DNA provides the instructions to make us how we look and contributes to our life expectancy. Identical twins have exactly the same DNA, so why are slightly different in many ways? The answer is epigenetics.

Epigenetics is the name given to the science that studies the way in which cells package DNA so that only certain genes are used in one tissue, and other genes are used in other tissues. “Epi” means above, so epigenetics means “above” genetics. It provides instructions about how to package DNA to tell our cells what sort of cells to be, for example skin, brain, or heart cells.

All of the different cells in our body contain the same DNA (the same genes) and epigenetic factors determine which genes become either silenced if unneeded, or active if needed to make cells. Epigenetic factors are chemical tags on the DNA or on proteins called histones. These chemical tags attach to the DNA and are responsible for providing the DNA-packing signals inside cells. There are lots of different epigenetic factors and the number of new chemical tags discovered are increasing.

The chemical tags on the DNA are inherited during embryonic cell division, but they can change during normal developmental processes, such as puberty and pregnancy. Importantly, epigenetic factors or the chemical tags can also change due to environmental factors (diet, stress, toxins) and in certain diseases, such as cancer.

We now understand that epigenetic changes commonly take place when cancer develops and that they’re intimately involved in switching “off” critical cancer genes that should be “on” in normal cells and vice versa. This process results in a normal cell turning into a cancer cell.

Our laboratory is focused on understanding the epigenetic changes that occur in different types of cancer, including prostate cancer. Our current finding identifies a critical epigenetic chemical modification that occurs on a single histone when prostate cancer develops. This epigenetic change appears to lock and unlock genes that prevent and trigger cancer.

Epigenetic factors are ideal drug targets in cancer management, as they don’t change the DNA sequence but change how that sequence is packaged. The aim is to switch or reverse the epigenetic chemical modifications to potentially turn cancer cells back into normal cells.

There are currently drugs for the treatment of cancers, such as leukemias, that can reverse epigenetic changes approved by the US Food and Drug Administration (FDA). These are showing promising results with minimal side effects.

The next challenge is to develop epigenetic drugs that can treat patients with solid tumours, such as lung, breast or prostate cancer. To achieve these goals, we need to fully understand all the epigenetic changes that lead to cancer and identify new epigenetic drug targets.

We have demonstrated that, in prostate cancer, when one of the histones (a variant called H2A.Z) is chemically modified (or acetylated), cancer genes are activated and tumour suppressor genes are silenced. We propose that the enzyme that leads to chemical acetylation of H2A.Z could be an ideal drug target for prostate cancer.

A more detailed understanding of what is controlling the packaging of DNA inside our cells will not only get us closer to understanding what determines how we look and what contributes to our life expectancy, this knowledge will also give us new exciting approaches to treating diseases, such as cancer.

Ovarian cancer risk reduced by prolonged lactation

31/01/13 By Susanna Wolz

Curtin University researchers have found that women who breastfeed their babies have significantly reduced rates of ovarian cancer in a study that extends what was known about the beneficial effects of breastfeeding on mothers.

A case-control study was undertaken in Guangzhou (China’s Guangdong Province), where information on the number of months of lactation and number of children breastfed was obtained from a sample of 493 incident ovarian cancer patients and 472 hospital-based controls.

Curtin’s Health Sciences Professor Colin Binns, a John Curtin Distinguished Professor said the study was conducted in China due to the high population size and therefore a higher number of ovarian cancer cases to examine.

“The lower incidence of ovarian cancer in China suggests there are factors operating there to reduce the incidence which we wanted to explore. We also knew that Chinese women breastfeed for longer than women in the western world so it was an ideal location,” Professor Binns said.

“The results of our study add further knowledge to the relatively limited amount of research from countries, such as China, with a low incidence of this disease and provides more detail on the breastfeeding variables associated with a reduced risk of ovarian cancer.

“Increased ovulation heightens the risk of cell mutation which can cause ovarian cancer. As breastfeeding often delays ovulation, we were able to effectively demonstrate that breastfeeding for 20 months would decrease the risk of ovarian cancer by 50 per cent, and that the 20 months of breastfeeding could be spread over a number of children and still have the same effect.

“The results of our study would recommend that mothers breastfeed for 12 months to gain substantial effect – and longer if they wish.”

Ovarian cancer is the seventh most common cause of cancer mortality among women and accounts for four per cent of all female cancers.

“As it is difficult to diagnose, treat and often has a poor prognosis (with an overall five-year survival rate of approximately 45 per cent), research into prevention strategies is essential to the health and wellbeing of women all over the world,” Professor Binns said.

The research, Ovarian cancer risk is reduced by prolonged lactation: a case-control study in southern China, will published in the American Journal of Clinical Nutrition next month.

The most popular addictive drug available in Australia right now is 1, 3, 7-trimethylxanthine, or C₈H₁₀N₄O₂. Let’s call it 137TX until we can come up with something catchier.

Most adults seem to feel a need to use it daily, and we hear people saying that they can’t function until they’ve had their “fix”. Wait, you may be saying, why haven’t I heard of this common drug? Well, you probably know it as caffeine, most commonly delivered in the form of coffee.

But why do we love caffeine so much? The list of its adverse effects should really put us off:

• it causes palpitations and headaches
• it impairs fertility and promotes reflux
• it increases levels of cortisol, the stress hormone, and increases the reaction to stress
• it increases calcium losses from our bones and may be a risk factor for low-impact fractures at high intakes
• it reduces sleep quality so profoundly that it has been used to simulate insomnia in experimental tests of sedative drugs

Just one cup of coffee at dinner time has a measurable effect on time to get to sleep and frequency of waking in the night. All this is news to nobody.

And now scientists at the Western Australian Institute for Medical Research have announced that coffee contains a substance associated with deadly accumulation of visceral fat.

So why would anyone want to risk experimenting with 137TX?

One possible answer is that we just can’t get enough of its stimulant effect, which is mostly caused by adenosine inhibition. This measurably improves performance in sport and in situations where alertness may be reduced by fatigue.

Perhaps the wearying effects of modern life have made us even more dependent on the lift we get from our morning espresso?

Also, unlike other available stimulants, it’s cheap, easy to obtain, and flavoursome. It’s fast, too, peaking in the bloodstream within about an hour of consumption and wearing off about four hours after an average dose in most people.

Dose me up

An average dose – a standard coffee or a small can of Red Bull or V – has between 80 and 100 milligrams of caffeine. In comparison, a can of normal cola or a cup of hot or iced tea may have around 30 to 50mg. And a decaffeinated coffee, a hot chocolate or chocolate milk or a square of dark chocolate may have about five milligrams.

Studies of caffeine in sport performance use doses of around 200 to 250mg. Most studies of “high” doses use 300 to 500mg, or around five milligram per kilo body weight. This amounts to five or six cups of strong coffee.

The dose can also be affected by how you consume it. A lighter coffee roast is higher in caffeine and adding milk or sugar to a caffeine drink slows its emptying from the stomach so that it’s absorbed more slowly.

Absorption and metabolism rates differ between individuals. This helps explain why one person can’t function without four cups a day, while another may steer clear of everything except decaf, citing unwanted side effects.

While the mechanism of caffeine’s effect is complex, we do know that it is metabolised in the liver to a variety of active substances. Some of these have opposing effects on the nervous system, blood pressure and molecules found in the blood. This may be another reason for the different effects of caffeine experienced by different people.

The bad bits

Overall, caffeine tends to increase urine production, and raises blood pressure by constricting the blood vessels, but only for a short while.

Chronic caffeine use does not seem to lead to chronic hypertension generally, although some individuals may be at higher risk. Similarly, reports of increased kidney stones seem to be limited to those who already have a higher-than-normal risk.

Caffeine does increase calcium losses, but this occurs at significant levels only when intake is more than two to four cups of coffee a day. And possibly only in people who already have a low calcium intake. Whether this effect is really important to bone health has been contested.

And the good points

In favour of caffeine are a number of studies suggesting that it has some interesting health benefits. It may, for instance, be associated with reduced risk of dementia.

Depression risk may be lower with increased caffeine intake too, according to a large cohort study of over 50,000 American women from the Nurses’ Health Study. And similar results were seen in a study of over 2000 Finnish men. In that latter study, however, the relationship was with coffee intake, not dose of caffeine.

Some of the other other benefits of coffee seem to be independent of its caffeine content, too. Reduced risk of diabetes was seen with regular and decaf coffee alike in another large cohort study.

And a similar phenomenon was observed with some of the studies indicating reduction in cancer risk. Coffee’s antioxidant content may be part of the reason.

Another might be chlorogenic acid, a component of coffee that is increasingly attracting attention. This is the substance that was used in the West Australian study on visceral fat.

At low doses, chlorogenic acid seems to be involved in the positive effects of coffee, improving insulin sensitivity and blood pressure. But, in high doses, it had the opposite effect – promoting fat accumulation around the organs and raising blood glucose levels.

The high doses of chlorogenic acid used in the West Australian study were equivalent to a daily intake of five cups of coffee over an extended period. Still, we should probably apply caution to the applicability of this research to real life, given that the study was conducted in rats following a high-fat diet, rather than humans eating normally.

In any case, it seems that coffee drinkers who stick to consistently-consumed moderate doses can feel confident that their 137TX habit isn’t harming their health.

27 September 2013, 6.45am AEST

        Gentle exercise is enough to keep your brain fit and healthy

Once upon a time we thought the brain was incapable of changing – if it was broken, it couldn’t be fixed. But that idea has been challenged in the last few decades with research suggesting that the brain is quite changeable or plastic.

In fact, we are discovering that the human brain has remarkable capacity for change. It can make new connections between nerve cells, enabling us to learn and remember complex information. And it can undergo a  massive reorganisation when damaged.

Young children who have half of their brain removed, due to severe epilepsy, manage to move and walk again. People with a slow-growing brain tumour may not show any symptoms for years, as nerve cells around the mass adapt and compensate for the lesion.

And for those with brain injury, the inherent capacity for change within the brain, which is known as neuroplasticity, is the dominant mechanism for recovering function.

Researchers around the world are investing huge resources to discover how we can harness and improve neuroplasticity in the adult brain. Many hope non-invasive brain stimulation may hold the key to promoting neuroplasticity, either by increasing the activity in the damaged areas of the brain or somehow correcting imbalances that exist between its different regions.

Non-invasive brain stimulation uses either electrical or magnetic currents to painlessly stimulate the brain, probing the connections between nerve cells to understand more about how these connections can be altered.

Preliminary studies of these techniques show promise, but to date, larger trials show that the effects of this type of therapy are not as efficacious as intensive rehabilitation, such as physiotherapy.

In a recent study, my colleagues and I took a different approach by looking at an intervention that acts across the whole brain, rather than at specific circuits. Our approach wasn’t high tech and didn’t have unwanted side effects – it was aerobic exercise.

Using non-invasive magnetic brain stimulation (transcranial magnetic stimulation or TMS) to investigate the effect of exercise on the motor areas of the brain, we tested whether low- or moderate-intensity exercise would promote neuroplasticity in the brains of healthy young adults.

We found that 30 minutes of low-intensity cycling on a stationary bike, compared to 15 minutes of moderate-intensity cycling or sitting (our control), encouraged short-term rewiring and neuroplasticity in the brain.

Interestingly, this effect was seen in the region of the brain that controls hand muscles, even though cycling only involved the legs. We observed the change after a single 30-minute session of aerobic exercise.

While it hasn’t been demonstrated with aerobic exercise before, such an immediate effect of exercise on the brain is not unique. We know running improves learning, and a number of other studies have shown that aerobic exercise is good for a variety of cognitive tasks, such as cognitive flexibility and executive function.

The exact mechanism for exercise encouraging neuroplasticity is unknown, but it’s likely to involve several key chemicals in the blood and in the brain.

In our study, we measured levels of two of these chemicals in the bloodstream, and found that the stress hormone cortisol increased with the moderate-intensity, but not with low-intensity, exercise.

Cortisol actually inhibits plasticity, suggesting that exercise at lower intensities may be better at promoting neuroplasticity.

The second chemical measured was brain-derived neurotrophic factor (BDNF), which is widely touted as having a key role in neuroplasticity. But we found BDNF did not increase in the blood stream, and we can’t yet determine whether exercise increased levels of it in the brain, as has been shown in animal studies.

So, what does all this mean for you?

Well, it shows that, for most of us, gentle aerobic exercise is good for our brain – keeping it sharp, alert and ready for action. We know that people who are regularly physically active have greater potential for neuroplasticity.

But for people with brain injury, gentle exercise may make the difference between walking again or being dependent on a wheelchair for the rest of your life.

Recent German research found that more than 70% of people with cancer supplement their regular hospital treatment with complementary and alternative medicine. More worryingly, many do so without advising their doctor.

This is important because interactions of the complementary medicines and their regular drugs could make cancer treatment ineffective, or worse still, cause toxic side-effects that could lead to death.

The study found a high degree of complementary medicine use by people with cancer across all age groups, and higher use among women than men. A small percentage (8%) of cancer patients were found to only use complementary medicines and shun conventional treatment.

A separate study also found that many parents of children with cancer (30%) also reported giving complementary medicines to their kids.

Studies in the United States, and across other European countries, found similarly high rates of complementary medicine use among cancer patients. Research of this sort hasn’t been conducted in Australia, but high complementary medicine use means it’s likely the same happens here.

Why people do it

According to the German study, people supplementing their treatment with complementary medicines do so in a variety of ways, and with different products. By far the most popular options are vitamins, metals such as selenium and other trace elements.

Some patients also try non-chemical or drug-based therapies, including prayer, relaxation and physical activity; but these tend to be the least used types of complementary therapies.

More than 50% of the participants in the German study expressed an interest in also using acupuncture or medical herbs, and a quarter were interested in trying mistletoe and homoeopathy treatments.

When asked why they were interested in complementary medicines, most people couldn’t give a reason, or said they’d used them before being diagnosed with cancer and merely continued that use. Some believed complementary therapies boosted their immune system and helped to “detoxify” their body.

Interestingly, more than a third of the German patients reported using complementary therapies simply because it enabled them to do something for themselves; it let them feel more in control of their treatment.

There’s considerable debate about the usefulness of complementary therapies, but what is more worrying about all three studies into complementary therapy use is that it happens without the knowledge of the patient’s doctor.

When asked about the source of their information on complementary medicines, the four most common responses in the German study were television and radio, family and friends, books, and the Internet.

The three least used sources of information were, in decreasing order, doctors, non-medical practitioners and pharmacists. In total, fewer than 10% of the people in the study using complementary medicines stated they gained information on them from health professionals.

This could be a problem because there’s no guarantee that popular sources of information about complementary therapies are accurate. Australian research from 2008 found that much of the information available in the media about complementary therapies is either incomplete or inaccurate.

Lurking dangers

Combining complementary medicine with conventional cancer treatment opens up the possibility of drug interactions that can make cancer treatment ineffective. Worse still, the drugs may interact to exacerbate side-effects of chemotherapy, which can be so severe they endanger the person’s life.

What’s more, many complementary medicines, particularly those marketed herbal or all natural, can contain ingredients not listed on the labels. So people don’t know what they are taking.

The Therapeutic Goods Administration regularly bans and issues safety advisories for complementary medicine products that patients are buying over the Internet because they contain unlisted, often prescription-only, ingredients.

Cancer patients should discuss any medicines they plan to use that are outside their normal treatment plan with their doctor. Many complementary medicines they choose will be safe.

Regardless of efficacy, complementary medicines provide people with an important way to gain a feeling of ownership over their treatment. Doctors will always be supportive of their patients and can help choose complementary medicines that are effective and safe for them to use.

Incontinence takes mental toll on younger women

This is a common problem. Look under “Womens Health problems – Bladder” on this web site to find out steps you can take to help your bladder function better. Read on…

Friday, 14 June 2013

New research from the University of Adelaide shows middle-aged women are more likely to suffer depression from a common medical problem that they find too embarrassing to talk about: urinary incontinence.

However, help is available for women if they seek medical advice, researchers say.

In a study of the experiences of women with urinary incontinence, researcher Jodie Avery found that middle-aged women with incontinence (aged 43-65) were more likely to be depressed than older women (aged 65-89).

Speaking in the lead up to World Continence Week (24-30 June), Ms Avery says the younger women’s self esteem is often hit hard by urinary incontinence, while older women tend to be more resilient and accepting of their condition.

“Women with both incontinence and depression scored lower in all areas of quality of life because of the impact of incontinence on their physical wellbeing,” says Ms Avery, a PhD student and Senior Research Associate with the University’s School of Population Health and School of Medicine.

“Key issues for younger women affected by incontinence are family, sexual relationships and sport and leisure activities.

“The most common difficulties women express about their incontinence are things like: ‘I can’t play netball’, ‘I can’t go to the gym’, ‘I can’t go for walks’, or ‘I can’t go dancing’, and these are real issues for women who are still in the prime of their lives.”

Urinary incontinence affects approximately 35% of the female population. The main cause in women is pregnancy, with the number of children they have increasing their chances of becoming incontinent.

“Our studies show that 20% of the incontinent population has depression, and this is something that we need both sufferers and GPs to better understand,” Ms Avery says.

“Sufferers of incontinence are often reluctant to get help, but attitudes are slowly changing. It is very important for them to seek advice about their condition. In some cases, urinary incontinence can be curable with an operation, and this is quite literally a life-changing operation for many women.

“GPs need to be aware that if their patient is suffering from incontinence, this condition is often linked with depression which needs to be treated to increase their quality of life.

“Ultimately, we hope that our research helps to raise awareness in the community about both the mental and physical issues associated with incontinence. We know it’s embarrassing, but if you discuss it with your GP, your life really can change.

Do We Have “Sexual Peaks”?

Feeling frisky, confident, and ready for a roll in the hay? You might just be hitting a sexual peak — a common term for a period of sexual maturity, competence, and desire. What’s the deal with these spikes? Are they even real? Read on for info on why this biological phenomenon is actually a myth, and how it affects how we think about gender and sexuality.

Peaks and Valleys — Why It Matters
Conventional wisdom (and plenty of women’s magazines) claims that men reach their sexual peaks as young teenage whippersnappers (18, to be exact), while late-blooming ladies don’t hit this milestone until their 30s. It’s easy to see why this myth has stuck around — early sexpert Alfred Kinsey himself proposed the theory on sexual peaks in his groundbreaking work “Sexual Behavior in the Human Female,” published way back in 1953. Since Kinsey first reported on male and female sexuality, the idea that men and women mature and think about sex differently has remained the prevailing theory about sexual peaks.

But as shocking as Kinsey’s work was at the time, it didn’t encompass much of what we now understand about doin’ the deed. If Kinsey were looking at hormonal levels alone, he’d be largely correct about sexual peaks. In men, testosterone levels reach their apex around age 18, while women’s estrogen (and fertility) hits a high-water mark during the mid- to late-20s. This hot-and-heavy stage of sexual maturity is known as the genital prime, because it’s when the body responds most quickly to arousal (it also explains all those stereotypes about high school boys…).

But a person’s genital or hormonal peak isn’t the same as his or her sexual prime. In fact, it’s difficult (if not impossible) to predict or claim that a certain age comprises a sexual peak, because it’s different for every adult. Being at the top of one’s sexual game is much more complicated than the number of sperm in the tank or the ease with which one can get pregnant — sex is also psychological. Mental factors like body confidence, personal sexuality, feelings of intimacy and trust with a partner, libido, and knowledge of sexual preferences take time and experience to develop.

Mountains Majesty — The Answer/Debate

Unsurprisingly, the idea that men and women have specific, but different, sexual peaks is pretty outdated. Regardless of hormonal maturity or concentrations, both men and women reach their sexual peak when they’re most comfortable with their own bodies and sexuality. And because hormones and relationships change throughout life, a so-called sexual peak can come at any time or age. Also, maintaining a healthy lifestyle can have a significant impact on sexual pleasure and performance [1]. According to Greatist Expert Dr. James Hardeman, regular exercise, a balanced diet, and not smoking can make psychological and physiological sexual peaks last longer.

But before we dismiss the idea of different sexual peaks once and for all, it’s important to consider the social repercussions of Kinsey’s theory. Kinsey’s report was so shocking because back in the 1950s, women often weren’t considered sexual beings at all. Even in the present day, sexuality presents different social pressures and stigmas for different genders. Many sources point out that women may embrace their sexuality later than men because they are pressured to appear “innocent” and “inexperienced” in comparison to men. (Cue the plot of most major romance novels.) The perception that women across the board have lower sex drives than men, and that females are consequently less interested in sex, is both old-fashioned and potentially harmful. Expecting women to stay sexually inexperienced (via social pressures such as “slut shaming”) makes it difficult for them to control their own sexual development and become sexually fulfilled adults.

Sexual stereotypes pose difficulties and pressures across the board, for men as well as women. Because men supposedly peak at age 18, many young male adults are expected to be “experienced”, which can create a culture of peer pressure for men to have sex before they’re ready. For both men and women, buying into the idea of “sexual peaks” is a waste of time, if not outright damaging. The best way for a person of any gender to develop their sexuality (and reach that confusing “sexual peak”) is to cultivate a positive relationship with their body, their sexuality, and their partner(s) — at any age.  

The Takeaway

Whether you call it a sexual peak, prime, or gold-star-worthy performance, everybody hits his or her stride in the bedroom department at some point. Exactly when this golden age happens is less certain — while our bodies may be more physiologically primed for baby-making at certain points in our lives, sexual peaks are more dependent on confidence and being comfortable in one’s body than on hormonal timetables.

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Personal Care

Magnets have long been promoted as treatment for a wide variety of disorders. Proponents claim magnets can minimize pain and anxiety, and treat cancer, heart disease, snoring, incontinence and just about everything else. While most of these claims are unproven, and most magnets on the market are unlikely to do any good at all, several studies do suggest that magnets may have something to offer for pain relief:

• A 1997 study at Baylor College of Medicine in Houston showed that 76 percent of patients treated with magnets for severe joint and muscle pain due to post-polio syndrome reported less pain compared to only 19 percent of those who received placebos.
• University of Virginia researchers said participants reported clinically meaningful improvements when using magnet therapy to reduce the intensity of pain from fibromyalgia (researchers also cautioned the overall results of their study were inconclusive).
• A University of Tennessee study showed that 60 percent of women with pelvic pain reported improvements after three weeks of magnet therapy compared to 33 percent of those treated with placebos.

Taken as a whole, studies suggesting that magnets help with pain relief are outnumbered by those that find no benefit.

If you do try magnet therapy, keep in mind that using magnets is not without risk, particularly for those with a pacemaker or other implantable medical device such as a defibrillator, insulin pump or liver infusion pump. In addition, therapeutic magnets are often pricey, there is no evidence that magnet therapy is safe during pregnancy, and there have been anecdotal reports of dizziness, nausea and prolongation of wound healing and bleeding among those wearing magnets.