Source notes

How can a food's effect on teeth be judged without confusing acid production with tooth decay? Tests of plaque, the bacterial film on teeth, can show whether a food leads to acid formation. The author reports that virtually all carbohydrate-containing foods tested lowered human plaque pH below 5.5, making it more acidic. Yet acidity alone did not distinguish foods with different cavity-causing potential. Cooked rice and beans also caused a drop, while studies in people with hereditary fructose intolerance, an inherited problem processing the sugar fructose, found low cavity-causing potential for those foods.

That example is specific to the population described; it is not proof that either food prevents cavities. The central distinction is between an intermediate measurement and damage. The author also describes experimental findings in which acid production and enamel dissolution were not directly correlated. A pH reading therefore answers a narrower question than whether cavities develop.

How Does This Show Up in Real Life?

Suppose you encounter a chart calling one food worse for teeth because it produces a lower pH reading. The useful question is what the test actually compared: acid formation, damage to enamel, or the appearance of cavities. Those are not interchangeable outcomes. It also matters whether the comparison used foods as people eat them. For example, testing powdered food is not the same as testing its usual physical form. A controlled experiment can make comparisons easier while changing the situation you care about. Another useful question is what served as the comparison. A result expressed relative to a reference food is not the same as your personal chance of developing a cavity. None of this means acid measurements are useless, or that an unfavorable result can simply be ignored. It means the claim should stay within what was measured. This paper mainly helps you judge the meaning of a food-risk claim. The available abstract does not provide a list of foods to eat or avoid, a personal estimate of cavity risk, or a tested prevention plan.

The methods discussed often captured only part of the processes involved in decay, including how foods affect bacteria on teeth. The available abstract is truncated and gives no sample sizes or numerical cavity-risk estimates. It cannot establish how reliably each laboratory result predicts long-term cavity development in an individual.

Give this work weight as a warning against letting an easy-to-measure signal answer a larger health question. Its value is in improving the question asked of a claim, not in settling which food is safest for every person.