The Alkaline Diet – Cancer-Killer or Just a Gimmick?

Is the alkaline diet yet another gimmick designed to prey on well-meaning but scientifically illiterate people? This post from Insufferable Intolerance turns the spot light on the alkaline diet fad and how people who never took high school biology love it.

As my fellow science warrior readers know, I love learning. Learning kicks arse. It means I get an upgrade in knowledge and a downgrade in bullshit especially if someone corrects me.

And today I have learned.

The latest trend in alternative medicine and fad dieting is the idea that consuming a “pH balancing diet” and “alkalising” your body (altering your blood pH through a change in diet to make it more alkaline) can cure illness, make you healthier and cleanse your body.  The fad hasn’t been around long thank fuck but it has definitely taken the scientifically illiterate world by storm and people have made a profit out of it. It’s like high schools don’t even have science classes anymore.

Firstly before we get into the nuts and bolts of why the alkaline diet fad is complete crap – lets look at what pH levels are.


In chemistry, the pH of a solution (in this case of today’s blog: the human body) is the measurement scale of how acidic or how alkaline that solution is. To get a bit more technical – the pH level of a solution is the measurement of hydrogen ion concentration, the lower the pH score (the more acidic the solution) the higher the hydrogen ion concentration. The higher the pH score (the more alkaline the solution) – the lower the hydrogen ion concentration.  The pH scale ranges from 1-14 with 1 being strongly acidic, 14 being strongly alkaline, and 7 being neutral. Anything below 7.0 (ranging from 0.0 to 6.9) is acidic, and anything above 7.0 (from 7.1 to 14.0) is alkaline (as known as basic) (source).

As you can see from the following chart distilled water would be at a pH 7 which is neutral, vinegar is approx pH 2 making it within the strongly acidic range and baking soda is around pH 9 making it a weak alkali (as known as base).




The alkaline diet fad promotes the idea that certain foods increase the acidity of your body’s pH therefore you need to eliminate those foods altogether and eat only alkaline foods, which somehow balances your pH rather than increasing your pH to strongly alikali. One would think that if you eat nothing but alkaline foods, it would increase the alkaline pH – not keep you pH at neutral 7.4.  Apple cider vinegar (a type of vinegar made from cider or apple must) is a favourite cure-all pushed by peddlers of the alkaline diet fad who believe that diseases and illness are caused by the body’s pH becoming too acidic. Even though apple cider vinegar is acidic, it is claimed to “release” alkaline bases into the body. Like all pseudoscience – the mechanism for how this is done is not fully explained. One website suggested because the end product of apple cider vinegar alters the pH level of your urine to a more alkaline level – this has an alkalising effect on the entire body. Continuing reading to find out why this is a bunch of horseshit – brace yourselves.

Not surprisingly websites scaring people with this particular pseudoscience also sell “pH testing kits” which typically consists of litmus paper that you place on your tongue or take a wee on to test your pH levels. Are we surprised a website scaring you about something, is the same site selling you a cure? It’s like a salesman stabbing you in the knee to sell you a wound dressings.


Different tissues in the body have different pH levels. Blood has a pH of about 7.4 which is slightly alkaline. The stomach is extremely acidic with a pH around 2. The mouth has a pH that ranges from 5.6-6.9. This is the optimal pH range for the enzyme amylase –  the active digestive enzyme in saliva, this enzyme kicks off the digestion process. As mentioned above, most “pH testing kits” will test the bodies pH level via the saliva in your mouth, this is a clever marketing gimmick designed to scare people into thinking the pH of the body needs adjusting. The pH of your mouth does not reflect the pH levels within the rest of your body. The litmus test used in pH testing kits is useless as an indication of the different pH levels within your body.

Your bodies pH level is carefully maintained via several ways mainly by the kidneys and the lungs. Blood pH is well maintained within a narrow range of about 7.4. Food starts to be broken down by your saliva and is then swallowed where it enters the stomach. The stomach digests food by using your stomach acid, this is as the name states – an acidic substance that is unchanged by the pH level in food. The food that leaves your stomach will be acidic however when it enters your intestines, secretions from your pancreas neutralise the stomach acids and the food becomes alkaline.

The alkaline food in your intestines will have no affect on the pH level of your blood. This is due to your blood having a number of different pH buffers which have evolved to tweak the pH level of your blood pH if any deviations happen. A pH buffer solution is one which resists changes in pH when small quantities of an acid or an alkali are added to it, basically the buffer is the thing that assists in tweaking the pH level of a solution so it doesn’t become saturated or overloaded (source). The proponents of the alkaline diet fad forget the one thing that screws up their entire plan:  If the buffers become overloaded and the pH of your blood is altered more than +/-0.4 (plus or minus) pH, death will result. Plus or minus 0.4 means anything above 7.7 and below 7 –  if your pH level increases or decreases by .4, it is fatal.

People with hard-ons for the alkaline diet fad conveniently forget the above information and tend to support their pseudoscience with the idea that foods can change the pH level of your urine therefore the rest of your body’s pH level can also be altered via food intake. While the pH level of your urine can be changed by the end products of certain foods (these end products are called ash), urine is contained in your bladder and does not affect the pH of any other part of your body. Also the pH level of your urine is not an indication of the pH levels of other parts of your body. This is another reason pissing on a piece of litmus paper is useless in testing the different pH levels in your body.

It is commonly claimed by alkaline diet fad proponents that cancer cells are killed in an alkaline environment therefore an alkaline diet can cure cancer. This is partly true, an alkalised human body does kill cancer cells but so are all other cells in the human body. Not surprisingly pseudoscientists who dropped out of highschool science class rely on people knowing shit-all about basic biology and chemistry.

While most diseases won’t affect blood pH – some do and we can use the alteration in pH level as a diagnostic tool.


One illness promoted as the main reason to change to an alkaline diet is acidosis, acidosis happens when there is an increase in acid in the blood. This illness will make someone intensely ill and is a very dangerous situation to be in. Acidosis is a condition that can happen with illnesses such as cancer, respiratory disease, severe diarrhoea, diabetes, excessive alcohol use, hypoglycemia and liver failure to name a few. The smart cookies over at Pseudoscience University have interpreted this to mean if you consume the “alkaline diet” (which they will conveniently sell you a book about and supplements) it will reduce the risk or even cure the above mentioned conditions, completely disregarding the fact food cannot change the pH of your body (except your pee and that doesn’t affect anything else within your body). They also disregard the fact the body has different levels of pH for different systems and the reason the body tightly regulates those pH levels without help is because any deviation outside of .4, means you would die.

The alkaline diet fad is yet another gimmick designed to prey on vulnerable people with illnesses and the never-ending line of well-meaning but scientifically illiterate people. If you see someone peddling the alkaline diet fad, run. Run fast.

Didn’t want to read the entire article? One word: Homoeostasis.

Source: The alkaline diet fad and the people who (never took highschool biology) love it – Insufferable Intolerance

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