Over time, the benefits of adding fluoride to drinking water may diminish. In a new review of the evidence, scientists found that while water fluoridation may still slightly reduce the risk of tooth decay in young children, its overall impact is likely to be smaller than it was 50 years ago, before fluoride was widely used in toothpaste.
Beginning in the 1950s, U.S. states and cities began adding fluoride to their drinking water supplies because research showed it could prevent tooth decay, especially in children. Today, water fluoridation is practiced in many other countries and is hailed as one of the most effective public health interventions of modern times. But there has long been debate about the specific benefits of water fluoridation, and whether potential risks offset those benefits. The Cochrane Library, a research organization respected for its comprehensive reviews of clinical trial data relevant to important public health topics, has now decided to take a closer look at fluoridation using the latest gold standard evidence available .
Researchers recently examined 22 studies of community water fluoridation programs, making sure to distinguish between studies conducted before and after 1975, when fluoride began to be widely added to toothpaste products. They focused on one specific question: whether the introduction or removal of these schemes affects people’s risk of tooth decay. Overall, they found that today’s program is still likely to slightly reduce cavities in children’s primary teeth and make more children completely cavity-free. But they also found that the benefits of water fluoridation may be even smaller than they were before 1975.
“Contemporary evidence using different research methods suggests that the benefits of fluoridated water have declined in recent decades,” said Tanya Walsh, professor of healthcare evaluation at the University of Manchester, in a study at the Cochrane Library. said in a statement.
The researchers noted that the most recent studies included in the review were conducted in high-income countries. People in many parts of the world still have high rates of tooth decay and limited access to fluoride toothpaste or other preventive treatments. Therefore, new water fluoridation programs in these areas may still have a greater positive impact on residents’ dental health. But much has changed in the past 50 years, the researchers added, and the risks and benefits of these programs should be more carefully assessed from now on, especially when deciding whether to launch new programs where they may be less needed.
“Oral health inequalities are an urgent public health issue that requires action. Water fluoridation is only one option and may not be best for all populations,” said Walsh.
A previous Cochrane review found these programs may increase young children’s risk of developing dental fluorosis, a condition caused by exposure to too much fluoride, which causes tooth discoloration. Some recent studies have also found a potential link between fluoride exposure and worsening kidney health in adolescents, and there is evidence that increased fluoride exposure in utero is associated with a higher risk of neurobehavioral problems in children by age 3. There are also many poorly supported ideas about the dangers of fluoridation, such as the idea that fluoride increases the risk of cancer.
The main takeaway from all this research and debate should be that science and the world around us are constantly evolving. In the best cases, we are able to adapt to new evidence and act accordingly. Of course, water fluoridation may no longer be the valuable public health measure it once was. But that doesn’t necessarily negate its past importance.
