HAVING your first child after 30, or not having children at all, could almost triple your chances of developing breast cancer, new research reveals.
Scientists found that women who delay face a much higher risk, especially if they also in adulthood.
The study, presented at the European Congress on Obesity in Malaga, in Span, looked at 48,417 women with an average age of 57.
Most had a body mass index (BMI) around 26, which is classed as .
Scientists from the University of Manchester split the women into groups based on whether they had their first baby before 30, after 30, or never had .
They also looked at how much weight each woman had gained since the age of 20.
This was worked out by asking them to recall their weight at 20 and comparing it to their current weight.
The women were then tracked for an average of 6.4 years. During that time, 1,702 of them were diagnosed with .
Breast cancer is the most common form of cancer in the UK, affecting one in seven women, according to.
Each year, around 56,000 women in the UK are diagnosed with breast cancer – and that figure jumps to about 300,000 in the US.
Around 85 per cent of women survive at least five years after being diagnosed.
The findings showed that women who gained over 30 per cent of their body weight in adulthood and had their first child after 30 – or never had children – were 2.73 times more likely to develop breast cancer.
In comparison, women who had a child before 30 and gained less than 5 per cent of their body weight had a much lower risk.
Lead researcher Lee Malcomson said these two factors – weight gain and delayed childbirth – appear to work together to increase the danger.
“More information about how age of motherhood and weight gain affects the risk of breast cancer would allow us to better work out who is most at risk of the disease and target lifestyle advice accordingly,”; he explained.
Previous studies have already shown that having children earlier in life can help protect against breast cancer after .
Gaining weight, on the other hand, is known to .
This study is the first to show how these two factors interact and that the benefits of early childbirth don’t cancel out the risks of putting on a lot of weight later.
Our study is the first to establish how weight gain and age of first birth interact to affect a woman’s risk of breast cancer.
Lee added: “It is vital that GPs are aware that the combination of gaining a significant amount of weight and having a late first birth – or, indeed, not having children – greatly increases a woman’s risk of the disease.”;
