Monthly Archives: March 2017

The incidence of stillbirth hasn’t changed in decades. We need to talk about why

Pregnant mother using laptop computer in bed
‘Learn about the risk factors and what steps might help avoid stillbirth.’ Photograph: Alamy

Six Australian babies will die today.

By the way, six babies died yesterday too, and six more babies will die tomorrow.

Apologies for the depressing start, but even more so, I’m so very sorry for the mothers whose babies will die today, and for all 2,200 Australian families this year that will lose a baby through stillbirth.

8 March is International Women’s Day. There is much to celebrate when it comes to progress for women throughout the world. There is also much to lament, both in relation to what still needs to be done and where the gains we have made risk going backwards.

Why? Stillbirth struggles on two fronts.

One, stillbirth is a thing that happens inside a woman’s body. In a male-dominated world, stillbirth is easily relegated as a private tragedy rather than as a public health matter.

Two, stillbirth is not a cause feminists want to champion. Even though stillbirth is a tragedy for thousands of women each year, most feminists don’t want to talk about the death of a baby inside its mother’s womb. Many feminists get uneasy about anything that gets a bit too close to abortion rights.

So let’s be clear: stillbirth happens to women who want to be mothers, who have chosen to take a baby to term. It has nothing to do with abortion. Many mothers of stillborn babies are pro-choice and would not seek to restrict women’s access to abortion services.

If feminists believe women’s choices should be respected, then there is nothing to fear from recognising a woman’s choice to be a mother. There is everything to gain from demanding that society take seriously a public health problem that devastates six women and their babies a day in Australia.

Let’s consider the experience of a woman who is the mother of a stillborn baby.

She finds out the baby that has been growing, moving and kicking inside her has died. She goes into labour, endures the pain of contractions and delivery, as well as the medical risks involved, and gives birth to a dead baby.

She is on a maternity ward, often a joyful place. For her it is torture.

She probably spends time with her dead baby, most likely takes some pictures, and gives the baby a name. She makes decisions about an autopsy, and chooses between burial and cremation. She takes medication to stop her milk from coming in. She experiences all the physical and hormonal after-effects of birth. She goes home to an empty crib.

She finds a way to tell everyone who saw her belly swell for six, seven, eight or nine months that her baby is dead.

If she is one of the most unfortunate 30% of still-mothers, she will get no answers from an autopsy. There will be no reason or explanation for her baby’s death.

For the rest of her life, she will never quite know how to answer the simplest questions: how many children do you have? Didn’t you ever want to try for a boy? (or a girl?) Have you ever thought of having another baby?

The physical and emotional impact of stillbirth on a woman is enormous, and her loss is great. Meanwhile, society doesn’t seem to pay attention to her experience.

The funding of research into the causes of stillbirth will fall largely to her, her baby’s father, and the thousands of other Australian families and their friends who have known this extraordinary sadness.

Even when the New South Wales government wrongly cremated two stillborn babies – in one case, before an autopsy could be done – it wasn’t enough to get people to pay attention. The then-premier Mike Baird refused a meeting with Stillbirth Foundation after the second such grotesque mistake, even as the organisation was offering to help his government avoid such errors in future.

Even when an economic impact study done by PwC put the economic cost of stillbirth in Australia at $681m over the next five years, it wasn’t enough to evoke new commitments of government or corporate funding for research.

Stillbirth Foundation is the only major body exclusively funding research in Australia. The foundation is only 12 years old and in that time it has raised just over $1m. The funds come largely from families, who desperately wish for answers so that others do not have to endure the same sense of searing loss. Its efforts have produced insights into maternal foetal monitoring, maternal sleep positions, and risk factors, and the foundation provides guidance on steps that might help reduce the risk of stillbirth.

Research can make a difference. For example, research reduced the incidence of sudden unexpected infant deaths, including SIDS, by 80% since 1989.

This International Women’s Day, what can be done?

Email your state and federal MP and tell them this is a public health tragedy Australia needs to address.

Learn about the risk factors and what steps might help avoid stillbirth.

If you know the mother of a stillborn child, reach out, use her baby’s name (or ask it if you don’t know), and ask her how she is going, how often she thinks about her child, if there is some way you could help honour her baby’s life.

Elevate the experience of women, demand that society pays attention, and support women who have suffered a great loss. This International Women’s Day, what could be a more feminist thing to do?

Kristina Keneally is the mother of three children, two teenage boys and a stillborn baby, Caroline. She is the patron of Stillbirth Foundation Australia.

Navigating Fertility Clinics With a Click

Navigating Fertility Clinics With a Click
By GLENN RIFKINJUNE 11, 2016

 

Photo

Deborah Bialis and Jake Anderson founded FertilityIQ after their own difficulties finding reliable information on doctors and clinics. They have since had a baby boy.

Credit Talia Herman for The New York Times

Jake Anderson and Deborah Bialis of San Francisco planned to start a family not long after their wedding in 2012. But they soon ran into a roadblock: infertility. At 27, Ms. Bialis was told that her prospects for a successful pregnancy were dim because of an earlier medical condition. Not sure where to turn, the couple sought out a fertility doctor to assess their options.

After two years, two doctors and three rounds of unsuccessful fertility treatments costing $75,000, they gave up and decided to try on their own.

“It attacks you emotionally in a way that’s hard to fathom,” Mr. Anderson, 36, said of the experience. “When you think you’ll be a parent someday and then realize it may not happen, it’s a crisis. It can drive a wedge between partners, and emotionally it is pure hell.”

Mr. Anderson was a partner at Sequoia Capital, a Silicon Valley venture capital firm, and Ms. Bialis worked for a start-up called Rise, a mobile nutrition app. Their personal experience led them to leave their jobs and start FertilityIQ, a website aimed at assessing fertility doctors and clinics.

They saw an opportunity because “we realized there was no accountability on the clinic level,” Ms. Bialis, now 30, said. “There was so much miscommunication.”

More than seven million women sought treatment for infertility from 2006 through 2010, according to a survey by the Centers for Disease Control and Prevention. The American fertility market, including treatments and drugs, is estimated to be $3 billion to $4 billion, and growing at 4 percent a year, according to Harris Williams, an investment bank. As women wait longer to begin having children, those numbers have risen. Fertility is tied to a woman’s age, and by the mid-30s, her ability to become pregnant declines considerably.

Many fertility patients need more than one treatment cycle. Each cycle costs $14,000 to $17,000, with three generally needed. Adding those to other treatments, the total cost comes to an average of $66,000, depending on where the patient lives, a recent article in The Journal of the American Medical Association reported.
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Mr. Anderson and Ms. Bialis found that the most common methods of finding a fertility doctor or clinic was word of mouth, a referral from an obstetrician/gynecologist, or cold-calling one of hundreds of fertility clinics around the country. Fertility patients are highly likely to leave their first doctor, frustrated by a lack of chemistry and emotional support, they said.

“I call this silent suffering,” said Dr. Alice Domar, a psychologist and director of integrative care at Boston IVF, a fertility clinic with more than 20 locations in New England. “It has to do with sex and female parts, and people don’t talk about it. It’s a huge industry, but very few things are offered to patients that address the emotional aspects of infertility.”

FertilityIQ, which went online this year, provides extensive assessments of doctors, clinics and treatment protocols from patients who fill in detailed questionnaires about their experiences.

For couples trying to make one of the most important and expensive decisions of their lives, useful data has been sparse. Dr. Christo Zouves, a San Francisco infertility doctor, said FertilityIQ had “information that nobody has ever really collected before.” Because of the expense, time commitment and emotional stress involved, “You can’t really afford not to have all your ducks in a row before you initiate that first cycle.”

Though most applaud FertilityIQ’s efforts, some in the field are skeptical of a website that offers reviews of doctors and clinics in a manner that some have compared to Yelp. As with Yelp, the reviews are subjective and may reflect individual biases that create a skewed portrait.

“I would not want to choose my doctor based on a website,” said Dr. Michael M. Alper, medical director of Boston IVF and an associate professor of obstetrics and gynecology at Harvard Medical School. “If a relative needed cardiac surgery, would you go to a website and choose? It could be very misleading.”

Dr. Alper, who has practiced infertility medicine for 30 years, noted that web surveys could provide inaccurate assessments, and that FertilityIQ, being so new, is relying on limited responses for individual doctors. Many of the doctors listed on the site have scores based on just one or two patient reviews.

“If you look through history, doctors and IVF centers have equated quality with pregnancy statistics,” Dr. Alper said. “Whoever had the highest numbers had the best quality. But the problem is, you can control your statistics by how you treat and who you treat.” Patients with complex problems may be turned away, and the best doctors who take on the tougher cases will have more failed attempts and generate lower ratings, he said.

Mr. Anderson is aware of such concerns and acknowledges that the site is a work in progress. But it has already evaluated more than 80 percent of all American fertility doctors and includes assessments from 5,000 verified fertility patients, meaning they have produced a bill to authenticate their treatment, he said. Tens of thousands of patients have visited the website, he added.

The website has been an important resource for Christine Turner, an executive director at Stella & Dot, a jewelry and accessory company. Married at 34, Ms. Turner and her husband tried to conceive right away and ran into fertility problems. Then living in Atlanta, they went to a clinic recommended by her obstetrician/gynecologist and met with a doctor with whom she did not feel comfortable. The couple spent $40,000 on two unsuccessful IVF cycles.

Now living in Houston, Ms. Turner went to the FertilityIQ website, created an account and began to search for a clinic that would match her needs. Through FertilityIQ, she found a doctor at a clinic in Colorado and was able to confirm through evaluations “who had the best bedside manner and who would be best for me,” she said.

“If I’m going to be spending that much money, I want to really make sure I’m putting the money in the right place and into the hands of the right clinic and doctor,” she said. She called FertilityIQ “invaluable and game-changing” because it connected her to a community of people she might not otherwise know about.

Though he applauds the effort, Dr. Alper warned that until the sampling numbers were far higher, “people will end up choosing centers for the wrong reasons.”

For now, the website is free. As FertilityIQ grows, eventually people will pay a fee for access to the data, but those who share their own data will become part of the community and retain free access, Mr. Anderson said. The site is free of advertising to avoid conflicts of interest.

The start-up is self-financed, and Mr. Anderson and Ms. Bialis have turned away potential investors. Mr. Anderson said he was in no hurry to monetize the site. He pointed to hugely successful Sequoia investments like WhatsApp and Instagram, which focused on building a large audience before generating revenue and were later acquired for a combined $20 billion.

Josh Manchester, a venture partner at Foundation Capital in Menlo Park, Calif., favored that approach. “If they are able to create a customer experience where users of the site benefit and go through the fertility process in as smooth and painless a way as possible, it creates high engagement and evangelical customers. That leads to a fast-growing user base.”

“Communities and networks are the most valuable businesses in the world,” Mr. Anderson said. “In the early years, they all build an audience, not revenue. The good ones are rewarded for patience and not trying to monetize early.”

He and Ms. Bialis have already been rewarded for their patience in another way. Their first child, a boy who was conceived naturally, was born at the end of April.

Which fruits are healthier, and in what form?

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Health Check: which fruits are healthier, and in what form?

July 11, 2016 2.45pm AEST

Most of us know eating fruit daily is a great way to try to stay healthy, with the Australian Guide to Healthy Eating encouraging us to eat two serves a day. This is because they are relatively low in energy content and rich in fibre, antioxidants and some phytochemicals that may have beneficial health effects.

Eating fruits regularly helps to prevent major diseases such as heart diseases, certain cancers, diabetes and obesity. It can also improve brain health.

Despite the benefits, less than half of Australians eat enough fruit. To try to make eating fruit easier, get the most nutritionally from what we eat and avoid wastage, it is important to consider the best stage to eat fruits from harvesting to over-ripening.

Australians eating inadequate fruit and vegetables. ABS 2013. Australian Health Survey: Updated Results, 2011–12. ABS cat. no. 4364.0.55.003. Canberra: Australian Bureau of Statistics., Author provided

Fruits vary in nutritional quality

Fruits contain a range of nutrients essential for health, from energy-producing nutrients (mostly carbohydrates with some fat and protein) through to vitamins, minerals and fibre. The amounts of these nutrients vary, however, from one fruit to another.

Predominant sugars vary. In peaches, plums and apricots, there is more glucose than fructose. The opposite is the case in apples and pears. Fruits vary greatly in terms of their glycaemic index and the effect on our blood sugar (glucose).

If we look at vitamin C, relatively high amounts are found in strawberries and citrus fruits compared to bananas, apples, peaches or pears.

Passionfruit contains more phosphorus, an essential mineral used in releasing energy, than papaya. However, the opposite occurs in the case of calcium, the most common mineral in the human body.

According to a recent study, higher consumption of some whole fruits, especially blueberries, grapes and apples, significantly reduced the risk of developing type-2 diabetes. But eating oranges, peaches, plums and apricots had no significant effect. However, this does not mean the latter ones are bad fruits.

Sometimes, combinations of fruits work better than each individual fruit. Mixtures of orange and star fruit juices had higher antioxidant capacity than pure juices.

Even certain stages in fruit maturation showed better health effects. Bioactive compounds are chemicals that occur naturally in fruit and are not technically nutrients but appear to result in health benefits. These are found in higher levels in green (unripened) jujube fruit (red date) than in the ripe fruit.

Green or yellow bananas, does ripeness matter?

Fruit ripening involves a range of complex chemical processes. These cause changes in colour, taste, smell and texture. Generally fruits are more tasty when fully ripened, but this is not always the case. Guava, for example, tends to be more appealing when partially ripe.

We can’t properly digest unripe bananas. Lotte Lohr/Unsplash, CC BY

Unripe fruits typically contain more complex carbohydrates, which can behave like dietary fibre and break down into sugars upon ripening. Unripe bananas contain higher levels of resistant starch (which we cannot digest, but can be a prebiotic acting as a food supply to the microbes in our gut), which is linked to lower risks of bowel cancer. This decreases during the ripening process.

With respect to vitamins and phytochemicals, researchers found the opposite is the case. The level of vitamin C decreases during the early stages of sweet cherry development but increases at the beginning of fruit darkening and accumulation of the pigment anthocyanin. Levels of glucose and fructose, the main sugars found in cherry fruit development, increase during ripening.

However, over-ripening leads to a loss of nutrients following harvest. It’s also linked to fruit darkening, softening and a general loss of sensory acceptability.

Impact of processing

Fruit can be processed by canning, freezing, drying, chopping, mashing, pureeing or juicing. Processing fruits can improve shelf life, but it can also lead to losses in nutrition due to physical damage, long storage, heating and chilling injury.

Usually, minimally processed fresh-cut fruits such as fresh fruit salad have the same nutritional qualities as the individual fruits. However, tinned fruit salad may contain added sugar as syrup and preservatives, which may be a less healthy option.

Eating whole fruit rather than drinking juice appears to be linked to better health. A study that gave participants whole fruit before a meal found it led to people eating less than if they drank juice. Additionally, those eating whole fruit appeared to have a lower risk of developing type 2 diabetes, although other studies suggest juices with added sugar may be the real problem.

Fruit juices can contain a lot of sugar, and some even contain added sugar too. freestocks.org/unsplash, CC BY

It is also likely some processing such as juicing may help increase availability and quicker absorption of the beneficial nutrients in fruit. The benefits of this need to be weighed against the sugar being more available too.

So which to eat?

Nutritional qualities of fruits vary and it is hard to predict which fruit might be best. Generally, the more different types of fruits you can include in your diet, the better. For many fruits, eating fresh at its correct ripening stage may be more beneficial, perhaps more for taste than nutrition.

Overripe fruits may be still good to eat or easily convert into smoothie, juice or used as an ingredient such as in banana bread. Eating an over-ripe fruit such as a banana does not mean that you are putting more sugars into your body as the total amount of carbohydrates in the fruit does not increase after harvesting.

While fruit products (juice, dried or tinned products) that are higher in sugars and also preservatives in some cases are not as good as whole fruit, consuming fruit in this form is better than consuming no fruit at all.

But fruits alone cannot do all the work. It is important to choose foods from all the core food groups within the Australian Guide to Healthy Eating to reap the maximum health benefits of fruits.

 

We’re all at risk from scary medicine side effects, but we have to weigh the risks with the benefits

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We’re all at risk from scary medicine side effects, but we have to weigh the risks with the benefits

September 8, 2016 6.08am AEST

Disclosure statement

Greg Kyle does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond the academic appointment above.

Partners

Queensland University of Technology provides funding as a member of The Conversation AU.

 

Media reports have emerged of psychotic episodes in children brought about by a common asthma medication, Singulair. The Therapeutic Goods Administration (TGA), which approves and monitors drugs in Australia, has apparently received 90 reports of psychiatric events.

So this leads to the question of how drugs are approved, and whether we are all at risk of harmful side effects from the medicines we take.

This issue is more complex than telling everyone about every possible side effect. First, there is no way to predict if an individual will be affected until they try the medication.

Second, to do so would be a scare campaign – as a pharmacist, I can scare anyone off taking anything if I put my mind to it, but that’s not my job. My job is to weigh risk and benefit – and taking any medication is a calculated risk.

How are side effects determined?

The list of side effects on the product information inside your medicine boxes is determined during clinical trials. Patients in the trial are monitored and regularly asked to report all symptoms they experience. At this stage, neither the patient nor the doctor knows if the patient is on the real (active) drug or the placebo.

All the reported symptoms are recorded and hence side-effect lists are developed, even if just one of the patients suffers this particular side effect once, and without knowing if they are in the active or placebo group.

The big thing missing in this recording process is causality – did the drug cause the effect, or was it coincidence?

For rare effects, the study size will probably not be large enough to pick them up. For example, a side effect that occurs in one in a million patients would be detected only about nine times if the entire Australian population (almost 18 million adults in 2015) was split into active and placebo groups for a trial.

So how do we find out about these effects? It happens through “pharmacovigilance”, or watching what happens once the drug is used in the general population. Only then will the rare things be seen. The Singulair® case is an excellent recent example of this – the company says tens of millions of patients have taken the drug (around the world), but the Australian market is much smaller.

The active drug in the medication, montelukast, has been available in Australia since 2000, and on the PBS since 2003. From listing in 2003 to December 2015, just over 2 million prescriptions for it have been dispensed. (Available statistics do not determine number of patients, or show figures from 2000-2003 when it was a private prescription not on the PBS.)

Singulair is an asthma medication in tablet form. from http://www.shutterstock.com

To put the new reports in context, the TGA received 90 reports of psychiatric events in just over 16 years. Out of these 90 reports, 16 were related to the specific event highlighted in the report (suicidal thoughts and depression). So 16 cases in over 2 million prescriptions makes this a truly rare effect.

This is not to make light of the seriousness of these effects for the people involved. Ideally, these effects would not occur. However, expecting such rare events to be included on warnings is not feasible. It was listed, however, on the medication product information.

When are warnings warranted?

To determine if an effect is caused by a drug, the pharmacovigilance experts at the TGA need to filter the “signal” (drug-caused) effects out from the “noise” (same effect occurring in the population without the drug).

A US study showed the rate of non-fatal suicide attempts in ten- to 17-year-olds was 197 per 100,000 people over a five-year study period. Fatal suicide was 6.4 per 100,000. While the same data aren’t available in Australia, we can use the US data as a rough benchmark.

If we assume (albeit unrealistically) the 2.049 million scripts were evenly spread over the 12 years and each patient took the drug continuously for that period (one prescription per month), then the number of prescriptions equates to a low estimate of 14,299 patients. The US suicide study was conducted over five years, so the annual incidence of non-fatal suicide attempts would average 39 people per 100,000 people.

Using data from the media reports, there was approximately one report (16 reports over 16 years) of suicidal ideation or depression per year per 14,229 patients. That’s an incidence of seven per 100,000 people per year, yet the US data show a “background” rate of 39 per 100,000 people per year. Therefore it can be difficult to find this “signal” within the background “noise”.

Drug risks and benefits

The TGA has determined a likely connection between the drug and the psychiatric events, so parents of affected children are asking why they weren’t warned. I answered this earlier – it’s all about risk and benefit. If patients (or their parents) were provided with a list of every side effect, many people would be scared off taking useful medicines.

Unfortunately, the Australian population (generally) does not have sufficient health literacy to be able to put such information into context – look at the anti-vaccination and other scare campaigns. Health professionals are usually time-poor and often do not do the best (or even a good) job explaining the potential side effects to patients.

Patients should be empowered and encouraged to ask questions and discuss risks and benefits with their health-care professionals, about a range of issues, not just medication.

Sometimes an effect is deemed by the TGA to constitute a major risk to the public and a specific warning is attached to product information and even the packaging. These effects pose a significant risk to health and occur with a frequency that warrants such warnings. There are no hard and fast cut-off values. Like most things in the medical world, it’s about judgement and shades of grey.

The information available at the time of prescribing or starting a medicine is often not complete, so the risk-benefit balance is not a certain science. Health professionals must ethically have their patients’ best interests as their primary concern, but when we try a medicine we need to watch carefully to see if it works for that individual.

Yes, some side effects can be scary, but put in the context of the good medicines can do, judgement calls need to be made. People make risk-benefit decisions throughout daily life, such as crossing the road, driving a car and other dangerous daily tasks.

Medical decisions are no different, but people feel less empowered because a product is recommended by an “expert” or they do not have sufficient knowledge to make an informed decision. This is why it’s important for patients to empower themselves by asking questions and making all decisions shared.

 

HRT and sleep quality

Sleep problems are common in older people, and especially during the menopause. I have had many posts over the years on insomnia and how to manage it. (search Ïnsomnia”on my web-site.)
Endocrine. 2016 Aug 11. [Epub ahead of print]

Efficacy of menopausal hormone therapy on sleep quality: systematic review and meta-analysis.

Author information

  • 1Mayo Graduate School, Mayo Clinic, Rochester, MN, USA.
  • 2Center for Sleep Medicine, Mayo Clinic, Rochester, MN, USA.
  • 3Knowledge and Evaluation Research Unit, Mayo Clinic, Rochester, MN, USA.
  • 4Evidence-Based Practice Center, Mayo Clinic, Rochester, MN, USA.
  • 5Mayo Medical Library, Mayo Clinic, Rochester, MN, USA.
  • 6Departments of Surgery and Physiology and Biomedical Engineering, Mayo Clinic, Rochester, MN, USA.
  • 7Knowledge and Evaluation Research Unit, Mayo Clinic, Rochester, MN, USA. murad.mohammad@mayo.edu.
  • 8Evidence-Based Practice Center, Mayo Clinic, Rochester, MN, USA. murad.mohammad@mayo.edu.
  • 9Division of Preventive Medicine, Mayo Clinic, Rochester, MN, USA. murad.mohammad@mayo.edu.

Abstract

Sleep complaints are reported by 40-60 % of menopausal women. Poor sleep is a risk factor for cardiovascular disease, diabetes, and obesity. The effect of menopausal hormone therapy on sleep quality is unclear. A systematic review and meta-analysis were conducted to summarize the efficacy of menopausal hormone therapy on self-reported sleep quality. Electronic databases (PubMed, Scopus, Ovid MEDLINE, EMBASE, EBM Reviews CENTRAL, and PsycInfo) were searched from 2002 to October 2015. Randomized trials assessing the effect of menopausal hormone therapy with a minimum follow up of 8 weeks were included. Titles, abstracts, and full texts were screened independently and in duplicate. Primary outcome included sleep items within a questionnaire, scale or diary. Standardized mean differences across trials were pooled using random-effects models. The search identified 424 articles, from which 42 trials were included. Seven trials at a moderate to high risk of bias enrolling 15,468 women were pooled in meta-analysis. Menopausal hormone therapy improved sleep quality in women who had vasomotor symptoms at baseline [standardized mean difference -0.54 (-0.91 to -0.18), moderate quality evidence]. No difference was noted when women without such symptoms were analyzed separately or combined. Across 31 sleep quality questionnaires, daytime dysfunction was the most evaluated sleep domain

. Menopausal hormone therapy improves sleep in women with concomitant vasomotor symptoms.

Heterogeneity of trials regarding study population, formulations, and sleep scales; limit overall certainty in the evidence. Future menopausal hormone therapy trials should include assessment of self-reported sleep quality using standardized scales and adhere to reporting guidelines.

How do our bodies balance themselves?

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Explainer: how do our bodies balance themselves?

November 16, 2016 6.06am AEDT

Balance is the vital sense that gives much-needed stability to our teetering, upright bodies. Good balance is usually associated with having stable posture, but it also has a lot to do with visual stability.

The importance of the balance system is shown by the vast number of connections it makes with the brain. These connections reveal that the forces of motion we create and encounter in the environment can go on to affect many parts of the brain, including those that control vision, hearing, sleep, digestion, and even learning and memory.

How does balance work?

Every sensory system uses detectors or receptors outside the brain to gather information about the environment. For example, the visual system uses light-sensitive receptors in the retina to detect visible light. The balance system relies on specialised motion-sensitive receptor cells in the inner ear.

While obviously associated with hearing, the inner ear is also the shelter for balance. It has a labyrinthine structure, made up of a series of fluid-filled canals and ducts. Within this labyrinth are five balance receptors that are ideally placed to detect different types of movement. There are three receptors for head rotation, another for horizontal acceleration, and one for vertical acceleration (or gravity).

Each balance receptor is an organ made up of thousands of cells with long hair-like projections. As a result of head movement, these so-called hair cells are excited when their projections are pushed in a particular direction by fluid called endolymph.

Movement of endolymph within the inner ear is complex. When you spin a bowl of water, for instance, the water takes time to “catch up” with the turning bowl. This lag is due to inertia and applies to all fluids, including endolymph.

When the head begins to move, the endolymph initially stays still. This actually translates to a fast relative movement of the endolymph in the opposite direction to the head. This relative movement excites the hair cells that are aligned to detect that particular head movement.

So in an elegant and precise way, endolymph and hair cells work in concert to provide a constant stream of information about head movement to the brain.

The inner ear balance organs are remarkable in their ability to detect head movements both small and large, fast and slow, and in any direction. The brain uses signals from the organs to orchestrate a suite of balance reflexes that control our muscles, right down to our toes!

However these reflexes not only control our muscles of posture but our eye muscles as well. Together, these reflexes underlie our ability to remain upright with stable vision in an ever-changing and ever-moving physical environment.

Why doesn’t our vision bounce up and down when we jog?

Maintaining our upright posture is an obvious job for our exquisitely sensitive and responsive balance system. However, it also has a profound effect on the control of our eye movements. The up-down movement generated when walking or jogging would have a destabilising effect on our vision.

Like footage from a hand-held camera, even a simple jog along a flat path or a smooth road would result in unstable and shaky images. When watching hand-held camera footage, it can be unpleasant and difficult to focus on stationary objects like trees because they are moving too violently.

But what about our eyes? Thankfully, our visual field is remarkably stable when we jog. This is due to a reflex most of us take for granted, called the vestibulo-ocular reflex.

The vestibulo-ocular reflex is one of the fastest and most active reflexes in the human body. It uses head movements detected by the inner ear to generate compensatory eye movements that are equal – but opposite in direction – to head motion. This subconscious, ongoing adjustment of eye position results in a stable visual field, despite significant movement of the head.

https://player.vimeo.com/video/188254998
Video: Infra-red camera tracking of eye movements while jogging in complete darkness. The vestibulo-ocular reflex works by activating extra-ocular muscles to move the eyes to compensate for head movements. The video begins with Alan standing still (rest), then jogging (jog), then standing still again (rest). Although the eye movements don’t appear to be big, they are exquisitely precise.

What happens when balance goes wrong?

For many, the idea of suddenly losing a sense like vision or hearing is terrifying (and rightly so), and a sudden loss of your sense of balance would be similarly catastrophic.

Initially, a debilitating and frightening dizziness would prevent you from completing even simple daily tasks without falling over. The worst symptoms would subside with time as you begin to rely more heavily on other senses such as vision. But even a partial loss of the vestibulo-ocular reflex would mean stopping and standing still every time you wanted to recognise a face or read the price of a grocery item.

The fact that we are almost totally unaware of this elegant reflex is evidence of the superb, undercover work the balance system does for us. It not only allows us to walk without falling over, but also gives us a constant and reliable view of a beautifully changing world

Healthy guts are swarming with bugs, so what do they do?

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Healthy guts are swarming with bugs, so what do they do?

October 11, 2016 6.03am AEDT

Our gut does more than help us digest food; the bacteria that call our intestines home have been implicated in everything from our mental health and sleep, to weight gain and cravings for certain foods. This series examines how far the science has come and whether there’s anything we can do to improve the health of our gut.


The healthy human body is swarming with microorganisms. They inhabit every nook and cranny on the surfaces of our body. But by far the largest collection of microorganisms reside in our gastrointestinal tract – our gut.

What is the human microbiome?

These tiny organisms, which can only be seen with the aid of a microscope, make up our microbiota. The combination of microbiota, the products it makes, and the environment it lives within, is called the microbiome.

The gastrointestinal tract. Christos Georghiou/Shutterstock

Great advances in DNA sequencing technologies have enabled us to study the gut microbiota in intricate detail. We can now take a census of all the microorganisms that are in the microbiota to help us understand what they are doing.

Typically, our gut microbiota consists of several thousand different types of bacteria, as well as other microbes such as viruses and yeasts. Some types will be in abundance, while other types will be rare.

The exact composition of each person’s microbiota is as unique as their finger prints. But unlike finger prints, the microbiota is constantly changing.

Microbes start to colonise our gut and skin the moment we are born. The mode of birth, either natural or by caesarean, determines the sort of microbes a baby first contacts. This can have a profound effect on the early development of the microbial populations that contribute to the microbiota.

Tiny organisms begin to colonise the gut as soon as we’re born. zlikovec/Shutterstock

The structure of the microbiota – that is, what microbes are present and the relative numbers of each type – undergoes significant change from its establishment at birth until it matures in early adolescence.

In healthy adults, changes over time are likely to be small. But major shifts in composition can occur when we radically change our diet or take antibiotics, which are, of course, designed to kill bacteria.

It’s also been found that, like our own body, the composition of our microbiota changes in old age, including a loss of diversity.

Our microbiota is not an accidental, free-loading passenger living in our gut and stealing the nutrients from our food. Over the millennia we have evolved with our microbiota. We now know it can affect many aspects of our biology, from our digestive system to our brain function.

How our bodies develop and function is dictated by our genes. We have approximately 20,000 genes encoded in our genetic material.

The different microbes that make up our microbiota have their own genes. As a rough estimate, the 2,000 different types of microbes may, on average, each carry 3,000 genes. That means the microbiota carries six million genes. Although many will have similar functions, it still indicates the microbiota has a much more complex =genetic complement= than we ourselves have.

This genetic complement of the microbiota means it can do things other parts of the body cannot. Our microbiota provides digestive enzymes to allow us to use food that otherwise we could not digest. It provides essential vitamins we cannot make ourselves. And it interacts with our hormonal and neural systems to help shape our physiology.

Perhaps most important of all, it helps to develop our immune system to fight off bugs. The body must be able to distinguish between the beneficial members of the healthy microbiota and invading pathogenic microorganisms that can cause disease. The immune system has to learn to live with and nurture the microbiota while fighting off pathogens.

Microbiota help develop our immune system. kikovic/Shutterstock

Disruption of the correct interaction between microbiota and the immune system may be one of the causes of the massive increase over the past few decades in immune-related diseases, such as diabetes, food allergies, rheumatoid arthritis, and inflammatory bowel disease.

Many of these diseases seem to be diseases of affluence, probably influenced by poor diets and excessive cleanliness, affecting the early establishment of an appropriate microbiota.

The intimate connection between host and microbiota and the rich contribution that each brings to the partnership has resulted in the concept of a metaorganism. This recognises that as humans, we are really the product of the mutual cooperation between our own bodies and our microbiota.

Indeed, our microbiota is so important and has such specific functions that it’s reasonable to view it as another organ of our body. It’s just as important as our liver or kidneys.