Alkaline diet for freedivers
How pH affects the blood and oxygen.

An alkaline diet is on the alternative side of science (The founder is said to have gotten the idea during psychic writing!) and it claims many healthy benefits - everything from fighting cancer and clearing sinuses to be directly anti-aging. It can also have some interesting effects on freedivers.


The diet is based on the fact that we have a certain PH in out bodies (different PH in different parts of the body, but the blood-plasma and cellular level PH is the most important), and the theory is that we should eat foods that are close to that PH-level, slightly alkaline. Obviously sweets, caffeine and refined foods are very acidic, and a lot of people today suffer from acidosis because of bad eating habits. Also, when your body is in a state of stress or illness the PH-level is lowered into the acidic scale..

An imbalance towards the acidic in the PH-levels can deplete the body of alkaline minerals such as sodium, potassium, magnesium, and calcium, making people prone to chronic and degenerative diseases.  Symptoms of excess acidity can be: low energy, fatigue, frequent colds, congestions, nervousness, irritability, headaches, muscle pain, leg cramps.. and so on. For freedivers with equalising problems it can be interesting to know that excess acidity also causes excess mucus. The worst offenders are dairy products, animal protein, white flour and pastas, chocolate, coffee and alcohol. Too much acidic food also promotes more free radicals that attack cell wall and membranes, which makes our immune system weaker.

Why would it work for freediving?

For healthy people the PH level is around 7.40. +/-0.05. As we get older it decreases to 7.30 or below. It seems like a small difference, but as the PH decreases it also decreases in hydroxyl ion (OH-), which is an oxygen donor. Because PH is logarithmic it would mean young people carry 23% more oxygen in their blood than old people. (There is no reference as to which age in the reports). So for overly acidic freedivers, this could be a good diet to boost the oxygen carried in the blood.

Another interesting fact is that alkaline tissues hold 20 times more oxygen than acidic tissues. But how much can we really affect the PH-levels of our tissues? The kidneys, lungs and blood continuously regulate the acid/alkaline status of the body.

Also, with rising alkalinity blood can increase its oxygen uptake, and the blood cells can hold more oxygen. The Bohr effect states that with rising blood alkalinity, the red blood cells can saturate themselves with ever more oxygen. The problem is, they can't let go of it. (Thatís the same problem as with hyperventilation.)
Eric Fattah says ďeating alkaline food increases your blood pH, giving you higher CO2 tolerance, which will delay the urge to breathe much like CO2 training doesĒ. Alkaline food doesnít affect the store of oxygen. The question is if the diet and having an alkaline body will also delay the onset of contractions.

As CO2 levels increase during a breath hold, the concentration of H+ ions also increases, and more H+ means more acid and a lower blood pH. This acidic state signals your brain that you need to breathe faster or deeper Ė does it also mean that the alkaline blood then turns acidic and lets go of the oxygen easier?? If that is so, it would be very good to start with alkaline blood (NOT from hyperventilating but an alkaline diet), delay the urge to breathe and then get hold of the oxygen from the blood as it turns acidic.  

The diet

The alkaline diet gets you back to basics and common sense and itís an easy adaptable diet. This is due to the fact that no foods are eliminated completely, just moderated. The main concept of this diet is whole, unprocessed foods with lots of raw fruits and vegetables. You donít have to buy any special shakes, bars, or pills. Itís not unhealthy in the way Atkins or the popular low-carb diets are. You donít even have to suffer that much - chocolate is alkaline!

The alkaline diet consists of almost 75-80% of alkaline foods and about 20-25% of acidic food. Then itís only up to you to find out which foods are alkaline and which are acidic. On the contrary to what you would think, foods that you find acidic outside the body, like lemons for instance, gives an alkaline response in the body. Once the body metabolizes the citric acid, it becomes alkaline.

The acidic part of the diet is as important as the alkaline, but it does have to be moderated to about 20% of your food intake. This category includes dairy, white flour, poultry, beef, coffee, and eggs. 

There are many charts of alkaline/acidic foods:

You will find plenty more just googling it the words "alkaline food chart".

Eventually I wanted more information on the REAL ph of foods, instead of trusting the above list of just dividing foods into "alkaline" or "acidic". This link: shows the PH-level of each food.

My experience

I tried a version of the diet last year for 6 weeks, cutting out wheat, refinded sugars and meat. It did feel great and it seemed the contractions came some half minute later in statics, but it can also have been because of the training. I haven't tried the full on diet yet, but I wil.

Small interesting facts I came upon: