What Is: Hormones

The "Chemical Messenger"
The Endocrine System and Chemical Communication
Image Credit: Scientific Frontline

The Silent Orchestrators

Hormones are the silent orchestrators of the human body. They are the unseen chemical messengers that, in infinitesimally small quantities, conduct the complex symphony of life. These powerful molecules control and regulate nearly every critical function, from our mood, sleep, and metabolism to our growth, energy levels, and reproductive functions.

At its most fundamental level, a hormone is a chemical substance produced by a gland, organ, or specialized tissue in one part of the body. It is then released—typically into the bloodstream—to travel to other parts of the body, where it acts on specific "target cells" to coordinate function.

The power of this system, which has identified over 50 distinct hormones in humans, lies in its exquisite specificity. Although hormones circulate throughout the entire body, reaching every cell, they only affect the cells that are equipped to listen. This is governed by the "lock and key" principle: target cells possess specific "receptors," either on their surface or inside the cell, that are shaped to bind only to a compatible hormone. This report will delve into the world of these powerful molecules, exploring the intricate system that creates them, the chemical language they speak, and the profound, lifelong impact they have on our daily health and well-being.

Why women's brains face higher risk: scientists pinpoint X-chromosome gene behind MS and Alzheimer's

Image Credit: Scientific Frontline / AI generated

New research by UCLA Health has identified a sex-chromosome linked gene that drives inflammation in the female brain, offering insight into why women are disproportionately affected by conditions such as Alzheimer’s disease and multiple sclerosis as well as offering a potential target for intervention. 

The study published in the journal Science Translational Medicine, used a mouse model of multiple sclerosis to identify a gene on the X chromosome that drives inflammation in brain immune cells, known as microglia. Because females have two X chromosomes, as opposed to only one in males, they get a “double dose” of inflammation, which plays a major role in aging, Alzheimer’s disease and multiple sclerosis.  

When the gene, known as Kdm6a, and its associated protein were deactivated, the multiple sclerosis-like disease and neuropathology were both ameliorated with high significance in female mice.  

What Is: Microplastics

Microplastic
Credit: Scientific Frontline

The Invisible Tide of Plastic

The modern era has been defined, in part, by the versatility and ubiquity of plastic. Yet, this celebrated 20th-century material has given rise to a paradoxical form of pollution—one so pervasive and minute that its scale was largely unrecognized until recently. Microplastics, the synthetic dust of our industrial age, represent a global environmental challenge of unprecedented complexity. These tiny particles, born from the fragmentation of larger debris and the intentional design of microscopic products, have infiltrated every corner of the planet. Scientific expeditions have confirmed their presence from the summit of Mount Everest to the abyssal depths of the Mariana Trench. More alarmingly, this invisible tide has crossed the final frontier, entering the human body itself, with researchers detecting microplastic particles in human blood, lung tissue, and even the placenta.

The ubiquity of microplastics signals a fundamental disruption of planetary systems. They are not merely inert debris but active agents in the environment, interacting with ecosystems and organisms in complex and often detrimental ways. Their journey spans the globe, carried by ocean currents, river systems, and atmospheric winds, connecting the most remote wilderness to the most densely populated urban centers in a shared system of contamination. This report provides a definitive, evidence-based synthesis of the current scientific understanding of microplastics. It aims to dissect the full scope of this issue, beginning with a fundamental definition of the pollutant and a detailed accounting of its myriad sources. It will then trace the environmental fate and transport of these particles through aquatic, terrestrial, and atmospheric systems. Finally, the report will conduct an exhaustive analysis of their multifaceted impacts on ecological integrity and human health, concluding with a critical evaluation of the policies, technologies, and strategies required to mitigate this pervasive threat.

Koala stress linked to disease threat

Many koalas in the study were successfully treated for Chlamydia before being released back into the wild.
Photo Credit: Currumbin Wildlife Hospital

Researchers have revealed a clear relationship between stress and increased disease risk in koalas in South East Queensland and on the New South Wales North Coast.

A study led by Dr Michaela Blyton at The University of Queensland measured and tracked the level of koala retrovirus (KoRV) in groups of captive and wild koalas.

“We wanted to see what happened to their KoRV loads over time and how it related to chlamydial infection and levels of the stress hormones cortisol and corticosterone in their feces,” Dr Blyton said.

“Virus load likely weakens the immune system, so those with a higher KoRV load are more at risk of diseases such as Chlamydia which can cause blindness, infertility and death.

“Poor quality or disappearing habitat may increase stress and the koalas with higher average cortisol levels had higher average KoRV loads.

Study links folic acid to gestational diabetes

Image Credit: Anna Mysłowska-Kiczek

New research led by Flinders University highlights the urgent need to establish a safe upper limit for folic acid intake during pregnancy and to improve guidelines on folic acid supplementation during pregnancy.

A new study by published in the journal Nutrients links the rise in gestational diabetes in part to excess maternal folate levels, due to the dual impact of folic acid (FA, or synthetic folate) in food fortification and higher-than-recommended supplementation doses during pregnancy.

National surveillance shows the incidence of gestational diabetes mellitus (GDM) in Australia has more than tripled, rising from 5.6% in 2010 to 19.3% in 2022.

Fluoride in Drinking Water

Photo Credit: Bluewater Sweden

Is Fluoride Safe in Drinking Water?

Do you ever stop to think about what's in your drinking water? While most of us are aware of the importance of clean water, the safety of fluoride in our water supply has been a topic of debate for many years. You might have heard about its benefits for preventing cavities, but also about potential health risks. This article aims to provide a comprehensive overview of the science and expert opinions surrounding fluoride in drinking water, exploring both its benefits and potential drawbacks.

Research Methodology

To ensure accuracy and comprehensiveness, this article draws on a variety of sources, including scientific studies, reports from reputable health organizations (such as the WHO and CDC), news articles, and expert opinions. By examining a wide range of perspectives, we aim to provide a balanced and well-informed analysis of the safety of fluoride in drinking water.

Researchers create lab model that could lead to new, non-hormonal birth control methods

Oregon Health & Science University researchers have developed a new lab model to study how changes in cervical mucus during the menstrual cycle help regulate fertility. This model could help develop new, non-hormonal birth control methods for women.
Photo Credit: OHSU/Christine Torres Hicks

Oregon Health & Science University researchers have developed a new lab model to study how changes in cervical mucus during the menstrual cycle help regulate fertility. This model could help develop new, non-hormonal birth control methods for women.

The study, published in the journal Biology of Reproduction, is part of ongoing work by senior author Leo Han, M.D., M.P.H., associate professor of obstetrics and gynecology in the OHSU School of Medicine and the OHSU Oregon National Primate Research Center. Han is a complex family planning specialist whose research focuses on developing new, non-hormonal contraceptives. 

In this study, his research team analyzed the genetic activity in lab-cultured cervical cells, identifying hundreds of different genes that could be drug targets for birth control that uses innovative new methods to block sperm. 

First atlas of the human ovary with cell-level resolution is a step toward artificial ovary

University of Michigan BME graduate student Jordan Machlin shows to prof. Ariella Shikanov and fellows grad student Margaret Brunette the images of oocytes in ovarian tissue she collected using RNA-fluorescence in situ hybridization.
Photo Credit: Marcin Szczepanski/Lead Multimedia Storyteller, Michigan Engineering

A new “atlas” of the human ovary provides insights that could lead to treatments restoring ovarian hormone production and the ability to have biologically related children, according to University of Michigan engineers.

This deeper understanding of the ovary means researchers could potentially create artificial ovaries in the lab using tissues that were stored and frozen before exposure to toxic medical treatments such as chemotherapy and radiation. Currently, surgeons can implant previously frozen ovarian tissue to temporarily restore hormone and egg production. However, this does not work for long because so few follicles—the structures that produce hormones and carry eggs—survive through reimplantation, the researchers say.

The new atlas reveals the factors that enable a follicle to mature, as most follicles wither away without releasing hormones or an egg. Using new tools that can identify what genes are being expressed at a single-cell level within a tissue, the team was able to home in on ovarian follicles that carry the immature precursors of eggs, known as oocytes.

Assessing the impact of sweeteners on appetite

Stevia
Photo Credit: Jan Haerer

Replacing sugar with artificial and natural sweeteners in foods does not make people hungrier – and also helps to reduce blood sugar levels, a significant new study has found. 

The double blind randomized controlled trial found that consuming food containing sweeteners produced a similar reduction in appetite sensations and appetite-related hormone responses as sugary foods - and provides some benefits such as lowering blood sugar, which may be particularly important in people at risk of developing type 2 diabetes. 

The use of sweeteners in place of sugar in foods can be controversial due to conflicting reports about their potential to increase appetite. Previous studies have been carried out but did not provide robust evidence. 

However, the researchers say their study, which meets the gold standard level of proof in scientific investigation, provides very strong evidence that sweeteners and sweetness enhancers do not negatively impact appetite and are beneficial for reducing sugar intake. The study is published in The Lancet eBioMedicine.  

Our study provides crucial evidence supporting the day-to-day use of sweeteners and sweetness enhancers for body weight and blood sugar control. 

Attacking metastatic prostate cancer early with combination treatment approach improves outcomes in preliminary study

Photo Credit: Accuray

A team of UCLA Health Jonsson Comprehensive Cancer Center investigators has shown the combination of a short course of powerful and intense hormonal therapy with targeted radiation is safe and effective in treating people with prostate cancer that has come back and has spread to other parts of the body.

In the small study, researchers found that 50% of the patients who were treated with the combination therapy had no signs of the cancer and remained free of recurrence six months after their treatment, with less than a quarter experiencing severe side effects from the treatment. 

“In contrast, without this combined treatment approach, we would expect approximately 1% of patients to have no evidence of disease at the six-month stage,” said Dr. Amar Kishan, professor of radiation oncology at the David Geffen School of Medicine at UCLA and senior author of the study. “These results suggest a substantial improvement and strongly suggest there can be a meaningful impact —namely, delaying the need for hormonal therapy and thus without the significant side effects of it— by attacking metastatic prostate cancer early.”

The results were published in the journal of European Urology.

Nearly all men who are diagnosed with metastatic hormone-sensitive prostate cancer are treated with androgen deprivation therapy, a type of hormonal therapy that aims to lower the levels of male hormones called androgens that can stimulate the growth of prostate cancer cells. 

Even small amounts of licorice raise blood pressure

Researchers have studied how licorice affects blood pressure, among other things.
Photo Credit: Marion Wellmann

It is known that large amounts of licorice cause high blood pressure. A study by researchers at Linköping University now shows that even small amounts of licorice raise blood pressure. The individuals who react most strongly also show signs of strain on the heart.

Licorice is produced from the root of plants of the Glycyrrhiza species and has long been used as an herbal remedy and flavoring. However, it is known that eating licorice can also raise blood pressure. This is mainly due to a substance called glycyrrhizic acid that affects the body’s fluid balance through effects on an enzyme in the kidney. High blood pressure, in turn, increases the risk of cardiovascular disease.

Both the European Union and the World Health Organization have concluded that 100 mg of glycyrrhizic acid per day is probably safe to eat for most individuals. But some people eat more licorice than that. The Swedish Food Agency has estimated that 5 per cent of Swedes have an intake higher than this level.

Alzheimer’s Drug Fermented with Help from AI and Bacteria Moves Closer to Reality

Photo-Illustration Credit: Martha Morales/The University of Texas at Austin

Galantamine is a common medication used by people with Alzheimer’s disease and other forms of dementia around the world to treat their symptoms. Unfortunately, synthesizing the active compounds in a lab at the scale needed isn’t commercially viable. The active ingredient is extracted from daffodils through a time-consuming process, and unpredictable factors, such as weather and crop yields, can affect supply and price of the drug. 

Now, researchers at The University of Texas at Austin have developed tools — including an artificial intelligence system and glowing biosensors — to harness microbes one day to do all the work instead. 

In a paper in Nature Communications, researchers outline a process using genetically modified bacteria to create a chemical precursor of galantamine as a byproduct of the microbe’s normal cellular metabolism.  Essentially, the bacteria are programmed to convert food into medicinal compounds.

“The goal is to eventually ferment medicines like this in large quantities,” said Andrew Ellington, a professor of molecular biosciences and author of the study. “This method creates a reliable supply that is much less expensive to produce. It doesn’t have a growing season, and it can’t be impacted by drought or floods.” 

How Proteins Control Genes to Prevent our Cells from Maldevelopment

Ole Nørregaard Jensen is a professor and head of research at the Department of Biochemistry and Molecular Biology.
Photo Credit: Stefan Kristensen

Every time a cell in our body prepares to divide, an extremely complex process begins to ensure that the mother cell's DNA is copied into a new daughter cell along with all the correct instructions for which genes on the DNA strand should be turned off and which should be activated.

If errors occur in this process and the new cell is not identical to the mother cell, damage and disease may occur.

Researchers are therefore interested in learning more about these processes and why the copying of DNA and instructions sometimes goes wrong.

Constant DNA replication of the cell

All humans have a unique DNA strand, originating from a single cell: the fertilized egg cell, which has divided and created the billions of cells that make up the whole human being. They all contain a copy of the DNA strand created at fertilization. However, different cells decode the DNA in different ways, allowing for the formation of more than 200 different cell types. Some cell types die quickly and need to be replaced many times during life; for example, skin cells and intestinal cells are renewed every few days. Each time a new cell is created, a copy of the unique DNA strand is made for the new cell.

Bariatric surgery provides long-term blood glucose control, type 2 diabetes remission

Photo Credit: Fernando Zhiminaicela

NIH-supported study shows long-term benefits of surgery compared to medication and lifestyle change.

People with type 2 diabetes who underwent bariatric surgery achieved better long-term blood glucose control compared to people who received medical management plus lifestyle interventions, according to a new study supported by the National Institutes of Health. The participants who underwent bariatric surgery, also called metabolic or weight-loss surgery, were also more likely to stop needing diabetes medications and had higher rates of diabetes remission up to 12 years post-surgery. Results of the study were published in JAMA and funded by the National institute of Diabetes, Digestive and Kidney Diseases (NIDDK), part of NIH.

“While there are many factors involved, and not all of them are completely understood, bariatric surgery typically results in greater weight loss that effects a person’s metabolic hormones, which improves the body’s response to insulin and ability to maintain healthy blood glucose levels,” said Dr. Jean Lawrence, NIDDK project scientist. “These results show that people with overweight or obesity and type 2 diabetes can make long-term, improvements in their health and change the trajectory of their diabetes through surgery.”

Mice study suggests metabolic diseases may be driven by gut microbiome, loss of ovarian hormones

Mice that received fecal implants from donors that had their ovaries removed gained more fat mass and had greater expression of liver genes associated with inflammation, Type 2 diabetes, fatty liver disease and atherosclerosis. The findings may shed light on the greater incidence of metabolic dysfunction in postmenopausal women. The team members included, from left: molecular and integrative physiology professor Erik R. Nelson; Kelly Swanson, the director of the Division of Nutritional Sciences and the Kraft Heinz Endowed Professor in Human Nutrition; and animal sciences professor Brett R. Loman.
  Photo Credit: Fred Zwicky

The gut microbiome interacts with the loss of female sex hormones to exacerbate metabolic disease, including weight gain, fat in the liver and the expression of genes linked with inflammation, researchers found in a new rodent study.

The findings, published in the journal Gut Microbes, may shed light on why women are at significantly greater risk of metabolic diseases such as obesity and Type 2 diabetes after menopause, when ovarian production of female sex hormones diminishes.

“Collectively, the findings demonstrate that removal of the ovaries and female hormones led to increased permeability and inflammation of the gut and metabolic organs, and the high-fat diet exacerbated these conditions,” said Kelly S. Swanson, the director of the Division of Nutritional Sciences and the Kraft Heinz Endowed Professor in Human Nutrition at the University of Illinois Urbana-Champaign who is a corresponding author of the paper.  “The results indicated that the gut microbiome responds to changes in female hormones and worsens metabolic dysfunction.”

Brain cell discovery sparks hope for fertility treatments

Photo Credit: Yoshihisa Uenoyama, Graduate School of Bioagricultural Sciences, Nagoya University

Researchers at Nagoya University’s Graduate School of Bioagricultural Sciences and the National Institute of Physiological Sciences in Japan have demonstrated how a specific type of neuron in the brain affects the release of hormones that control ovarian function, such as follicular development and ovulation in females. These findings, published in the journal Scientific Reports, could help researchers understand and treat reproductive disorders in both animals and humans.  

Kisspeptin neurons in the brain regulate the release of hypothalamic gonadotropin-releasing hormone (GnRH) and pituitary follicle-stimulating hormone/luteinizing hormone (LH). This process is important for reproduction, as pituitary hormones stimulate the ovaries to perform their reproductive functions. Examples include follicular development and ovulation in all mammals, including humans.   

There are two main areas of the brain involved in the process: the arcuate nucleus (ARC), in which kisspeptin neurons maintain the regular rhythmic (pulsatile) secretion of GnRH/LH that maintains normal follicular development and sex steroid production; and the anteroventral periventricular nucleus (AVPV), in which kisspeptin neurons trigger a surge of GnRH/LH that leads to ovulation.  

New research shows exercise can reduce the risk of stroke after menopause

Regular exercise could reduce the risk of stroke in post-menopausal women, according to new research partly undertaken in Swansea.
Photo Credit: Marcus Aurelius

The pilot study, which will now be followed by a more extensive, longer-term trial, suggested that the greatest benefits were to those women who exercised during or shortly after the menopause rather than many years later.

The study team, including Adrian Evans, Professor of Emergency Medicine at Swansea University Medical School, has now published its findings in the journal Heart and Circulatory Physiology.

Professor Evans said: “A vascular disease such as stroke is more common as you get older. But the incidence of stroke is higher in post-menopausal women than in men of a similar age and we are not sure why that is.

“One of the reasons, it is thought, is that before they go through the menopause, the estrogen – the hormones – have a protective effect. Post-menopause, the estrogen level is significantly reduced.

“And when they go through the menopause, they get an immune inflammatory response, which may produce abnormal clotting and changes in their blood flow, which in turn could cause a stroke.”

New Research Suggests Why Males and Females Respond Differently to Social Stress

Emily Wright, researcher, in a UC Davis lab.
Photo Credit: Jerry Tsai

Women are nearly twice as likely as men to be diagnosed with an anxiety disorder, but among boys and girls the likelihood is the same. New University of California, Davis, research has identified changes in the brain during puberty that may account for differences in how women and men respond to stress.

A team of psychologists has found that testosterone is the key hormone that drives gender-based differences in responses to social stress. The study encompassed six separate experiments with mice to isolate what changes in the brain drive these differences between males and females. The study was published in the Proceedings of the National Academy of Sciences, or PNAS, today.

“This research shows how the body’s hormones shape the complex interplay between the brain’s circuitry and behavioral responses to stress,” said Brian Trainor, a professor of psychology in the College of Letters and Science at UC Davis and the study’s corresponding author.

How plant-derived nutrients can affect the gut and brain

PD Dr. Veronica Witte
Photo Credit: Leipzig University/Antje Gildemeister

Can plant-derived nutrients alter gut bacteria to affect brain function? Scientists from the University of Leipzig Medical Center, the Max Planck Institute for Human Cognitive and Brain Sciences and the Helmholtz Centre for Environmental Research investigated this question in a study of overweight adults. Their findings, published in the journal Gut, suggest that dietary fiber can exert influence on both the composition of gut bacteria and the reward signals in the brain and associated food decision-making.

Prebiotics are used to foster the colonization of beneficial bacteria in the gut. These indigestible dietary fibers are found in plant-derived foods such as onions, leeks, artichokes, wheat, bananas, and in high concentrations in chicory root. They support gut health by promoting the growth and activity of beneficial gut bacteria. Researchers have now investigated whether certain prebiotics can also influence brain function by improving communication between the gut microbiome and the brain.

Why women with multiple sclerosis get better when pregnant

Women suffering from the autoimmune disease multiple sclerosis temporarily get much better when pregnant.
Photo Credit: Neal E. Johnson

Women suffering from the autoimmune disease multiple sclerosis temporarily get much better when pregnant. Researchers have now identified the beneficial changes naturally occurring in the immune system during pregnancy. The findings can show the way to new treatments.

Pregnancy is a very special condition from an immunological point of view. The immune system serves to defend us against foreign substances. However, although half of the genetic material of the fetus comes from the father, it is not rejected by the mother’s immune system. One reason why this balancing act is almost always successful is that during pregnancy the mother’s immune system is adapted to become more tolerant.

In multiple sclerosis, MS, nerve function is hampered due to the immune system attacking the fat that serves as an insulating sheath around the nerve fibers. The nerves become inflamed, which could lead to nerve damage. Although new and more effective treatment options are available, most MS patients deteriorate over time.

Researchers believe that the temporary dampening of the immune response could explain why women with MS actually get better when pregnant. Periods of symptoms, i.e. relapses, decrease by 70 percent during the last third of pregnancy. Also, some other autoimmune diseases, such as rheumatoid arthritis, temporarily ameliorate during pregnancy. But the reason for this has not been clear. This is why the researchers behind this study wanted to investigate what mechanisms that could be of particular importance for the decrease in symptoms during pregnancy, as a step to finding future treatment strategies that give the same effect in MS and possibly also other similar diseases.