In order to thrive, humans require a pH level of approximately 7.4 or slightly alkaline. And so, the alkaline diet was born. It’s that easy to contribute to the thousands (or is that millions?) of weight loss fads on the market these days. Let’s examine the facts.
The alkalinity theory is based on the fact that the consumption of alkaline foods creates an overall alkaline load and offers protection from chronic and degenerative conditions such as cancer, osteoporosis and muscle wastage. In general, fruits and vegetables are alkali forming, whereas animal products and grains are acid forming. Neutral foods are those that don’t contain protein, sulfur, or minerals such as pure fats, sugars, and starches.
In the alkaline diet, the overall load is measured with pH test strips and both saliva and urine can be tested. And herein lies our first problem with the alkaline diet: foods don’t influence our blood pH. Our body tightly regulates blood and extracellular pH, through mechanisms that are beyond the scope of this article. The important point is that regardless of what you eat, your blood pH will be very close to our required 7.4. Access the relevant research here and here.
Proponents of the alkaline diet also state that in order to keep blood pH constant, the body pulls minerals from our bones to neutralize any excess acid that is produced from our diet. They believe that diets with a net acid load therefore, cause bone demineralization and lead to osteoporosis. This is incorrect. The kidneys regulate blood pH and we are equipped with a very efficient buffering system in response to the consumption of acidic foods such as animal protein. Furthermore, adequate protein is necessary for the prevention of osteoporosis and multiple studies have found improved bone health with higher protein intake.
But acidic foods give you cancer? Some foods certainly can (e.g. trans fats, refined seed oils and refined sugar) but this has nothing to do with a net acid load. Food can’t change our blood pH remember, and cancer is also capable of growing in an alkaline environment, as this study shows. So please, eat your eggs.
While there seems to be a significant lack of clinical evidence to support the avoidance of acid-forming foods, an alkaline diet is still important for your health, but not because of why you may have originally thought.
The benefits of an alkaline diet are:
- More fruit and vegetables;
- Less grains;
- Less dairy;
- Less sugar (although not acid-forming, it is discouraged in many popular alkaline diets).
But the even better news is that you don’t need a diet to achieve this. The answer is simple: just eat real food.
Bonjour J. (2013). Nutritional disturbance in acid–base balance and osteoporosis: a hypothesis that disregards the essential homeostatic role of the kidney. British Journal of Nutrition, 110, 7, 1168-1177.
Dawson-Hughes B, Harris SS, Ceglia L. (2008). Alkaline diets favor lean tissue mass in older adults. American Journal of Clinical Nutrition, 87, 3, 662–665.
Koeppen BM. (2009). The kidney and acid-base regulation. Advances in Physiological Education, 33, 4, 275-281.
Martínez-Zaguilán R, Seftor EA, Seftor RE, Chu YW, Gillies RJ, Hendrix MJ. (1996). Acidic pH enhances the invasive behavior of human melanoma cells. Clinical and Experimental Metastasis, 14, 2, 176-86.
Munger RG, Cerhan JR, Chiu BC. (1999). Prospective study of dietary protein intake and risk of hip fracture in postmenopausal women. American Journal of Clinical Nutrition, 69, 1, 147-52.
Schwalfenberg G. (2012). The Alkaline Diet: Is There Evidence That an Alkaline pH Diet Benefits Health? Journal of Environmental and Public Health. Volume 2012.
Tucker KL, Hannan MT, Kiel DP. (2001). The acid-base hypothesis: diet and bone in the Framingham Osteoporosis Study. European Journal of Nutrition, 40, 5, 231-7.
Image credit here.