Monthly Archives: May 2018

My cancer is in remission – does this mean I’m cured?

My cancer is in remission – does this mean I’m cured?

So you’ve been through cancer treatment and your doctor has called you in for “some good news”. Satisfied, she tells you your cancer is “in remission.”

What does this mean? Are you cured? Is the cancer gone forever? And what about all those stories you’ve heard of someone who thought they’d “won the battle” – but then their cancer came back?

Detecting cancer

Your cancer is in complete remission when, after treatment, no cancer can be detected. The term “cure” can only be used in hindsight. Commonly, years after the cancer has gone into remission, if it has not returned (or relapsed), it is said to have been cured.

However, a secondary cancer could occur if the same conditions that triggered the first are present.

Read more: Explainer: what is cancer?

When a cancer can no longer be detected, it’s cured only if the treatment has killed every cancer cell. But it’s difficult to know if that’s the case due to our inability to detect small amounts of cancer.

A skilled specialist may be able to feel a breast lump that is half-a-centimetre wide. A plain chest X-ray can be expected to detect cancers from 1cm wide. And a CT scan will detect smaller cancers to a few millimetres.

But a cancer 1cm across on a scan has about 100 million cancer cells; even a 0.5cm cancer has about 10 million cells. A 1mm cancer, which would not show up on scans, has 100,000 cancer cells.

So, even when a cancer can no longer be seen and is no longer causing symptoms, there can still be millions of cells remaining. They can keep growing and eventually the cancer will be large enough to be detected again. That’s when the cancer is said to have relapsed.

We don’t always know if all the cancer cells have been killed. from

Some cancers, like testicular cancer, produce proteins (alpha FP and Beta HCG) that can be measured in blood. Measuring these is more accurate than scans in detecting small amounts of cancer.

Better still, chronic myeloid leukaemia (CML) – a rare form of leukaemia – has a characteristic genetic abnormality, which a very sensitive blood test can detect. This is helpful in determining whether a treatment has eradicated microscopic disease. The holy grail would be to develop such sensitive blood tests for every cancer.

Read more: A new blood test can detect eight different cancers in their early stages

Additional therapies

Because we can’t tell whether remission means cure for most cancers, treatment strategies have been devised to increase the likelihood of cure. If a cancer is being treated with chemotherapy and becomes undetectable, further courses will be given to continue to reduce the remaining microscopic disease.

Some cancers, like breast and bowel cancer, where there is no visible disease after surgery, are given additional treatment in case some cells are still present near the operation site or have spread more widely through the bloodstream. Radiotherapy is given after the cancer has been removed by surgery to kill any remaining cells in the breast.

When it comes to brain cancer, it’s difficult to know if it has been completely cleared. The extent of surgery is limited because of the damage to normal tissues and function, and we don’t have very effective therapies to follow up the surgery. This is why it’s so difficult to cure.

Read more: Three charts on: brain cancer in Australia

Chemotherapy, hormone therapy (for breast cancer) or both are given to kill any cells that might have escaped to more distant sites. Although we can’t see the cancer shrinking with the additional (adjunct) treatment, we know from trials comparing patients who receive additional treatment with those who do not that the additional treatment results in more patients being cured.

Chemotherapy, hormone therapy or both are given to kill any cells that might have escaped to more distant sites. from

It is common to use multiple types of treatment – surgery, radiotherapy or drug therapy – to improve the chances of a cure.

Chemotherapy may not be able to kill all of a cancer because it kills cells only when they are dividing, which means resting cells escape. Only a percentage of cells are dividing at any one time. In cancer that percentage is higher than in most normal tissues, so cancer suffers more damage than normal tissues with chemotherapy. Multiple doses might catch the resting cells when they begin to divide.

Another problem is that, after initially shrinking some of the cancer, some cells are found to be resistant, or become resistant, to the chemotherapy and are left untreated. Drug combinations are given as cells resistant to one drug might be susceptible to another.

Read more: Explainer: what is chemotherapy and how does it work?

Five-year outcomes

It’s common when reporting cancer outcomes to compare the five-year survival rate, which is the percentage of patients who survive five years after diagnosis. Five years is a convenient interval at which everyone can collect statistics so comparisons can be made between cancers – or the outcomes of cancers between treatment centres, states or countries.

As it happens, with many cancers in remission, to have survived five years does mean they are probably cured. But there are differences for different cancer types.

A person diagnosed with an aggressive lymphoma whose cancer achieves remission is most likely to have been cured if the cancer has not returned in two years. This is because any residual lymphoma would be expected to regrow rapidly.

The opposite is the case for breast cancer. Although the chance of relapse after complete remission is greatest in the first two years and becomes smaller over time, and the five-year survival rate is 90%, relapses have been recorded up to 20 years later.

It is important to note, though, that survival rates have greatly improved over time and are always improving. In the 1970s, only one cancer patient in three made it through the first five years after diagnosis. Today, this figure is around 70%, and exceeds 85% for some cancers that were previously fatal.

So, remission might mean cure but we only know that over time.

Clearing Up the Confusion About Salt


Credit Paul Rogers

If you’re confused about salt, I’m not surprised. There’s been a steady back-and-forth on claims that reducing dietary sodium (which represents 40 percent of the salt molecule) is crucial to our well-being, countered by claims that following this advice can sometimes be a health hazard.

While some studies have concluded that only people with hypertension on high-salt diets need to reduce salt intake, the overwhelming strength of scientific findings bolsters advice from major health organizations that most Americans should cut back on sodium for the sake of their health. Excess sodium is responsible for most cases of hypertension in Western societies, and hypertension is a leading risk factor for heart attacks, strokes and kidney failure.

Because salt added to our foods by processors and restaurants, not that from our saltshakers, is the main source of sodium in our diets, protecting the health of the most vulnerable requires a society-wide reduction in sodium.

The recommended daily intake for healthy American adults — 2,300 milligrams of sodium a day, or the amount in about 1⅛ teaspoons of salt — will be reflected in the new nutrition facts label, scheduled to take effect, depending on the size of the companies, beginning in mid-2018 until January 2021. Currently, the average American consumes more than 3,400 milligrams a day, an amount often found in a single restaurant meal. A lunch of soup and a sandwich can easily add up to a day’s worth of sodium.

Seventy-five countries, including the United States, have adopted or advocated salt-lowering goals, and wherever this is happening, rates of hypertension and deaths from cardiovascular disease are declining.

To be sure, sodium is an essential nutrient, as is chloride that makes up the rest of the salt molecule. We evolved from ocean-dwellers, and human tissues still swim in a salty sea.

Our kidneys are fine-tuned machines for keeping blood levels of sodium within a physiologically healthy range; when there’s too much sodium on board, the kidneys dump it into urine for excretion, and when more is needed, they reabsorb it from urine and pump it back into the blood.

Unfortunately, faced with a chronic excess of sodium to deal with, the kidneys can get worn out; sodium levels in the blood then rise along with water needed to dilute it, resulting in increased pressure on blood vessels and excess fluid surrounding body tissues (read, swelling).

So why, you may wonder, is there any controversy? Shabby science, resulting in claims that is it unsafe to reduce sodium intake below 1,500 milligrams a day, is one reason, according to Bonnie Liebman, director of nutrition at the Center for Science in the Public Interest, a health advocacy organization in Washington, D.C.

“Very few people consume so little sodium, and most of those who do are sick to begin with, so they eat less and consume less sodium,” she explained. “It’s a phony issue.”

But when a study is published that runs counter to prevailing beliefs, it tends to get undue media coverage. “The media like ‘man bites dog’ stories, and studies with surprising results make headlines,” Ms. Liebman said.Sign Up

In 2015 New York City pioneered a requirement that chain restaurants place a high-salt warning — a saltshaker icon — next to menu items that contain 2,300 milligrams or more of sodium in a serving. Even some fast-food salads can exceed that amount. The ruling recently withstood a court challenge by the National Restaurant Association.

Six years earlier, the city created a National Salt Reduction Initiative, which now has more than 500 partners, including some food companies and restaurant chains, that seeks to lower sodium levels for restaurant-prepared and processed foods.

A nationwide sample of 172,042 households revealed that between 2000 and 2014 the amount of sodium from packaged foods and drinks purchased declined by 396 milligrams a day on average per person, although most households still exceeded recommended amounts.

Hats off to a companies like General Mills, which lowered sodium in 10 categories of foods and snacks by 18 percent to 35 percent by the end of 2015. Kudos as well to companies like Pepperidge Farm, Sara Lee and Oroweat, which market whole grain breads with no more than 140 milligrams of sodium in each slice, and thus qualify for a low-sodium claim on the label. Years earlier, General Mills test-marketed reduced-sodium Wheaties, a company staple, and it fizzled. The company later simply lowered the sodium content of this top-selling cereal without ballyhooing the change, and sales stayed the same.

“Consumers are sometimes wary of low-sodium products, thinking they will lack flavor,” Ms. Liebman observed. But when sodium is reduced gradually and without fanfare, they hardly notice it.

That, in fact, is the key to cutting back on salt generally: do it a little at a time to give taste buds a chance to adjust. While I still like some salt, highly salted foods I once enjoyed, like corned beef, cured olives and smoked fish, are now unpleasantly salty to me.

A culinary trick worth trying is to prepare foods without adding salt, then sprinkle some on at serving time. You’ll get a bigger bang for that salt buck while consuming less sodium. Some producers of chips rely on this tactic — consumers taste only the salt on the surface, which to my taste is more than enough on chips labeled “low sodium.”35Comments

Likewise, when buying canned or packaged soups, select ones labeled low-sodium and, if desired, add some salt at the table. Better yet, enhance the flavors of low-sodium soups with herbs, peppers, garlic and other salt-free seasonings. Also helpful, for reasons beyond sodium reduction, is to eat more fruits and fresh vegetables. They are naturally low in sodium and many are high in potassium, which helps to lower blood pressure.

Often, most of the salt in a restaurant dish comes from the sauce or dressing; ask for it served on the side and use only a small amount on the food. For dishes cooked to order, ask for them prepared without salt; you can always add some at the table, if desired

DHEA vaginal suppository good alternative to estrogen creams

January 5, 2016 / 3:15 PM / 2 years ago

DHEA vaginal suppository good alternative to estrogen creams

(Reuters Health) – A vaginal suppository containing the hormone known as DHEA is a good alternative to estrogen for treating vaginal issues related to menopause, according to a new trial.

Pain during sex and vaginal dryness improved more in postmenopausal women taking the daily suppositories than in women using placebos, researchers report. Gynecologists said the overall vaginal health of those taking the suppositories improved more, too.

The new ovule-shaped suppositories are as good as estrogen creams applied inside the vagina, said Dr. Fernand Labrie, who led the trial for EndoCeutics Inc in Quebec, Canada.

Before menopause, estrogen produced by the ovaries keeps the vaginal lining healthy. With menopause, the ovaries stop working, and the vaginal lining becomes thinner, dryer and less elastic. The loss of estrogen and effects on the vagina may cause other complications, such as pain during sex.

Estrogen cream can be prescribed to replace the hormones, but that may not be an option or choice for some women, according to Dr. James Woods, who is past chair of the Department of Obstetrics and Gynecology at the University of Rochester School of Medicine in New York.

For example, breast cancer is sometimes driven by estrogen, and women with those cancers take drugs to block their body from making the hormone. They also can’t risk increasing the amount of estrogen circulating in their bodies.

“For people who can’t take estrogen into their system, this is a huge advantage for them, because it brings them back to more of a normal life,” said Woods, who was not involved with the new trial.

DHEA – or dehydroepiandrosterone – is a hormone that can be transformed into male and female sex hormones. It’s thought that when DHEA is delivered directly to the vagina, the nearby tissue convert it to the estrogen known as estradiol without raising levels of the hormone in the rest of the body.

“This has been such a positive contribution for the breast cancer patients,” said Woods, who added that doctors currently prescribe a compounded DHEA cream to patients.

Compounded creams, however, must be made-to-order at special pharmacies. The suppositories tested in the study, if approved by the U.S. Food and Drug Administration, would be commercially available with a prescription.

For the new study, the researchers assigned 325 postmenopausal women to take a 0.5 percent DHEA suppository daily for 12 weeks. Another 125 were assigned to take a placebo, with inactive ingredients. All women answered questionnaires and were examined throughout the study period.

Overall, women taking the daily DHEA suppository improved more than the placebo group on measures of dryness and thinning of the vaginal lining, the researchers reported in Menopause: The Journal of The North American Menopause Society.

The women using DHEA also reported a significantly larger decrease in pain during sex, compared to women taking the placebo.

Woods said the findings did not surprise him since the percentage of DHEA in the suppository is the same as what is used in compounded creams.

The only side effect was reported by six percent of women, who said they had vaginal discharge from the suppository dissolving.

The question, Woods said, is how the compounded cream and the suppository will differ in terms of cost, if and when the FDA approves it.

SOURCE: Menopause: The Journal of The North American Menopause Society, online January 5, 2016.

Efficacy of Transdermal Estradiol and Micronized Progesterone in the Prevention of Depressive Symptoms in the Menopause

Original Investigation
February 2018

Efficacy of Transdermal Estradiol and Micronized Progesterone in the Prevention of Depressive Symptoms in the Menopause Transition. A Randomized Clinical Trial

Author Affiliations

  • 1Department of Psychology, University of Regina, Regina, Saskatchewan, Canada
  • 2Department of Psychiatry, University of North Carolina at Chapel Hill
  • 3Section on Behavioral Endocrinology, National Institute of Mental Health, Department of Health and Human Services, Bethesda, Maryland
JAMA Psychiatry. 2018;75(2):149-157. doi:10.1001/jamapsychiatry.2017.3998

Question  Is 12 months of transdermal estradiol and intermittent micronized progesterone more effective than placebo in preventing the development of depressive symptoms in the menopause transition and early postmenopausal period?

Findings  In this randomized clinical trial that included 172 perimenopausal and early postmenopausal women, 32.3% of women receiving placebo developed clinically significant depressive symptoms, while 17.3% of women taking transdermal estradiol and intermittent micronized progesterone did so.

Meaning  If confirmed in future research, clinicians may consider prescribing hormone therapy to mitigate the increased risk of clinically significant depressive symptoms that accompany the menopause transition and early postmenopausal period.

Importance  The menopause transition and early postmenopausal period are associated with a 2- to 4-fold increased risk for clinically significant depressive symptoms. Although a few studies suggest that hormone therapy can effectively manage existing depression during this time, to our knowledge, there have been no studies testing whether hormone therapy can prevent the onset of perimenopausal and early postmenopausal depressive symptoms.

Objective  To examine the efficacy of transdermal estradiol plus intermittent micronized progesterone (TE+IMP) in preventing depressive symptom onset among initially euthymic perimenopausal and early postmenopausal women. A secondary aim was to identify baseline characteristics predicting TE+IMP’s beneficial mood effects.

Design, Setting, and Participants  Double-blind, placebo-controlled randomized trial at the University of North Carolina at Chapel Hill from October 2010 to February 2016. Participants included euthymic perimenopausal and early postmenopausal women from the community, aged 45 to 60 years.

Interventions  Transdermal estradiol (0.1 mg/d) or transdermal placebo for 12 months. Oral micronized progesterone (200 mg/d for 12 days) was also given every 3 months to women receiving active TE, and identical placebo pills were given to women receiving placebo.

Main Outcome Measures  Scores on the Center for Epidemiological Studies–Depression Scale (CES-D), assessed at baseline and months 1, 2, 4, 6, 8, 10, and 12 after randomization, and the incidence of clinically significant depressive symptoms, defined as a CES-D score of at least 16.

Results  Of 172 participants, 130 were white (76%), and 70 were African American (19%), with a mean household income of $50 000 to $79 999. The mean age was 51 years, and 43 developed clinically significant depressive symptoms. Women assigned to placebo were more likely than those assigned to TE+IMP to score at least 16 on the CES-D at least once during the intervention phase (32.3% vs 17.3%; odds ratio [OR], 2.5; 95% CI, 1.1-5.7; P = .03) and had a higher mean CES-D score across the intervention period (P = .03). Baseline reproductive stage moderated the effect of treatment (β, −1.97; SEM, 0.80; P for the interaction = .03) such that mood benefits of TE+IMP vs placebo were evident among women in the early menopause transition (β, −4.2; SEM, 1.2; P < .001) but not the late menopause transition (β, −0.9; SEM, 0.3; P = .23) or among postmenopausal women (β, −0.3; SEM, 1.1; P = .92). Stressful life events in the 6 months preceding enrollment also moderated the effect of treatment on mean CES-D score such that the mood benefits of TE+IMP increased with a greater number of events (β, 1.22; SEM, 0.40; P = .003). Baseline estradiol levels, baseline vasomotor symptoms, history of depression, and history of abuse did not moderate treatment effects.

Conclusions  Twelve months of TE+IMP were more effective than placebo in preventing the development of clinically significant depressive symptoms among initially euthymic perimenopausal and early postmenopausal women.

Laugh a little.

Surgery isn’t the only option for prostate cancer yet many men aren’t offered others

Surgery isn’t the only option for prostate cancer yet many men aren’t offered others

August 22, 2017 5.19am AEST

Australian men with a recent diagnosis of prostate cancer that require active treatment, as opposed to careful monitoring, are often not given all the options available to them.

This means not all men are getting the necessary information and support to make a decision on what treatment is best. A growing body of evidence and treatment guidelines support the fact that less invasive radiation therapy is equally effective in curing or controlling cancer as surgical removal of the prostate, known as radical prostatectomy.

Read more: How’s your walnut, mate? Men rarely talk about their enlarged prostate

While all patients see a urologist – the specialist surgeon who does the biopsies and gives the diagnosis – they only see a radiation oncologist if the urologist or GP refers the man on. In this way, the urologist is the gatekeeper to men receiving optimal (or sub-optimal) care. The fear of cancer and a natural emotional response to get it out may lead to a less than fully-informed decision for surgery, and to possible regret of this decision later on.

Bias in medicine is a reality, and it is not surprising doctors favour familiar treatments. But it is problematic when bias creates a hurdle to men getting accurate, balanced information. There is plenty of evidence men aren’t getting the chance to hear about their radiation therapy options. A recent US study found that men seeing both a radiation oncologist and urologist were six times more likely to choose radiation therapy compared with men seeing only a urologist.

In Australia, the proportion of men receiving radiation is much lower than research on effectiveness of radiation therapy would predict if men with prostate cancer were exhibiting truly informed choice. Meanwhile, prostate surgery rates are higher and continue to rise, especially in the case of robotic surgery.

Prostate Cancer Foundation of Australia.

The gold standard of care

The gold standard of care for prostate cancer begins with the patient and his support person talking with the experts – the surgeon (urologist), a radiation oncologist and a specialist nurse. In doing so, the man is provided with the relevant information and impartial advice he needs to make an informed decision about his preferred treatment.

Virtually all specialist doctors who treat cancer profess to be part of a multi-disciplinary team, that includes surgeons, medical and radiation oncologists and other experts, and attend meetings where the relevant health professionals discuss patient “cases” to decide on management. These team meetings are valuable, but they are only one aspect of a high quality service. Meetings do not include the patient, the man with prostate cancer, who is integral to the decision-making process.

The multi-disciplinary team model has been successful in the treatment of breast cancer. There is nearly always more than one good treatment option available for men with prostate cancer, sometimes several. For men with low risk cancers, many may not require active treatment up front (or ever) and are appropriately managed by active surveillance or careful monitoring.

Read more: Latest research shows surgery for early stage prostate cancer doesn’t save lives

But other men with prostate cancer require active treatment to reduce the chance of dying, or suffering symptoms, from cancer. Alternative treatment pathways are very different for the individuals involved, in terms of patient experience, potential side-effects, the need for additional treatments, and potential out-of-pockets costs. This is why the man with prostate cancer has to be the most important member of the team who decides on the treatment.

Putting the patient at the centre

Only the patient can weigh up the trade-off between the risk of bowel problems (with radiation therapy) and the risk of urinary incontinence (with surgery). Likewise, the choice between attending the cancer centre for radiation treatment every weekday over several weeks versus hospitalisation and time off work for recovery after surgery. There are many other pros and cons that may sway a man to prefer one approach over another.

As already mentioned, the ideal model for decision-making for prostate cancer treatment is that the man has a consultation with a urologist and a radiation oncologist. As the two types of prostate cancer specialists have distinct expertise in different areas, seeing both is the only way men can get complete, up-to-date information.

The man can then consider his options and discuss these with his family and GP if he wishes. The good news is that men can take time to do this, as most prostate cancers are relatively slow-growing.

In the United Kingdom, Canada, and select centres including some in Australia, prostate cancer teams do place the man at the centre of decision-making. But this must become the rule rather than the exception and Australian men should be strongly encouraged and assisted to see all experts.

Ultimately, men need to be empowered in their decision-making through being part of a process that enables and supports them in making fully informed choices. Until then, men who require active prostate cancer treatment need to insist on seeing all the specialists in the area, including a radiation oncologist.

Myths about palliative care.

Five common myths about palliative care and what the science really says

This article is part of our series on demystifying palliative care, where experts explain the process of end-of-life care in Australia.

We may have heard it said, and in that curiously familiar tone, something along the lines of: “They’re having palliative care now.” And it’s almost as if the meaning of those words is so universally understood they need no further explanation. Most people simply assume they mean the person is now dying.

Yet, when a health professional suggests “palliative care” might be a useful addition to a patient’s care, they most likely mean something different.

So what is it the patient actually takes from the suggestion? We asked this question of people being treated for cancer in hospital, as well as their families. We wanted to explore people’s initial perceptions of palliative care when this term, or suggestion, was first raised with them in a clinical setting.

We found people held narrow, often inaccurate and outdated understandings of palliative care. Below are some of the common beliefs about palliative care, and what the science actually says.

Myth 1. It’s just nursing care

From its inception, palliative care has definitely always involved nurses. But by today’s standard there is much more to it than, for example, a nurse assisting a person with showering.

Palliative care is delivered by a multidisciplinary team of experts, such as social workers, counsellors, nurses and volunteers, who are trained to respond to the needs of people with serious illness.

For most patients, this will include consultation with a specialist palliative care doctor who has undergone additional medical training to become an expert in managing and treating the concerns that commonly arise from serious illness.

Palliative care has always involved nursing care, but it’s evolved to be a lot more than that. from

Myth 2. It’s just about pain relief

Palliative care is often called on to provide expert advice on optimal pain relief. But, just as frequently, palliative care is there to help manage symptoms other than pain that result from a serious illness or its treatment.

For example, a palliative care specialist has particular experience with medications and strategies that may help with problems such as nausea, breathlessness or constipation – which, left unattended, may reduce a person’s quality of life.

Read more: What is palliative care? A patient’s journey through the system

Myth 3. It’s a place to wait for death

Palliative care does provide care for those at the end of life who may prefer to receive care or have needs best attended to in hospital or at a hospice. However, it is not just about end-of-life care.

Palliative care is available at any stage of serious illness. Palliative care can be helpful and is recommended early in an illness to work alongside other medical teams to diagnose and treat the cause of symptoms, manage medications, help with communication or decision-making about treatment options, or provide family support.

Palliative care is not just about end-of-life care. Yevgeniy Gradov/Unsplash, CC BY

Myth 4. Palliative care services are offered only in the hospital

Palliative care does provide support to people in the hospital, but just as frequently palliative care services in the community provide care to people in their own homes.

Additionally, just as a person with heart disease may go to a clinic at the hospital to see a cardiologist, people with serious illness can attend an appointment to see a palliative care specialist.

Read more: Governments must ensure palliative care is available to all who need it

Myth 5. It means depending on others for care

The principal goal of palliative care is actually the opposite of dependency. It aims to support a person to maintain their independence and quality of life while living with serious illness.

This may mean providing equipment or strategies that may be needed to ensure a person can continue to live their life to the fullest.

The aim of palliative care is to help the person maintain independence. Lukas Budimaier/Unsplash, CC BY

What does the science say?

There are now over ten high-quality, randomised clinical (human) trials, conducted internationally, that demonstrate the benefits of accessing palliative care if faced with serious illness.

Read more: Randomised control trials – what makes them the gold standard in medical research?

These studies, mostly conducted with people recently diagnosed with a serious cancer, compare the outcomes of people randomly allocated to receive either just best-practice cancer care or best-practice cancer care with palliative care.

Collectively, this science shows that people with a serious cancer who access palliative care soon after their diagnosis, alongside their recommended cancer treatments, have better outcomes.

They report feeling better, with fewer symptoms associated with their cancer and its treatment, improved mood and better quality of life. There is also growing evidence to show the people receiving palliative care live longer.

So, next time we hear a friend is receiving palliative care, we should also remember the science and think of the possibilities, accomplishments and high-quality care they may receive.

Ten facts you need to know about the chicken and eggs on your table


Ten facts you need to know about the chicken and eggs on your table

July 27, 2016 5.52am AEST

Disclosure statement

Sonia Yun Liu receives funding from Rural Industries Recent and Development Corporation.


University of Sydney provides funding as a member of The Conversation AU.


When I am asked by friends what I do for living, I tend to raise eyebrows because my job is somewhat odd to many city people. That’s because I’m a poultry nutritionist.

Typically, the conversation turns into a friendly debate on the myths around eating chicken. Do we feed chicken hormones? Are any chickens genetically engineered? Do free range chickens taste better? And so on.

So to save everyone some time, here are some of the most common questions I get asked, and the answers I give.

1) Should you buy hormone-free chicken?

The truth is that no chickens or eggs produced in Australia contain added hormones, and they have not been given hormones for decades.

Independent tests by the Department of Agriculture, Fisheries and Forestry, as part of the National Residue Survey, confirm that Australian chicken meat is free of added hormones.

Not that it would be easy to give them hormones anyway. Growth hormones are proteins similar to insulin used to treat diabetes.

Like insulin, they can only be injected into the body because they are broken down in the digestive tract. Therefore, it is pointless to provide chickens growth hormones in their food because they would be rendered ineffective.

And given a typical commercial shed may accommodate 40,000 to 60,000 birds per shed, it is simply logistically impossible to inject hormones into each chicken.

2) Are meat chickens genetically modified to grow fast?

Our chickens are not genetically modified, and their genes have not been altered artificially. Modern meat chickens grow more quickly and are more “meaty” than chicken breeds available decades ago due to selective breeding and optimal nutrition.

Just like pedigree dog breeders breed their puppies for desired traits, selective breeding involves those animals that show the desirable characteristics being selected as the parents for the next generation in the breeding program, and this process being repeated over many generations.

In the 1960s, the goal of selective breeding in meat chickens was simply increased growth rate and increased meat production. Nowadays, the focus has changed from growth and yield to a broad spectrum of outcomes, with a clear emphasis on improving animal welfare, reproduction and overall fitness.

3) Are meat chickens raised in cages?

All commercial meat chickens are kept in large poultry sheds on litter floors, covered with things like rice hulls or wood shavings. They are not kept in cages.

Additionally, some meat chickens also have access to the outdoors, such as those often referred to as either free-range or organic. A simple comparison is shown below.

4) Are free range chickens healthier?

Not always. In fact, free range chickens are more likely to catch diseases, get injured and die earlier than those kept inside.

In the UK, free range egg layers have a mortality rate of 8-10%, which is far higher than caged hens’ death rate of 2-4%.

The contact between free range chickens and wild birds also increases the risk of spreading bird flu. And birds can die from over-consuming grass.

Cannibalism can also happen in egg layers and it is a big challenge for free range egg production systems in particular.

We always assume animals behave in a civilised manner. But the fact is free range layer hens may peck each other to death. Cannibalism in poultry is part of their natural behaviour and, unfortunately, it has proven difficult to get rid of.

5) Do free range or organic chickens taste better?

There is very little data supporting the idea that free range or organic chickens actually taste better than conventionally farmed ones.

Commercial meat chickens do not tend to like running around, as they were selected to maximise their growth. So it’s a myth that more exercise makes chicken meat more tender.

Is it organic? Does it matter? Shutterstock

6) Why are some meat chickens yellow in colour?

In some cultures, chickens with yellow fat and skin are considered to be better quality. However, this is not true.

The yellowness of the skin, fat and egg yolk depends on the level of beta carotene in the diets. So those yellow chickens are fed with a corn-based diet, which is higher in beta carotene.

7) Are meat and egg laying chickens the same breed?

The meat and egg industries have different requirements, and use different breeds of bird.

The only eggs produced in the meat industry are those needed to produce the next generation of chickens.

Ross and Cobb birds are the two common commercial breeds selected for meat production.

The egg industry houses their hens quite differently and uses very different breeds of chickens, which are bred selectively over many generations to exhibit optimal egg producing characteristics.

The common breeds of laying hens in Australia are the Hyline Brown and the Isa Brown.

8) Why are some eggs white and others brown?

The colour of eggshells is the result of pigments being deposited during egg formation. The type of pigment depends upon the breed and is genetically determined.

To get a hint about the egg colour, look at the colour of the chicken’s ear lobes!

Interestingly, people have strong preferences for different egg shell colours in different markets. In Australia and parts of Asia, brown eggs are preferred, whereas in the US and Japan, people prefer white eggs.

The nutritional value of the egg only depends on the chickens’ diet, not the system of production or the colour of the egg shell.

For example, it has been shown that vitamin D-enhanced eggs can be produced if the diet is supplemented with high level of an active form of vitamin D.

9) What types of chickens do restaurants use?

It is often difficult to tell.

Fast food chains are more likely to use chickens produced conventionally unless specially labelled. Restaurants vary in the chickens they use. If you prefer a particular type of chicken, be sure to ask before you order.

10) Does Australia import chickens from elsewhere?

All the raw chicken meat available in Australia is grown in Australia.

According to Australian Chicken Meat Federation, we consumed 45.3kg of chicken meat per person in 2015, which means 870 grams of chicken meat per week.

Last year, more than 1.1 million tonnes of chicken meat was produced in Australia and almost all of it was consumed here.

The claim “produced in Australia” is applicable to almost all chicken meat sold in Australia with only very small quantities of cooked chicken meat being imported from New Zealand and some canned products containing chicken also potentially imported.

Sonia will be online for an Author Q&A between 1:30 and 2:30 on Wednesday, 27 July, 2016. Post any questions you have in the comments below.

NOTE: The word “happier” was removed from question number 4 as the answer focuses exclusively on the health of the chickens.

How we can protect our brains from memory loss and dementia

What is ‘cognitive reserve’? How we can protect our brains from memory loss and dementia

June 23, 2017 12.46pm AEST

As we get older we have a greater risk of developing impairments in areas of cognitive function – such as memory, reasoning and verbal ability. We also have a greater risk of dementia, which is what we call cognitive decline that interferes with daily life. The trajectory of this cognitive decline can vary considerably from one person to the next.

Despite these varying trajectories, one thing is for sure: even cognitively normal people experience pathological changes in their brain, including degeneration and atrophy, as they age. By the time a person reaches the age of 70 to 80, these changes closely resemble those seen in the brains of people with Alzheimer’s Disease.

Even so, many people are able to function normally in the presence of significant brain damage and pathology. So why do some experience symptoms of Alzheimer’s and dementia, while others remain sharp of mind?

It comes down to something called cognitive reserve. This is a concept used to explain a person’s capacity to maintain normal cognitive function in the presence of brain pathology. To put it simply, some people have better cognitive reserve than others.

Evidence shows the extent of someone’s cognitive decline doesn’t occur in line with the amount of biological damage in their brain as it ages. Rather, certain life experiences determine someone’s cognitive reserve and, therefore, their ability to avoid dementia or memory loss.

How do we know?

Being educated, having higher levels of social interaction or working in cognitively demanding occupations (managerial or professional roles, for instance) increases resilience to cognitive decline and dementia. Many studies have shown this. These studies followed people over a number of years and looked for signs of them developing cognitive decline or dementia in that period.

As we get older we have a greater risk of developing impairments in cognitive function, such as memory. from

Cognitive reserve is traditionally measured and quantified based on self reports of life experience such as education level, occupational complexity and social engagement. While these measures provide an indication of reserve, they’re only of limited use if we want to identify those at risk of cognitive decline. Genetic influences obviously play a part in our brain development and will influence resilience.

Brain plasticity

The fundamental brain mechanisms that underpin cognitive reserve are still unclear. The brain consists of complex, richly interconnected networks that are responsible for our cognitive ability. These networks have the capacity to change and adapt to task demands or brain damage. And this capacity is essential not only for normal brain function, but also for maintaining cognitive performance in later life.

This adaptation is governed by brain plasticity. This is the brain’s ability to continuously modulate its structure and function throughout life in response to different experiences. So, plasticity and flexibility in brain networks likely contribute in a major way to cognitive reserve and these processes are influenced by both genetic profiles and life experiences.

A major focus of our research is examining how brain connectivity and plasticity relate to reserve and cognitive function. We hope this will help identify a measure of reserve that reliably identifies individuals at risk of cognitive decline.

Strengthening your brain

While there is little we can do about our genetic profile, adapting our lifestyles to include certain types of behaviours offers a significant opportunity to improve our cognitive reserve.

Activities that engage your brain, such as learning a new language and completing crosswords, as well as having high levels of social interaction, increase reserve and can reduce your risk of developing dementia.

Regular physical activity increases cognitive reserve. Jenny Hill/Unsplash, CC BY

Regular physical activity also improves cognitive function and reduces the risk of dementia. Unfortunately, little evidence is available to suggest what type of physical activity, as well as intensity and amount, is required to best increase reserve and protect against cognitive impairment.

There is also mounting evidence that being sedentary for long periods of the day is bad for health. This might even undo any benefits gained from periods of physical activity. So, it is important to understand how the composition of physical activity across the day impacts brain health and reserve, and this is an aim of our work.

Our ongoing studies should contribute to the development of evidence-based guidelines that provide clear advice on physical activity patterns for optimising brain health and resilience.

Man flu is real, but women get more autoimmune diseases and allergies

Man flu is real, but women get more autoimmune diseases and allergies

August 7, 2017 6.12am AEST

Men and women respond differently to diseases and treatments for biological, social and psychological reasons. In this series on Gender Medicine, experts explore these differences and the importance of approaching treatment and diagnosis through a gender lens.

We know that sex hormones drive characteristic male and female traits such as breast enlargement and hip widening in women, or increased muscle mass and growth of facial hair in men. But now we also recognise they have a major impact on the immune system – our body’s inbuilt mechanism that helps fight and protect us against disease.

Research suggests this has an evolutionary basis: survival of the species may mean men are harder hit by viruses, but a woman’s reactive immune system leaves her more susceptible to autoimmune diseases and allergies.

Viruses see men as weaker

Men die significantly more often from infectious diseases than women. For instance, men are 1.5 times more likely to die from tuberculosis, and twice as likely to develop Hodgkin’s lymphoma following Epstein–Barr virus (EBV) infection. Men are also five times more likely to develop cancer after infection with human papillomavirus (HPV), than women.

This is because women’s immune systems mount a stronger response against foreign invaders, particularly viruses. While the male hormone testosterone tends to dampen immune responses, the female hormone oestrogen increases the number of immune cells and the intensity of their response. So women are able to recover more quickly from an infection.

All this may reflect a sneaky evolutionary trick used by viruses to enable their survival. Women have developed multiple mechanisms to transmit infections; mainly through passing bugs from mother to child during gestation or birth, or through breastfeeding. So women are better vessels for viruses.

Viruses may have signalled men out as the weaker sex. Michael Verhoef/Flickr, CC BY

Meanwhile, viruses have singled men out as the weaker sex. While popular culture has come up with the term “man flu”, suggesting men are over-dramatising flu symptoms, evidence suggests they may in reality be suffering more due to this dampening down of their immune responses.

Read more – Health Check: is man flu real?

However, this increased susceptibility of men to infection may not be an advantage for the long-term (over tens of thousands of years) survival of a disease-causing organism (pathogen), if it induces such severe disease that it results in the death of the host.

Pathogens modify themselves so they can be transmitted by women during pregnancy, birth or breast feeding. Because of this, many have adapted to be less aggressive in women allowing wider infection, generally across a population.

However, this feature alone is not likely to be sufficient to ensure the ongoing survival of a virus. The fitness of both sexes is necessary to reproduce long-term and thus provide new hosts for invading pathogens. Thus, the hit to the male sex must somehow be balanced by other advantages to their immune system.

Autoimmune diseases

Women are good hosts for viruses. Romanova Anna/Shutterstock

The most striking sex differences in the immune system are seen in autoimmune diseases. Autoimmune disease affects about 8% of the population, but 78% of those affected are women. Women are three times more likely than men to develop these types of disease.

Autoimmune diseases occur when the immune system turns on and attacks the body’s own cells or tissues, initiating a chronic cycle that results in damage or destruction of specific organs. These diseases include type 1 diabetes, lupus, rheumatoid arthritis, multiple sclerosis, and up to 80 different diseases that affect systems such as the intestine, bones, joints and nervous systems.

Read more – Explainer: what are autoimmune diseases?

In the case of lupus, the immune system mistakenly attacks the person’s own DNA (the structure that carries a person’s genetic code) causing damage to multiple organs that will lead to weight loss, anemia and eventually heart and kidney failure. Nine out of ten patients with lupus are women and clinical observations suggest that, again, hormones are the culprits.

These differences of susceptibility between males and females tend to appear after puberty, and flare-ups increase during pregnancy. On the contrary, menopause is associated with a lower disease severity.

Studies have linked oestrogen levels with the exacerbation of lupus. Oestrogens directly act on a particular immune cell (called the plasmacytoid dendritic cell) to promote their capacity to secrete inflammatory signals, which exacerbate lupus symptoms. Although these dendritic cells are generally important for fighting viral infections, in the context of lupus and multiple sclerosis, they cause significant harm.

Hormones and allergies

One in nine Australians (more than 2.5 million in total) suffer from asthma – a disease that causes swelling and narrowing of the airways. This makes it difficult to breathe when we encounter environmental allergens such as pollen.

Twice as many women develop asthma compared to men. Photosmatic/Shutterstock

Twice as many women develop asthma compared to men. Interestingly, males are more susceptible to asthma before to the onset of puberty but, after puberty, females are more affected and develop more severe asthma than men. Until now, the reasons for this were not obvious, but hormones were speculated to play a role.

In a recent study, we showed that high levels of testosterone in males protect them against the development of allergic asthma. During puberty, the level of testosterone increases.

Testosterone acts as a potent inhibitor of a recently discovered immune cell called an innate lymphoid cell (ILC2), which accumulates in the lungs and initiates asthma. ILC2 cells release inflammatory signals that drive the swelling and airway narrowing characteristic of asthma when people are exposed to pollen, dust mites, grass or other common allergens. Testosterone reduces the numbers of ILC2 in the lungs of males, while female hormones provide no protective effect.

Read more: Do kids grow out of childhood asthma?

Immunity and sex are far more intricately linked than we had previously appreciated. More research needs to be done to better understand the triggers involved in the different responses of males and females. But the recent discoveries open the door for tactics to potentially target hormonal pathways or receptors that are preferentially expressed on male or female immune cells.