Founded in the belief that certain foods can affect the acidity of blood and urine, the Alkaline Ash Diet focuses on eating foods to promote an alkaline pH in the body to avoid health problems associated with an acidic Western diet. (Alkaline is another word for basic.)
A substance is acidic or alkaline based on its pH: 0-6.9 is acidic, 7 is neutral, and 7.1-14 is alkaline. Our blood is a little alkaline at 7.4 and our stomach acid is very acidic at 3.5.
When we break down food in our body, an ash byproduct is left behind which can be acidic or alkaline. The composition of the ash determines whether it is allowed in the Alkaline Ash Diet. The original pH might be very different from the by-product ash, for example lemons are very acidic, but once digested they produce an alkaline ash and are allowed in the Alkaline Diet. Examples of acceptable alkaline ash foods include most fruit, vegetables, soy, nuts, seeds, and legumes. Acid forming foods such as alcohol, caffeine, dairy, meat, eggs, grains, and processed foods are not allowed.
Looking at evidence-based research, eating different foods can change the pH of urine but does not change blood pH. Blood pH is tightly regulated by the lungs and kidneys, a change in blood pH is associated with critical illness.
There is no scientific evidence the Alkaline Ash Diet prevents or treats cancer. However, eating a good amount of fruit, vegetables, and minimally processed foods can reduce risk. A plant-based diet is also beneficial for cardiovascular health. Cutting out certain food groups might aid in weight loss but ensuring essential micronutrient intake is important. Eggs, dairy, and whole grains provide a great source of protein, B vitamins, and fiber which are essential for fighting disease.
The Alkaline Ash Diet lacks scientific evidence supporting its claims, but eating more fruits, vegetables, legumes, and minimally processed foods are healthy benefits to embrace.