Do women’s periods synchronise when they spend time together?

Talk to a woman about her period and she will probably give you an example of the time her cycle aligned with a friend, partner, colleague or family member. Many of us have noticed that the closer we get to another woman the more we seem to get crampy, grumpy, tired, bloated and spotty at the same time. It’s as if our uteruses, in a monthly show of solidarity, are saying hey, why not go with the flow? Let’s do this painful, stigmatised, and bloody expensive thing together, and take advantage of the three-for-two tampon offers in the process.

However, a new scientific study – thought to be the largest of its kind – has found data showing women’s periods do not synchronise when they live together after all. The study – carried out by period tracking and fertility app Clue in partnership with the University of Oxford – received 1500 responses, which were narrowed down to 360 pairs of women. Analysing three consecutive cycles in each pair, the research found the vast majority – 273 pairs – had a greater difference in period start dates at the end of the study than at the beginning. In other words, menstrual syncing is a myth up there with periods being tied to the waxing and waning of the moon. Not only that, women’s menstrual cycles are more likely to diverge than come together over time.

“It’s very unlikely that cycle syncing is a real phenomenon,” says Clue’s data scientist Marija Vlajic. “Menstrual syncing amongst the sample we had did not exist. We’ve also done some statistical tests and found that the difference in cycles actually grows. This doesn’t mean that pairs go out of sync – it means they were never in sync in the first place. It’s the nature of two mathematical series that keep repeating: the series will diverge as the numbers grow.”

This has been my experience. I have been with my female partner for 13 years, living together for 11 years. In that time, our periods have never synced for more than a month or two, because our cycles are different lengths.

“Exactly,” Vlajic says. “So there will be a time every six months, say, when your periods sync but that doesn’t mean the difference is getting smaller.” Has Vlajic ever experienced her period syncing with another woman? “My background is scientific,” she notes. “So when I say to my friends that I have my period and they have theirs too I don’t conclude that we are syncing. I just think it’s information bias; our brains looking for patterns.”

Still, the belief in menstrual synchrony persists, with a study published in 1999 revealing that 80% of women believed in the phenomenon and 70% saying they enjoyed it. The editor who commissioned this piece told me that she syncs with her sister whenever they spend time together and gets her period at the same time as her closest colleague. The idea has been around for centuries, though because menstrual health has long been overlooked by the scientific research community it was not until 1971 that it was first documented in a study.

In a Harvard research paper titled Menstrual Synchrony and Suppression, psychologist Martha McClintock tracked 135 female college students living in the same dorm and found “a significant increase in synchronisation of onset dates”. She concluded: “the evidence for synchronicity is quite strong, indicating that in humans there is some interpersonal physiological process which affects the menstrual cycle.”

The idea that pheromones enable women to become sexually receptive at the same time has been researched in various groups as well as in rats, baboons and chimpanzees. Themain evolutionary explanation is that it permits female species to avoid being monopolised by a single dominant male. But McClintock’s paper has been discredited on methodological grounds and a whole host of other studies, like this new one, continue to prove that menstrual synchrony is a myth.

So why won’t we let this one go? And how does Vlajic explain all the anecdotal evidence of our periods synchronising? “I like the idea myself of this dominant super uterus in a group of women that makes everyone adjust their cycles,” she admits. “I can see how it gives you a special connection with a woman to go through that at the same time. It feeds into a feeling of connection, support, and sisterhood. Even though we do it every month, t Periods are personal and the thought of sharing with someone makes the idea powerful. That’s why we continue to look for patterns even when they don’t exist.”

Chitra Ramaswamy

Do women’s periods synchronise when they spend time together?

We need to stop being coy about periods and tampons

Periods are no fun, even when you’re safe at home with a drawer full of tampons, pads and a hot-water bottle. So it’s little surprise that some girls are missing school because they can’t afford the right equipment. Imagine the mess, anxiety and shame they could be facing. And that’s on top of all the other unpleasantness. This being on the women’s pages of the website, you’re probably already familiar with it: unpredictable bleeding – sometimes seeping, sometimes in worrying great blurts – the aches, smells and dealing with a part of your body that you may not be too keen on. But perhaps the people in charge of public happiness, health and hygiene don’t know all this. Maybe they think that periods are a breeze.

I have only had one tiny bad experience of having no access to sanitary products. There I was – 14, at home with asthma, mum in hospital nearly dead from a brain haemorrhage, dad at work, a childminder looking after me – and, late one night, I got my first period. The minder initially refused to give me a sanitary towel as she needed the few she had for herself. And those were the days of scratchy, nonabsorbent toilet paper. Eventually, she gave me one. Horrid, but not a microscopic patch on what those schoolgirls, plus refugees, homeless or incarcerated women and millions in the developing world have to deal with.

You’d think we’d be managing by now to supply women here in the UK with such necessities, but we’re even lagging behind the US. New York City gives away tampons, while poor women here are using old socks and newspapers. But we’re still rather coy about it. Even in newspaper features about periods, blood has been referred to as “fluid”. Blood is fine in horror films, but somehow becomes taboo when it’s pouring from vaginas. But pour it does, and we need to mop it up efficiently, and keep ourselves clean. And so, to free toilet paper, soap and towels in schools, colleges, prisons and all public lavatories, we must add free sanitary items, like the caring, compassionate country we are meant to be.

We need to stop being coy about periods and tampons

How periods really affect a woman’s working life

Many women won’t be surprised by the results of a BBC survey in which more than half of female workers said they’d experienced period pain that affected their ability to do their job.

But while some might report feeling drained of energy and motivation when their period is due, others find they actually perform better at mental and physical tasks at that time of the month.

This is because of variations in the way different women react to hormonal changes in their monthly cycle. While intellectual tasks, such as completing a logic puzzle or doing an IQ test, rely on electrical circuits in the brain, how well the neurons perform is subtly affected by the ‘hormonal soup’ which surrounds them.

The female sex hormones oestrogen and progesterone can alter the brain’s reward system, affecting motivation and how ‘sharp’ you feel, but when this takes place isn’t predictable – some women feel at their best a week after their period, while others do so just before.

Of course, severe pain can affect our mental agility too – another reason it might be a good idea for companies to introduce flexible ‘period leave’.

Dr Daniel Glaser is director of Science Gallery at King’s College London

How periods really affect a woman’s working life

How Sitting For Prolonged Periods May possibly Contribute To Certain Cancers

Sitting for extended periods of time has been a sort of 21^st century epidemic – TV-gazing isn’t new, but streaming movies and tablets aren’t helping our habit of sitting. In research, sedentariness has been connected to obesity, metabolic syndrome, cardiovascular ailment and diabetes it’s even linked to an earlier death. Now, a new research in the Journal of the National Cancer Institute suggests that sitting is also linked to cancer – not all types, but to colon and endometrial (uterine) cancer. And it is not just because sitting requires us away from doing exercises – even individuals who sit a lot and exercising have an elevated danger for these cancers. This indicates that there is some thing intrinsic about the unhealthiness of sitting apart from lack of physical exercise.

To study this query, the group from University of Regensburg carried out a meta-evaluation of 43 earlier studies, such as above four million folks. The research had all periodically queried the participants on how significantly time they invested sitting – Television-related sitting, occupational sitting, and complete sitting time. More than the years, there had been almost 69,000 cancer cases.

English: A little one watching Tv. (Photo credit score: Wikipedia)

The more a particular person sat, the increased the cancer chance for two varieties of cancer: Endometrial and colon. Sedentariness was linked to a 24% increased threat of colon cancer and a 32% increased chance of establishing endometrial cancer. For every single two-hour boost in total sitting time, the danger of cancer rose 8% for colon cancer and ten% for endometrial cancer (it rose 6% for lung cancer, but the association was just borderline).

On the upside, breast, rectal, ovarian, prostate, abdomen, esophagus, testicular, kidney, and non-Hodgkin lymphoma had been not linked in any way to sitting.

Of course, the famously negative pastime of sitting-although-watching-Tv was associated with the biggest chance: a 54% improved threat of colon cancer and 66% higher chance for endometrial cancer. But it’s very most likely that physique weight plays a part here, given that Tv-viewing is often accompanied by snack foods and soda – and bodyweight is a acknowledged danger issue for particular cancers (much more on this below).

“We identified that Tv viewing was connected with an enhanced risk of cancers of the colon and the endometrium,” says lead author Daniela Schmid. “We additional observed that the outcomes have been independent of physical action, displaying that sedentary habits represents a prospective cancer danger factor distinct from physical inactivity.”

And this final level she makes is the more striking locating – that the connection amongst sitting and cancer was evident regardless of the workout a individual received. In other phrases, even individuals who sat a great deal and exercised had the elevated danger. This means that there is anything intrinsically negative about sitting, apart from lack of workout.

What are the mechanisms that could probably make clear this? Schmid tells me that portion of the connection could definitely be mediated by entire body bodyweight. “Obesity could mediate carcinogenesis via a number of pathways, like insulin resistance…and reduced-grade systemic inflammation,” she says. She adds that in postmenopausal women, excess fat tissue represents the primary source of estrogen obese and obesity are a effectively-identified threat aspects for endometrial cancer

“Moreover,” Schmid adds, “vitamin D deficiency, which far more typically happens in obese folks compared to normal excess weight individuals poses a risk for improvement of colon cancer.”

But there seems to be one thing else going on, because even holding physique bodyweight consistent, there’s even now a website link between sitting and cancer. One possibility might be that lack of motion triggers an inflammatory cascade that contains a rise in the biomarkers C-reactive protein (CRP) and interleukin-6 (IL-6).

“In experimental trials, 14 days of bed rest in youthful volunteers elevated C-reactive protein and pro-inflammatory interleukin six levels,” says Schmid. Animal studies have arrived at comparable results, she adds.

Much more research will be necessary to comprehend why a lack of motion may be connected to cancer development. But at least we know what the remedy is. Exercising a lot more isn’t adequate – you have to punctuate extended intervals of sitting with normal periods of movement.

“Cutting down on Tv viewing and sedentary time is just as important as turning out to be far more energetic,” says Schimd. “For these whose jobs demand them to sit at a desk for most of the day, we advocate breaking up the time spent sitting by incorporating quick bouts of light bodily activity into the everyday program.”

Here are a number of much more ideas:

- Walk over and speak to your colleagues rather than emailing or calling.

How Sitting For Prolonged Periods May possibly Contribute To Certain Cancers