Thursday, May 21, 2015

The Alkaline Diet and Cancer

Photo Credit: Jenny 
Brixton Market Produce 

Originally, I planned to write about the benefits and downfalls of the alkaline diet as a whole. However, as I read more and more about the diet, the less I understood it. Growing up, the most common dietary advice I heard was “eat more fruits and veggies and limit your consumption of red meats, fats, and dairy.” From what I’ve read, this is basically what the alkaline diet proposes (though I’ve found conflicting recommendations). So this used to just be called “eating healthy,” but now someone put a different name to it and somehow incorporated pH (incorrectly) into the mix.

The alkaline diet is a bit of a misnomer because it is based on the ash of the ingested food, not on the pH of the food itself (though some claim it’s all based on the pH of the food). Thus, acidic foods such as citric fruits, which have an acidic pH, are considered alkaline foods because they produce alkaline ash. Does that make sense to you? If it does, perhaps you can explain it to me.

Nevertheless, the one common claim that kept grabbing my attention was the belief that an alkaline diet can not only prevent cancer but also cure it. Many websites and online diet activists such as and Freelee the banana girl support these ideas. These claims seem to be based on a complete misunderstanding of what pH is, how it is regulated in the body, and how it plays a role in cancer. As a scientist who works in developing next-generation cancer treatments, I find statements like these to be completely asinine, especially because they are not only wrong on numerous scientific levels but also because they offer unrealistic benefits to patients who are truly suffering.

It’s not realistic to post here a comprehensive discussion of cancer, its causes, preventative measures, diet, and treatments (this would be a small library), but I hope to succinctly convey some basics of cancer and the underlying flaws in these anti-cancer claims of the alkaline diet. 

So what is the link between cancer and pH?

Many alkaline diet advocates claim that cancer is caused by an acidic environment which can be controlled through diet. Thus, eating an alkaline diet will reduce the acidity of cells and therefore prevent cancer. This is pseudoscience at its worst. Cancer is not caused by low pH levels, rather it’s the other way around. 

The simplest example I could think of is if a person poured concentrated sulfuric acid on their hands. Would their hands get cancer? No, they would just be in terrible pain because the acid is dissolving their skin and tissues. Using a less cynical example, let’s consider the stomach. The stomach is naturally very acidic (pH typically between 2-3 for a normal person). If acidic environments alone caused cancer, everyone and their dog would have stomach cancer. 

Cancer can be caused by numerous factors including radiation, toxins, carcinogenic chemicals, and viruses to name a few, but the most commonly believed pathway (especially for slow growing cancers) is that a handful of mutations occur at the DNA level which ultimately results in uncontrolled cell division and growth. The cancerous cells typically have a lower pH (more acidic), but this is a result of the abnormalities in the cell itself. Cancer cells have the mutations necessary to inhibit cell death as well as promote rapid cell growth. Rapid cell growth requires extra energy. What happens? The cell increases the rate of glycolysis (metabolism of glucose = energy) which results in an increased production of lactic acid, and this is the primary culprit responsible for the higher acidity levels found in cancerous cells. 

But don’t our enzymes work most efficiently at a slightly alkaline pH?

There is a grossly over-simplified statement that enzymes work most efficiently at a slightly alkaline pH. This is true for many enzymes but not all. The human cell is highly compartmentalized, and different parts of the cell have different pH levels depending on their purpose. 

For example, the lysosome (often described as the garbage disposal of the cell) is a compartment of the cell that has a very acidic pH because its purpose is to enzymatically break down biomolecules such as proteins, carbs, and lipids. The enzymes in the lysosome actually operate very efficiently in this acidic environment. Everyone has acidic lysosomes in their cells. 

Does that mean the lysosome promotes cancer? No, that’s absolutely ridiculous. In fact, the lysosome actually plays a major role in cancer prevention because it has the unique ability to trigger cell death. What this means is that disruption of the lysosome (by a carcinogenic material or mutated protein for example) can trigger an event that causes the cell to commit suicide (apoptosis), which is a preventative measure in our cells to help PREVENT cancer (mitochondria have this ability as well). However, what happens in most cancerous cells is that these preventative programs become inhibited (or overridden), and thus the cancer cell does not die. What does any of this have to do with pH specifically? Nothing, and that is the point! 

Keep in mind that this is also an over-simplification of what’s occurring at the molecular level (it’s quite complex but absolutely amazing), but it’s already enough to contradict claims such as “enzymes work most efficiently at slightly alkaline pH” and “acidic pH environments cause cancer.”

Can’t we treat tumors (and other diseases) by maintaining our alkaline pH or by making it even more alkaline?

The other thing that these diet proponents seem to forget is that solid tumors are an entirely different beast than normal human tissue. Solid tumors have a convoluted vasculature, meaning that the blood supply and lymphatic drainage are not nearly as efficient as normal body tissue. Thus, the microenvironment surrounding tumors maintain a very different nutritional and metabolic environment. 

The other thing to remember is that the pH of human blood is highly regulated and maintained at around 7.4 (slightly alkaline) regardless of a person’s diet. Therefore, if alkaline pH could prevent and cure cancer, humans would never get most cancers (especially blood cancers). Even if someone consumes an alkaline diet, the pH of their blood will not become more alkaline because the body maintains the blood pH at a relatively constant level regardless of what food is consumed in the diet. Likewise, eating acidic foods doesn’t have a significant effect on blood pH because the human body has an amazing buffering capacity and has excellent regulation of maintaining a constant pH (there are a few exceptions to this rule, such as those with kidney problems). 

So does the alkaline diet have any effects on cancer at all?

The foods recommended in the alkaline diet, such as fruits and vegetables, have phytochemicals that demonstrate powerful anti-cancer properties (not to mention all the benefits from vitamins, minerals, and fiber). Also, many meta-analyses show that regular consumption of fruits and vegetables show a decreased risk of cancer as well as heart disease and diabetes (click to learn about the benefits of avocado, chia seeds, cocoa, coffee, popcorn, and sweet potato). Thus, following an alkaline diet has the POTENTIAL to lower the risk of certain cancers simply because you are eating healthy foods (not because of pH). However, no one should expect to be free of cancer risk or expect to be cured of cancer simply by following an alkaline diet. 

Cancer is not easy to prevent, and it’s even harder to cure.

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