Monthly Archives: June 2021

A strong coffee half an hour before exercising increases fat-burning

A strong coffee half an hour before exercising increases fat-burning

MedicalXpress Breaking News-and-Events|March 24, 2021

Scientists from the Department of Physiology of the University of Granada (UGR) have shown that caffeine (about 3 mg/kg, the equivalent of a strong coffee) ingested half an hour before aerobic exercise significantly increases the rate of fat-burning. They also found that if the exercise is performed in the afternoon, the effects of the caffeine are more marked than in the morning.

In their study, published in the Journal of the International Society of Sports Nutrition, the researchers aimed to determine whether caffeine—one of the most commonly consumed ergogenic substances in the world to improve sports performance—actually does increase oxidation or “burning” of fat during exercise. Despite the fact that its consumption in the form of supplements is very common, the scientific evidence for its beneficial claims is scarce.

“The recommendation to exercise on an empty stomach in the morning to increase fat oxidation is commonplace. However, this recommendation may be lacking a scientific basis, as it is unknown whether this increase is due to exercising in the morning or due to going without food for a longer period of time,” explains the lead author of this research, Francisco José Amaro-Gahete of the UGR’s Department of Physiology

A total of 15 men (mean age, 32) participated in the research, completing an exercise test four times at seven-day intervals. Subjects ingested 3 mg/kg of caffeine or a placebo at 8am and 5pm (each subject completed the tests in all four conditions in a random order). The conditions prior to each exercise test (hours elapsed since last meal, physical exercise, or consumption of stimulant substances) were strictly standardized, and fat oxidation during exercise was calculated accordingly.

Maximum fat oxidation

“The results of our study showed that acute caffeine ingestion 30 minutes before performing an aerobic exercise test increased maximum fat oxidation during exercise regardless of the time of day,” explains Francisco J. Amaro. The existence of a diurnal variation in fat oxidation during exercise was confirmed, the values being higher in the afternoon than in the morning for equal hours of fasting.

These results also show that caffeine increases fat oxidation during morning exercise in a similar way to that observed without caffeine intake in the afternoon.

In summary, the findings of this study suggest that the combination of acute caffeine intake and aerobic exercise performed at moderate intensity in the afternoon provides the optimal scenario for people seeking to increase fat-burning during physical exercise.

To read more, click here

Postbiotics: The next wave of dietary supplements?

Postbiotics: The next wave of dietary supplements?

Naveed Saleh, MD, MS|June 22, 2021

You’ve likely heard of prebiotics and probiotics. Prebiotics are substances derived from fiber and other carbohydrates that are consumed by the helpful bacteria in the gut. Probiotics are live bacteria found in certain foods and supplements, such as Lactobacillus in yogurt. A person examines a bottle of supplements at a pharmacy.

Postbiotics do not contain live microorganisms, so the risks associated with their intake are minimized.

But what are postbiotics?

Postbiotics are substances released or produced via metabolic activity of the microorganism that provide benefit to the host either directly or indirectly. They include any substance released by or produced through the metabolic activity of microorganisms. As postbiotics do not contain live microorganisms, the risks associated with their intake are minimized, according to the authors of a review published in Nutrients.

Importantly, postbiotics exert their effects at the level of gut microbiota, the composition of which is strongly linked to various diseases. 

“As an imbalance in the intestinal microbiota can lead to the development of several diseases (eg, type 1 diabetes, cancer, among others), the use of prebiotics, probiotics, and postbiotics to alter the gut microbiome has attracted recent interest,” the authors wrote.

Let’s take a closer look at examples of different types of postbiotics currently available as functional foods or supplements.

Short-chain fatty acids

The intestinal microbiota produce short-chain fatty acids (SCFAs) through fermentation of plant polysaccharides. Common SCFAs include acetic, propionic, and butyric acids. 

Butyrate is a key energy source for enterocytes, and it plays a role in the renewal of intestinal epithelium. It is also able modulate gene expression via the incomplete inhibition of histone deacetylases. Butyrate also has immunosuppressive effects and can establish food tolerance via boosting the expression of immunosuppressive cytokines and downregulating several cytokines and proinflammatory receptors.


Antioxidant enzymes produced by microorganisms protect against reactive oxygen species, which can damage lipids, proteins, carbohydrates, and nucleic acids. Examples of these antioxidant enzymes include glutathione peroxidase (GPx), peroxide dismutase (SOD), catalase, and NADH-oxidase.

In mouse models, enzymes produced by Lactobacillus have relieved symptoms of Crohn’s disease. They have also decreased inflammation secondary to inflammatory bowel disease, as well as the prevention of colon cancer.

Cell-free supernatants

These mixes of biologically active metabolites are secreted by bacteria and yeast into their surroundings and can be extracted and filtered from cell cultures. 

Depending on origin, supernatants exert different health effects. For instance, Lactobacillus acidophilus and Lactobacillus casei supernatants possess anti-inflammatory and antioxidant effects in intestinal epithelial cells, macrophages, and neutrophils. 

These effects are mediated by decreased secretion of pro-inflammatory tumor necrosis factor α (TNF-α) cytokine and increased secretion of the anti-inflammatory cytokine interleukin 10 (IL-10).

Cell wall fragments

Immunogenic potential is expressed by different components of the bacterial cell wall including lipoteichoic acid (LTA). This molecule is located in the cell walls of Gram-positive bacteria and can be released into the environment.

LTAs derived from Lactobacillus and Bifidobacteria are indicated for the treatment of skin infections. They act by releasing anti-infectious peptides. Although debate surrounds other health benefits, LTAs may also have anti-inflammatory, antineoplastic, and immunomodulatory effects. 


Microorganisms manufacture biopolymers as they grow. These biopolymers harbor different chemical properties and are released outside the bacterial cell wall, thus yielding a soup of different substances called exopolysaccharides. These substances are used in food production as stabilizers, emulsifiers, and water-binding agents. 

Although their exact biologic functions remain to be elucidated, research demonstrates that they may modulate immune response via interaction with dendritic cells and macrophages, as well as enhance the proliferation of T and NK lymphocytes. 

Furthermore, exopolysaccharides produced by tofu may ameliorate phagocytic potential of macrophages and trigger nitric oxide production. Intriguingly, exopolysaccharides isolated from fermented durian fruit have antimicrobial and antioxidant properties. Exopolysaccharides can also inhibit the absorption of cholesterol.

Bottom line

The health benefits of postbiotics listed here likely represent only the tip of the iceberg. Much more research needs to be done. 

To date, researchers have suggested that postbiotics may confer a laundry list of benefits involving anti-inflammatory, immunomodulatory, anti-obesogenic, antihypertensive, hypocholesterolemic, anti-proliferative, and antioxidant pathways. In the aggregate, postbiotics are considered safe and have long shelf lives, which make them a topic of much interest.

Superfoods Every Doctor Should Eat


Superfoods Every Doctor Should Eat

By Jonathan Ford Hughes on May 3, 2019

I know what you’re thinking: Eat? Who has time for that?

As a busy physician, most of your meals are probably the grab-and-go variety. As a result, you may be missing out on some key micronutrients as well as properly balanced macronutrients. Getting as much of the following superfoods as you can should help keep you sharp, energized, and healthy, as well as boost your brain power and longevity.

Superfood 1: Berries

Berries have the benefit of being a sweet, tart treat with a relatively low glycemic index. They’re also nutrient-dense. Blueberries pack potent flavonoids, which have been shown to have cardiovascular- and metabolic-health benefits, in addition to anti-inflammatory and cancer-fighting properties. Berries happen to pair well with a few of the other superfoods on this list (more on that at the end of this post).

Superfood 2: Kale

Once a seldom-eaten restaurant garnish, kale is now a cultural meme of health-consciousness — for good reasons. Dark, leafy greens, such as Kale, contain vitamins and minerals, such as zinc and folate. A recent study highlighted how dark, leafy greens like kale may have memory-preserving properties. Many people dislike the bitter taste of kale. If you’re sautéing it, try adding some fresh lemon juice to the pan. The acidity will reduce the bitter flavor.

Superfood 3: Nuts

Nutrient-dense nuts are replete with healthy fats. A review of this superfood published in Nutrients extolls their virtues, including lower chronic disease risk, high fiber content, and phytosterols, which have been shown to lower LDL levels. A word for the wise: If you’re looking to lose weight, be mindful of portion size as nuts are calorically rich.

Superfood 4: Salmon

Fatty fish like salmon are a great source of omega-3 fatty acids. Current research is inconclusive or dismissive of the health benefits of omega-3s. However, it does appear that people who eat seafood 1-4 times weekly have an increased risk of death by heart disease. Whether that’s causation or correlation is another matter. However, you do need protein in your diet. Poultry can get boring and any amount of processed meat eaten regularly increases the risk of stomach and colorectal cancers. Mix it up with some fish now and then — but not too much. Excessive fish consumption can increase the amount of heavy metals in your blood and body.

Superfood 5: Green Tea

Get your (lighter) caffeine buzz with the benefits of antioxidants. Perhaps the most fascinating compound in green tea is the catechin epigallocatechin gallate (EGCG). A 2011 study published in Biological Pharmacology sheds some light on the potential of this antioxidant, which may affect tumor cell response to chemotherapy. EGCG seems to affect apoptosis of tumor cells and activate caspases, which play a critical role in cell death. Another study, published in 2016, shows that green tea can protect against chemotherapy-induced cardiotoxicity. A side benefit: If you find yourself dragging midday, the lower caffeine-content of green tea has a better shot of being metabolized by the time your head hits the pillow.

Superfood 6: Kefir and Yogurt

Why Keifer, specifically? It’s fermented. The goal here is to consume probiotics. You can get similar benefits from yogurt, but stick to fermented varieties, such as Greek yogurt. Kefir also tends to be better tolerated by those who have trouble digesting dairy. Another bonus: Yogurt is protein packed. Choose a reduced- or no-fat option, and you’ll get a lot of protein with a lower caloric load. We’re just beginning to scratch the surface, from a research standpoint, on probiotics. Right now, research shows some benefit for antibiotic-related diarrhea and irritable bowel.

Superfood 7: Turmeric

This lustrous, goldenrod spice is one of the ingredients that gives Indian cuisine its inviting color. Research shows that turmeric may be a good option for pain control, due to its anti inflammatory properties. Additionally, a double-blind, placebo-controlled study published in Affective Disorders showed that turmeric may be effective in treating depressive disorders.


Cash in on the benefits of these superfoods for longevity and overall health.

  1. Berries
  2. Kale
  3. Nuts
  4. Salmon
  5. Green tea
  6. Kefir and yogurt
  7. Turmeric

Looking to get as many of these superfoods into your system in one shot? Make a breakfast smoothie. In a blender, combine a cup of mixed berries, two leaves of Kale, a tablespoon of almond butter, a dash of matcha powder and a cup of Greek yogurt. Add almond milk to achieve desired consistency.

Which is the best vaccine for COVID?

Which is the best vaccine for COVID? Experts have an answer, of sorts

ScienceAlert Latest|June 17, 2021

With the rollout of COVID-19 vaccines accelerating, people are increasingly asking which vaccine is best?

Even if we tried to answer this question, defining which vaccine is “best” is not simple.

Does that mean the vaccine better at protecting you from serious disease? The one that protects you from whichever variant is circulating near you? The one that needs fewer booster shots? The one for your age group? Or is it another measure entirely?

Even if we could define what’s “best”, it’s not as if you get a choice of vaccine. Until a suite of vaccines become available, the vast majority of people around the world will be vaccinated with whichever vaccine is available.

That’s based on available clinical data and health authorities’ recommendations, or by what your doctor advises if you have an underlying medical condition. So the candid answer to which COVID vaccine is “best” is simply the one available to you right now.

Still not convinced? Here’s why it’s so difficult to compare COVID vaccines.

Clinical trial results only go so far

You might think clinical trials might provide some answers about which vaccine is “best”, particularly the large phase 3 trials used as the basis of approval by regulatory authorities around the world.

These trials, usually in tens of thousands of people, compare the number of COVID-19 cases in people who get the vaccine, versus those who get a placebo. This gives a measure of efficacy, or how well the vaccine works under the tightly controlled conditions of a clinical trial.

And we know the efficacy of different COVID vaccines differ. For instance, we learned from clinical trials that the Pfizer vaccine reported an efficacy of 95% in preventing symptoms, whereas AstraZeneca had an efficacy of 62-90%, depending on the dosing regime.

But direct comparison of phase 3 trials is complex as they take place at different locations and times. This means rates of infection in the community, public health measures and the mix of distinct viral variants can vary. Trial participants can also differ in age, ethnicity and potential underlying medical conditions.

We might compare vaccines head to head

One way we can compare vaccine efficacy directly is to run head-to-head studies. These compare outcomes of people receiving one vaccine with those who receive another, in the same trial.

In these trials, how we measure efficacy, the study population and every other factor is the same. So we know any differences in outcomes must be down to differences between the vaccines.

For instance, a head-to-head trial is under way in the UK to compare the AstraZeneca and Valneva vaccines. The phase 3 trial is expected to be completed later this year.

How about out in the real world?

Until we wait for the results of head-to-head studies, there’s much we can learn from how vaccines work in the general community, outside clinical trials. Real-world data tells us about vaccine effectiveness (not efficacy).

And the effectiveness of COVID vaccines can be compared in countries that have rolled out different vaccines to the same populations.

For instance, the latest data from the UK show both Pfizer and AstraZeneca vaccines have similar effectiveness. They both reliably prevent COVID-19 symptoms, hospitalisation and death, even after a single dose.

So what at first glance looks “best” according to efficacy results from clinical trials doesn’t always translate to the real world.

What about the future?

The COVID vaccine you get today is not likely to be your last. As immunity naturally wanes after immunisation, periodic boosters will become necessary to maintain effective protection.

There is now promising data from Spain that mix-and-matching vaccines is safe and can trigger very potent immune responses. So this may be a viable strategy to maintain high vaccine effectiveness over time.

In other words, the “best” vaccine might in fact be a number of different vaccines.

Variant viruses have started to circulate, and while current vaccines show reduced protection against these variants, they still protect.

Companies, including Moderna, are rapidly updating their vaccines to be administered as variant-specific boosters to combat this.

So, while one vaccine might have a greater efficacy in a phase 3 trial, that vaccine might not necessarily be “best” at protecting against future variants of concern circulating near you

The best vaccine is the one you can get now

It is entirely rational to want the “best” vaccine available. But the best vaccine is the one available to you right now because it stops you from catching COVID-19, reduces transmission to vulnerable members of our community and substantially reduces your risk of severe disease.

All available vaccines do this job and do it well. From a collective perspective, these benefits are compounded. The more people get vaccinated, the more the community becomes immune (also known as herd immunity), further curtailing the spread of COVID-19.

The global pandemic is a highly dynamic situation, with emerging viral variants of concern, uncertain global vaccine supply, patchy governmental action and potential for explosive outbreaks in many regions.

So waiting for the perfect vaccine is an unattainable ambition. Every vaccine delivered is a small but significant step towards global normality.

—Wen Shi Lee, Postdoctoral researcher, The Peter Doherty Institute for Infection and Immunity and Hyon Xhi Tan, Postdoctoral researcher, The Peter Doherty Institute for Infection and Immunity.

What to drink with dinner to get the most iron from your food (and what to avoid)


What to drink with dinner to get the most iron from your food (and what to avoid)

April 21, 2021 4.59pm AEST


  1. Evangeline Mantzioris Program Director of Nutrition and Food Sciences, University of South Australia

Disclosure statement

Evangeline Mantzioris receives funding from NHMRC.


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A drink with your breakfast, lunch or dinner can make your meal more enjoyable. But have you considered whether your drink of choice may affect the way your body absorbs the nutrients in your food?

Dietary factors that can increase the uptake of other nutrients are called enhancers, while those that can reduce the uptake of other nutrients are called inhibitors, or anti-nutrients.

One of the most common nutrient deficiencies worldwide is iron, and can result in a condition called iron deficiency anaemia.

So if you’re looking to increase your iron levels, it’s worth thinking not just about what you’re eating — but what you’re drinking too.

Get your news from people who know what they’re talking about.

A bit about iron

Iron deficiency can develop when we don’t get enough iron, or don’t absorb iron to the extent our body needs. It’s more common in women, and can cause weakness and fatigue, among other symptoms.

If you’re worried you may be iron deficient, you can get a blood test from your general practitioner.

There are two forms of iron in our diets; haem iron and non-haem iron. Haem is an iron-containing protein that forms part of the haemoglobin, a protein in your red blood cells that transports oxygen around your body.

Haem iron is found in animal sources of food, like meat, and is more easily absorbed into the body.

Non-haem iron is found in plant foods, like grains, beans and nuts, and is less easily absorbed.

Read more: I’ve been diagnosed with iron deficiency, now what?

Some enhancers

Choosing a drink that contains vitamin C — such as orange, tomato or grapefruit juice — around the time of your meal will increase the amount of the non-haem iron you can absorb.

In one study, 100mg of vitamin C increased iron absorption four-fold. This is roughly equivalent to what you’d get from one glass of orange juice.

Keeping this in mind is particularly important for people who don’t eat meat, as all of their dietary iron will be non-haem iron.

Some inhibitors

Tea is a popular drink with meals and is often enjoyed with Asian cuisine. But tea contains a bioactive compound called tannin, which is an inhibitor of non-haem iron absorption.

Tannin is classed as an organic compound called a polyphenol. It’s also found in many foods including cocoa, almonds, grapes, berries, pomegranates, and spices (for example, vanilla and cinnamon), which may find their way into drinks like smoothies.

Kombucha, a popular fermented tea drink, still contains some tannins.

Unfortunately the news is no better for coffee drinkers — coffee contains tannins too. And the chlorogenic acid in coffee is also an important inhibitor of iron absorption.

A woman in a striped jumper holds a mug.
Tea and coffee contain tannins, which inhibit iron absorption. Shutterstock

Tea and coffee are considered the strongest inhibitors of iron. A cup of tea reduces iron absorption by about 75%-80%, and a cup of coffee by about 60%. The stronger you make them, the greater the effect will be.

So it’s best to avoid tea and coffee while eating and for two hours before and after the meal. This is roughly the length of time food and drinks sit in your stomach before they’re fully absorbed.

This includes breakfast, a meal at which many people most commonly consume tea and coffee. For most of us breakfast normally consists of cereal and/or bread. Both of these naturally contain significant levels of iron and sometimes these products have iron added.

So if you’re iron deficient, it may be time to consider opting for a small glass of orange juice at breakfast, or preferably the whole orange (as you get fibre with it too), and saving the tea or coffee for a little later.

Read more: What is kombucha and how do the health claims stack up?

A little from column A, a little from column B

There has always been speculation dairy may inhibit iron absorption, but to date the evidence seems to suggest it has no effect.

However plant-based milks, such as soy milk, contain phytates, a compound that stores phosphorus in plants, which inhibit iron absorption.

A group of people drinking beers with a meal.
Beer increases iron absorption. But that doesn’t mean you should have it with every meal. Shutterstock

Meanwhile, alcohol increases the absorption of iron, so a beer would be classed as an enhancer.

If you favour a glass of wine, you should select a white over a red. Red wine contains more tannins and other polyphenols, so overall red wine inhibits iron absorption.

But as we know drinking alcohol increases the risk of cancer and is linked to other health concerns, you shouldn’t start drinking alcohol to increase iron absorption.

Read more: Should I let my kids drink juice? We asked five experts

So what’s the take-home message?

The bioactives I’ve mentioned also provide many nutritional and health benefits, and they’re all found in plant products. It would be virtually impossible to avoid tannins in your diet and still be consuming the healthy number of serves of fruit and vegetables.

This advice is mostly relevant if you’ve been diagnosed as iron deficient or with iron deficiency anaemia. And even if this is the case, you can still enjoy these drinks outside of meal times.

If your iron levels are within the normal range there’s no need to be concerned as your body is absorbing enough to meet your needs with what you’re drinking and eating.

Menopause and Memory loss

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Menopause and cognitive complaints: are ovarian hormones linked with subjective cognitive decline?

R. Reuben, L. Karkaby, C. McNamee, N. A. Phillips & G. Einstein Received 25 Sep 2020, Accepted 12 Feb 2021, Published online: 15 Mar 2021


Subjective cognitive decline (SCD) and the loss of ovarian hormones after menopause have been independently linked to later-life Alzheimer’s disease (AD). The objective of this review was to determine whether menopause and the loss of ovarian hormones contribute to cognitive complaints and SCD in women. This would suggest that SCD at the menopausal transition might be an important marker of eventual cognitive decline and AD. We conducted a literature search using PubMed, PsycINFO and Web of Science in July 2020. All English-language studies assessing SCD and cognitive complaints with respect to menopause and ovarian hormones were included. A total of 19 studies were included. Studies found that cognitive complaints increased across the menopause transition and were associated with reductions in attention, verbal and working memory, and medial temporal lobe volume. Women taking estrogen-decreasing treatments also had increased cognitive complaints and reduced working memory and executive function. The current literature provides impetus for further research on whether menopause and the loss of ovarian hormones are associated with cognitive complaints and SCD. Clinicians may take particular note of cognitive complaints after menopause or ovarian hormone loss, as they might presage future cognitive decline.

Are chemicals shrinking your penis and depleting your sperm? Here’s what the evidence really says


Are chemicals shrinking your penis and depleting your sperm? Here’s what the evidence really says

May 4, 2021 6.08am AEST


  1. Tim Moss Adjunct Associate Professor, Department of Obstetrics and Gynaecology, Monash University

Disclosure statement

Tim Moss is Health Content Manager at Healthy Male (formerly Andrology Australia). He is the current President of The Perinatal Society of Australia and New Zealand.


Monash University

Monash University provides funding as a founding partner of The Conversation AU.

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A doomsday scenario of an end to human sperm production has been back in the news recently, now with the added threat of shrinking penises.

Professor Shanna Swan, a US epidemiologist who studies environmental influences on human development, recently published a new book called Countdown.

In it, she suggests sperm counts could reach zero by 2045, largely owing to the impact of a range of environmental pollutants used in manufacturing everyday products: phthalates and bisphosphenol A (BPA) from plastics, and per- and poly-fluoroalkyl substances (PFAS) used, for example, in waterproofing. Under this scenario, she says, most couples wanting to conceive would need to rely on assisted reproductive technologies.

She has also warned these chemicals are shrinking penis size.

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Such extraordinary claims require extraordinary evidence. I would argue the evidence is not strong enough.

Correlation doesn’t equal causation

Epidemiologists find associations between disease and potential contributing factors, like lung cancer and smoking. But their work can’t identify the causes of disease — just because two things are associated doesn’t mean one is causing, or caused by, the other.

An article written by environmental activist Erin Brockovich in The Guardian in March leads by referring to “hormone-disrupting chemicals that are decimating fertility”. But causation is far from established.

It’s reasonable to expect chemicals that affect hormone function in our bodies, like BPA and PFAS, could affect reproduction in males and females, given available evidence. But we don’t have irrefutable proof.

A man and a pregnant woman outside with their dog.
Could environmental pollutants be leading to infertility? Establishing cause and effect isn’t clear-cut. Shutterstock

Selective reporting

In 2017, Swan and several colleagues published an exhaustive review study showing an apparent drop in men’s sperm counts of 59.3% between 1973 and 2011. This research informs the arguments Swan makes in Countdown and those we’ve seen in the media.

What’s not often mentioned is the fact the researchers only observed a decline in sperm count in groups of men from North America, Europe, Australia, and New Zealand, but not in groups of men from South America, Asia or Africa.

When Swan and her colleagues combined the data from all countries, they saw a decline because the studies of “Western” men outweigh those of men elsewhere (in the number of studies and participants).

Read more: Huge drop in men’s sperm levels confirmed by new study – here are the facts

Swan and her colleagues worked hard to avoid bias when conducting their study. But selection bias (related to how study participants are chosen), publication bias (resulting from researchers’ tendency to report only observations they think will be of interest) and other limitations of the original work used as the basis for their investigation could be influencing the results of the larger study.

Many studies from different parts of the world show declining sperm counts, which is concerning, but we don’t fully understand the reasons for the apparent decline. Blaming chemicals in the environment overlooks other important factors such as chronic disease, diet, and obesity, which people can act on to improve their fertility.

The problem with extrapolation

Swan’s 2017 study boils down to a straight descending line drawn between sperm counts of groups of men studied at different times between 1973 and 2011.

Just because a straight line can be drawn through the data, this doesn’t justify extrapolation of that line beyond its earliest and latest data points. It’s unscientific to assume trends in data exist outside the range of observations.

We know sperm counts of men in the early 1940s were around 113 million sperm per ml of semen, not the roughly 140 million/ml you get from extrapolating backwards from Swan’s research. Concluding sperm counts will reach zero in 2045, based on extrapolating forward from the available data, is just as likely to be incorrect.

When Swan told news website Axios “If you look at the curve on sperm count and project it forward” she was encouraging unjustifiable and unscientific interpretation of her data — even though she acknowledged it was “risky” to extrapolate in this way. Unfortunately this caution is too often unmentioned.

For example, Brockovich writes: “That would mean no babies. No reproduction. No more humans.” That’s hyperbole. It’s just not science.

An illustration of sperm.
Swan has extrapolated from recent data to predict sperm counts could reach zero by 2045. But this isn’t necessarily accurate. Shutterstock

Relax, your penis isn’t shrinking

Claims of shrinking penises are obvious clickbait. But only a single study, of 383 young men from the Veneto region in northeastern Italy, links men’s penis size to the types of chemicals Swan attributes to declining sperm counts.

Within Veneto there are geographic zones with varied levels of PFAS contamination. A group of 212 men who live in areas with high or intermediate PFAS exposure and have high levels of these chemicals in their bodies, had an average penis length of 8.6cm, about 10% lower than the average of a group of 171 men from an area without exposure (9.7cm).

Read more: Science or Snake Oil: do men need sperm health supplements?

But a few features of this study affect the reliability of the observations and whether we can generalise them to other populations.

  1. men were grouped according to where they lived, not where they were born. Since genital size is determined before birth, the environment during their mothers’ pregnancies is more relevant to penis size than where the men lived at the time of the study. Some men will likely have relocated from their place of birth but how many, and where they may have moved to and from, we don’t know
  2. the levels of PFAS exposure for men living in the contaminated regions of Veneto are extreme, because of decades of industrial pollution. How the potential effect of such large exposures relates to smaller and more common exposures to pollutants, like from plastic food wrap, we don’t know
  3. the study is missing details about its subjects and the conditions under which measurements were made. It’s usual to exclude people with conditions that might affect study outcomes, such as congenital abnormalities, but it’s not clear whether this happened in the study. Variables that influence penile measurements (such as room temperature, posture, and whether the penis is held straight or hanging) are not mentioned.

And from a semantic perspective, for penises to be “shrinking” they must be getting shorter over time, on either an individual or population basis. I cannot find any reports of men’s penises shortening as a consequence of environmental pollution. Available data don’t suggest a decline in penis size over the past few decades.

While environmental pollution is a pressing concern, the evidence suggests the catastrophic collapse of human reproduction and accompanying penis shrinkage is thankfully a pretty unlikely prospect.


SINK COVID-19 study: Can common drugs offer 2-step approach to combat deadly virus?

Beaumont News Releases
04 May 2020

Researchers at Beaumont Hospital, Royal Oak have begun enrolling patients in a new clinical study aimed at treating COVID-19 patients with two common drugs – naltrexone and ketamine. It’s called SINK COVID-19, or the Study of Immunomodulation using Naltrexone and Ketamine for COVID-19.

Medicine specialist talks treatments for lingering COVID-19 symptoms

03 March 2021

Functional medicine specialist Dr. Aaron Hartman says the solution to potentially treating Long-COVID isn’t new. He’s been following evidence that suggests that using a low dose of a drug called naltrexone, which is typically used for a drug overdose, could improve the condition.

Got Inflammation? How LDN can help in the times of Covid-19.

Rhyena Halpern
20 May 2020

There is something you can do to help lower the inflammation in your cells, organs and body. It is a prescribed drug called LDN. LDN, or low dose naltrexone, is used to relieve people from chronic, non-responsive pain that results from inflammation. LDN works by staying in the body for a very short time, supporting the body’s ability to produce endorphins and to kick start the immune system into gear. (High dose naltrexone does not work in the body the same way.) Of course, a healthy diet of low inflammatory, nutrient dense foods, lotsa rest, supplementation and mindfulness also rounds out the picture of optimal wellness.

Phase 2 Trial to Evaluate Safety and Efficacy of CYTO-205 in Mild COVID-19
13 January 2021

The aim of the study is to assess the safety and clinical efficacy of low-dose naltrexone (CYTO-205; Cytocom, Inc) in reducing the proportion of higher risk patients who progress from mild COVID-19 to a more severe disease category.

Low-Dose Naltrexone for Fibromyalgia and ME/CFS

Verywell Health
04 November 2020

A series of Stanford University studies have shown as much as a 30% decline fibromyalgia symptoms compared to placebo. Researchers say results are best in people with higher sedimentation rates, which indicates an inflammatory response. Results also indicate that the drug is well tolerated. However, these studies have all been small and more work needs to be done before we know how safe and effective LDN is for this condition.

Quality of life and the role of menopausal hormone therapy

  • Review Climacteric

. 2012 Jun;15(3):213-6. doi: 10.3109/13697137.2012.655923.

Quality of life and the role of menopausal hormone therapy

A Pines  1 D W SturdeeA H MacLennan Affiliations


The quality of life of countless menopausal women world-wide has been significantly diminished following the sensationalist reporting of the Women’s Health Initiative (WHI) and the resulting 50% or more decline in the use of hormone replacement therapy (HRT) over the subsequent 10 years. Quality of life is difficult to measure as there are so many contributing factors and a large number of different instruments, some of which assess general health and only a few which specifically include symptoms related to menopause. HRT improves quality of life of symptomatic menopausal women and some studies of the effects of HRT provide reliable evidence on quality of life other than reduction in vasomotor symptoms. Until there is a better understanding of the minimal risks of HRT for the majority of women, too many will continue to suffer a reduced quality of life unnecessarily.

It’s time to teach the whole story about ovulation and its place in the menstrual cycle


It’s time to teach the whole story about ovulation and its place in the menstrual cycle

May 26, 2021 5.39am AEST


  1. Felicity Roux Researcher, Curtin University

Disclosure statement

Felicity Roux currently receives a scholarship through the Australian government’s Research Training Program. In 2020, the project received awards from the Western Australian Institute for Educational Research and Fogarty Foundation, Curtin Medical School and Curtin Business School. She serves on the Board of Directors for the Australasian Institute for Restorative Reproductive Medicine, and she volunteers on the 2021 committees of the Gynaecological Awareness Information Network, Positive Education Schools Association and the Western Australian Institute for Educational Research.


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Health education frequently fails to teach the menstrual cycle in its full entirety, focusing mostly on the bleeding part of the story and glossing over the ovulation chapter. In other words, many girls* often only get half the story about how their bodies work.

That’s a shame because knowledge of your own reproductive function is useful for monitoring and making decisions about personal health. Focusing on the period part of the cycle is like skipping to the last chapter of a book. In reality, ovulation is the protagonist of the menstrual story rather than a minor character to skim over.

For those who want to get pregnant, understanding ovulation is clearly crucial but research shows few can accurately identify their fertile window.

Beyond that, however, understanding ovulation can help you understand more about your health in general.

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Read more: Explainer: what is polycystic ovary syndrome?

What exactly is ovulation?

Ovulation occurs when an ovary releases an egg (sometimes more than one). A typical teaching describes a 28-day cycle with Day 1 as the start of period bleeding and ovulation around Day 14 or 15.

But this textbook 28-day cycle is not meant to be a one-size-fits-all and is not everyone’s experience. There are healthy ranges across the different stages of life (such as adolescence, adulthood and in the later years).

The simple skills for recognising ovulation have been around for over 40 years. Once taught what to look out for, most women find it easy to tell if they are likely ovulating. One tell-tale sign is changes in cervical mucus which a woman can recognise from different sensations at her vulva.

Understanding the cycle is a useful way to get the most out of exercising and supporting good mental health.

High school students in uniform gather in a park.
Many young people only get half the story about how their bodies work. AAP Image/Daniel Munoz

If cycle difficulties such as painful periods or pre-menstrual tension emerge, knowing the fixed days between ovulation and the next period gives a fair heads-up to put self-care strategies in place.

A practical example is the preventative use of non-steroidal anti-inflammatory drugs such as ibuprofen for primary period pain; in other words, taking painkillers before the pain arrives, because you know when it is coming.

Read more: 3 out of 10 girls skip class because of painful periods. And most won’t talk to their teacher about it

If cycle difficulties become more complex, understanding the cycle helps a woman work with doctors to get the care she needs.

A role for educators and teachers

When it comes to teaching cycles in schools, the period dominates the story; probably because it is bleeding obvious and you have to manage it.

Educating boys about the cycle needs more research. At this stage, it is task enough to give girls the knowledge and confidence they need.

A recent review found school programs tended to focus on menstrual problems.

While these are important topics, it would also help to frame the cycle in a positive light, explain it fully and talk about the connection between biology, psychology, and socio-environmental factors (what researchers call the “biopsychosocial” aspects).

It is a wise teacher who is vigilant about both misinformation and pedagogically appropriate information. But professional development support is often limited for teachers and the curriculum is overcrowded.

This may explain the tendency for schools to parachute in external facilitators for sexuality education teaching.

The problems with this approach are a lack of available specialist expertise, potential loss of capacity-building within the school and the infrequent learning opportunities for students. External facilitators are there to reinforce what is already taught rather than be a substitute for it.

Health education frequently fails to teach the menstrual cycle in its full entirety, focusing too much on the bleeding part of the story. Shutterstock

A role for parents

One role for parents is to encourage their adolescent children to start taking responsibility for their own health. This includes adopting healthy lifestyle choices (such as nutritious eating, keeping fit and getting enough sleep).

Read more: Back to school: how to help your teen get enough sleep

These choices can impact the menstrual cycle. Parents can support their daughters’ discipline in tracking their cycles and understanding their unique patterns.

Knowing this information can also help young women advocate for themselves and make informed health-care choices if cycle difficulties arise.

A research team at Curtin University has worked on developing a program called My Vital Cycles, which is currently being trialled in Western Australia. This school-based ovulatory-menstrual health literacy program aims to give teachers, parents and teenagers the tools they need to understand the whole cycle, including ovulation’s place in it.

Given the span of years from menarche (a girl’s first bleed) to menopause, ovulatory-menstrual cycle knowledge and skills are useful over a lifetime. They are what women ought always to have had, and it is time for the whole story to be told.

The information in this article is for general information purposes only and is not intended to be a substitute for professional medical advice, diagnosis or treatment. The terms *girls, women, and daughters are used in relation to a person’s sex, namely their biological characteristics or reproductive organs. This may differ from gender identity. The author believes anyone who menstruates should have the knowledge and skills necessary to understand and manage their cycle.