Dementia: how to make sense of the link with people who struggle to hear over background noise
August 25, 2021 2.24am AEST
- Thomas Littlejohns Senior Epidemiologist, University of Oxford
Thomas Littlejohns does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.
University of Oxford provides funding as a member of The Conversation UK.
We believe in the free flow of information
Republish our articles for free, online or in print, under Creative Commons licence.
The number of people living with dementia is projected to treble from 50 to 150 million worldwide by 2050. Although there’s currently no cure for the condition, researchers are continuing to learn about how people can reduce their risk through making lifestyle changes (such as exercising more or quitting smoking) and managing health issues (including diabetes and hypertension).
Hearing loss may also be a potential target for preventing dementia. Studies show that hearing impairment is linked to a greater risk of dementia – and that managing hearing problems early may be key to reducing risk.
Our recent paper confirmed these findings, while focusing on an area that has received less attention: people who struggle to pick out speech in noisy environments. The hearing of people in this category is often deemed “normal” in traditional tests, but we were able to show with a large cohort for the first time that they too are at greater risk of going on to develop dementia.
Previous studies looking at the link between hearing impairment and dementia have used a method of hearing assessment known as pure-tone audiometry to measure participants’ hearing. This is usually the gold standard to testing a person’s hearing, and works by measuring a person’s ability to detect sounds – specifically tones – in a quiet environment.
However, many people whose test shows that they have “normal” hearing can still have issues hearing when different assessment methods are used. This includes those who struggle to pick out speech in noisy places, which is known as speech-in-noise hearing.
Speech-in-noise hearing is akin to the kind of hearing we do in everyday life. To find out whether speech-in-noise hearing impairment was similarly linked with increased dementia risk, we looked at data from a total of 82,039 people aged 60 or over.
Participants’ speech-in-noise hearing was measured using what’s known as a digits triplet test. This involved asking participants to identify three spoken numbers presented in varying levels of background noise. Based on their performance, we then grouped participants into three categories: “normal”, “insufficient” and “poor”.
Participants were followed up over 11 years to see who developed dementia. A total of 1,285 people from the 82,039 total received a dementia diagnosis over that period. We found those with insufficient and poor speech-in-noise hearing had a 61% and 91% greater risk of developing dementia compared to those with normal speech-in-noise hearing. The dementia risk of those with poor speech-in-noise hearing was virtually identical to what previous studies found about people with hearing impairments that are picked up by pure-tone audiometry.
Finding the cause
There are several suggestions for why there is a link between hearing impairment and dementia. One possibility is that impaired hearing increases the likelihood of other risk factors for dementia, such as social isolation or depression. But we found little evidence to support this, with depressive symptoms and social isolation only explaining a small percentage (less than 7%) of the association between speech-in-noise hearing impairment and dementia.
It’s also possible that our findings (and those from other studies) might be detecting an association between dementia and hearing impairment when in fact both are caused by something else altogether. While we took a range of factors into account in our analyses – such as age, education level and socioeconomic status – we can’t rule out the possibility that other factors might be involved that we didn’t look at.
The other possibility is that dementia causes hearing impairment. This might seem an unusual explanation, as in our study dementia was diagnosed after hearing was measured. But the pathology of dementia typically develops years before a person receives a diagnosis. It often occurs before memory problems and other cognitive issues become apparent. This “pre-clinical” pathology results in other symptoms – such as weight loss – and could potentially cause issues with hearing.
We explored this possibility in two ways. The first was to see whether hearing impairment was associated with dementia diagnosed a long time after hearing was measured. This is because pre-clinical symptoms are more likely to manifest close to a diagnosis.
When looking at dementia diagnosed nine to 11 years after the hearing test, insufficient and poor speech-in-noise hearing was associated with a 54% and 85% increased risk of dementia. This is similar to the main findings of our study. You would have expected this group to have a lower correlation with hearing problems if pre-clinical dementia was causing them.
Our second approach was to only include people who described their health as “good”, “very good” or “excellent” at the time hearing was measured. This is because worse health might reflect the early pre-clinical symptoms of dementia. People with worse health are also probably more likely to have hearing problems.
Again, the number of people in this group who went on to develop dementia after being identified with a hearing impairment was similar to those of our initial findings. Had dementia been causing the impairment, you might have expected a disproportionately high number of those who went on to develop dementia to have been the ones already reporting generally poor health.
In both cases, this is tentative evidence that dementia might not be causing hearing impairment. But even so, some early pre-clinical symptoms of dementia can manifest decades before a diagnosis. Studies which diagnose dementia 15 or even 20 years later are necessary to disentangle these complex relationships further.
While our findings are preliminary, they add to the growing body of evidence that hearing impairment is a promising target for preventing dementia. In fact, it’s thought that if hearing impairment is indeed a cause of dementia, addressing it could prevent 8% of dementia cases in instances where dementia is not otherwise evident. This statistic is based on pure-tone audiometry hearing – so it could very well be higher when considering issues with speech-in-noise hearing.
Don’t fool around with these nuts
After eating Brazil nuts 2-3 hours prior, a man had unprotected intercourse with his 20-year-old partner who had a documented Brazil nut allergy. The woman developed urticaria, angioedema, and dyspnea. To figure out the cause of this hypersensitivity reaction, UK researchers did a skin prick test in the woman using the boyfriend’s semen both before and after eating Brazil nuts.
Apparently, some nut protein got into the semen.
“We believe this to be the first case of a sexually transmitted allergic reaction,” the researchers wrote in the Journal of Investigational Allergology and Clinical Immunology. Of note, Brazil nuts are the second most frequent nut allergy in the United Kingdom. Unfortunately for science, the couple broke up before the investigators could confirm the results.
“Our demonstration of an allergenic Brazil nut protein in the semen clearly proves the ability of such protein(s) to resist digestion. Additionally, to enter the semen, the protein would require circulation in the blood to the prostate or other reproductive organ.”
Notably, severe allergic reactions have been demonstrated in those with crustacean allergy following exposure from kissing. Also, penicillin exposure leading to allergic reaction could occur secondary to intercourse, per the literature.
The moral of this study? If you have food allergies, you might want to find out what your partner recently ate, before you get too close
Supporting menstrual health in Australia means more than just throwing pads at the problem
August 27, 2021 1.02pm AEST
- Erin C. Hunter Lecturer in Global Health, University of Sydney
- Julie Hennegan Senior Research Fellow, Burnet Institute
Erin C. Hunter has received funding for research on menstrual health. She has conducted menstrual health research funded by the Bill & Melinda Gates Foundation, Grand Challenges Canada, and The Johns Hopkins Center for Qualitative Studies in Health and Medicine. She is currently an investigator on a National Health and Medical Research Council grant to study menstrual health in Myanmar.
Julie Hennegan has received funding for research on menstrual health. This has included from foundations (The Case for Her, Bill & Melinda Gates Foundation) and research councils (she is currently an investigator on a National Health and Medical Research Council grant developing a menstrual health intervention in Myanmar). She led the development of the definition of Menstrual Health as part of the Terminology Action Group of the Global Menstrual Collective.
University of Sydney provides funding as a member of The Conversation AU.
We believe in the free flow of information
Republish our articles for free, online or in print, under Creative Commons licence.
Menstruation has recently had a bit of a moment in Australia.
Attention to menstruation is exciting and long overdue. But hurried efforts to provide free pads are not enough, particularly after decades of policy neglect.
To truly meet the needs of women, adolescent girls, and all people who menstruate, we must ask smart questions and develop evidence-based strategies for the long term.
Get your news from people who know what they’re talking about.
What is menstrual health and how do we achieve it?
This year, a collaboration of global stakeholders and experts defined menstrual health as a state of complete physical, mental and social well-being in relation to the menstrual cycle.
The authors also shed light on the breadth of menstrual health needs. These extend well beyond access to pads, and highlight a number of things we need to consider if we’re going to better support menstrual health in Australia.
1. Information about the menstrual cycle
Knowledge about menstrual biology, reproduction and self-care practices is important. Understanding the body helps prevent distress and facilitates informed decision-making. This might include choice of menstrual product or decisions to seek medical support for period-related difficulties.
Studies in high-income countries have found women and girls don’t have enough information about menstruation, and research on menstrual disorders in Australia has found deficits in menstrual health literacy.
So we must ensure adolescents have comprehensive and timely education about menstruation in schools to promote body literacy and support their menstrual health.
2. Materials and facilities to care for the body
Beyond having enough products to manage a period, menstrual health requires supportive spaces to change products, dispose of single-use materials (for example, pads and tampons) or wash reusable products (for example, menstrual cups). Spaces need to be comfortable and private.
In high-income countries, little attention has been given to whether school and workplace facilities are adequately meeting these needs. This is especially relevant as reusable products such as menstrual underwear and cups are growing in popularity.
3. Diagnosis, care and treatments for discomforts and disorders
But 92% of adolescents and young women in Australia report painful periods.
We need to see comprehensive policy that acknowledges the breadth of menstrual needs, and the varied levels of pain and discomfort associated with menstruation.
4. Positive and respectful environments
Menstruation continues to be stigmatised around the world. Social pressure to hide any sign of menstruation can dissuade girls and women from talking about their experiences or seeking support and advice. This can harm well-being.
Family members, education institutions, workplaces and government policies all have a role to play in creating environments that support those who menstruate.
For example, freedom to visit the toilet during the school day or to work flexibly around period pain can shape experiences of menstruation.
What’s the impact of unmet menstrual health needs?
A survey of young people in New Zealand found 8% reported missing school due to a lack of menstrual products.
A review of multiple studies estimated 12% of young women in high-income countries have missed school or university because of period pain.
But we have more to learn about the magnitude of these issues across populations and sub-groups.
Providing free menstrual products may seem like a “silver bullet”. But evidence from low- and middle-income countries has shown providing such products is not enough to improve menstrual health.
This is also likely to be the case in high-income countries like Australia where stigma and inadequate education around menstruation remain challenges.
What are we overlooking?
A narrow focus on providing pads and tampons also risks suppressing menstrual product choice, and overlooks opportunities to support more environmentally friendly options.
Policies in Australia focus on providing single-use products, which are not very good for the environment. A menstruating person will use thousands of disposable pads and tampons over their lifetime — a large proportion of which is plastic waste.
Technologies such as menstrual underwear, reusable pads and menstrual cups present environmentally and economically sustainable alternatives. The median cost of a menstrual cup is A$32 and it can be used for up to ten years: that’s just 25 cents per period.
Australian adolescents’ feelings about reusable products remain largely unexplored. If research shows they’re receptive to these options, funding could be directed accordingly.
For example, installing wash basins or toilet hoses inside toilet cubicles in schools could facilitate the use of menstrual cups.
To inform effective policy responses, we need robust research exploring menstrual health needs in Australia and the extent to which these contribute to broader health and education outcomes.
And if we are to sustain the support of governments over the long term, we need evidence of what works. We must invest in developing effective responses and commit to evaluating the effects of our policies in supporting girls, women and all people who menstruate.
Depression and Osteoporosis
This is another article by Professor John Studd. See his CV in my last Blog – Dracula Depression.
Download this article as a PDF (63Kb)
Published in ‘Climateric’. 2010
“PROFOX” – The post HRT nightmare
The imaginary hybrid drug PROFOX is an anxious prediction of a therapeutic disaster for post menopausal women who need treatment for low bone density, depression , pelvic atrophy and vasomotor symptoms but are denied estrogens.
Physicians and psychiatrists have been slow to accept the clear benefits of estrogen therapy in the treatment of osteoporosis and depression. Is it an honest fear of side effects, ignorance of hormone therapy, misinterpretation of the data or simply a territorial hold on the condition which then condemns women to sub optimal therapy?
Although estrogens have been proven to prevent fractures in a mixed risk population and that the benefits on bone density and histology are dose dependant it has been relegated to a treatment to be used if others fail or if the woman has severe menopausal symptoms. This protection from estrogens effects not only the skeleton but also the intervertebral discs which make up one quarter of the length of the spinal column. This latter benefit is not produced by bisphosphanates. This failure of physicians to familiarise themselves with estrogen therapy has, in their minds, been justified by the results of the WHI study and by the regulatory bodies who have advised that estrogen should not be first choice therapy for osteoporosis. But in reality the physicians objections to estrogen therapy antedated the WHI study by many years. Specialists are a product of their training which for non gynaecologists does not include the subtleties of the use , the dose and route of various estrogens , gestogens and occasionally androgens.
Updated information and interpretation of the WHI study indicates that HRT, particularly estrogen alone, is both safe and protective in the younger postmenopausal woman below the age of 60. Such therapy is associated with fewer fractures , less colon cancer , fewer heart attacks , possibly less breast cancer and certainly fewer deaths. It should, in the minds of many workers, be first line therapy in this situation. However, Fosamax Once Weekly is an inexpensive alternative recommended by NICE as first line therapy and preferred by physicians. It produces lesser skeletal and systemic benefit than estrogens but it does not confuse the medical attendant with hormonal side effects such as bleeding, mastalgia and occasional PMS symptoms. These are problems that can be dealt with by any competent general practitioner but have not been learned by specialist bone physicians and rheumatologists who also seem to be complacent about considerable long term side effects of bisphosphanates.
A similar ‘turf war’ occurs with the commonplace depression in perimenopausal women. These women with estrogen responsive depression often have a history of postnatal depression and premenstrual depression which have all been shown to be effectively treated by transdermal estrogens in good controlled trials in the most prestigious journals . It is therefore surprising that none of these studies have been repeated by those mostly responsible for the treatment of depression in women. This neglect is either due to the unlikely belief that these studies are perfect or because psychiatrists and the pharmaceutical industry do not want to show the benefits or even the superiority of estrogens. For example there is only one placebo controlled study demonstrating that transdermal estrogens are effective in treating severe premenstrual depression by suppressing ovulation but there are now 50 similar studies showing that SSRIs are useful. Why should the industry fund studies that reveal that their high profit in patent drug is less effective than the much less profitable estrogens?
Psychiatrists almost invariably refuse to accept these data relying upon psycho therapy , SSRI’s and even ECT particularly in the private sector. Once again it is to the disadvantage of the women that psychiatrists have not chosen to become aware of this modality of treatment. It is commonplace to see women with perimenopausal depression who have been taking many mood stabilizing drugs for many years .They claim to have been last well during their last pregnancy after which they started or recommenced antidepressants for post natal depression , later pre menstrual depression and climacteric depression. It is difficult to obtain precise data but antidepressants are now used by about 30% percent of women in the UK and there is even a move to use this drug for the treatment of vasomotor symptoms. It is barely effective but it is becoming a new indication for SSRI therapy.
The nightmare for the future is that postmenopausal women with hot flushes, depression , sexual problems and low bone density, who need estrogens perhaps with testosterone, will be given a SSRI and bisphosphanate combination . PROFOX, a Frankenstein combination of PROzac and FOsamaX . As these two drugs are now available as cheap generics they are already being prescribed together. Unfortunately this warning of a single preparation is not a fanciful aberration as we already have close to the market a combination of a SERM for osteoporosis combined with oestrogens to prevent the symptoms of oestrogen deficiency. This was a joke comment at a British Menopause Society debate 10 years ago but has now become a reality. Unless the regulatory authorities consider the current safety data in the under 60s and modify their resistance to HRT the spectre of PROFOX will be upon us. It is a vision of the future which must be avoided.
This article below appeared on Dr John Studd’s web site recently. (www.studd.co.uk). A look at Dr Studd’s CV would show that he is one of the worlds foremost experts on womens health and hormones’. He discusses a recent artilcle in a medical journal by a psychiatrist writing about the treatment of Depression in women, and their hormones.
Here is his Biography:
Professor John Studd, DSc,MD,FRCOG was Consultant Gynaecologist at the Chelsea & Westminster Hospital, London and also Professor of Gynaecology at Imperial College. He qualified in 1962 and has worked and trained in Birmingham. Zimbabwe and London. He was Consultant Gynaecologist in Salisbury, Rhodesia and Consultant and Senior Lecturer at the University of Nottingham and moved to London in 1974 as Consultant Obstetrician and Gynaecologist at King’s College Hospital. Six years ago he was invited to join the staff at the new Chelsea & Westminster Hospital, London.
His early research was on chronic renal disease and high blood pressure in pregnancy (MD thesis) but later started the first menopause clinic in the county in Birmingham in 1969. This hormone treatment for the menopause was so controversial at that time that the clinic was closed down for three months following protests from the BMA. However, the optimism placed in HRT has been confirmed and John Studd has continued to work on specific treatments for menopausal symptoms. He pioneered the sequential oestrogen/progestogen treatment and also the continuous combined oestrogen/progestogen non-bleeding treatment. He has championed the use of hormone implants for women with osteoporosis or with severe depressive or sexual problems after the menopause and as an almost routine route of HRT after hysterectomy.
He first described the use of oestrogen patches and oestrogen implants for the treatment of severe PMS and runs a PMS/Menopause clinic at the Chelsea & Westminster Hospital, the Lister Hospital and the Wellington Hospital.
He is also shows the efficacy of moderately high dose transdermal oestrogens for the treatment of hormone responsive depression in women, particularly post-natal depression, pre-menstrual depression, menopausal depression and post-hysterectomy depression. He has a D.Sc. for 25 years of published work on oestrogen therapy in women. He has written more than 500 scientific articles and written or edited more than 25 post-graduate books on gynaecology and realises the he needs to write one for the public. This is much more challenging.
He is Founder and Vice-President of the National Osteoporosis Society and has been a Council Member of the Royal College of Obstetricians and Gynaecologists for 12 years and a Past-President of the Section of Obstetrics and Gynaecology at the Royal Society of Medicine. In 2005-2007 Professor Studd was Chairman of the British Menopause Society.
Dr O has two items in The Obstetrician & Gynaecologist, which confirm my belief that oestrogen to psychiatrists is like garlic to Dracula. It is equally illogical. It is unbelievable that for an article on Postnatal Depression, oestrogen has a brief last paragraph footnote informing that oestrogen can act like an antidepressant by the effect upon the dopaminergic and serontonergic receptors. Indeed it does and for this and other logical reasons as well as scientific and clinical evidence that should be used in those conditions of depression in women related to changes in oestrogen levels. These will include premenstrual depression, postnatal depression and peri-menopausal depression. These have all been shown in double blind trials to be responsive, greater than placebo to transdermal oestrogens, yet the original Lancet paper showing the beneficial effect of this on postnatal depression is not featured in the text or references although the co-authors were psychiatrists, Dr Alan Gregoire and the distinguished expert on postnatal depression the late professor Chani Kumar .It is bad enough that these studies have not been repeated by those responsible for the care of depression i.e. psychiatrists but the refusal to reference and discuss such a paper is intolerable.
There is good evidence that postnatal depression, premenstrual depression and peri-menopausal depression confirm the same vulnerable women and it is a commonplace experience that depressed 45-year-old women will say that they were last well when they were last pregnant 10+ years ago. They then developed postnatal depression and were put on antidepressants. When the periods returned they developed a cyclical depression and towards the menopause the depression became less cyclical so they no longer even have 7 good days a week but every day as the depression is now continuous.
The tragedy is that these women were given antidepressants of doubtful value and certain side effects at the time of their postnatal depression. Over the years they then suffer ineffective multi-drug therapy frequently with ECT (particularly in the private sector). At this stage it is difficult for women to come off these powerful drugs, which they probably shouldn’t have had in the first place. It is true that women with postnatal depression and other types of hormone responsive depression do not have different hormone levels than those without depression. Nobody ever said that they did. It is simply a response to changes of oestrogen and no doubt progesterone in women, who, for some reason, are biochemically vulnerable to these hormonal changes.
The diagnosis of reproductive depression is not based upon blood tests but on the history relating the current depression to the history of being in good mood during pregnancy followed by postnatal depression. There is also a history of previous premenstrual depression and perhaps the history of menstrual headaches is a further clue to the cyclical and endocrinological basis for this condition.
I am very pleased that Dr. O reports that the article most read by psychiatrists last month was ‘Oestrogen relieves psychotic symptoms in women with schizophrenia’. This has of course been known for more than ten years. I am not reassured that psychiatrists have an interest in this but I would be more impressed if they actually used oestrogens for such an indication. But they do not. Similarly psychiatrists must learn how to use oestrogens for certain sorts of depression in women as an effective safe alternative to their usual armamentarium. It would surprise them to discover how frequently “bipolar depression” disappears once the cyclical mood changes of PMS are ablated by transdermal estrogens. In reality the psychiatrist’s dismissal of the evidence and refusal to study the issue further is merely a turf war resulting from their inadequate knowledge of the basic practicalities of hormone therapy.
How does COVID affect the brain? Two neuroscientists explain
August 11, 2021 6.14am AEST
- Trevor Kilpatrick Professor, Neurologist and Clinical Director, Florey Institute of Neuroscience and Mental Health
- Steven Petrou Professor and Director, Florey Institute of Neuroscience and Mental Health
Steven Petrou is an equity holder and paid consultant of Praxis Precision Medicine, though the company is not currently doing any work that relates to COVID-19. He receives funding from the Australian Government’s Medical Research Future Fund and Praxis Precision Medicines.
Trevor Kilpatrick does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.
We believe in the free flow of information
Republish our articles for free, online or in print, under Creative Commons licence.
Scientists are becoming more and more concerned with the emergence of a syndrome termed “long COVID”, where a significant percentage of sufferers of COVID-19 experience long-lasting symptoms.
The risk of long COVID is no longer thought to be directly linked with either age or the initial severity of the COVID illness. So younger people, and people with initially mild COVID, can still develop long-COVID symptoms.
Some long-COVID symptoms begin quickly and persist, whereas others appear well after the initial infection has passed.
Symptoms include extreme fatigue and ongoing breathing complications.
What particularly concerns us as neuroscientists is that many long COVID sufferers report difficulties with attention and planning — known as “brain fog”.
So how does COVID affect the brain? Here’s what we know so far.
How does the virus get to our brains?
There’s evidence connecting respiratory viruses, including influenza, with brain dysfunction. In records of the 1918 Spanish flu pandemic, reports abound of dementia, cognitive decline, and difficulties with movement and sleep.
Evidence from the SARS outbreak in 2002 and the MERS outbreak in 2012 suggest these infections caused roughly 15-20% of recovered people to experience depression, anxiety, memory difficulties and fatigue.
There’s no conclusive evidence the SARS-CoV-2 virus, which causes COVID, can penetrate the blood brain barrier, which usually protects the brain from large and dangerous blood-borne molecules entering from the bloodstream.
But there’s data suggesting it may “hitchhike” into the brain by way of nerves that connect our noses to our brains.
Researchers suspect this because in many infected adults, the genetic material of the virus was found in the part of the nose that initiates the process of smell — coinciding with the loss of smell experienced by people with COVID.
How does COVID damage the brain?
These nasal sensory cells connect to an area of the brain known as the “limbic system”, which is involved in emotion, learning and memory.
In a UK-based study released as a pre-print online in June, researchers compared brain images taken of people before and after exposure to COVID. They showed parts of the limbic system had decreased in size compared to people not infected. This could signal a future vulnerability to brain diseases and may play a role in the emergence of long-COVID symptoms.
COVID could also indirectly affect the brain. The virus can damage blood vessels and cause either bleeding or blockages resulting in the disruption of blood, oxygen, or nutrient supply to the brain, particularly to areas responsible for problem solving.
The virus also activates the immune system, and in some people, this triggers the production of toxic molecules which can reduce brain function.
Although research on this is still emerging, the effects of COVID on nerves that control gut function should also be considered. This may impact digestion and the health and composition of gut bacteria, which are known to influence the function of the brain.
The virus could also compromise the function of the pituitary gland. The pituitary gland, often known as the “master gland”, regulates hormone production. This includes cortisol, which governs our response to stress. When cortisol is deficient, this may contribute to long-term fatigue.
This was a recognised phenomenon in patients who were diagnosed with SARS, and in a disturbing parallel with COVID, people’s symptoms continued for up to one year after infection.
Given the already significant contribution of brain disorders to the global burden of disability, the potential impact of long COVID on public health is enormous.
There are major unanswered questions about long COVID which require investigating, including how the disease takes hold, what the risk factors might be and the range of outcomes, as well as the best way to treat it.
It’s crucial we begin to understand what causes the wide variation in symptoms. This could be many factors, including the viral strain, severity of the infection, the effect of pre-existing disease, age and vaccination status, or even the physical and psychological supports provided from the start of the disease.
While there are many questions about long COVID, there’s certainty about one thing: we need to continue doing everything we can to prevent escalating COVID cases, including getting vaccinated as soon as you’re eligible.
Poor gut health can lead to these chronic diseases
Recent studies have shown that certain diets can lead to poor gut health—which, in turn, can increase the risk of several neurodegenerative diseases and other chronic conditions.
Research increasingly shows that gut health plays a role in the development of brain diseases.
According to a recent review published in the Journal of Neuroinflammation, evidence is mounting that the microbiota in your gut can influence cognitive dysfunction, neurodegeneration, and the pathogenesis of certain cerebrovascular diseases. Gut microbiota can prompt the activity of cytokines and inflammation in the central nervous system, which can lead to an increased risk of developing brain conditions like depression, Alzheimer disease, autism, stroke, and more.
Authors of the review cite studies that have shown that gut health plays a role in “bidirectional brain-gut signaling through humoral, neural, and immunological pathogenic pathways.” Bacteria in the gut are altered by the kinds of foods you eat, among other factors, resulting in the production of neurotransmitters or neuromodulators in the intestine, which affect the central nervous system.
Moreover, studies using animal models have indicated that gut microbiota can affect the blood-brain barrier (BBB). For example, experiments using rodents indicate that a loss of “normal intestinal microbiota” can lead to increased permeability of the BBB, while a pathogen-free microbiota can boost BBB functionality.
While further research is required to fully understand the relationship between gut health and brain health, currently available evidence indicates that what you eat affects your gut microbiome, which affects your chances of developing certain conditions.
Based on current research, here are five diseases spurred by poor gut health, and how to tailor your diet to avoid them.
According to the aforementioned review, gut microbiota play a large role in the development of depression, stress, and anxiety.
People living with irritable bowel syndrome are more likely to exhibit symptoms of depression or anxiety, and often experience mild verbal memory dysfunctions. Evidence suggests that a contributing factor is gut-derived isovaleric acid crossing the BBB and disrupting synaptic neurotransmitter release. Fortunately, treatment with probiotics like Lactobacillus rhamnosus, can help alleviate symptoms of depression, stress, and anxiety.
While neurodegenerative diseases are characterized by the loss of neurons, one of their common features is neuroinflammation and higher intestinal permeability. According to the aforementioned review, gastrointestinal disorders are closely linked to these conditions, including Parkinson disease (PD).
Researchers noted that PD is associated with a range of intestinal dysfunctions, and that bowel inflammation can lead to neuroinflammation, which prompts dopaminergic neuronal loss. Evidence suggests that butyrate-producing and anti-inflammatory bacteria (like Blautia, Coprococcus, and Roseburia) tend to be found in significantly lower quantities in PD patients, while the pro-inflammatory Ralstonia is increased.
Studies have recently illuminated the role that microbial dysfunction plays in the activation of neuroinflammation and the formation of amyloids in the brain, both of which characterize Alzheimer disease (AD).
According to the Journal of Neuroinflammation review, the release of lipopolysaccharides (which are found in the outer membrane of gram-negative bacteria) has been found to trigger inflammation and promote amyloid fibrillogenesis in the brain. The authors also noted that the presence of bacterial metabolites in the gut has been shown to worsen AD. Conversely, research shows that probiotics (like Lactobacilli and Bifidobacteria) may improve symptoms of AD, including memory and learning dysfunction, in animal models.
While it’s commonly known that environmental factors, like obesity and smoking, can contribute to the pathogenesis of multiple sclerosis (MS), the review notes that changes to the microbiome and prevalence of “leaky gut” are often found in MS patients.
The authors of the review cite a small study, which found that poor gut microbiota profiles (for example, those with an abundance of Fusobacteria) were associated with increased risk of relapses in MS patients. Other studies have found that certain bacteria are commonly found in increased amounts in MS patients, implying that changes in the intestinal microbiota ecosystem are linked with the development of MS.
Finally, the review states that gastrointestinal microflora and infection have been linked with the immune system and, in turn, ischemic stroke processes.
The authors cite a study which demonstrated that treatment with antibiotics can increase regulatory T cells and assist in the trafficking of effector T cells following the occurrence of a stroke. Other research suggests that increases in gram-negative bacteria can increase risk of stroke.
Tailor your diet to protect your brain
Diets rich in fruits, vegetables, whole grains, and fish, like the Mediterannean-style diet or the DASH diet, have been shown to benefit brain function and lower the risk of neurodegenerative diseases by lowering gut inflammation.
On the other hand, a diet that’s high in sugars, saturated fatty acids, and animal proteins, has been shown to increase levels of bacteria like Firmicutes and Proteobacteria, which in turn increase the risk of brain dysfunction.
I often get told by patients that they are told that there is no need to take progesterone after a hysterectomy. That is WRONG. The natural Progesterone that I use has many benefits (compared to the synthetic form) and the study below confirms some of them. Also, search “Benefits of Progesterone”on my web- site to find many of the other good things that natural Progesterone does.
Review Altern Ther Health MeD
. 2017 Nov;23(6):24-32.
In Defense of Progesterone: A Review of the Literature
- PMID: 29055286
Context • The medical literature on the use of progesterone in postmenopausal women is often confusing and contradictory. Some physicians implicate natural progesterone in an increase in the risk of breast cancer. The chemical structure of natural progesterone (P4) is quite different from chemically altered, synthetic chemicals called progestins, which results in different actions at the cell level.
Objective • The research team intended to review the literature to examine the benefits and safety of natural progesterone and determine whether it can cause an increase or decrease in breast cancer risk.
Design • A review of the medical literature to examine the benefits and safety of natural progesterone as compared with synthetic progestins.
Intervention • Studies examined compared controls not receiving hormone therapy with women receiving estrogen alone and in combination with natural progesterone and with various synthetic progestins, such as medroxyprogesterone acetate-the most commonly used synthetic progestin.
Outcome Measures • Outcome measures included factors such as progression and survival of breast and other cancers and other epidemiological and laboratory data.
Results • A meta-analysis of 3 studies involving 86 881 postmenopausal women reported that the use of natural progesterone was associated with a significantly lower risk of breast cancer compared with synthetic progestins. Anovulation and low levels of serum progesterone have been associated with a significantly higher risk of breast cancer in premenopausal women. Use of progesterone has been linked to lower rates of uterine and colon cancers and may also be useful in treating other cancers such as ovarian, melanoma, mesothelioma, and prostate. Progesterone may also be helpful in preventing cardiovascular disease and preventing and treating neurodegenerative conditions such a stroke and traumatic brain injury.
Conclusions • Physicians should have no hesitation prescribing natural progesterone. The evidence is clear that progesterone does not cause breast cancer. Indeed, progesterone is protective and preventative of breast cancer
What’s up with this ‘fake’ food group?
You may have heard of “fake meat”—those plant-based meat alternatives made famous by offerings like the Impossible Whopper at Burger King, Beyond Meat, Tofurky, and many others. But, have you heard of “pseudograins”?
Have you heard of pseudocereals? Read on, they are not fake food.
Also called “pseudocereals,” these may sound like another category of “fake” food but, in fact, the term refers to plant-based grains like quinoa, amaranth, chia, and buckwheat—which have been consumed by humans since ancient times.
Unlike cereals, these plant foods include non-grasses that are dicotyledonous rather than monocotyledonous like the cereal family. Of note, the term cotyledon refers to an embryonic leaf in seed-bearing plants. Pseudocereals, however, harbor similar starch content, palatability, and texture as members of the cereal family. They are also cooked in much the same way, and are considered highly nutritional.
Let’s take a closer look at pseudocereals and their health benefits.
In precolonial times, pseudocereals were a main food source in countries such as Peru, Bolivia, and Ecuador. After the Spanish conquest, however, tastes changed, and cultivation dropped off in favor of cereals and barley, according to the authors of a review published in Critical Reviews in Food Science and Nutrition.
The authors characterized pseudocereals as “subexploited” foods, which refer to foods that have been eaten by various populations for hundreds of years but were replaced in the early 20th century by other grains and foods that are more popular in the world population diet.
They added, “Due to their agronomic characteristics, ecological adaptability to adverse conditions and high nutritional value, pseudocereals’ relevance is economic, social, ecological, nutritional and functional.”
Pseudocereals contain high-quality proteins and peptides, as well as flavonoids, phenolic acids, fatty acids, vitamins, and minerals, which contribute to proposed antioxidant, anti-inflammatory, and cardiovascular benefits. They are also gluten-free.
Pseudocereals increase natural resource diversity, and thus are environmentally friendly. They are acclimated to thrive in hostile growing conditions, thus making them an enviable alternative in countries that lack valuable protein sources and where food production is limited.
This often-mispronounced pseudocereal (keen-wa) is one of the few vegetable sources that contains all essential amino acids. Although originally endemic to the Andes, interest in this interesting crop has spread worldwide.
The authors of the aforementioned review cite research indicating the antiproliferative effects of quinoa in colon cancer cells. Preclinical research has also shown that the peptides released by quinoa digestion may have antidiabetic properties. Other properties include radical scavenging and ACE inhibition, which is important in blood pressure control.
To learn more, read Don’t miss out on these 9 essential amino acids, on MDLinx.
Long before chia became a popular food item, it was famous for being the “fur” (or “hair”) on Chia pets (ch-ch-ch-Chia!). Chia is an herbaceous plant native to Mexico and Guatemala. To date, commercial interests have focused on oil extraction, which is rich in polyunsaturated fatty acids. The seeds, however, are also a great source of protein, minerals, dietary fibers, and phenolic compounds. These nutritional benefits have contributed to the use of chia seeds in yogurts, salads, breads, and beverages.
The authors of the aforementioned review cited research supporting the antihypertensive, antioxidant, antimicrobial, and anti-inflammatory benefits of chia.
This genus of plant consists of more than 60 species and is mostly endemic to the Andes, but is grown in other parts of Central and South America to a lesser degree. Its health benefits have been hypothesized to include decreasing cholesterol levels, hindering ACE activity, and exerting antineoplastic effects in cancer cells.
“Amaranth protein-based diets have been found to reduce food intake and body weight through reduction of rat plasma ghrelin levels and increase of postprandial leptin and cholecystokinin levels, and to modify microbiota composition in a diet-induced obesity mouse model,” according to the authors of the Food and Chemical Toxicology review. “Moreover, amaranth protein improved glucose tolerance and increased plasma insulin in a streptozotocin-induced diabetes model while protein hydrolyzates exerted significant anti-hypertensive activity in spontaneously hypertensive rats, and antithrombotic effects in Wistar rats.”
Click here to learn more about amaranth and other grains at MDLinx.
Among the pseudocereals, buckwheat has the highest levels of resistant starches. These starches are hardest to digest and absorb by the small intestine. They reach the colon where they are digested by microorganisms to yield short-chain fatty acids, which are plenty healthy, and have been demonstrated to change chemotaxis and phagocytosis, trigger reactive oxygen species (ROS), modify cell proliferation and function, and exert anti-inflammatory, antitumorigenic, and antimicrobial effects, as well as changing gut integrity.
According to the authors of the aforementioned review in Food and Chemical Toxicology, resistant starches have demonstrated three proven health benefits. First, they regulate blood glucose and lipid levels. Second, they facilitate intestinal microbiota. Lastly, they reduce obesity.
How to actually fix a lost voice, according to science (hint: lemon and honey doesn’t work)
April 16, 2021 5.52am AEST
- Sandra Rojas Speech pathologist and Lecturer in Voice Disorders, Department of Speech Pathology, Orthopedics & Audiology, La Trobe University
Sandra Rojas does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.
La Trobe University provides funding as a member of The Conversation AU.
View current jobs from La Trobe University
We believe in the free flow of information
Republish our articles for free, online or in print, under Creative Commons licence.
Losing our voice, having a hoarse voice, or having any difficulties with our voice can be challenging, especially for those who need to use it for work.
For centuries, and across different cultures, people have believed home remedies to be a handy solution for different illnesses. Losing our voice isn’t an exception.
However, put simply, there’s no evidence these home remedies work to recover a lost voice. And there’s a dearth of information out there on what actually works for treating voice issues.
As a speech pathologist and lecturer in voice disorders, I help people with voice issues every day. Here’s what actually helps you recover a lost voice.
Why have I lost my voice?
There are many reasons we can develop problems with our voice. Voice quality issues can be brought on by viral infections, overuse or misuse of our voice, damage to the vocal folds, or nodules and polyps which are benign, noncancerous growths than can form on the vocal folds.
Some people such as teachers, singers, actors, clergy and lawyers are at a greater risk of developing voice difficulties. This is because they talk a lot for a living, often very loudly. https://platform.twitter.com/embed/Tweet.html?dnt=false&embedId=twitter-widget-0&features=eyJ0ZndfZXhwZXJpbWVudHNfY29va2llX2V4cGlyYXRpb24iOnsiYnVja2V0IjoxMjA5NjAwLCJ2ZXJzaW9uIjpudWxsfSwidGZ3X2hvcml6b25fdHdlZXRfZW1iZWRfOTU1NSI6eyJidWNrZXQiOiJodGUiLCJ2ZXJzaW9uIjpudWxsfX0%3D&frame=false&hideCard=false&hideThread=false&id=383913018410930176&lang=en&origin=https%3A%2F%2Ftheconversation.com%2Fhow-to-actually-fix-a-lost-voice-according-to-science-hint-lemon-and-honey-doesnt-work-158230&sessionId=f8c1b967711356555dd4b2d2370d749bb06598cb&siteScreenName=ConversationEDU&theme=light&widgetsVersion=ff2e7cf%3A1618526400629&width=550px
More often than not, what you might call “losing your voice” is the result of laryngitis, which is inflammation of the voice box (larynx). It’s often caused by a virus or overuse, and will tend to resolve in a couple of weeks.
Most home remedies don’t work for your voice
Home remedies like salt water gargles and tea with honey are mostly harmless, although there’s no evidence they work for fixing laryngitis. If you have a sore throat, they might temporarily alleviate some of this pain. But they definitely won’t reduce the roughness, hoarseness or “breathiness” of your voice.
These remedies can’t improve our voice because our vocal folds are protected by the epiglottis, so when swallowing tea or honey (or anything!), the epiglottis comes down and covers the vocal folds. The epiglottis also prevents food and drink from entering our lungs. Nothing should have direct contact with your vocal folds — if something did, it could get into the lungs and cause aspiration and pneumonia.
One thing to beware, especially if you have a reflux disorder, is consuming excessive amounts of tea and lemon. Lemon is acidic, and so are some teas, so having a lot of them could actually lead to acid reflux coming up the oesophagus and irritating your throat and vocal folds.
Read more: Explainer: what is gastric reflux?
What’s more, if you’re using home remedies, you might delay seeking professional medical attention, for example from a speech pathologist or an ear, nose and throat specialist (ENT). Delaying treatment could have further negative consequences if your voice issues are due to something more sinister than a cold or flu.
If your voice takes more than a week or two to recover, or you’re worried about your voice, it’s good to seek medical advice. Make sure to visit your GP at first, who may recommend a speech pathologist or ENT specialist.
So what does work for a lost voice?
Research suggests using a humidifier might be an effective option. This can help by keeping vocal folds hydrated, helping with the vibration of the vocal folds and therefore reducing roughness and hoarseness. Because the tiny water droplets in humidified air are inhaled rather than swallowed, they can bypass the epiglottis and have direct contact with our vocal folds.
Drinking lots of water can also benefit our vocal folds. Even though water doesn’t have direct contact with our voice box, it hydrates the cells in our body.
You should also rest your voice, although it depends on what’s causing your symptoms. In a case of acute laryngitis caused by an infection, your doctor might suggest you completely rest your voice. Similarly, if you’ve had trauma or surgery to your voice box, your doctor might suggest refraining from talking at all for a certain period.
But some ENTs won’t recommend completely resting your voice in other instances. For some voice disorders, your specialist might recommend you start doing voice exercises. One example is “straw phonation”, where you put a straw into a glass of water and speak through it in various ways, depending on the desired outcomes of the treatment.
If you have a hoarse voice but cannot rest it, it’s better to talk at a low volume in a consistent tone — but don’t whisper! Whispering too much can put more strain on your voice box than regular speech.
So if you lose your voice, don’t forget: drink lots of water, use a humidifier if you can, rest your voice, and don’t worry about gargling salt water or drinking lemon and honey tea.