High salt diets may delay puberty according to a study presented at the European Congress of Endocrinology in Dublin. As the salt content of Western diets continues to increase these findings could have significant consequences for the reproductive health of future generations.

Researchers from University of Wyoming, USA led by Ms Dori Pitynski are investigating the effect of varying levels of dietary salt on the onset of puberty in rats. They found that rats fed a high salt diet (equivalent to 3 or 4 times the recommended daily allowance for humans) had a significant delay in reaching puberty compared to those fed a normal (low) salt diet. Interestingly, rats that had salt completely excluded from their diet also had delayed puberty.

Ms Pitynski and colleagues concluded that salt intake is necessary for onset of puberty but that excesses can affect reproductive health. Late onset of puberty can lead to behavioural problems, stress and reduced fertility.

To date, while work has been done on the effect of varying levels of dietary fats on puberty, nobody has yet looked at the effect of dietary salts. “Our work shows that high levels of fat and salt have opposite effects reproductive health” said Ms Pitynski. “High fat diet is thought to accelerate the onset of puberty but our work demonstrates that rats fed a high salt diet even with a high fat diet will still show a delay in puberty onset.”

Ms Pitynski, “our research highlights for the first time that the salt content of a diet has a more significant effect on reproductive health than the fat content.”

Recent guidelines from WHO state that populations around the world are consuming much more salt than is physiologically necessary, and certainly more that the WHO recommended daily allowance of 5 g of salt per day for adults.

Sodium is found naturally in a variety of foods, including milk, cream and eggs. It is also found, in much higher amounts, in processed foods, such as bread, processed meats like bacon, snack foods as well as in condiments such as soy sauce and stock cubes; which are becoming more prevalent in the Western diet. “Current salt-loading in Western populations has the potential to drastically affect reproductive health, and warrants further attention” said Ms Pitynski.