A little science secret to spice things up in the bedroom!
Written by Amanda Edward (@mlle_capsaicin), Mitchell Moffit and Greg Brown
Instagram and Twitter: @whalewatchmeplz and @mitchellmoffit
Despite significant gains in gender equity over the last few decades, a bias still reigns in one area of medicine. The lack of female representation in both preclinical studies and clinical trials has put women at greater risk of adverse events from medical interventions. But there’s now light at the end of the tunnel.
Treating women equally as subjects in scientific studies may seem obvious today, when we have evidence of varied disease susceptibility and severity among the sexes. And of differences in men’s and women’s response to drugs and treatment outcomes. But this has not always been so.
Differences between the sexes, or sexual dimorphism, is a key evolutionary adaptation in most species. It has existed in human life expectancy in almost every country for as long as records have been kept: women still live longer, on average, than men. Perhaps that’s partly because suicide rates are three times higher in men than women.
It’s not really surprising that after millions of years of evolution, fundamental differences exist in many aspects of our biology. Differences between the sexes have been documented in cardiovascular disease and stroke, chronic fatigue syndrome, asthma and several types of cancer.
Biological differences between the sexes include variation in genetic and physiological factors such as telomere attrition, mitochondrial inheritance, hormonal and cellular responses to stress, and immune function, among other things. These factors may account for at least a part of the female advantage in human life expectancy.
Research has highlighted gender differences in autoimmune diseases, such as rheumatoid arthritis, lupus and multiple sclerosis, and psychological disorders such as bipolar disorder, schizophrenia, autism spectrum disorder (ASD), eating disorders and attention deficit hyperactivity disorder (ADHD).
Rheumatoid arthritis, for instance, is approximately twice as common in females as in males. And a study found that while the relative risk of schizophrenia was greater in men up to 39 years of age, it reversed to a greater risk in women over the age of 50.
The reasons for these gender differences are varied and complex. Behavioural and social issues, such as uptake of smoking and body image, are different between men and women. This may partially explain differences in diseases such as lung cancer and eating disorders.
Normal physiological differences, such as a lower red blood cell count, may lie behind the poorer stroke outcomes in women. Women also tend, though, to suffer from stroke at an older age, which may account for some of the observed differences.
Biological differences also exist within the dopaminergic neurons of the brain and may explain varied prevalence of a number of neurological conditions. Indeed, fundamental genetic differences between the sexes may contribute to males under 20 years of age experiencing higher mortality rates from a wide array of conditions in 17 of 19 major disease categories.
What’s more, men and women differ in their response to drug treatment. Women experience a higher incidence of adverse drug reactions than men, although the reasons for this are not well understood. But we do know female response to many commonly used pharmaceutical agents can be different to males.
And we know the differences in drug responses are partly due to differences in body weight, height, body surface area, body composition, total body water, drug metabolism and drug clearance. Adult males have greater arm muscle mass, larger and stronger bones and reduced limb fat, but a similar degree of central abdominal fat.
Sex differences in body composition are primarily attributable to the actions of sex steroid hormones, which drive gender differences during pubertal development. Oestrogen, for instance, is important not only in body fat distribution but also in the female pattern of bone development, which predisposes women to a greater risk of osteoporosis in old age.
For the last two decades, the largest US funder of grants for biomedical research, the National Institutes of Health (NIH), has required studies involving human subjects to test both men and women. But Australia’s NIH equivalent, the National Health and Medical Research Council (NHMRC) currently has no comparable policy.
Medical research in Australia is substantially funded by the taxpayer, with the unambiguous goal of improving health for all citizens. From this viewpoint, there may be a need for policy reflecting that of the NIH’s here.
But the picture changes substantially in light of recent advances in medical science. Current thinking revolves around concepts such as “precision medicine”, which recognises that variability exists not just between the sexes, but between individuals.
So, the goal now is to ensure that every patient receives the correct treatment and dose at the right time, with minimum adverse side effects. Women may have been neglected by medical research for a couple of decades but the march of technology is now bound to take them forward as individuals.
A new study from Flinders University is some of the sexiest science I have seen lately… literally. The study documents the earliest instance of sex involving penetration for sperm transfer and was published in Nature.
A profound new discovery announced in Nature today (October 20, 3:30am, ACDT) by world-renowned palaeontologist, Flinders University Professor John Long, reveals how the intimate act of sexual intercourse first evolved in our deep distant ancestors.
In one of the biggest discoveries in the evolutionary history of sexual reproduction, Professor Long has found that internal fertilisation and copulation was invented by ancient armoured fishes, called placoderms, about 385 million years ago in Scotland.
The video below is a terrific visual summary of the study!
In one of the biggest discoveries in the evolutionary history of sexual reproduction, Flinders Professor John Long has found that internal fertilisation and copulation was invented by ancient armoured fishes, called placoderms, about 385 million years ago in Scotland.
Sarah Jones has written a nice post for Wall of Separation looking at the never-ending battle between science fact and fiction in Arizona health education. The current debate is over what should be included in a school curriculum as fact, centering around classification of contraceptive devices as a method for abortion.
Medical science is, of course, very clear: IUDs do not cause abortions. Neither does the birth control pill, or the implant or any other contraceptive method (including Plan B).
It’s obvious that medically accurate sex education works. Students deserve to get real medical information, not dogma, and it’s time for school districts to make sure they get it.
California expanded its sex ed programs and required them to be comprehensive and medically accurate. The result? By 2011, teen birth rates had dropped by almost 60 percent. During roughly the same time period, Arizona’s teen pregnancy rate dropped by 38 percent. Nationally, the teen birth rate isconsistently highest in states that use abstinence-only sex ed.
The Guardian reports that 5 geckos have died after being sent into space by Russia to study zero-gravity and sexual behavior.
The federal space agency released a statement saying the landing apparatus of the Photon-M satellite had returned to earth as planned, falling into Russia’s Orenburg region at 1.18pm Moscow time, and that the entire herpetological crew had perished at some point during their odyssey. With four female lizards and one male on board, Russian scientists had hoped to learn how zero gravity would affect the sexual habits of geckos.
The space agency statement said simply that a “preliminary examination” found the geckos dead, and that “the date and conditions of their deaths will be determined by specialists”.
While this is sad news and there has been a number of recent incidents with the Russian Space agency, previous animal missions have been completed successfully.
Gerbils, newts, spiders, butterflies, snails and bacteria all successfully traversed the cosmos in 2007, when international scientists launched them from Russia for a set of 45 experiments.
This week in Nature there are 2 opposing viewpoints on the NIH mandate for inclusion of both sexes in preclinical studies. For background, the NIH is pushing for inclusion of both male and female animals or cells in preclinical scientific studies. Read this previous Nature Comment from Francis Collins and Janine Clayton describing new policies and why they are important. Essentially, the idea is that men and women respond differently to treatments and drugs in clinical settings (for example, the difference in preventative effects of low-dose aspirin, or differences in pain after surgery), so research should take this into account. The first viewpoint from R. Douglas Fields is that an NIH mandate will cost time, money, and in some cases is not justifiable. The second viewpoint, from Louise McCullough, Margaret McCarthy and Geert de Vries, states that the costs of NOT analyzing sex differences are higher than mistakes made with the status quo. These include failed clinical trials (including failed translation from lab to clinic), misdiagnosis, and inappropriate treatment, given what we already know about sex differences.
This debate has also broken its way into news reporting and the political scene. The Hill reported this week that 22 Democratic lawmakers have requested that NIH disclose the demographic data for clinical trials, especially to look at inclusion of women and minorities. Given what we know about the biology of sexual dimorphism (or differences), especially relevant to clinical treatment of men and women, it seems that the NIH is headed in the right direction. However, the policies mandating what research should include both sexes should be implemented in a way that moves preclinical science forward, while not holding back science that may not relate to, or be effected, by sex differences.