Research led by the University of Kent has discovered evidence of a biorhythm in human primary teeth that is associated with weight gain during adolescence. An international research team led by Dr Patrick Mahoney at Kent’s School of Anthropology and Conservation discovered the biorhythm in primary ‘milk’ molars, Retzius periodicity (RP), is related to aspects of physical development during early adolescence. A faster dental biorhythm produced smaller gains in weight and mass.
RP forms through a circadian-like process, occurring with a repeat interval that can be measured with a resolution of days. The rhythm relates to the period in which tooth enamel forms and is consistent within the permanent molars of individuals that do not retain evidence of developmental stress. The human modal RP has a near seven-day cycle but can vary from five to 12 days.
The first-of-its-kind research published by Nature’s Communications Medicine found that adolescents with a faster biorhythm (five- or six-day cycle) weighed less, gained the least weight, and had the smallest change in their body mass index over a 14-month period compared to those with a slower biorhythm. Those with a slow biorhythm (seven- or eight-day cycle) produced the greatest weight gain.
Dental histologists have known about the biological rhythm for over 100 years, but its significance for body mass and growth emerged recently in studies that compare mammalian species. Research has now focused on the meaning of the rhythm for humans. Rapid change in body size is a natural consequence of adolescence, but excessive weight gain during puberty can have vast consequences for health, such as obesity in adulthood.