South Africa’s Traditional Medicines Should be Used in Modern Health Care

Both the Khoi and the San believed in a mythical animal, resembling a cow, whose horns were thought to have medicinal attributes. This centuries-old medicine horn contained herbal remedies used by the Khoi-san. Credit: Rodger Smith

By Zelna Booth

Traditional medicines are part of the cultural heritage of many Africans. About 80% of the African continent’s population use these medicines for healthcare.

Other reasons include affordability, accessibility, patient dissatisfaction with conventional medicine, and the common misconception that “natural” is “safe”.

The growing recognition of traditional medicine resulted in the first World Health Organization global summit on the topic, in August 2023, with the theme “Health and Wellbeing for All”.

Traditional medicines are widely used in South Africa, with up to 60% of South Africans estimated to be reliant on traditional medicine as a primary source of healthcare.

Conventional South African healthcare facilities struggle to cope with extremely high patient numbers. The failure to meet the basic standards of healthcare, with increasing morbidity and mortality rates, poses a threat to the South African economy.

In my opinion, as a qualified pharmacist and academic with a research focus on traditional medicinal plant use in South Africa, integrating traditional medicine practices into modern healthcare systems can harness centuries of indigenous knowledge, increasing treatment options and provide better healthcare.

Recognition of traditional medicine as an alternative or joint source of healthcare to that of standard, conventional medicine has proven challenging. This is due to the absence of scientific research establishing and documenting the safety and effectiveness of traditional medicines, along with the lack of regulatory controls.

What are traditional medicines?

Traditional medicine encompasses a number of healthcare practices aimed at either preventing or treating acute or chronic complaints through the application of indigenous knowledge, beliefs and approaches. It incorporates the use of plant, animal and mineral-based products. Plant-derived products form the majority of treatment regimens.

Traditional medicine practices also have a place in ritualistic activities and communicating with ancestors.

South Africa is rich in indigenous medicinal fauna and flora, with about 2000 species of plants traded for medicinal purposes. In South Africa the provinces of KwaZulu-Natal, Gauteng, Eastern Cape, Mpumalanga and Limpopo are trading “hotspots”. The harvested plants are most often sold at traditional medicine muthi markets.

Uses of medicinal plants

Medicinal plants most popularly traded in South Africa include buchu, bitter aloe, African wormwood, honeybush, devil’s claw, hoodia, African potato, fever tea, African geranium, African ginger, cancer bush, pepperbark tree, milk bush and the very commonly consumed South African beverage, rooibos tea.

The most commonly traded medicinal plants in South Africa are listed below along with their traditional uses:

Buchu – Urinary tract infections; skin infections; sexually transmitted infections; fever; respiratory tract infections; high blood pressure; gastrointestinal complaints.

Bitter aloe – Skin infections; skin inflammation; minor burns.

African wormwood – Respiratory tract infections; diabetes, urinary tract disorders.

Honeybush – Cough; gastrointestinal issues; menopausal symptoms.

Devil’s claw – Inflammation; arthritis; pain.

Hoodia – Appetite suppressant.

African potato – Arthritis; diabetes; urinary tract disorders; tuberculosis; prostate disorders.

Fever tea – Respiratory tract infections; fever; headaches.

African geranium – Respiratory tract infections.

African ginger – Respiratory tract infections; asthma.

Cancer bush – Respiratory tract infections; menstrual pain.

Pepperbark tree – Respiratory tract infections; sexually transmitted infections.

Milk bush – Pain; ulcers; skin conditions.

Rooibos – Inflammation; high cholesterol; high blood pressure.

There are many ways in which traditional medicine may be used. It can be a drop in the eye or the ear, a poultice applied to the skin, a boiled preparation for inhalation or a tea brewed for oral administration.

Roots, bulbs and bark are used most often, and leaves less frequently. Roots are available throughout the year. There’s also a belief that the roots have the strongest concentration of “medicine”. Harvesting of the roots, however, poses concerns about the conservation of these medicinal plants. The South African government, with the draft policy on African traditional medicine Notice 906 of 2008 outlines considerations aimed at ensuring the conservation of these plants through counteracting unsustainable harvesting practises.

Obstacles to traditional medicine use

The limited research investigating interactions posed should a patient be making use of both traditional and conventional medicine is a concern.

During the COVID-19 pandemic, many patients used traditional remedies for the prevention of infection or treatment.

Understanding which traditional medicines are being used and how, their therapeutic effects in the human body, and how they interact with conventional medicines, would help determine safety of their combined use.

Certain combinations may have advantageous interactions, increasing the efficacy or potency of the medicines and allowing for reduced dosages, thereby reducing potential toxicity. These combinations could assist in the development of new pharmaceutical formulations.

Sharing information

The WHO in its Traditional Medicine Strategy for 2014-2023 report emphasised the need for using traditional medicine to achieve increased healthcare.

Key role players from both systems of healthcare need to be able to share information freely.

The need for policy development is key. Both conventional and traditional medicine practitioners would need to be aware of and engage with patients on all the medicines they are taking.

Understanding the whole patient

Patients often seek treatment from both conventional and traditional sources, which can lead to side effects or duplication in medications.

A comprehensive understanding of a patient’s health profile makes care easier.

This could also prevent treatment failures, promote patient safety, prevent adverse interactions and minimise risks.

A harmonious healthcare landscape would combine the strengths of both systems to provide better healthcare for all.

Zelna Booth, Pharmacist and Academic Lecturer (Pharmacy Practice Division, Department of Pharmacy and Pharmacology, University of the Witwatersrand), University of the Witwatersrand

This article is republished from The Conversation under a Creative Commons license.

Source: The Conversation

Employment Insecurity can Increase the Risk of Premature Death by 20%

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People without secure employment can reduce their risk of premature death by 20% if they gain permanent employment, according to a study published in The Journal of Epidemiology and Community.

‘Precarious employment’ is a term that is used to describe jobs with short contracts such as temping, low wages and a lack of influence and rights, all of which lead to a working life without predictability and security. In this study, Karolinska Institutet researchers examined how this affects the risk of death.

“This is the first study to show that changing from precarious employment to secure employment can reduce the risk of death,” says the paper’s last author Theo Bodin, assistant professor at the Institute of Environmental Medicine, Karolinska Institutet. “It’s the same as saying that the risk of early death is higher if one keeps working in jobs without a secure employment contract.”

The researchers used registry data from over 250 000 workers in Sweden between the ages of 20 and 55 gathered over a period from 2005 to 2017. The study included people who worked under insecure working conditions and who then shifted to secure working conditions.

Those who switched from precarious to secure employment had a 20 percent lower risk of death, regardless of what happened afterward, compared to those who remained in precarious employment. If they remained in secure employment for 12 years, the risk of death decreased by 30 percent.

“Using this large population database allowed us to take account of many factors that could influence mortality, such as age, other diseases that workers can suffer from or life changes like divorce,” explains Nuria Matilla-Santander, assistant professor at the same institute and the study’s first author. “Because of the methods we used, we can be relatively certain that the difference in mortality is due to the precariousness of employment rather than individual factors.”

She continues: “The results are important since they show that the elevated mortality rate observed in workers can be avoided. If we reduce precariousness in the labour market, we can avoid premature deaths in Sweden.”

Dr Matilla-Santander says that the next stage of the research is to examine the specific causes of mortality in this regard.

Source: Karolinska Institutet

New Genes, Natural Toxins Offer Hope for Patients with Head and Neck Cancer – and Maybe Others

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Research led by Queen Mary University of London and published in Molecular Cancer has revealed two new genes that cause head and neck cancer patients to be resistant to chemotherapy. The study also shows that silencing either gene can make cancer cells that were previously unresponsive chemotherapy subsequently respond to it.

The two genes discovered actively ‘work’ in most human cancer types, meaning the findings could potentially extend to other cancers with elevated levels of the genes.

The researchers also looked through a chemical library, commonly used for drug discovery, and found two substances that could target the two genes specifically and make resistant cancer cells almost 30 times more sensitive to a common chemotherapy drug called cisplatin. They do this by reducing the levels of the two genes and could be given alongside existing chemotherapy treatment such as cisplatin. One of these substances is a fungal toxin – Sirodesmin A – and the other – Carfilzomib – comes from a bacterium. This shows that there may be existing drugs that can be repurposed to target new causes of disease, which can be cheaper than having to develop and produce new ones.

The research is the first evidence for the genes NEK2 and INHBA causing chemoresistance in head and neck squamous cell carcinoma (HNSCC) and gene silencing of either gene overturning chemoresistance to multiple drugs.

The scientists first used a method known as data mining to identify genes that may be affecting tumour responsiveness to drug therapy. They tested 28 genes on 12 strains of chemoresistant cancer cell lines, finding 4 ‘significant’ genes that were particularly responsive that they then investigated further and tested multidrug-resistance.

Senior study author Dr Muy-Teck Teh, from Queen Mary University of London, said: “These results are a promising step towards cancer patients in the future receiving personalised treatment based on their genes and tumour type that give them a better survival rate and treatment outcome.

“Unfortunately, there are lots of people out there who do not respond to chemotherapy or radiation. But our study has shown that in head and neck cancers at least it is these two particular genes that could be behind this, which can then be targeted to fight against chemoresistance.

“Treatment that doesn’t work is damaging both for the NHS and patients themselves. There can be costs associated with prolonged treatment and hospital stays, and it’s naturally extremely difficult for people with cancer when their treatment doesn’t have the results they are hoping for.”

90% of all head and neck cancers are caused by HNSCCs, with tobacco and alcohol use being key associations. In the UK, there are 12 422 new cases of head and neck cancer each year, and the overall 5-year survival rate of patients with advanced HNSCC is less than 25%. A major cause of poor survival rates of HNSCC is because of treatment failure that stems from resistance to chemotherapy and/or radiotherapy.

Unlike lung and breast cancer patients, all HNSCC patients are treated with almost the same combinations of treatment irrespective of the genetic makeup of their cancer.

Source: Queen Mary University of London

Statins Might Reduce the Risk of Colorectal Cancer in Those with Ulcerative Colitis

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New research published in eClinicalMedicine suggests that statins might protect patients with ulcerative colitis from developing and dying from colorectal cancer. The study, by Karolinska Insitut researchers, also found that statin treatment was associated with a lower risk of death regardless of cause in patients with ulcerative colitis or Crohn’s disease.

First author Jiangwei Sun notes that previous studies have shown that the risk of colorectal cancer in patients with IBD, such as ulcerative colitis and Crohn’s disease, is 50% higher than in the general population. This is likely to be because of the chronic gut inflammation that these patients have. Researchers have long sought drugs that can reduce the inflammation-related cancer risk.

“Even though more studies are needed to confirm our results, our study suggests that statins can prevent colorectal cancer in patients with inflammatory bowel disease (IBD), which is a high-risk group for this kind of cancer,” says Dr Sun.

The observational study conducted by Dr Sun and his colleagues compared over 10 500 IBD patients from around the country, of whom half were statin users; the other half of the group, who were matched with the first, were not. After a follow-up period of, on average, 5.6 years, 70 of the statin group and 90 of the non-statin group had been diagnosed with colorectal cancer.

The effect increased over time

The protective effect was directly proportional to the length of time the patient had been on statins and could be demonstrated after two years’ treatment.

There were also fewer deaths from colorectal cancer in the statin group (20) than in the non-statin group (37) during the study period, and deaths regardless of cause (529 versus 719).

The study shows that some 200 IBD patients need to be treated with statins to avoid one case of colorectal cancer or death from the cancer within ten years of treatment onset. The protective effect was only statistically valid for patients with ulcerative colitis.

“We think this is because the study contained fewer patients with Crohn’s disease,” explains Dr Sun. “More and larger studies compiling data from patient populations in many countries will probably be needed to achieve statistical significance for Crohn’s disease.”

Significantly fewer deaths

To avoid death regardless of cause during the same ten-year period, the number of treated patients dropped to 20, on account of how statins also protect against more common conditions, such as cardiovascular disease. Statins were linked to fewer deaths in both ulcerative colitis and Crohn’s disease patients.

The study was based on the ESPRESSO-cohort, which is run by its initiative-taker Jonas F Ludvigsson, paediatrician at Örebro University Hospital and professor at Karolinska Institutet, and the study’s last author.

“In that we can combine tissue data from patients with colorectal cancer with data from Swedish health registries, we’re uniquely placed to study the long-term effects of drugs for IBD,” he says. “Our hope is that these studies will improve the care of IBD patients.”

The most solid evidence so far

According to the researchers, the new results provide the most solid evidence so far that statins could be an effective prophylactic for colorectal cancer among people with IBD. However, more knowledge must be gathered before the treatment can be recommended in general guidelines.

“More studies are needed to ascertain if there is a causal relationship, at what point of the pathological process statins should be administered, what a reasonable dose would be and how long treatment needs to last if it’s to be of benefit,” says Dr Sun.

Source: Karolinska Institut


Clinical Researchers Discover Four New Factors that Predict Atrial Fibrillation

UK researchers have developed a new way of identifying patients at risk of atrial fibrillation (AF). While not life threatening, the condition increases people’s risk of having a transient ischaemic attack (TIA) or stroke by up to five times. A new study, published in the European Journal of Preventive Cardiology, reveals four specific factors that can predict which patients will have atrial fibrillation.

The researchers investigated clinical and echocardiographic parameters for AF and found that the combination of advanced age, increased DBP, increasing lateral PA (time interval from the beginning of the P wave on the surface electrocardiogram to the beginning of the A′ wave on pulsed wave tissue Doppler of the lateral mitral annulus), and impaired LA reservoir strain is associated with AF. Other studies have linked most of these factors have been linked with an increased risk of AF in stroke survivors.

The team went on to create an easy tool for doctors to use in practice to identify those at high risk, which they hope will help diagnose and treat more patients, reducing their risk of future strokes.

Lead researcher Prof Vassilios Vassiliou, from UEA’s Norwich Medical School and Honorary Consultant Cardiologist at the Norfolk and Norwich University Hospital, said: “Identifying who is at high risk and more likely to develop atrial fibrillation is very important.

“This is because it requires specific treatment with anticoagulants, commonly known as blood thinners, to reduce the risk of future strokes.

“Patients who have had a stroke usually undergo multiple investigations to determine the cause of the stroke, as this can influence the treatment they receive long-term.

“These investigations include prolonged monitoring of the heart rhythm with a small implantable device called a loop recorder, and an ultrasound of the heart, called an echocardiogram.”

The research team collected data from 323 patients across the East of England, treated at Cambridge University Hospitals NHS Foundation Trust, who had had a stroke with no cause identified- known as Embolic Stroke of Undetermined Source.

They analysed medical records as well as data from prolonged heart rhythm monitoring. They also studied their echocardiograms.

Prof Vassiliou said: “We determined how many of these patients were found to have atrial fibrillation up to three years following their stroke, and went on to perform a thorough assessment to identify if there are specific parameters that are connected with atrial fibrillation identification.

“We identified four parameters that were linked with the development of atrial fibrillation, which were consistently present in patients that had this arrhythmia. We then developed a model that can be used to predict who will show atrial fibrillation in the next three years, and is therefore at increased risk of another stroke in the future.”

“This is a very easy tool that any doctor can use in clinical practice,” he added.

“And it can potentially help doctors provide more targeted and effective treatment to these patients, ultimately aiming to highlight the people at higher risk of this arrhythmia that can benefit from prolonged heart rhythm monitoring and earlier anticoagulation to prevent a future stroke.”

Source: University of East Anglia

Study Reveals Global Differences in Sleep Patterns

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Using data from a consumer sleep tracker, a new study has shown that not only do people in Asia go to sleep later and have shorter sleep, they also have lower sleep quality than those in other parts of the world. The study, published in Sleep Medicine, also showed that South Africans, Australians and New Zealanders went to bed and rose earlier than the other parts of the world included in the research, but also got the most sleep.

This finding surfaced after a team of researchers from the Centre for Sleep and Cognition at the Yong Loo Lin School of Medicine, National University of Singapore (NUS Medicine) in partnership with Oura Health Oy (Finland), analysed 50 million nights of anonymised sleep data, contributed by over 220 000 users of the “Oura Ring”, a consumer sleep tracker, from across 35 countries. Most of the users were working adults, aged between 30 and 55 years. To provide a comprehensive analysis of sleep measures for each user, the team gathered sleep data from multiple nights across a whole year – on average, each user contributed 242 nights of data. Weekday and weekend sleep were analysed separately to assess the impact of the working week on sleep patterns.

The results showed that people in Asia have shorter sleep, and display higher variability in both sleep timing and duration on weekdays. They also fall asleep later than those living in Europe, Oceania and North America. Previous studies have shown that shorter sleep duration is usually associated with higher sleep efficiency as people try to make the most of their sleep opportunity; however, in this study, despite sleeping less, people in Asia also had lower sleep efficiency. This may be because factors that result in short sleep (eg, work-related anxiety) also lead to lower quality sleep.

People often sleep for longer at the weekends than during the week, a phenomenon known as weekend sleep extension. While there was a clear association between shorter weekday sleep and longer weekend sleep extension, suggesting that people caught up on sleep at the weekend, even after accounting for this, people in Asia had the shortest weekend sleep extension.

While there are many socio-cultural factors that affect sleep patterns, the team hypothesises that because it plays such a fundamental role in our lives, work (and the broader work culture) is one of the most influential factors affecting how we sleep. Previous evidence from time use studies have demonstrated a strong association between long work hours and short sleep. Additionally, there is evidence that preoccupation with work demands and the inability to stop thinking about work contribute to sleep disturbances.

Dr Adrian Willoughby, Senior Research Fellow at NUS Medicine’s Centre for Sleep and Cognition, said, “In Europe, weekends are generally considered time for relaxation, and engaging in social activities with friends and family. In Asia, however, people may use the weekends to catch up on work, do the things they didn’t have time for during the week or attend to more family responsibilities. We think that longer working hours and the difference in work culture in Asia means that people don’t catch up on sleep as much at the weekends, but try to catch up whenever they have the opportunity over the course of the week.”

Prof Michael Chee, Director of the Centre for Sleep and Cognition at NUS Medicine said, “Sleep is a significant issue to address, especially for people living in Asia, who seem to sleep less than other global regions. Access to such a large dataset has allowed us to have unique insights into global sleep patterns. This research enables us to work towards our goal of giving customised sleep advice that considers individual sleep needs, environment factors and larger socio-cultural pressures that affect sleep. We want people to practise sleep routines that fit different contexts, but also promote health, well-being and performance.”

Source: National University of Singapore, Yong Loo Lin School of Medicine

Antioxidants Boost Tumour Growth by Stimulating Blood Vessel Formation

In this image from a genetically engineered mouse model, lung cancer driven by the Kras oncogene shows up in purple. As a key driver in many types of cancer, the Kras gene makes a promising target for new cancer therapies. Credit: National Cancer Institute, National Institutes of Health

A new study from Karolinska Institutet shows that vitamin C and other antioxidants stimulate the formation of new blood vessels in lung cancer tumours. Published in The Journal of Clinical Investigation, this discovery corroborates the idea that dietary supplements containing antioxidants can accelerate tumour growth and metastasis.

“We’ve found that antioxidants activate a mechanism that causes cancer tumours to form new blood vessels, which is surprising, since it was previously thought that antioxidants have a protective effect,” says study leader Martin Bergö, professor and vice president of Karolinska Institutet in Sweden. “The new blood vessels nourish the tumours and can help them grow and spread.”

Antioxidants neutralise free oxygen radicals, which can damage the body, and are therefore commonly found in dietary supplements. But overly high doses can be harmful.

“There’s no need to fear antioxidants in normal food but most people don’t need additional amounts of them,” says Professor Bergö. “In fact, it can be harmful for cancer patients and people with an elevated cancer risk.”

Previously unknown mechanism

Professor Bergö’s research group has previously shown that antioxidants like vitamin C and E accelerate the growth and spread of lung cancer by stabilising a protein called BACH1. BACH1 is activated when the level of free oxygen radicals drops, which happens, for example, when extra antioxidants are introduced via the diet or when spontaneous mutations in the tumour cells activate endogenous antioxidants. Now the researchers have been able to show that the activation of BACH1 induces angiogenesis, the formation of new blood vessels .

While hypoxia is known to be required for angiogenesis to occur in cancer tumours, the new mechanism identified by the researchers demonstrates that tumours can form new blood vessels in the presence of normal oxygen levels as well. The study also shows that BACH1 is regulated in a similar way as the HIF-1α protein – a mechanism that was awarded the 2019 Nobel Prize in Physiology or Medicine and that allows cells to adapt to changes in oxygen levels. HIF-1α and BACH1 work together in the tumours, the new research shows.

Hoping for more effective drugs

“Many clinical trials have evaluated the efficacy of angiogenesis inhibitors, but the results have not been as successful as anticipated,” says Ting Wang, doctoral student in Professor Bergö’s group at Karolinska Institutet. “Our study opens the door to more effective ways of preventing angiogenesis in tumours; for example, patients whose tumours exhibit high levels of BACH1 might benefit more from anti-angiogensis therapy than patients with low BACH1 levels.”

The researchers used a range of cell-biological methods and concentrated most of their work on lung cancer tumours by studying organoids, as well as mice and samples of human breast and kidney tumours. Tumours in which BACH1 was activated, either via ingested antioxidants or by overexpression of the BACH1 gene, produced more new blood vessels and were highly sensitive to angiogenesis inhibitors.

“The next step is to examine in detail how levels of oxygen and free radicals can regulate the BACH1 protein, and we will continue to determine the clinical relevance of our results,” says Ting Wang. “We’ll also be doing similar studies in other cancer forms such as breast, kidney and skin cancer.”

Source: Karolinska Institute

Fathers Who Smoked as Young Teens Pass Epigenetic Changes to Offspring

A new study suggests boys who smoke in their early teens risk damaging the genes of their future children, increasing their chances of developing asthma, obesity and low lung function.

This research, published in Clinical Epigenetics, is the first human study to reveal the biological mechanism behind the impact of fathers’ early teenage smoking on their children.

Researchers from the University of Southampton and the University of Bergen in Norway investigated the epigenetic profiles of 875 people, aged 7 to 50, and the smoking behaviours of their fathers.

They found epigenetic changes at 19 sites mapped to 14 genes in the children of fathers who smoked before the age of 15. These changes in the way DNA is packaged in cells (methylation) regulate gene expression (switching them on and off) and are associated with asthma, obesity and wheezing.

“Our studies in the large international RHINESSA, RHINE and ECRHS studies have shown that the health of future generations depends on the actions and decisions made by young people today – long before they are parents – in particular for boys in early puberty and mothers/grandmothers both pre-pregnancy and during pregnancy,” says Professor Cecilie Svanes from the University of Bergen and Research Director of the RHINESSA study. “It is really exciting that we have now been able to identify a mechanism that explains our observations in the cohorts.”

‘Unique markers’

“Changes in epigenetic markers were much more pronounced in children whose fathers started smoking during puberty than those whose fathers had started smoking at any time before conception,” says co-lead author of the paper Dr Negusse Kitaba, Research Fellow at the University of Southampton. “Early puberty may represent a critical window of physiological changes in boys. This is when the stem cells are being established which will make sperm for the rest of their lives.”

The team also compared the paternal preconception smoking profiles with people who smoked themselves and those whose mothers smoked before conception.

“Interestingly, we found that 16 of the 19 markers associated with fathers’ teenage smoking had not previously been linked to maternal or personal smoking,” says Dr Gerd Toril Mørkve Knudsen from the University of Bergen and co-lead author of the study. “This suggests these new methylation biomarkers may be unique to children whose fathers have been exposed to smoking in early puberty.”

Teenage vaping ‘deeply worrying’

The number of young people smoking has fallen in the UK in recent years. But co-author Professor John Holloway, from the University of Southampton and the NIHR Southampton Biomedical Research Centre, is concerned about children taking up vaping.

“Some animal studies suggest that nicotine may be the substance in cigarette smoke that is driving epigenetic changes in offspring,” says Professor Holloway. “So it’s deeply worrying that teenagers today, especially teenage boys, are now being exposed to very high levels of nicotine through vaping.

“The evidence from this study comes from people whose fathers smoked as teenagers in the 60s and 70s, when smoking tobacco was much more common. We can’t definitely be sure vaping will have similar effects across generations, but we shouldn’t wait a couple of generations to prove what impact teenage vaping might have. We need to act now.”

The new findings have significant implications for public health. They suggest a failure to address harmful exposures in young teenagers today could damage the respiratory health of future generations, further entrenching health inequalities for decades to come.

Source: University of Southampton

Can Taking Statins after an Intracerebral Haemorrhage Reduce the Risk of Another Stroke?

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Patients who have had an intracerebral haemorrhage who take cholesterol-lowering drugs called statins may have a lower risk of having another stroke, especially ischaemic stroke, compared to people who also had an intracerebral haemorrhage but were not taking statins, according to a new study published in Neurology, the medical journal of the American Academy of Neurology.

“Previous research has had mixed results on the risk of stroke in people who are taking statins and have already had a bleeding stroke, so we evaluated this further,” said study author David Gaist, MD, PhD, of the University of Southern Denmark in Odense and a member of the American Academy of Neurology. “We looked at whether use of statins after a bleeding stroke is associated with the risk of any additional stroke, including both those caused by bleeding and by blood clots. We found that those who used statins had a lower risk of stroke, notably ischaemic stroke, while there was no change in the risk of bleeding stroke.”

For the study, researchers looked at health records in Denmark and identified 15 151 people who had a first bleeding stroke.

People were followed from 30 days after their first bleeding stroke until the first occurrence of another stroke, death, or the end of follow-up, which on average lasted 3.3 years. Researchers used prescription data to determine information on statin use.

Researchers then compared 1959 people who had another stroke to 7400 people who did not have another stroke who were similar in age, sex and other factors. Of those who had another stroke, 757 people, or 39%, took statins compared to 3044 people, or 41%, of those who did not have a second stroke.

After adjusting for factors like hypertension, diabetes and alcohol use, statin use was associated with a 12% lower risk of another stroke.

Then they compared 1073 people who had an ischaemic stroke to 4,035 people who did not have another stroke. Of those who had an ischaemic stroke, 427 people, or 40%, took statins compared to 1687 people, or 42%, of those who did not have another stroke.

After adjusting for similar factors, statin use was associated with a 21% lower risk of an ischaemic stroke after the initial bleeding stroke.

They also compared 984 people who had another bleeding stroke to 3755 people who did not have another stroke. Of those who had a recurrent bleeding stroke, 385 people, or 39%, took statins compared to 1532 people, or 41%, of those who did not have another stroke.

After adjustments, researchers did not find a link between statin use and recurrent bleeding stroke.

“The results of our study are good news for people taking statins who have had a bleeding stroke,” Gaist added. “While we did find a lower risk of having another stroke, it is important to note that when looking at the data more closely, that lower risk was for ischaemic stroke. Still, we found no increased risk for bleeding stroke. More studies are needed to confirm our findings.”

A limitation of the study was that it only included the Danish population, which is primarily people of European ancestry, and may not be generalisable to people from other populations.

Source: American Academy of Neurology

High Levels of Metal In Blood and Urine of Exclusive Marijuana Users

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Researchers have detected significant levels of metals in the blood and urine among marijuana users, concluding that marijuana may be an important and under-recognised source of lead and cadmium exposure. This is among the first studies to report biomarker metal levels among marijuana users and most likely the largest study to date, that links self-reported marijuana use to internal measures of metal exposure, rather than just looking at metal levels in the cannabis plant. The results are published online in the journal Environmental Health Perspectives.

Measurements reported by participants for exclusive marijuana use compared to nonmarijuana-tobacco had significantly higher lead levels in blood (1.27ug/dL) and urine (1.21ug/g creatinine). 

“Because the cannabis plant is a known scavenger of metals, we had hypothesised that individuals who use marijuana will have higher metal biomarker levels compared to those who do not use,” said first author Katelyn McGraw, postdoctoral researcher. “Our results therefore indicate marijuana is a source of cadmium and lead exposure.”

The researchers, from Columbia University Mailman School of Public Health, combined data from the National Health and Nutrition Examination Survey for the years 2005-2018, a biannual programme of studies designed to assess the health and nutritional status of adults and children in the U.S.

McGraw and colleagues classified the 7254 survey participants by use: non-marijuana/non-tobacco, exclusive marijuana, exclusive tobacco, and dual marijuana and tobacco use. Five metals were measured in the blood and 16 in urine. 

The researchers used four NHANES variables to define exclusive marijuana and tobacco use: current cigarette smoking, serum cotinine levels, self-reported ever marijuana use, and recent marijuana use. Exclusive tobacco use was defined as individuals who either answered yes to ‘do you now smoke cigarettes, or if individuals had a serum cotinine level >10ng/mL.

The study found higher levels of cadmium (Cd) and lead (Pb) in blood and urine among participants reporting exclusive marijuana use compared to non-smokers. Cd and Pb levels were also higher in exclusive marijuana users who reported using marijuana within the last week. Cd biomarker levels were higher in those who smoked only marijuana than , either because of differences in frequency of use or differences in Cd levels in the tobacco and cannabis plants themselves. However, blood and urinary Pb levels among exclusive marijuana users and exclusive tobacco users were similar. Dual marijuana and tobacco users also had higher levels of Cd and Pb compared with non-smokers.

These observations marijuana use is an important and underrecognised source of Cd and Pb exposure independent of tobacco use, the researchers concluded.

Marijuana is the third most commonly used drug in the world behind tobacco and alcohol. As of 2022, 21 states and Washington D.C., covering more than 50 percent of the U.S. population, have legalised recreational use of marijuana; and medical marijuana is legal in 38 states and Washington D.C. However, because marijuana is still illegal at the federal level, regulation of contaminants in all cannabis-containing products remains piecemeal and there has been no guidance from federal regulatory agencies like the FDA or EPA. As of 2019, 48.2 million people, or 18% of Americans, report using marijuana at least once in the last year.

While 28 states regulate inorganic arsenic, cadmium, lead, and total mercury concentrations in marijuana products, regulation limits vary by metal and by state. 

“Going forward, research on cannabis use and cannabis contaminants, particularly metals, should be conducted to address public health concerns related to the growing number of cannabis users,” said Tiffany R. Sanchez, PhD, assistant professor of environmental health sciences at Columbia Public Health, and senior author.