August 27, 2008

Diet and Cancer

[Special Guest Post by Christine Hanley]

Note: this is a 3-part post by Christine of Póg Mo Thóin Slán Leat. You may want to bookmark it, because it is one of the best explanations I've ever seen as to why eating healthy can reduce your cancer risk. It's very informative and motivating, not to mention amusing, which is hard to pull of when writing about cancer. Thanks Christine!--Crabby]

What is Cancer?

One way to understand Cancer is to think of your body as a nice, posh, invite-only wine and cheese ‘do at your house. When the party (your body) is functioning properly, the number and quality of party attendees (cells) is regulated. If someone turns out to be an inappropriate guest (a cell damaged beyond repair), you ask them to leave and everything is back to normal (this is your body’s natural process of cell death, aka apoptosis).

However, let’s say something has caused you to be incapacitated for some reason (your body’s natural cell death system is not functioning properly). A real jerk shows up to your party and starts off by chugging a bottle of wine, messing with the stereo and annoying your guests, but you can’t get out there to get rid of him. Then he gets on the phone and starts inviting all his jerky friends over (the bad cell, having not gone through natural cell death, begins to replicate). The jerks start taking over for real now, since all of them are phoning their jerky friends over (all the cells are replicating uncontrollably) and they’re starting to get into areas that the party was not even supposed to be in, crowding out the nice guests you invited (regular, healthy neighbouring cells) and oh look, now there’s a disgustingly raunchy threesome with all sorts of questionably legal acts happening in your marriage bed. Like, I'm talking, one of the participants is a goat. Cancer is nasty business folks, and it’s got no respect for anyone or anything.

Now, hopefully by this stage, someone will have called the cops (you’ll have noticed something has gone wrong and gotten yourself to the doctor). Because, if this situation goes completely unchecked, some of these drunkards will get into their cars and start driving down the roads and invading other parties in town (new parts of your body) and the whole thing will start there as well. This is metastasis, where pieces of the Cancer break off and go to completely new places and grows new tumors.

So in short, Cancer is caused by your cell security system (cell death) breaking down and causing damaged cells to replicate uncontrollably, invading other tissues and possibly metastising via the blood and lymph systems into new parts of the body.

Cancer Prevention

Since Cancer is basically a bunch of bad cells dividing uncontrollably without anything to tell them to take a hike, we can infer that Cancer is therefore best avoided by preventing the loss of your cell security system. This cell security system is hard coded into your genetic code, aka your DNA. All Cancers are caused by DNA anomalies: mutations.

Mutations can be caused by any number of things; you can be born with them (Genetics), or you can acquire them, through plain old DNA replication errors, (when your cells divide normally, each cell gets a new copy of DNA made especially for it, and sometimes it’s copied wrong like a badly executed Xerox) or through something physically interfering with the DNA molecule. This last cause, physical interference, is where diet comes in to play. I’ll talk about two major types of physical interference: intercalation and oxidization.

Something to remember, however, is that you have a LOT of security. In fact, your DNA’s security systems definitely outstrip that of even a post 9/11 airport. So you need a LOT to go wrong before you get Cancer. Clearly, though, it does happen.


Certain types of nefarious molecules can sort of slide into your DNA like an issue of Penthouse into a Harvard Library bookshelf. High falutin’ scientists call this “intercalation”. Basically, it means that your DNA is like a big huge stack of plates. Every plate is the exact same size and type so there’s no problem stacking them so high and it’s quite stable. Intercalation is like sliding a mismatched plate into the middle of the DNA molecule. This throws off the whole stack, and can screw up all loads of things. If it screws up a part of your DNA responsible for the cell security system, you can get a runaway cell that causes Cancer.

Molecules that cause intercalation are, by and large, “flat” molecules. They’re often kind of disc shaped, usually. Polycyclic Aromatic Hydrocarbons (PAHs) are one of these: you can tell by the name: “cyclic”. Like a circle. Disc shaped. They are formed when fat is burned over high heat – so when you barbeque a steak. Another is Acrylamide, which is formed when you brown starchy foods – like when you toast a slice of bread or fry a potato.

However, the body does do a wonderful job of policing the molecules that get into it: people have a family of enzymes called Cytochrome P450s that alter alien molecules so that they don’t fit into DNA, and making them water soluble so that your body flushes them out with the rest of your wee. This is why it’s ok to eat toast and steak in moderation: because as long as you don’t give your body a deluge of these toxic compounds, your body can handle them just fine, it’s got built in defences against most of what you can throw at it as long as you’re generally treating it right.


The second process I’ll talk about which alters your DNA and therefore can cause Cancer is called oxidization. This is a process in which your DNA gets damaged, (oxidation is the same process that's rusting your car right now). Again, if the cell security system takes a hit… I’m pretty sure you’ve figured out by now what that means.

When you digest food, you are essentially breaking chemical bonds. Sometimes the breaking of a chemical bond creates something called a Free Radical, which is missing an electron, which will sometimes search out a stable molecule from which to steal an electron. This is considered to be a major factor in DNA damage, which not only causes Cancer, but aging in general as well.

Here is where that all powerful anti-oxidant comes in: they neutralize the Free Radicals before they can damage your DNA. Anti-oxidants are bodyguards for your DNA. To prevent Cancer, you want to make sure you have enough anti-oxidants to neutralize any Free Radicals that might occur. There is NO such thing as too many anti-oxidants.

The Cancer Most Linked to Diet

By and large, the number one Cancer that you can prevent through diet is Colorectal Cancer. It is the third most common Cancer in both men and women in the US, so it’s certainly worth pausing to think about. People don’t like to talk about it though, since it’s fundamentally Ass Cancer.

I’m sure I don’t need to tell you that a large risk factor for the development of Colorectal Cancer is a diet high in fat and low in fibre – which is essentially the Western diet. Researchers figured this out when they found that people from Swaziland have nearly NO Colon Cancer, which they thought might be due to the fact that the Swazilanders eat hugely fibrous Betel Nuts which make them take about 3 or 4 dumps a day. Freakin’ impressive, man. (They then did a lot of fun studies on Intestinal Transit Times involving timing how long coloured pellets took to “emerge”. Interestingly, English boarding schools were the most anal retentive. I totally wish I had a source for that one besides my University Chemistry professor.)

Anyway, since then there have been a lot of studies corroborating the fibre/colon Cancer protection link. There are a number of theories as to why this occurs, the two most popular being that fibre increases fecal bulk, thus diluting Cancer causing compounds in the intestines; as well as decreasing the amount of time the crap (literally) hangs around in your colon, thus limiting your intestines' exposure to the toxins within.

Take Home Messages

  • Your body is well equipped to deal with all sorts of intruders, as long as you don’t launch a full on dietary blitzkrieg on it. Eat foods with known carcinogens (such as BBQed meats) in moderation and your body will dispatch them quite efficiently.
  • Make sure you eat plenty of anti-oxidant containing foods (by and large these are your fruits and veggies) to provide your DNA with plenty of protection from the wear and tear of daily life.
  • Lastly, eat whole foods high in fibre: they’re your best defence against Colorectal Cancer, by getting the toxins in your poo out of your body ASAP.

Christine Hanley isn't a dietician or a doctor or anyone with any fancy shmancy right to tell you what to eat, but she did study Biology for four years at McGill University and ended up with a BSc. Which has proved to be totally useless so far, but hey, she's not bitter. She usually blogs at Póg Mo Thóin Slán Leat.


  1. Wow and Thank you! That's a wonderfully written and accurate explanation. I just love the party guest comparison. Many thanks and I'll be eating brocolli tonight, I promise.

  2. Incredible !! You should be lecturing somewhere, seriously and/or writing books!! That was just so informative and interesting to read even given the subject matter.

    Well done and thanks!

  3. *sigh*
    they stole my comments.
    how about:

    I love your personal blog because you so funny.
    now I see you smart too.

    I hereby dub thee RENAISSANCE WOMAN.


  4. Christine you definitely should consider teaching...that was awesome. And yes, you somehow made cancer fun and entertaining. And now I have a real understanding on how eating right can help fight cancer.

    Thank you!

  5. Aw you girls are making my day :D

    Jenn... it is actually my life's ambition to be a secondary school biology teacher.

  6. Entertaining, informative, clear, simple, well-written, and fun. It ought to be available everywhere. Thanks you for this wonderful post.

  7. Christine - this was the best-written explanation I've seen for explaining the process of cancer. I loved the party guest analogy!
    And yes, you should be teaching!
    Thanks so much for this.

  8. Very great description of cancer, simplified so the non-biologist can understand it well!

    I'd just like to remind people not to go crazy about monitoring what they eat! You can eat and enjoy plenty of foods that have the potential to be harmful without adverse effect. Your body is great at getting rid of these compounds and policing the cells that may get damaged. Eat healthy and you'll be fine. Besides, there is no way I am giving up peanut butter, which has been shown to contain potential carcinogens.

  9. Fascinating post. Love how you compared cancer to alcoholics - appropriate in so many ways, really:) Interesting stuff about the fiber. Although i just finished reading a study that says if you eat too much fiber (apparently it is possible) then your intestines aren't able to absorb all the nutrients from your food... still now I'm intrigued with Betel nuts.

  10. Christine, it's been said before but that's not going to stop me from saying it again -- great post!

  11. Wow. I've been wanting to get started on my Master's in Nutrition, and right now my brain's going "I am not worthy" (like Mike Myers in Wayne's World).

    Not about the Masters thing though. In the I wish I could write that well.

  12. SCIENCE!
    Thanks for all the info - I've been to lectures in university that weren't that good - bravo.
    You took a tricky topic and made it interesting and I learned something. Thanks.

  13. Succinct and entertaining. I will try to get my Sweetie to read it. Then maybe he will stop asking that every bite he eats be browned in bacon fat.


  14. I vote "great post" too!! And I too immediately thought, I'm getting ScottieDog to read this. And my next thought was, time to get that colonoscopy. (Darn, I should have put that one on my goals list. Maybe I should substitute it for one I can lose.)

    (BTW, to those who've kindly been keeping track, I lost four pounds last week. !!!! AND I had a Snickers last Friday. Seems like not dieting is working for me!)

  15. I love the metaphor! It's just perfect for the layperson like me who hasn't taken real science since high school (I'm figuring soft science doesn't count).

  16. Brava! Extremely informative and entertaining post, very well written and I also think you should be writing for the complacent general public (and making good money from it) because you make the complex very accessible.

    Thanks for taking the guilt away from the occasional Mickey D's fries (3 times a year maybe) and especially cooking on my little Weber Q grill a couple or 3 times a month. I can even grill broccolini and it comes out great!

    Also for the colonoscopy prod, I am at that magic suggested age and I am um, resistant.

    I'm awaiting parts 2 & 3 with great anticipation!

  17. Hee! I know what cancer is, and a bunch of reasons why it's caused, but that was entertaining enough to read the whole thing, anyway! LOL at "party crashing jerks!"

  18. My husband died of "ass cancer" in 2001. Not a pretty picture and NO FUN AT ALL. He was 50. His diet consisted of salami and other fatty mixed meats. I could not convince him to change.

    That was a great write-up. I loved how serious it was and how all of a sudden you went into "ass cancer." Too freaking funny.

    I also noticed that there aren't very many comments and I believe that it is because people seem to NOT want to read or know about cancer. They shy away. They look the other direction. They don't want to know. They are scared. Either that or they are all at their oncologist appointments today.

    Again, thank you. Great article.

  19. I think a lot of people took this week (or at least part of the week) off. One last vacation before school starts :(

  20. Truly amazing! I love the information you brought to the table and your down to earth way of doing it. Thanks so much for bringing these issues to the forefront and doing it in a way that everyone gets it without becoming completely overwhelmed and frightened. Very nice!

  21. pod, I'm very sorry to hear that you lost your husband to colon cancer - it's a truly terrible illness.

    Thanks to everyone who enjoyed the post - I'm glad you did. TK, I'm afraid that was parts 1 through 3 so there's no more where that came from for now.

  22. "I'm afraid that was parts 1 through 3 so there's no more where that came from for now."



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