You’re making sure to avoid unnecessary toxins, you’re steering clear of sugar wherever possible and you’ve lowered your calorie intake. Meanwhile, you’re not spending too long in the sun and you’re going to the gym plenty. All seems well on the health front, pat yourself on the back!
But then you come across an article online that claims you need to ‘alkalize your body’ or risk a number of health problems (cancer included, of course). Does it never end? Is this one more thing you have to worry about? Or is it more misguided advice from the internet?
The Theory Behind Alkaline Diets
Alkaline diets are beloved by celebrities (aren’t all diets?) and claim that they can help you lose weight as well as preventing arthritis and cancer. As the name suggests, the basic objective is to alter your body’s pH and thereby to put it in its healthiest state.
If your ‘BS’ alarms are going off at this point then well done, you’ve nearly completed your training!
As you probably remember from high school science, pH measures acidity with 0 being completely acidic and 14 being completely alkaline. 7 is neutral.
Blood is very slightly alkaline with a pH of somewhere between 7.35 and 7.45 and this is no doubt where the inspiration for the alkaline diet comes from. These diets suggest you eat more fruits, nuts, legumes and vegetables in order to get your calcium, magnesium and potassium and thus keep your blood at the right pH. Easy!
Your stomach on the other hand is very acidic at about 3.5 or lower which is how it breaks down food; this is where the problems with ‘alkalizing’ your body start to come in…
Should You Alkalize?
You see, anything you eat will simply get dissolved by your stomach and the nutrients will be absorbed into the bloodstream. Your body maintains its own pH levels by removing anything you don’t need in your urine and through the use of biocarbonate ions to neutralize acids (1) among other methods. What’s more, different parts of the body have different pH levels – and if your blood was out of the healthy range, then you’d know about it. Your body has ‘acid-base homeostasis’ and your blood’s pH does not change.
Proponents of alkaline diets recommend using litmus paper to test the acidity of your urine. They then use the fact that your urine can change pH as proof that the diet is working. But that’s actually all that’s changing – your urine. Your body is simply eliminating more alkaline compounds and there is absolutely zero impact on your blood pH.
Osteoporosis, which alkaline diets claim to treat, is a progressive bone disease that is caused by a decrease in bone mineral content. It has nothing to do with alkaline foods. Likewise, a comprehensive review of all the literature confirms that there is no direct link between acidity and cancer (2).
So how do you ‘alkalize’ your body? You can’t. And if you could, there would still be no point.