Acid Alkaline Diets and Cancer, an ethical question

Jacob Schor, ND

December 12, 2007

I find myself stumped by an ethical question.  The question is one of those, “Do the ends justify the means” types.  You’ve probably found yourselves in a similar quandary.

A cancer patient tells me they are following an alkalinizing diet to combat their cancer and asks my approval.  Should I tell them the theory is malarkey even though the diet is still a good idea for them to follow?

Malarkey is a lovely word for this theory. My dictionary defines malarkey as ‘bunkum and nonsense.’  While learned writers debate the actual etymological derivation of the malarkey, there is a clear consensus that the word originated in San Francisco.

Any religion worth its salt comes with dietary codes telling adherents what not to eat.  As our adherence to these strictures weaken, people turn elsewhere for direction.  We have an almost inborn need to categorize foods into good or bad, be it Kosher or Halal, organic or low carb. One such classification system that won’t go away is this idea of acid and alkaline foods.

We need to go all the way back to Marcellin Berthelot to understand where this concept of acid and alkaline diets originated.


Marcellin Pierre Eugène Berthelot

October 25, 1827 - March 18, 1907

Berthelot was a French chemist, famous for loads of important things that are not relevant to this article.  In 1864, Berthelot moved on from other interests to study thermochemistry which is important to this discussion. In his 1879 book Mecanique chimique, in which he introduced the concepts of ‘endothermic’ and ‘exothermic’ reactions, he described a gadget he had invented for his experiments called a bomb calorimeter. 

A bomb calorimeter consists of a chamber pressurized with oxygen and suspended in a water bath.  A sample is added to the chamber and once everything is set up, ignited.  The pressurized oxygen pretty much guarantees that whatever is inside the bomb rapidly incinerates and all that remains is ash.  The heat released by this controlled explosion is absorbed by the water bath and the increase in temperature is used to calculate the calories given off by the sample.  This is how the amount of calories in a food is figured out.

After the experiment is done, all that is left inside the bomb is ash.  Now if you mix that ash with water you can measure its pH and tell whether it is acidic or alkaline. Way back in 1912, Sherman and Gettler published a paper that classed foods that had been tested in this way by the pH of the leftover ‘bomb ash.’  The original paper can be viewed at:

The current alkaline-ash diet comes from these once upon a time experiments.  This is not what we call cutting edge science.  In general, fruits and vegetables leave an alkaline ash.  In general, meats and grains leave acidic ash.  Remember this last bit, we will come back to it.

Bomb calorimeter

There is a widespread belief that following an alkalinizing diet, that is avoiding foods that produce acidic ash and choosing to eat foods that leave an alkaline ash, is a valid treatment for cancer. 

Dr. Neil McKinney, who teaches naturopathic oncology at Boucher Institute of Naturopathic Medicine doesn’t think much of this theory. He writes,

“To put it bluntly, suggesting cancer can be treated or cured by alkalinizing the body is pure rubbish.  Treatments based on alkalizing are quackery.”

McKinney tells me that this fallacy began with Otto Warburg, whose research on the biochemistry of sugar metabolism in the 1920’s to 1940’s won him a Nobel Prize.  He observed that cancer cells often live in hypoxic, very low oxygen, and acidic conditions and that they derive energy from sugars by fermenting them the way yeast do. He came up with a theory that these low oxygen and high acidic conditions were the cause of cancer.

"Cancer, above all other diseases, has countless secondary causes. But, even for cancer, there is only one prime cause. Summarized in a few words, the prime cause of cancer is the replacement of the respiration of oxygen in normal body cells by a fermentation of sugar." -- Dr. Otto H. Warburg


Current science explains this phenomenon differently. For a tumor to survive it needs to stimulate the growth of blood vessels.  Otherwise, it can’t get all the oxygen it needs to metabolize sugar. Tumor cells stimulate blood vessel growth by producing vascular endothelial growth factor (VEGF). Even with this stimulation, tumor cells often outpace  the growth of new blood vessels.  When they do so, they don’t have enough oxygen.

When oxygen deficient, tumors change how their cells metabolize sugar.  They start breaking it down through fermentation.  This isn’t ideal; fermentation releases only about 5% of the energy that would have been produced if oxygen were available.   The tumor cells do this to survive, not because they like to. Fermentation of sugar without adequate oxygen produces large amounts of lactic acid.  Lactic acid builds up in hypoxic areas where cancer cells have grown too fast.  This is because not only aren’t there enough blood vessels to bring oxygen to the tumor cells, there also aren't enough blood vessels to flush away wastes like lactic acid

Otto Heinrich Warburg 1883-1970

Low oxygen and acidic tissue environments are no longer considered the cause of cancer.  Instead, it is the other way around.  Cancer cells create an environment that is acidic and short of oxygen.

Rapidly growing tumors create an acidic environment lacking in oxygen.  It is not acid and lack of oxygen that cause cancer.

Still, the idea persists that neutralizing the acid produced by tumors and bringing oxygen to tumor cells can cure cancer.  It doesn’t.  Changing the pH of a tumor does not change its growth rate significantly, nor does it seem to lead to cell death.  In 2004, Wenzel and Daniel published results of several experiments using quercetin and other flavones that trigger apoptosis (cellular suicide) in cancer cells.  They found that apoptosis occurred independent of changes in alkalinity and acidity of the cellular environment; it was shown that altering pH did not appreciably effect survival or death of cancer cells.

Even if it were true that raising the pH of a tumor was a useful therapy, there is no easy way to make this happen.  The body holds the pH in blood and body fluids within a narrow range. Even a slight shift in pH would change the way enzymes act and the body does everything it can to prevent this from happening.  Mechanisms in the body buffer any attempt at raising or lowering the body’s pH.  

Dr. McKinney writes, “I worked for years in radiation therapy research on the hypoxic cell problem.  Cancer does not ever form due to an acidic or a low oxygen environment - rather, advanced tumors create these conditions as they outstrip their angiogenesis capacity. It is not possible to alkalize tumors by any oral supplement, … even IV bicarb will not harm tumors.”

The idea that oxygen will kill cancer cells is equally absurd.  Cancer cells like oxygen; lack of oxygen slows their growth.  Remember those drugs called angiogenesis inhibitors? by preventing the growth of new blood vessels to tumors, they suffocate the cancer cells.  But let’s stick with this alkaline and ash pH business.

This misplaced and outdated desire to increase the cancer’s pH has gotten cobbled together with the even older old bomb calorimeter ash data.  Books and especially websites urge cancer patients to eat alkaline ash producing foods on the theory that this will neutralize the acidic environment that created cancer.

As I said, it is malarkey.

I also said it was a good idea.


Remember fruits and vegetables top the list of foods that burn down to alkaline ash.  The theory behind this whole business is nonsense but the result is good.  Telling someone to eat alkaline foods is telling them to eat fruits and vegetables, foods that contain chemicals proven to prevent and fight cancer.  Telling someone to avoid eating foods that produce acidic ash is telling someone to avoid foods that increase the risk of cancer.  It has nothing to do with pH; it has everything to do with the other chemicals present in the food. 

So here is the ethical question:

Should we let people believe in bad and outdated science for the purpose of getting them to do something good for them?  Do we let our patients eat from these alkaline food lists, knowing that the theory that supports their diet is malarkey?

In day to day practice, I find myself torn.  Often I leave people to follow this theory without saying anything.  I do find I speak up when they push it a step further and are spending money on supplements or treatments promising to 'alkalinize the body' or 'oxygenate the blood.'  It's unlikely that either work as promised.  If they did they would be dangerous.

One last note:

There is just one exception that should be mentioned.  Chad Aschtgen, ND who works for Cancer Treatment Centers of America pointed out one specific instance when alkalinizing agents may be useful in cancer treatment.  Several papers suggest oral sodium bicarbonate (baking soda) taken along with the chemotherapy drug Irinotecan may decrease the drug's tendency to cause diarrhea.



Tamura T, et al. Prevention of irinotecan-induced diarrhea by oral sodium bicarbonate and influence on pharmacokinetics. Oncology. 2004;67(5-6):327-37

Valentí et al. Prevention of irinotecan associated diarrhea by intestinal alkalization. A pilot study in gastrointestinal cancer patients. Clin Transl Oncol. 2006 Mar;8(3):208-12.

Warburg, Otto. The Prime Cause and Prevention of Cancer - A lecture at the meeting of the Nobel-Laureates on June 30, 1966 at Lindau, Lake Constance, Germany.

Wenzel U, Daniel H. Early and late apoptosis events in human transformed and non-transformed colonocytes are independent on intracellular acidification. Cell Physiol Biochem. 2004;14(1-2):65-76.