ALKALINE DIET-A KEY TO LONGEVITY ?

Human body is maintained at a very narrow pH range of 7.35 to 7.45. Our kidneys and lungs are efficiently working to do so. Levels above 7.45 are referred as ‘alkalosis’ whereas levels below 7.35 as ‘acidosis’. Both are potentially serious conditions. Various practitioners of Alternative Medicine practice alkaline diet by making some incorrect assumptions about how some foods can affect the pH of the body for treating a range of diseases. They propose that since the normal pH of blood is slightly alkaline, goal is to mirror this by eating a diet that is alkaline producing as well. They believe that cancer grows in acidic environment and such a diet will help to prevent/treat cancer, forgetting the fact that cancer cells rapid growth creates this acidic ambience in the body.  

History

This diet has its roots in nineteenth century when French Biologist Claude Bernard observed the change in urine from alkaline to acidic on changing the diet of rabbits from herbivore to carnivore.

Mechanism

There are some foods that produce alkaline ash i.e. residue left on combustion of food rather than its acidity, which have to be avoided as per the proposals of this diet. The alkalinity is measured by PRAL scale i.e. potential renal acid load, which means how acidic they make the urine. Foods that have negative PRAL score are considered alkaline such as lemon and most fruits & vegetables. Foods with a positive score are acidic such as grains, animal protein (meat, fish, poultry), dairy (cheese) and fruits & vegetables except cranberries, prunes and plums. Now, the irony is citrus fruits that are generally considered acidic are usually considered alkaline producing in this diet. This diet also proposes avoiding processed foods, white sugar, white flour and caffeine.

Claims of this diet

This diet claims to treat cardiovascular disease, rheumatoid arthiritis, osteoarthiritis  and will increase energy levels in the body. It is also asserted to shed body weight. But no scientific evidence is available for supporting such assertions.

Myth or a good approach?

This is a strong misconception because there is not enough research to support the claim the mechanism of this diet, so it is generally not recommended. American Institute of Cancer Research calls this a “myth”. Body’s natural regulatory mechanisms don’t require a special diet to work, eating an alkaline diet will only change pH minimally. Such “extreme” diet plans have more risks than advantages for a cancer patient. Because of the avoidance of some of the basic food groups such as grains, meat, eggs etc., this diet is not well-balanced and may lead to nutrient deficiencies in the body.

The final word

The core of this diet is to consume fruits and vegetables in abundance. So, it’s good and healthy for the cardiovascular health and weight loss promotion, in general. Firstly, this diet is a real struggle to maintain adequate protein intake because the only sources recommended are pulses and tofu. Secondly, such a restrictive diet can lead to nutrient deficiencies. Thirdly, what we eat can play a direct role in cancer risk, but for this, alkalinity or acidity of foods is not important. Focus should be on making healthy dietary choices - eating a wide variety of fruits & vegetables, whole grains and beans, limiting consumption of red meats, consuming alcohol in moderation.