This will get me a lot of backlash, no doubt, but I feel I have to say it for any cancer patients
who come along down the road and read posts here about low carb being good for cancer. I'm zipping up my kevlar suit.
First, let me say that I AM experimenting on myself with a low carb AND calorically restricted diet to hopefully keep my breast cancer from recurring.
BUT please understand that at this stage with the knowledgde we have, that you ARE EXPERIMENTING with yourself and you COULD BE MAKING YOUR CANCER WORSE by going low carb. I just want desperate cancer patients to make an informed decision before following the "low carb will cure cancer" mantra. Maybe, maybe not.
Here's some facts that have been a bit skewed in the press.
There is epidemiological evidence that low carb diets may help prevent SOME cancers. There has been at least one statistical analysis showing this in breast, prostate and esophogeal cancers. On the contrary, a low fat diet was shown to reduce risk of ovarian cancer. But the thing to understand
here is that this shows a correlation and it's not a cause. So you can't read these studies and say that a high carb diet causes cancer. That is simply not what they're saying.
A tumor has different stages. Initiation is when the tumor begins to grow. Promotion is when you already have cancer. It's tempting to think that what works to prevent initiaion will work
to stop promotion (i.e., cure cancer), but that's not necessarily the case. Here's one study that actually found
something that worked for preventing breast cancer actually increased its growth. There's others out
there.
http://carcin.oxfordjournals.org/cg...t/18/8/1679.pdf
One of the biggest promoters of study of a ketogenic diet for cancer is Thomas Seyfried at Boston College. He has some really interesting ideas and research going on. However, he has found that is it necessary to combine a ketogenic diet with a calorie restricted diet to have a benefit. He took 4 groups of mice with a nasty brain tumor. 1 was fed an unrestricted diet, 2 was fed an unrestricted ketogenic diet (similar to Atkins), 3 was fed a low calorie diet, 4 was fed a ketogenic low calorie diet. Only groups 3 and 4 had a benefit for their tumors and there was not a difference between the two. So it was the calorie restriction and not the low carb diet that showed the benefit. And the benefit was not a cure - the tumors simply grew a little more slowly. Promising, but not conclusive. And it contradicts studies like the one above that showed that calorie restriction promoted at least one kind of cancer. It also worked on a type of tumor that has very high glucose uptake - who's to say it is at all relevant to other tumors that don't?
http://clincancerres.aacrjournals.o...full/10/16/5622 (It's interesting to note that Seyfried was very clear the results he got in his study were from a calorie restricted diet, but the press very often reported it wrongly as a ketogenic or low carb diet had the benefit. Not true.)
The German experiment with feeding end-stage cancer patients a high fat no carb diet has been reported by the press (see Time magazine
http://www.time.com/time/health/art...1662484,00.html)
but it has not yet been published or peer reviewed. It does show some
promise, but here's a few facts. Only 5 patients were able to stick to the regimen. Their tumors did slow down, stop growing or shrink. 2 patients had their tumors continue to grow. Several other patients dropped out of the study because they couldn't tolerate it. So it's a really small, basically
anecdotal study at this point that worked for some but not other patients. And it was only for tumors that showed a lot of glucose uptake. So
you can't just assume that this would work for your tumor.
Not all tumors show high glucose uptake. So why would low carb work for these tumors? The one type of tumor where there may really be a benefit is a glioma (nasty brain tumor). There MAY be some benefit for prostate, breast, and pancreatic cancer. There very likely is not a benefit for other types of tumors that don't show high glucose uptake. There may even be harm. Do you want to guess if your particular kind of tumor is "glucose hungry"?
Eating sugar and carbs is not the body's only source of glucose. The liver and kidneys are very good at producing glucose, especially when there is a surplus of energy. So, this means that you can eat no
carbs, but too much fat and/or protein and still have too much glucose in your body. Atkins claim of "eat all you want" does NOT apply to cancer patients who are going low carb. Go back and look at Seyfried's work and you'll see that the mice on unrestricted ketogenic diets did NOT have a drop
in blood glucose. (Maybe why some here have trouble losing weight until they cut calories?) The mice on restricted diets (high or low carb) did show a decrease in blood sugar and even more importantly, the insulin-like growth factor and other markers for cancer.
A study that comes out and says XYZ helps cancer may have a couple of problems. First, you can very often find that there's another study showing XYZ makes cancer worse. Second, the amount of benefit may be very small. Third, it can be very difficult to really know if it was XYZ that helped the cancer. Was it the low carb or the low calorie or the combination of both that helped?
Much of the research has been in mice and rats. It may or may not translate to humans. Sometimes mice studies do and sometimes they don't.
There is not a conspiracy among doctors to keep good information from us. Oncologists who do not recommend a low carb diet are not doing anything wrong. There isn't evidence that it works. There isn't evidence that it's at least not harmful for cancer patients, although we may be starting to see that now in SOME cases. All the drugs they have to work with have been studied in the context of a normal carb diet, and we don't know how they'll
work on a low carb diet. The diet may even make them ineffective or harmful. So it is actually responsible in my mind for an oncologist to not recommend something where there isn't strong non-contradictory evidence. Sorry folks, but the evidence for low carb is still conflicting at this stage. (Anyone remember how low fat got started? By doctors recommending something for
which there was little evidence. Maybe they've learned their lesson and won't do that again.)
My advice to cancer patients is to do your own research, but not from what you read on most internent sites. Look at that skeptically because it's often misreported. One example, the Livin la vida low carb web site stated that a ketogenic diet helped reduce tumors. The author of the paper (Seyfried) actually emailed Jimmy to point out that wasn't what his study found.
But Jimmy's article has been picked up and reposted around the web with the error in it.
Cancer is not a single disease. It's many diseases and each cancer is different. That's why when you're sitting in the chemo room, everyone up and down the row is on different drugs. One treatment does not fit all. How likely is it that low carb will fit all?
Just please understand that you ARE experimenting on yourself if you go low carb at this time. I am doing that, (after I finished my conventional treatment of surgery and chemo) but believe me I sweat every time I read a study that indicates I may be doing myself more harm than good. Low carb appears to be a good approach to PREVENT many cancers. But we just don't know
if it helps or hurts when you already have cancer. There's evidence in both directions.
Cancer patients, enjoy your life, go for a walk and enjoy God's beautiful world, enjoy the time you have with your family, donate to cancer research.
Use low carb to prevent cancer but think twice before using it to treat cancer. Have a good discussion with your oncologist first.
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