Day: January 17, 2022

MS Likely Caused by Epstein-Barr Virus

Source: NCI on Unsplash

Multiple sclerosis (MS) is likely caused by infection with the Epstein-Barr virus (EBV), according to a new Harvard University study.

“The hypothesis that EBV causes MS has been investigated by our group and others for several years, but this is the first study providing compelling evidence of causality,” said senior author Professor Alberto Ascherio. “This is a big step because it suggests that most MS cases could be prevented by stopping EBV infection, and that targeting EBV could lead to the discovery of a cure for MS.” The findings were published in Science.

Currently incurable, MS is a chronic inflammatory disease of the central nervous system that attacks the myelin sheaths protecting neurons in the brain and spinal cord. One of the top suspects for its cause is EBV, a herpes virus that can cause infectious mononucleosis and establishes a latent, lifelong infection of the host. Establishing a causal relationship between the virus and the disease has been hard because EBV infects approximately 95% of adults, MS is relatively rare, and the onset of MS symptoms begins about ten years after EBV infection. To determine the connection between EBV and MS, the researchers conducted a study among over 10 million US military personnel, identifying 955 who were diagnosed with MS during their period of service.

The team analysed serum samples taken twice a year by the military and determined the soldiers’ EBV status at time of first sample and the relationship between EBV infection and MS onset during the period of active duty. In this cohort, the risk of MS increased 32-fold after infection with EBV but remained unchanged after infection with other viruses. Serum levels of neurofilament light chain, a biomarker of the nerve degeneration typical in MS, increased only after EBV infection. The findings cannot be explained by any known risk factor for MS and suggest EBV as the leading cause of MS.

The delay between EBV infection and the onset of MS may be partly a result of the disease’s symptoms being undetected early on and partly the evolving relationship between EBV and the host’s immune system, which is repeatedly stimulated whenever latent virus reactivates.

“Currently there is no way to effectively prevent or treat EBV infection, but an EBV vaccine or targeting the virus with EBV-specific antiviral drugs could ultimately prevent or cure MS,” Prof Ascherio said.

Source: Harvard University

Consumption of Olive Oil Reduces Risk of Premature Death

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A new study has found that people who consume higher amounts of olive oil may lower their risk of premature death overall and from specific causes including cardiovascular disease, cancer, and neurodegenerative disease, compared to people who never or almost never consume olive oil. People who consumed olive oil instead of animal fat were also found to have a lower risk of total and cause-specific mortality.

“Olive oil consumption has been linked to lower cardiovascular disease risk, but its association with premature death was unclear,” said Marta Guasch-Ferré, a senior research scientist in the Department of Nutrition at Harvard Chan School. “Our findings confirm current dietary recommendations to replace animal fats with plant oils for the prevention of chronic diseases and premature death.”

The researchers used health data collected between 1990 and 2018 for 60 582 women participating in the Nurses’ Health Study and 31 801 men in the Health Professionals Follow-up Study. All participants were free of cardiovascular disease or cancer at the study start.

Participants were asked how often they used olive oil in salad dressings, added to food or bread, or in baking or frying. According to the findings, people in the highest category of olive oil consumption (> 7g/day) had 19% lower risk of total and cardiovascular disease mortality, 17% lower risk of cancer mortality, 29% lower risk of neurodegenerative mortality, and 18% lower risk of respiratory mortality, compared with those who never or rarely consumed olive oil. Compared to margarine, butter, mayonnaise, or dairy fat, olive oil usage was correlated with reduced risk of total and cause-specific mortality. However no significant risk reduction was seen compared to use of other vegetable oils.

“Clinicians should be counselling patients to replace certain fats, such as margarine and butter, with olive oil to improve their health,” advised Guasch-Ferré. “Our study helps make specific recommendations that will be easy for patients to understand and hopefully implement into their diets.”

The findings were published in the Journal of the American College of Cardiology.

Source: Harvard University

Ozone Linked to Cognitive Impairment with Age

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A robust link has been established between long-term ozone exposure and an increased risk of cognitive impairment in older adults, according to a large-scale study published in Environment International.

Air pollution has long been considered a major risk factor for an ageing society. Fine airborne particulate matter can lead to dementia and other cognitive disabilities. But beyond airborne particles, little is known about the way in which other pollutants can pose a similar danger.

The researchers chose to focus on ambient ozone, a highly reactive gas that exists in much of smog at ground level. They then observed health outcomes in nearly 10 000 older adults across China and analysed the extent to which long-term ozone exposure may have impacted their cognitive ability over time.

The results, they found, were startling. For every 10 microgram increase of yearly average ozone exposure, the risk for cognitive impairment grew by more than 10%. Through their analysis, the researchers also found that this association held even when they abstracted away individual risk factors such as smoking, drinking and education level. That is, older adults in China who were exposed to high levels of yearly ozone pollution were more likely to develop cognitive disabilities later in life, no matter what other activities they were involved in.

“Our findings suggest potential benefits in delaying the progression of cognitive decline among older adults if ozone levels are reduced below the new WHO Global Air Quality Guideline for ozone pollution,” said Kai Chen, Ph.D., assistant professor at the Yale School of Public Health and the study’s lead author.

The researchers acknowledged limitations such as observational data being unable to establish a causal link. More research is needed into ozone’s destructive mechanism. And since many older adults in China spend more time indoors, their ozone exposure may be different.

Nonetheless, the findings match what other researchers have found in areas across the globe: Over the past several years, studies have traced a similar link in adults in the United States and in Taiwan, and have also found an association between ozone exposure and other neurological diseases.

The study shows that ozone exposure needs to be curbed worldwide to prevent healthcare systems from being overwhelmed as populations age and pollution increases.

Study co-author Professor Robert Dubrow said what makes this issue more urgent is that “ozone pollution is projected to be worsening under climate change.” Reducing this threat could bring significant benefits to public health and improve quality of life.

Source: Yale University

Politics Makes People Sick – Literally

Photo by Andy Feliciotti on Unsplash

According to a new US study, all the political jockeying is harmful to our health, has been for some time, and even a change in party power didn’t help.

Political scientist Kevin Smith followed up a landmark 2017 survey study where he measured the effects of the political climate on Americans’ physical, social, mental and emotional health. Smith repeated the same 32-question survey twice in 2020 – two weeks prior to the election, and two weeks after. The 2020 findings mirrored the 2017 results, and again found that a large proportion of American adults blame politics for causing them stress, loss of sleep, fractured relationships and more.

Similar to the 2017 findings, the results of the 2020 surveys, published in PLOS One, showed that an estimated 40% of Americans identified politics as a significant source of stress. Between a fifth and a third of US adults also blamed politics for causing fatigue, feelings of anger, loss of temper and triggering compulsive behaviours. About a quarter of adults reported they’d given serious consideration to moving because of politics.

That the results remained mostly stable after nearly four years is cause for alarm, Smith said.

“This second round of surveys pretty conclusively demonstrates that the first survey was not out of left field – that what we found in that first survey really is indicative of what many Americans are experiencing,” Smith, chair and professor of political science, said. “It’s also unpleasant to think that in that span of time, nothing changed. A huge chunk of American adults genuinely perceive politics is exacting a serious toll on their social, their psychological and even their physical health.”

Smith repeated the survey with the same group of people both before and after the election to see if the election’s outcome would recast people’s perceptions.

“We wondered if a change in presidency, which indeed was the case, would shift attitudes, and the short answer is no,” Smith said. “If anything, the costs that people perceive politics is exacting on their health increased a little bit after the election.”

Smioth was most surprised at the repeated finding that 5% of Americans blame politics for having suicidal thoughts.

“One in 20 adults has contemplated suicide because of politics,” Smith said. “That showed up in the first survey in 2017, and we wondered if it was a statistical artifact. But in the two surveys since, we found exactly the same thing, so millions of American adults have contemplated suicide because of politics. That’s a serious health problem.”

Those most likely to be negatively affected by politics were younger, more often Democratic-leaning, more interested in politics and more politically engaged.

“If there’s a profile of a person who is more likely to experience these effects from politics, it’s people with those traits,” Smith said.

This could mean problems for democracy if this trend continued. Smith suggested investigating whether civic education had a positive effect, as those who were more knowledgeable about politics seemed to be less affected.

Source: University of Nebraska

Fourth Wave Ending as COVID Becomes Endemic

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Speaking to  the media on Friday, Dr Joe Phaahla said that vaccinations had “uncontestably” lowered the rate of hospitalisations as seen by reduced hospital admissions in the fourth wave. saying that there has been a decoupling between new infections and hospital admissions and deaths. An article awaiting peer review on the medRxiv preprint server shows evidence of this in Cape Town.

Vaccinations were still lower than expected, despite a renewed vaccination drive from 17 December, a situation he attributed to people focussing on their festivities. As of Thursday, 45.5% of all SA adults had received at least one dose, with just under 40% being fully vaccinated. However, only 31.6% of 18–34 year olds have been vaccinated. About one million doses have been administered to the newly opened 12–17 year age group.

In an interview with eNCA, Dr Phaahla said that he concurs with experts that COVID is heading towards becoming an endemic disease, emphasising that South Africa is prepared for this. A new dashboard is to be unveiled which will show the number of vaccinated and unvaccinated in hospitals.

Dr Phaahla has also said that the issue of mandatory vaccinations is currently being deliberated by the government and that an announcement will be made in due course. In the US, the Supreme Court blocked President Biden’s vaccine mandate for large companies, which is seen as a significant blow to his administration’s COVID response plan.

The NICD’s Dr Michelle Groome said that almost 99% of all COVID cases sequenced are caused by Omicron. Gauteng, has exited the fourth wave with a low rate of new cases (1.4 cases per 100 000) and slight (2.2%) increase, likely attributable to increased testing. All other provinces had observed a decrease in weekly incidence of new cases, save Northern Cape (21.9 per 100 000, 18.3% increase). A 14.3% positivity rate was seen as of 13 January, down from highs above 35% in mid-December.

Test positivity rate had fallen from 25–30% in the last week of 2022 to 14% on Thursday.