Living in the countryside could delay the menopause by more than a year, a study has suggested.
Scientists found women surrounded by green space went through ‘the change’ by an average of 16 months later.
Researchers led by a team at the University of Bergen in Norway believe the delay may be down to lower stress levels.
They said the study, based on records of almost 2,000 women, was the first to look at a link between green space and menopause.
The team claim it has ‘broad implications’ because going through the menopause younger may put women at higher risk of heart disease or bone weakness.
It comes months after other major reports found living in polluted areas or working night shifts also made women more likely to stop menstruating sooner.
Women who have the most plants in the 300m surrounding their homes are more likely to have a later menopause and therefore potentially better long-term health, researchers claim (stock image)
Researchers from across Europe, led by Dr Kai Triebner at the University of Bergen, looked at the health records of 1,955 ageing women over 20 years.
The study began in 1990 and surveyed the women again between 1999 and 2001 and 2010 and 2013.
It found women living with the most foliage in the 300m (985ft) surrounding their homes hit the menopause at 51.7 years of age.
While those with the least greenery could be expected to stop their periods almost a year and a half earlier, at age 50.3.
Dr Triebner’s team suggested the link adds to two streams of past research which have shown that higher stress levels may induce earlier menopause, and that living in more rural areas makes people less stressed.
They explained this in terms of a hormone called oestradiol, which is significantly lower in women who have hit the menopause, and the stress hormone cortisol.
The team wrote in their paper: ‘Stress in humans is reflected by a high level of cortisol, which is reduced by exposure to greenspace.
HOW DOES STRESS AFFECT FERTILITY?
The link between stress and fertility or menopause is controlled by chemicals and hormones in the body.
Regular, or high levels of, stress causes quantities of the hormone cortisol – known as the stress hormone – to spike.
High levels of cortisol have been found in studies to reduce how much estradiol the body produces. This is a form of the female sex hormone oestrogen.
Low levels of oestrogen, usually caused by a natural decline as a woman gets older and exits child-bearing age, are what triggers the menopause, because the sex hormone becomes so unavailable to the body that it is no longer fertile and the reproductive system begins to shut down.
Therefore, higher stress levels – which can be caused by living in busy urban areas – may reduce levels of oestrogen faster than in women who are less stressed and bring forward the age at which they begin the menopause.
‘Lower cortisol levels have in turn been associated with higher oestradiol levels, which makes it plausible that women with less stress, thus lower cortisol, might maintain higher oestradiol levels and therefore transition later into menopause.’
They added that more green space has been linked with a lower risk of depression, which is itself linked to starting the menopause at a younger age. Pollution had little effect, the team added.
Menopause is the time when women stop releasing eggs from their ovaries and become naturally infertile – usually because they’re reaching old age.
It usually happens between the ages of 45 and 55 and, although natural, can have unpleasant side effects such as hot flushes, night sweats, vaginal dryness and a low sex drive, sleep problems and mood problems or anxiety.
The symptoms may begin before a woman’s periods actually stop and continue for years afterwards.
Dr Triebner and his colleagues said starting the menopause later was tied to a longer life expectancy and a lower risk of dying from heart disease or getting osteoporosis.
They acknowledged that women living in greener areas may be wealthier and therefore in better general health.
In the study they used satellite images to give each woman a score based on how green the area around their house was – the participants lived in Spain, France, Germany, Belgium, the UK, Sweden, Estonia, Iceland and Norway.
These scores were compared with the age at which the women started natural menopause, defined by having not had a period for 12 months.
Other factors believed to affect the timing of the end of menstruation included a woman’s weight, whether she smoked, how much exercise she did and whether she took the Pill when she was younger.
A study by the University of Dalhousie in Canada found women who work night shifts were at least nine per cent more likely to go through an early menopause.
In a paper published in March they suggested this was because an erratic sleep pattern could reduce oestrogen levels and disrupt the function of the ovaries.
Another study, published in June by the University of Modena in Italy, showed breathing in car exhaust fumes could shorten a woman’s fertility and bring on early menopause.
Pollutants such as nitrogen dioxide could reduce women’s levels of anti-Mullerian hormone which are lower in those who have fewer eggs left so are less fertile.
Dr Triebner and his colleagues published their work in the journal Environment International.
LIVING NEAR BUSY ROADS ‘RAISES THE RISK OF EARLY MENOPAUSE’
Women who live in areas with high pollution may risk experiencing an early menopause, a study suggested earlier this year.
Researchers fear breathing in toxic air disturbs a crucial hormone which regulates the number of eggs in the ovaries.
The findings are believed to be the first to show that exposure to pollutants, such as nitrogen dioxide from car fumes, ‘severely reduce ovarian reserves’.
For the first study, Italian scientists from the University of Modena took blood tests to analyse the levels of anti-Mullerian hormone (AMH) in 1,318 women.
Low levels typically indicate a woman has a poor ovarian reserve – the number of resting immature eggs, or follicles.
The levels of AMH among the women, living in Modena in Italy between 2007 and 2017, were then compared with their addresses.
Around six in 10 women whose homes were on busy roads were at risk of infertility because they had low AMH.
In comparison, the rate among women residing in less congested areas was fewer than four in 10.
Richard Anderson, professor of clinical reproductive medicine at the University of Edinburgh, said on the findings: ‘While this does not suggest a short-term problem for women trying to fall pregnant, it might indicate that women exposed to high levels of pollution might have a shorter opportunity to achieve a family, and even an earlier menopause.’
It was not clear why the link existed but exposure to high levels of exhaust pollutants PM10, PM2.5 and NO2 was thought to disrupt the body’s hormone balance.