How does your alkaline diet work?

  • Discussion
  •  Twitter Foodie #47

    I’ve been trying to find how an alkaline diet works and I found a tweet about pH Spectrum diet at

    It looks much easier than your alkaline diet charts. Is this better than PRAL?

  •  Keith Taylor #401
    Ŧallars: Ŧ 1,060.98

    Sorry for the delay in replying.

    You are right that the diet looks easier. But, it isn’t an alkaline diet. That chart, and similar looking graphics, are all over the Internet, but they are fundamentally flawed.

    They are all based on a technique that was investigated many years ago. It involves incinerating food, then measuring the pH of the resulting ash. The data is still included in the USDA databases that I use. The difference is, I ignore it because it is meaningless as far as diets are concerned. In fact, it is worse than that – it is misleading.

    Coincidentally, there are many healthy foods in my PRAL tables that also produce alkaline ash. But this is not the basis for a healthy diet.

    PRAL estimates the effect of food on the kidneys. The alkaline affect happens due to how our bodies digest the nutrients that form the PRAL calculation. There are other factors that affect acid load at the kidneys, but those are the most significant food related items.

    This does not mean to say that you cannot eat healthily on an ash-based diet. However, you have no accurate way of planning or assessing your food intake if you rely on ash calculations.

    With PRAL, you can assess your total diet, and you can also use PRAL tables to improve your alkaline diet. By changing some of your food to a lower PRAL value, you will always reduce the acid load on your kidneys.

    Remember though, the objective is not to minimize your PRAL score. A healthy diet must include up to 25% acid forming foods, but the overall balance must always be alkaline. Your best approach is to achieve this with a wide range of different fruits and vegetables.

    I hope this makes it clear. If not, please log-in and ask further questions.

    If anyone has trouble logging in, you can ask questions, and share opinions via the red Help button. This will add a ticket to the Foodary Helpdesk, but please note that I give priority to forum discussions, and helpdesk responses may take several days.

  •  Foodary Helpdesk #403
    Ŧallars: Ŧ -10.50

    Your chart for alkaline baked foods shows (Leavening agents, baking soda) as 0.00 are you sure that’s right? I find it very Alkaline.

    Please explain.

    •  Keith Taylor #405
      Ŧallars: Ŧ 1,060.98

      Hi gwsheetmetal and thanks for your question about PRAL.

      I hope you can see from that PRAL is not directly associated with measuring pH. As I suggested above, you can reduce the average PRAL of your total food intake, and this should increase the pH of your urine – i.e. make it more alkaline.

      This happens due to the way you digest food, and is the result of a complex series of organic reactions. As I said, PRAL is an estimate of what will happen at your kidneys based on normal food digestion. It is designed to measure food intake.

      However, acid load at the kidneys (renal acid load) can also be changed by many other factors. Chemicals from food additives, supplements, medicines, and other sources can affect renal acid load. These chemicals do not occur in food in abundance, so they are ignored from the PRAL calculation.

      This is done to make PRAL useful for food analysis. There is another calculation for estimating renal acid load, called NEAP. This is often deemed to be more accurate, as it includes bicarbonates in the calculation. That might be true in the lab, but it is rarely relevant in the kitchen.

      In a healthy diet, baking soda should not form a significant part of your total food intake. Therefore, PRAL is accurate enough to guide us towards healthier eating. There is no doubt that bicarbonates in baking soda and other chemicals will reduce the acid load on your kidneys. However, this is not relevant to healthy diet.

      If you have a medical condition where alkalizing urine is important, such as certain kidney stones, then bicarbonate supplementation usually helps. Sodium bicarbonate (baking soda), potassium bicarbonate, and potassium citrate are all used medically for this purpose. However, they are usually irrelevant to PRAL calculations, and they are not food.

      The whole point of PRAL is to use it as a guide towards healthy diet. However, it is not a target in itself. False alkalization using chemicals will not improve your health. Alkaline foods balanced with less acid foods is the only way to achieve good health. In the same way, you should ignore any processed supplements and drinks that claim to be healthy just because they are alkaline.

      Alkalizing is a product of a healthy diet. Alkalizing is not a goal in it’s own right.

  •  Keith Taylor #459
    Ŧallars: Ŧ 1,060.98

    I’ve just had a further thought about PRAL scores in different circumstances. Prompted by a comment on my alcoholic alkaline drinks page.

    That comment, and my response, are about the physical pH measurement of drinks, compared to the effects of drinks on alkalizing urine after digestion.
    I wonder if there are some illnesses where the physical pH matters? Please let me know your thoughts.

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