Ask the RD

Question: I keep hearing and reading about the alkaline diet. Can you explain how it works and if it’s as good as it appears to be?

Answer: You are right—the alkaline diet seems to be having “a moment.” While the theory behind the diet has yet to be scientifically proven, at its core it is a healthy regimen.

THE BODY’S PH

The pH scale, which ranges from 1 to 14 levels, is a measure of how acidic (1–6) or alkaline (8–14) a substance is. A neutral pH is 7. The pH levels within our body vary. Our stomach has a very low pH (1.3–3.5), while our blood tends to have a higher pH (7.4). The pH of our urine varies (4.6–8.0), as our kidneys serve as buffering agents to keep things stable. As we age, there is a gradual decline in how efficiently our kidneys can maintain this acid-base balance.

THE THEORY BEHIND THE ALKALINE DIET

Proponents of the alkaline diet say eating foods that keep our bodies more alkaline will protect us from chronic disease and help us to control our weight. Because minerals are used as buffers to maintain pH levels, consuming foods high in mineral content (such as fruits and vegetables) and drinking plenty of water will keep the pH of our blood high and prevent fluctuations, which is the ultimate benefit. In addition, acid-producing foods such as refined sugars, dairy, wheat, meat, caffeine and alcohol must be avoided.

BOTTOM LINE

Whether or not you believe the alkaline hypothesis, there is nothing wrong with consuming a diet full of fruits and vegetables plus drinking copious amounts of water. As a final note, keep in mind that soil quality directly affects the mineral content of the plants grown in it, which is yet another reason to care about how your food is grown.