Just about everything an individual consumes is converted into energy. Once the nutrients are digested and metabolized by the body, they leave behind an ash that’s either acidic, alkaline or neutral, explained Lisa Suriano, a nutrition and food science expert based in Ridgewood, N.J.
In general, most vegetables and fruits leave behind an alkaline ash; meats, dairy, fats and many processed foods leave behind an acidic ash, Suriano said. Even healthy foods, such as lean meat and cholesterol-lowering oatmeal, can leave behind an acidic ash that needs to be balanced with alkaline dietary options.
“Competitive athletes are always trying to fight muscle fatigue, so most people know to stay hydrated and prevent carbohydrate depletion,” Suriano said. “But acidic pH levels, possibly reaching an acidosis level, will really hinder their performance as well.”
Signs and symptoms of acidic pH levels include cramping, overall soreness and stiffness, headaches, and even foggy thinking, she said. Human bodies operate optimally when they’re slightly alkaline between 7.35 and 7.45, Suriano said—so athletes have to consume more alkaline foods to reduce acid levels.
However, it’s more complicated than that, Kuhl said.
“When you burn down food into ash, there will be an acidic or alkaline residue, but in the human body there’s something called biochemical individuality,” she said, meaning that each person’s chemical makeup and nutritional needs, are unique. “Two human beings can eat the exact same nutrients or take the exact same medication and have completely opposite responses. For instance, some people who take antihistamines get wired instead of drowsy. This biochemical individuality is not just isolated to medications; it’s even with very healthy foods.”