tag:theconversation.com,2011:/us/topics/hyperbaric-oxygen-30770/articlesHyperbaric oxygen – The Conversation2021-09-15T10:02:20Ztag:theconversation.com,2011:article/1678182021-09-15T10:02:20Z2021-09-15T10:02:20ZAlzheimer’s disease: hyperbaric oxygen proposed as treatment in new study<figure><img src="https://images.theconversation.com/files/420827/original/file-20210913-18-r4oh3m.jpg?ixlib=rb-1.1.0&rect=12%2C24%2C8012%2C5305&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">People wearing masks while having oxygen therapy in hyperbaric chamber.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/group-mixed-age-people-wearing-masks-1400143358">Drazen Zigic/Shutterstock</a></span></figcaption></figure><p>Alzheimer’s disease, the most common form of dementia, has long been associated with a build-up of plaques (clumps of protein) in the brain. <a href="https://www.aging-us.com/article/203485/text">Scientists in Israel</a> have shown that a type of oxygen therapy can stop new plaques forming and even remove existing plaques in mice with Alzheimer’s.</p>
<p>The scientists used a mouse model of Alzheimer’s disease called 5xFAD. The genetically modified mice were treated with hyperbaric oxygen therapy to see if they could halt or slow the disease progression.</p>
<p>Hyperbaric oxygen therapy involves breathing pure oxygen in a pressurised chamber. In the chamber, the air pressure is increased two to three times higher than normal air pressure. It is commonly used to treat decompression sickness (a condition scuba divers can suffer from), carbon monoxide poisoning, and some forms of stroke or brain injury. It works by forcing increased oxygenation of tissues with low oxygen levels (hypoxia). And it could improve blood flow to the brain to nourish brain cells that are usually deprived of blood, and hence oxygen, in Alzheimer’s disease.</p>
<p>The scientists, from the University of Tel Aviv, treated 15 six-month-old mice (about 30 human years) with hyperbaric oxygen therapy for an hour a day, five days a week for four weeks. The therapy not only reduced the number and size of plaques in the brains of the mice, it also slowed the formation of new plaques, compared with a control group of mice who did not receive hyperbaric oxygen therapy. </p>
<p>Blood flow to the brain is reduced in people with Alzheimer’s. This study showed increased blood flow to the brain in the mice receiving oxygen therapy, which helps with the clearance of plaques from the brain, and reduces inflammation – a hallmark of Alzheimer’s.</p>
<p>By improving blood flow to the brain, reducing plaque levels and reducing hypoxia, the mice undergoing daily oxygen therapy began to show improvements to their cognitive abilities, such as their spatial recognition memory as well as contextual memory – the ability to remember emotional, social, spatial or temporal circumstances related to an event.</p>
<h2>Not just mice</h2>
<p>The researchers then used these findings to assess the effectiveness of oxygen therapy in six people over the age of 65 with cognitive decline. They found that 60 sessions of oxygen therapy, over 90 days, increased blood flow in certain areas of the brain and significantly improved the patients’ cognitive abilities – improved memory, attention and information processing speed.</p>
<p><a href="https://pubmed.ncbi.nlm.nih.gov/34483143/">An earlier study</a> found that oxygen therapy reduced plaques in the brain in another mouse model of Alzheimer’s disease. And, before that, my colleagues and I <a href="https://pubmed.ncbi.nlm.nih.gov/32371859/">published a study</a> in Scientific Reports which showed that pure oxygen at normal atmospheric pressure can increase the blood volume in the brains of six-month-old mice with Alzheimer’s disease, and this may be able to increase the clearance of plaques from the brain. </p>
<p>Taken together, these findings suggest that oxygen therapy may be able to reduce cognitive decline associated with ageing and dementia in both mice and people. </p>
<p>“I don’t think this can ‘cure’ Alzheimer’s in humans,” Professor Uri Ashery, lead author of the research, <a href="https://www.timesofisrael.com/oxygen-therapy-may-slow-alzheimers-say-israeli-researchers-after-mice-study/">told The Times of Israel</a>, “but it may be able to significantly slow its progression and severity.” </p>
<p>However, it is important to note that the Israeli study was too small to draw any firm conclusions. Also, 60 sessions of pressurised oxygen therapy lasting an hour each is simply not feasible for most people. </p>
<p>Hyperbaric oxygen therapy cannot yet be offered at home or in a care home, where most people with Alzheimer’s will be based. And daily visits to a hospital or clinic is not a practical thing to do for most people with the disease. </p>
<p>The chambers cost up to £100,000, with around an additional £1,500 on maintenance a year. And treatments cost between £40 and £250 per session. Given that there are close to a million people with dementia in the UK alone, it is clear that offering every patient hyperbaric oxygen therapy for 60 days is not currently workable or economically viable. And the results, while promising in mice, still need to be confirmed in people with Alzheimer’s in large clinical trials.</p><img src="https://counter.theconversation.com/content/167818/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Osman Shabir 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.</span></em></p>Hyperbaric oxygen therapy helped to reduce plaques in the brains of mice with Alzheimer’s disease.Osman Shabir, Postdoctoral Research Associate, University of SheffieldLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/978142018-08-06T10:38:30Z2018-08-06T10:38:30ZWhy stretching is (still) important for weight loss and exercise<figure><img src="https://images.theconversation.com/files/226553/original/file-20180706-122253-dtg8nn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Many athletes stretch before and after exercise, but they may not be gaining benefits from doing so.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/portait-blond-girl-getting-streching-her-171343079">ESB Basic/shutterstock.com</a></span></figcaption></figure><p>There seems to be a lot of confusion regarding the value – or lack thereof – of <a href="https://www.tandfonline.com/doi/full/10.1080/15438627.2016.1258640">muscle stretching</a> to accelerate recovery after exercise. “Stretching clears out your lactic acid,” and other similar claims abound. Is any of this true?</p>
<p>Sort of.</p>
<p>First, it is important to understand the difference between stretching for recovery and stretching for remodeling. </p>
<h2>Recovery</h2>
<p>During exercise, muscles are called upon to work. During this work, fuel is used up, waste products are created and muscle fiber structure is disrupted by multiple micro tears. Imagine a banquet, for comparison, during which the food is eaten, garbage is accumulated (napkins, chicken bones, etc.), and the table settings disrupted. Before the next banquet, the food needs to be restocked, the garbage cleared, and the tables reset. </p>
<p>For muscles, this process of resetting for the next event is called recovery. The muscle is returned to <a href="https://www.frontiersin.org/articles/10.3389/fphys.2018.00403/full">full function</a> without soreness. </p>
<p>This is not the process that leads to body change per se, but it is important for athletes who wish to compete at their highest level multiple times during a short period. </p>
<p>Athletes have tried many things to speed up recovery: cryotherapy, massage, compression, ice water immersion, stretching, <a href="https://sbrsport.me/2017/06/21/hyperbaric-medicine-injury-recovery-basics/">hyperbaric oxygen</a>, anti-inflammatories and <a href="https://breakingmuscle.com/learn/science-says-electrical-myostimulation-can-speed-recovery">electromyostimulation</a>, just to name a few. These interventions are aimed at decreasing lactic acid, inflammatory markers and other molecules that build up following intense exercise.</p>
<p>Of these, only massage is consistently effective. Multiple studies have shown that stretching does not aid significantly in <a href="http://www.wingate.org.il/_Uploads/17barnett-usingrecovery-2006.pdf">waste removal</a> or serve in any capacity to accelerate muscle recovery. </p>
<h2>Remodeling</h2>
<p>Most of us aren’t training for professional competitions, though, but are exercising to be healthy, lose weight and improve our moods. </p>
<p>For that, we need to focus on our body’s <a href="https://www.sciencedirect.com/science/article/pii/S1550413112005037">remodeling response</a> to exercise, which is not the same as recovery from exercise.</p>
<p>Plainly said, when we exercise consistently, our bodies adapt to that stressor by changing our muscle structure, metabolism and physiology. It is that change, that remodeling, that leads to all the positive benefits of exercise. To stick with our banquet example, if we realized that 500 people are going to show up at every event, but we only have 10 tables set at present, we would change our capacity to be ready for the next event. We would increase the efficiency in the kitchen and set more tables. Likewise, our body remodels itself to adapt to increasing exercise.</p>
<p>Many studies also have been conducted to determine how to optimize the body’s remodeling response to exercise. After <a href="https://www.ncbi.nlm.nih.gov/pubmed/29623692">35-plus years of study</a>, six variables emerge as consistently aiding the body in its effort to reorganize in response to exercise: timing of nutritional intake (specifically protein), type of exercise, massage, sleep, low-dose creatine and – you guessed it – stretching. </p>
<p>Perhaps the most well-known and accepted benefits of muscle stretching exercises are improved or maintained range of motion, or both; alignment of bones and joints; and strengthening of connective tissues – all elements that optimize performance. Many studies have shown that <a href="https://www.sciencedirect.com/science/article/pii/S0167945716301786">flexibility training</a> (dedicated attention over time to muscle stretching as part of an exercise program) directly improves muscle function, and ultrasound images have documented favorable alterations in muscle architecture following weeks of regular stretching, such as longer fibers. What’s more, a recent study has clearly shown that <a href="https://www.ncbi.nlm.nih.gov/pubmed/29623692">stretching</a> over time improves blood flow to the muscles during subsequent exercise in animals. </p>
<p>Prior negative commentary around <a href="https://well.blogs.nytimes.com/2013/04/03/reasons-not-to-stretch/">muscle stretching</a> may be misleading to the casual observer. It is true that studies have shown static stretching routines (reach, hold for 30 seconds, release, next stretch) prior to a workout or competition lead to decreases in strength during that event, and that stretching before activity does not prevent injuries, as was long thought. But these are very specific circumstances that don’t apply to most people. </p>
<h2>So do I stretch or not?</h2>
<p>If you are an elite athlete trying to decrease injury, increase strength or accelerate muscle recovery right before your next event – then no.</p>
<p>If you are most people, exercising to lose weight, be well and improve mood – then yes. It will help with muscle remodeling, connective tissue strengthening, range-of-motion improvement, joint alignment and potentially blood flow during subsequent exercise – all beneficial effects in the long run.</p><img src="https://counter.theconversation.com/content/97814/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>J. David Prologo does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Who hasn’t been told to stretch before and after exercise to prevent injury and improve performance? There may be no scientific evidence to back that up, although stretching has other benefits.J. David Prologo, Associate Professor, Department of Radiology and Imaging Sciences, Emory UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/644052016-09-01T09:05:26Z2016-09-01T09:05:26ZMultiple sclerosis survivors swear by hyperbaric oxygen – but does it work?<figure><img src="https://images.theconversation.com/files/135530/original/image-20160825-6604-m3202w.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="http://www.shutterstock.com/pic-372222991/stock-photo-pocatello-idaho-usa-july-22-2010-hyperbaric-chambers-in-a-wound-care-centerto-sped-healing.html?src=QWomzBGTmTc12487VVZilg-1-3">B Brown/Shutterstock</a></span></figcaption></figure><p>There is no cure for multiple sclerosis (MS) yet. As a complex neurodegenerative disease of the brain, it is incredibly difficult to treat. Despite the development of new and sophisticated therapies to control the inflammation and physical symptoms of the disease, these treatments don’t work for everyone. This is because MS comes in many guises and one treatment does not fit all. Perhaps for this reason people with MS are turning to alternative means of controlling their condition. </p>
<p>Many of the 100,000 people with MS in the UK have taken charge of managing their treatment. With the assistance of 60 or more independent charitable MS therapy centres, people with the disease regularly enter a chamber and breathe oxygen under moderate pressure (<a href="https://www.hyperbaricoxygentherapy.org.uk">hyperbaric oxygen</a>). Some people have done so for <a href="http://www.jpands.org/vol10no4/maxfield.pdf">more than 20 years</a>. </p>
<p>The air we breathe contains 21% oxygen, but 100% oxygen is considered a drug and is prescribed in hospitals to aid people’s recovery. In the case of MS, people <a href="http://www.oxygenunderpressure.com/category/multiple-sclerosis/">self-prescribe the hyperbaric oxygen</a>, which is delivered to them by trained operators. But does breathing pure oxygen under pressure on a weekly basis do them any good? </p>
<p>The idea to use oxygen as a treatment for MS began over 45 years ago. In 1970, two Romanian doctors, Boschetty and Cernoch, treated patients with brain injuries with pressurised oxygen <a href="http://www.ncbi.nlm.nih.gov/pubmed/4314654">to help more oxygen enter their tissues</a> – oxygen helps protect nerve cells from damage and maintains the integrity of the <a href="http://www.brainfacts.org/brain-basics/neuroanatomy/articles/2014/blood-brain-barrier">blood-brain barrier</a>. In a study of MS patients, they found that symptoms in 15 out of 26 volunteers improved. This led to further interest in the use of hyperbaric oxygen to treat MS specifically. </p>
<p>Since Boschetty and Cernoch’s discovery, around 14 clinical trials have been conducted. The trials have been on relatively small numbers of people and have reported conflicting results, <a href="http://onlinelibrary.wiley.com/doi/10.1111/j.1755-5949.2009.00129.x/full">ranging from great improvements to none at all</a>. This has led to a dilemma: should clinicians endorse the use of hyperbaric oxygen for MS or not? </p>
<h2>Not officially sanctioned</h2>
<p>The clinical regulatory bodies in the US and the UK, <a href="http://www.fda.gov/ForConsumers/ConsumerUpdates/ucm364687.htm">the FDA</a> and <a href="https://www.nice.org.uk/donotdo/interventions-affecting-disease-progression-hyperbaric-oxygen-should-not-be-used-in-patients-with-multiple-sclerosis-because-research-evidence-does-not-show-beneficial-effects-on-the-course-of-the">NICE</a> respectively, do not feel the clinical trial evidence is strong enough to endorse the procedure, yet thousands of people in the UK and elsewhere continue to treat themselves with hyperbaric oxygen. Between 1982 and 2011, over 20,000 people with MS in the UK used hyperbaric oxygen <a href="http://www.hjernebarnet.dk/fileadmin/_temp_/Philip_James_-110405.pdf">over 2.5m times</a>. </p>
<p><a href="http://www.nhs.uk/conditions/Multiple-sclerosis/Pages/Introduction.aspx">Multiple sclerosis</a> is a chronic inflammatory disease of the brain. It is usually diagnosed between the ages of 20 and 40. Lesions in the brain develop as a result of inflammatory autoimmune cells crossing the blood-brain barrier and destroying the protective protein coat (myelin) that surrounds the axon of some nerve cells. Over time MS develops into a neurodegenerative disease, leading to problems with vision, bladder control and mobility. </p>
<p>The brain’s ability to repair some of this damage helps people with MS to feel better for a while before relapsing once more. Eventually the disease becomes chronic and the ability to repair the damage and undergo remission declines. Most conventional treatments focus on the early phases of the disease. Unfortunately, there are few treatments for the later stages of MS. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/135521/original/image-20160825-6625-11w4vb8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/135521/original/image-20160825-6625-11w4vb8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=444&fit=crop&dpr=1 600w, https://images.theconversation.com/files/135521/original/image-20160825-6625-11w4vb8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=444&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/135521/original/image-20160825-6625-11w4vb8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=444&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/135521/original/image-20160825-6625-11w4vb8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=558&fit=crop&dpr=1 754w, https://images.theconversation.com/files/135521/original/image-20160825-6625-11w4vb8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=558&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/135521/original/image-20160825-6625-11w4vb8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=558&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption"></span>
</figcaption>
</figure>
<p>Perhaps the inability of prescribed drugs that work for all people with MS, or indeed work for some but <a href="http://www.ncbi.nlm.nih.gov/pubmed/15596735">produce unpleasant side-effects</a>, has driven people to seek other treatments. Despite the scepticism of some doctors, many people with MS claim that hyperbaric oxygen therapy <a href="http://www.express.co.uk/life-style/health/452441/Oxygen-therapy-Fresh-air-relief-for-Multiple-Sclerosis-patients">has benefits</a>. The <a href="http://www.msntc.org.uk/downloads/Perrins_and_James_IJNN_vol_2_issue_1_2005.pdf">benefits</a> include improvements in mobility, bladder control, pain relief and gait. However, since the treatment is transient, regular exposure to pressurised oxygen is required to sustain any benefit. </p>
<p>The increase in oxygen to the brain may lead to a number of effects such as speeding repair to damaged tissue, or inhibiting the ability of immune cells to cross the blood-brain barrier and cause damage. These possibilities are <a href="https://www.dovepress.com/safety-and-efficacy-of-hyperbaric-oxygen-therapy-in-chronic-wound-mana-peer-reviewed-fulltext-article-CWCMR">being investigated</a>. </p>
<h2>Poorly designed trials</h2>
<p>So why are many clinicians sceptical of hyperbaric oxygen? The main reason is various MS disability-status scores are used to judge improvement. In the former clinical trials, hyperbaric oxygen was not used over a sustained periods of time (only a few weeks) and often people with irreversible damage were used, so no or <a href="http://www.nejm.org/doi/full/10.1056/NEJM198301273080402">very little improvement in scores was seen</a>. </p>
<p>So are poorly controlled clinical trials to blame for the conflict of opinion? Probably, yes. Until we understand more at the molecular level about how oxygen under pressure can make sustained changes to various biological processes in the brain, people with MS will continue to use the treatment and the majority of the medical community will remain unconvinced of its merits.</p><img src="https://counter.theconversation.com/content/64405/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Paul Eggleton 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.</span></em></p>There is conflicting medical evidence.Paul Eggleton, Senior lecturer in Immunology, University of ExeterLicensed as Creative Commons – attribution, no derivatives.