Sugar is everywhere, hidden in drinks, snacks, and even foods we think of as healthy. For decades, it has been at the center of debates on obesity, diabetes, and heart health. But now, the World Health Organization (WHO) is sounding the alarm on another consequence of our sugar-heavy diets: tooth decay.According to the agency, removing or even sharply reducing sugar intake could protect billions worldwide from the world’s most common noncommunicable disease.
What WHO has said
WHO estimates that over 2.5 billion people currently live with dental caries, including more than 2 billion adults with cavities in permanent teeth and over half a billion children with decayed baby teeth.
The agency identifies free sugars—those added to processed foods and drinks, or naturally present in items like syrups, honey, and fruit juices—as the key dietary risk factor. Its recommendation is firm: limit free sugar intake to less than 10% of daily calories, and ideally under 5%, to significantly lower the risk of decay across a lifetime.
Understanding dental caries
Dental caries, often referred to as tooth decay or cavities, is more than a cosmetic concern. It is a disease process where the structure of the tooth is gradually destroyed by acid produced when bacteria in plaque metabolize sugar. The first signs may be mild sensitivity, but if left untreated, decay can lead to persistent toothache, pain while chewing, and visible pits or holes.Advanced cases cause infection, tooth loss, and even difficulty eating, speaking, or sleeping, which can take a serious toll on overall health and quality of life.
How it develops
Tooth decay develops through a continuous cycle. After consuming sugary foods or drinks, bacteria in plaque break down those sugars into acids. These acids attack the enamel—the hard protective layer of the tooth—weakening it over time. If the cycle continues unchecked, cavities form and progress deeper, eventually reaching the inner tooth structures.
The real culprit
While multiple factors can contribute to poor dental health, WHO is clear that sugar is the main driver of caries worldwide. Hidden sugars in sodas, packaged juices, breakfast cereals, sauces, and even so-called health bars mean that many people exceed safe levels without realizing it.And it is not just cavities, that one needs to worry about. Diets high in free sugars contribute to obesity, type 2 diabetes, and cardiovascular disease.
How to prevent tooth decay ?
The good news is that tooth decay is largely preventable. Cutting down on sugar is the most effective step, but it must be paired with daily oral hygiene, including brushing twice with fluoride toothpaste and flossing to remove plaque. Regular dental check-ups can help detect early signs before they progress to more serious problems. On a wider scale, WHO calls for public health policies such as taxing sugary drinks, reformulating processed foods, and educating families about sugar’s hidden presence in everyday diets.