Before you take that sip to quench your thirst, make sure the water isn't too high in fluoride content, as it can cause depression and weight gain, claims a new study.
According to the researchers at the University of Kent, water fluoridation above a certain level is linked to 30 percent higher than expected rates of underactive thyroid and high hypothyroidism, which can lead to weight gain and depression, the Daily Express reported.
The study said the effects of fluoride on the thyroid have long been observed, but there have been no population studies that have examined this, and the findings have important implications for public health policy in the countries where fluoride is added to drinking water or in other forms such as fluoridated milk and salt.
Researchers conducted the study by analyzing the prevalence of underactive thyroid diagnosed by GPs in 2012 to 2013 in one model and also by comparing data from West Midlands and Greater Manchester in another.
The fact that hypothyroidism was more common in women and increased with age was taken into account.
The study is published online in the Journal of Epidemiology and Community Health.