Summer-Born Kids More Likely To Be Healthy Adults, Says Study

A new study has found that summer-born children are more likely to be healthy as adults.

British researchers from the University of Cambridge have found that aside from having a warm-weathered birthday that enables kids to have more fun under the sun, kids born in June, July, and August, are slightly heavier than other babies at birth; enter puberty at a later age; and tend to be taller as adults when compared to kids born in winter months.

"Those are all markers of growth and development that have been associated with higher risks of adult diseases," Dr. Ken Ong, a pediatric endocrinologist at the unit and co-author of the study, told The Huffington Post. "I hope people will find it fascinating that events in early life can have very long-lasting benefits."

The study is published in Heliyon.

In a press release, the researchers reported that they looked at whether birth months affect birth weight, puberty onset, and adult height, and arrived at the aforementioned characteristics.

“When you were conceived and born occurs largely ‘at random’ – it’s not affected by social class, your parents’ ages or their health – so looking for patterns with birth month is a powerful study design to identify influences of the environment before birth,” said study lead author Dr. John Perry, a Senior Investigator Scientist at the Medical Research Council (MRC) Epidemiology Unit in the University of Cambridge.

Using data from the UK Biobank study, the researchers analyzed data from around 450,000 men and women in UK. The results showed that in general, men and women born in June, July and August had a heavier birth weight and a taller height as adults, compared to those born in winter months.

Additionally, summer-born women were found to have started puberty later, which indicates better health in adulthood.

“This is the first time puberty timing has been robustly linked to seasonality,” said Dr Perry.

Although the mechanisms that relate birth months and health benefits are still not fully known, the researchers believe that sunlight is the factor that sets the difference between those born in summer and winter. During summer, pregnant mothers are able to expose themselves in sunlight, which determines the amount of vitamin D she receives while having a baby in her womb.

“We think that vitamin D exposure is important and our findings will hopefully encourage other research on the long-term effects of early life vitamin D on puberty timing and health,” said Dr. Perry.