Girls who drink more than one sugary drink a day are likely to start having periods sooner, say scientists.
A new study of almost 6,000 adolescent girls links the consumption of sugary drinks to earlier menstruation.
The research found those drinking more than 1.5 sugar-sweetened beverages a day had their first period 2.7 months earlier than those consuming two a week or fewer.
The discovery is important as the risk of getting breast cancer later in life increases when periods start early.
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The research found those drinking more than 1.5 sugar-sweetened beverages a day had their first period 2.7 months earlier than those consuming two a week or fewer
Sugary drinks are also said to be contributing to the obesity epidemic in children.
US lead researcher Dr Karin Michels, from Harvard Medical School, said ‘Our study adds to increasing concern about the widespread consumption of sugar-sweetened drinks among children and adolescents in the USA and elsewhere.
‘The main concern is about childhood obesity, but our study suggests that age of first menstruation (menarche) occurred earlier, independently of body mass index, among girls with the highest consumption of drinks sweetened with added sugar.
‘These findings are important in the context of earlier puberty onset among girls, which has been observed in developed countries and for which the reason is largely unknown.’
A one year reduction in age at first period is estimated to raise breast cancer risk by five per cent.
The impact of bringing forward menarche by 2.7 months was likely to be ‘modest’ said the scientists.
But they expected some girls to be consuming more sugary drinks than reported which would lead to an ‘even more dramatic’ drop in the age of menstruation.
The researchers said there could be significant public health implications and, importantly, it was possible to encourage less sugary drink consumption.
Altogether 5,583 girls were included in the research, drawn from a US-wide Growing Up Today study, says a report published in the journal Human Reproduction (must credit).
Questionnaires were used to ask the girls about their diets at several points between 1996 and 2001, and collect information about what they drank.
A drink serving was defined as either a can or a glass. Sugary drinks included drinks such as Coca Cola and Pepsi, sodas, fruit drinks, lemonade, iced tea and the powder mix Koolaid.
The study found no link with fruit juices or diet colas with added sweeteners.
By the end of the five year period, all but three per cent of the girls had started menstruating.
The average first period age for girls consuming the most sugary drinks was 12.8 years compared with 13 years for those drinking the least.
The average first period age for girls consuming the most sugary drinks was 12.8 years compared with 13 years for those drinking the least.
After taking account of Body Mass Index (BMI), girls drinking the most were 22 per cent more likely to start their period in the month after being questioned about their diet than the lowest consumers.
The researchers found artificially added sugar was chiefly responsible for their findings rather than natural sugars In fruit juices.
Drinks with added sugar can lead to rapid ‘spikes’ of the hormone insulin.
Boosted insulin can result in higher concentrations of sex hormones, and large changes in the levels of these have been linked to periods starting earlier, said the scientists.
Dr Ken Ong, from the Medical Research Council Epidemiology Unit at Cambridge University, said ‘This is a very large study, which was representative across the USA, and the findings are strongly statistically significant.
‘From previous research we know that sugar-sweetened beverages (SSB) intake promotes weight gain, and that weight gain promotes early puberty in girls.
‘The surprise here is the claim that the association is independent of childhood size - there is a more direct effect of SSB on puberty. This is unexpected.’
Prof Ieuan Hughes, Head of Paediatrics, University of Cambridge, questioned whether a difference of 2.7 months was ‘biologically relevant’.
He said ‘The authors admit that future studies should examine the impact of early childhood nutrition on menarche.
‘It seems to me that the observation in this study suggests that it is weight related so that the message is clear about the dangers of such sugary drinks.’
A spokeswoman for the British Soft Drinks Association (BSDA), said: 'Neither this study nor the body of science shows that sugar-sweetened beverage consumption causes early onset of menstruation.
'What the body of science supports is that adolescent girls are reaching puberty earlier than prior generations; however, there is no scientific consensus concerning the cause of this trend.'
Read more: http://www.dailymail.co.uk/news/article-2929215/Sugary-drinks-bring-girl-s-periods-earlier-Youngsters-drink-one-day-start-nearly-three-months-earlier.html#ixzz3Q8HdVP2b
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