cancer, and found that in countries where red meat is eaten, but predominantly not beef (ie mutton or goat), incidences are still relatively low compared to North America, Europe and Australia, where the incidence is high.

Lastly, zur Hausen considered that beef is often served ‘rare’, and that this could affect the ability of viruses to survive cooking. He said that papillomavirus, polyvirus and single strand DNA viruses can endure a roasting at 80 degrees Celsuis for 30 minutes. Much beef is cooked more lightly than this. And zur Hausen’s hypothesis may explain the rise in bowel cancer cases in Japan, where the staple protein is traditionally fish, rather than beef.  

Zur Husen says that if we can find an infection that causes colorectal cancer, then 35 per cent of the world’s cancer cases could be traced back to an infection. At the moment, 21 per cent of cancers are known to stem from infections, including Hepatitis B, Helicobacter, Schistosoma. And, of course, zur Hausen won his Nobel prize in 2008 by proving that high risk HPV virus causes cervical cancer. The cancer of the cervix is the second most frequent cancer in women with 530,000 cases a year, globally – and 86 per cent of these cases are in developing countries. 

The first vaccine to prevent cancer was the Hepatitis B vaccine, developed in Taiwan in 1984. But the vaccine everyone’s talking about is the HPV vaccine, which can protect close to 100 per cent of previously non-exposed women, and likewise prevents the infection of cervical precursor lesions. Zur Hausen said that high risk HPV can be completely eliminated if all girls are vaccinated before reaching sexual maturity – and the vaccination of boys will close the circle of infection. 

He said that we should look for more infections that cause cancer. Could all cancers be linked to an infection? You can watch zur Hausen’s lecture in full, below. As for beef, I’ll be having mine well done in the future.

About the author: Christine Ottery is a freelance science writer who writes on for the Guardian, TheEcologist.co.uk, SciDev.net and Wired magazine. She recently graduated from a MA Science Journalism at City University London, U.K. She blogs at Open Minds and Parachutes and tweets at @christineottery.

The views expressed are those of the author and are not necessarily those of Scientific American.

Cross-posted on the official site of the Lindau Nobel Community —the interactive home of the Lindau Meetings: Infections that cause cancer – Harald zur Hausen






Comments 5 Comments

Add Comment
  1. 1. jtdwyer 8:07 pm 06/27/2011

    Very interesting end encouraging if this hypothesis can lead to the development of a cure!

    Is your statement, "21 per cent of cancers are known to stem from infections, including Hepatitis B…" intended to indicate that 21 percent of all incidences of cancers stem from infections or that 21 percent of all types of cancers stem from infections?

    Regarding Hepatitis B, I’m not aware that it is considered by anyone to be a form of cancer. While it (like viral Hepatitis C) can increase the incidence of liver cancer, it does not necessarily do so, correct?

    Link to this
  2. 2. OBagle 10:29 pm 06/27/2011

    Mr. jtdwyer, as much as I have enjoyed your observations through the past years, it astounds me how it has escaped your attention that sloppy journalism is the cause of confusion here. SA clearly thinks that revenue can be increased through hiring attractive young girls with no discernible interest in the subject matter to which they were assigned to report.

    Taiwan couldn’t invent toilet paper without Western technical assistance, let alone a vaccine for HBV.

    Miss Ottery should have stated more clearly that 21 percent of cancer types are known to be probably caused by pathogens. But we could surmise this anyway, being that the top 3 cancers comprise 80 percent of all cancers by occurrence; lung, colon, breast – none of which appear to be viral or bacterial induced.

    Certainly, no one will deny that the HPV vaccine is a stunning medical success story, as was Hep B vaccine. If a viral component can be found for colon or lung cancers, then of course, take my tax dollars, PLEASE!

    Unfortunately, stress-induced corticosteroid exposure is undoubtedly the missing link in most cancer formations. Adrenaline and cortisone play a role in the body’s emergency response protocol, making available large amounts of latent energy reserves in short but massive bursts. Sort of like the kill-or-be-killed ethos of the Jurassic era. However, even school children know that there is no such thing as a free lunch, a benefit without a price, boom without bust, aggression or fear without DNA degradation.

    Horror movies induce imaginary fear in some people, as do stock indices, office politics, and "community college open-book exams". It is this trigger for the emergency hormones that causes cancer. If you are one of those "nervous wrecks" whose neurotic obsession with personal safety or personal property is causing health problems – great! Your worst fears are about to be realized, and then you can say "I told you so!"

    Link to this
  3. 3. jtdwyer 1:00 am 06/28/2011

    Thank you very much – I’ll accept your kind compliment and apologize if I was swayed by Ms. Ottery’s pretty face. Or, perhaps it was a side effect of my most recent dose of Carvedilol (congestive heart failure) – I do have my ups and downs these days. Your point is very appropriate, but I also have to point out that not all causes of stress are imaginary neuroses, including post traumatic stress disorder. Sometimes they really are out to get you!

    To the extent that epinephrine (adrenaline) is involved in the development of colon cancer, perhaps I’ll receive some coincidental benefit regarding an apparent hereditary predisposition to it. Then too, I’m also prescribed Lovaza (omega-3) for treatment of high triglyceride levels – perhaps I’ll be doubly lucky!

    I’m still curious about the reference to HBV as a cancer…

    Link to this
  4. 4. christineottery 4:44 am 06/30/2011

    Hi both.

    Try this link from the WHO for more information on the link between HBV and cancer of the liver: http://www.who.int/mediacentre/factsheets/fs204/en/

    I wrote: "The first vaccine to prevent cancer was the Hepatitis B vaccine…" This causal relationship means you might read the following statement with a different emphasis – "At the moment, 21 per cent of cancers are known to stem from infections, including Hepatitis B, Helicobacter, Schistosoma." The examples I give are instances of infections that cause cancer, not cancers themselves.

    RE Taiwan and the HBV vaccine, thanks for pointing out my error. I said it was developed in Taiwan in 1984, when in fact what happened was that a national vaccine programme starting in Taiwan in 1984 was successful at reducing the cancer risk. You can read about a pivotal study explaining this here: http://www.nejm.org/doi/full/10.1056/NEJM199706263362602#t=articleBackground

    Link to this
  5. 5. jtdwyer 8:07 am 06/30/2011

    Thanks for your reply.

    Your WHO link does refer to both Hepatitis B and C under the heading "Viral Cancers" and goes on to state:
    "Hepatitis B vaccine is 95% effective in preventing HBV infection and its chronic consequences, and is the first vaccine against a major human cancer."

    I find this quite misleading since its own information indicates that most people who suffer from either disease do not eventually develop liver cancers.
    But, I’m all for efforts to eradicate, so I won’t quibble further.

    Link to this

Add a Comment
You must sign in or register as a ScientificAmerican.com member to submit a comment.

More from Scientific American

Scientific American Back To School

Back to School Sale!

12 Digital Issues + 4 Years of Archive Access just $19.99

Order Now >

X

Email this Article

X