Washington, Jul 23 (AP/UNB) — Millions of people who take aspirin to prevent a heart attack may need to rethink the pill-popping, Harvard researchers reported Monday.

A daily low-dose aspirin is recommended for people who have already had a heart attack or stroke and for those diagnosed with heart disease.

But for the otherwise healthy, that advice has been overturned. Guidelines released this year ruled out routine aspirin use for many older adults who don't already have heart disease — and said it's only for certain younger people under doctor's orders.

How many people need to get that message?

Some 29 million people 40 and older were taking an aspirin a day despite having no known heart disease in 2017, the latest data available, according to a new study from Harvard and Beth Israel Deaconess Medical Center. About 6.6 million of them were doing so on their own — a doctor never recommended it.

And nearly half of people over 70 who don't have heart disease — estimated at about 10 million — were taking daily aspirin for prevention, the researchers reported in Annals of Internal Medicine.

"Many patients are confused about this," said Dr. Colin O'Brien, a senior internal medicine resident at Beth Israel who led the study.

After all, for years doctors urged people to leverage aspirin's blood-thinning properties to lower the chances of a first heart attack or stroke. Then last year, three surprising new studies challenged that dogma. Those studies were some of the largest and longest to test aspirin in people at low and moderate risk of a heart attack, and found only marginal benefit if any, especially for older adults. Yet the aspirin users experienced markedly more digestive-tract bleeding, along with some other side effects. .

In March, those findings prompted a change in guidelines from the American Heart Association and American College of Cardiology:

—People over 70 who don't have heart disease — or are younger but at increased risk of bleeding — should avoid daily aspirin for prevention.

—Only certain 40- to 70-year-olds who don't already have heart disease are at high enough risk to warrant 75 to 100 milligrams of aspirin daily, and that's for a doctor to decide.

Nothing has changed for heart attack survivors: Aspirin still is recommended for them.

But there's no way to know how many otherwise healthy people got the word about the changed recommendations.

"We hope that more primary care doctors will talk to their patients about aspirin use, and more patients will raise this with their doctors," O'Brien said.

Sydney, July 19 (Xinhua/UNB) -- Tooth decay and other oral diseases present a major global public health crisis with sugar as the main culprit, according to a Series on oral health published in The Lancet medical journal on Friday.

The Series brought together 13 experts from 10 different countries to explore why oral diseases have persisted globally over the last three decades, despite scientific advancements in the field.

Currently, oral diseases are among the most common in the world, affecting an estimated 3.5 billion people, yet oral health has been largely ignored by the global health community, the experts said.

Co-author, Professor Marco A Peres from Australia's Griffith university joined his colleagues in calling for radically improved global dental care, increased regulation of the sugar industry and more transparency of scientific studies which may be falling victim to conflicts of interest.

"I think that there is a global health challenge regarding oral disease," Peres told Xinhua.

"It's a big challenge and we recognize in the papers that the traditional approach to managing dental disease probably fails."

Peres and his colleagues identify three main determinants, being sugar, tobacco and alcohol, among which sugar is the single greatest contributor to deteriorating oral health worldwide.

While there have been some countries which have adopted a tax on sugar products with promising results, according to Peres in other countries such as Australia, powerful interest groups are exerting their influence to avoid the measure.

"Many public health, academic and consumer groups support a tax on sugar, but political support is limited and there is a strong lobby against the implementation of a sugar tax led by sugary drinks companies," he said.

The Series authors also suggest that oral health be less removed from general health, with dentistry rarely being thought of as a mainstream part of healthcare policy, despite its intrinsic link to health and wellbeing.

"A clear need exists for broader accessibility and integration of dental services into healthcare systems, especially primary care, and for oral health to have more prominence within universal health coverage commitments," said Dr. Jocalyn Clark, an executive editor at The Lancet.

"Everyone who cares about global health should advocate to end the neglect of oral health."

Beijing, July 19 (Xinhua/UNB) -- Chinese scientists will begin the second-phase clinical trial of an HIV vaccine on 160 volunteers, Friday's China Daily reported.

The candidate vaccine, DNA-rTV, relies on replication of the DNA of HIV to stimulate effective immunization, according to Shao Yiming, a chief HIV researcher at the Chinese Center for Disease Control and Prevention, adding that it's the first such HIV vaccine to begin a second-phase clinical trial.

This vaccine under development, which contains DNA segments from HIV instead of the full human immunodeficiency virus, will have a stronger and longer-lasting effect. It is also designed to target the HIV strains that are most common in China, Shao was cited by the newspaper as saying.

More than 130 volunteers have been recruited so far, and the initial work is underway at a hospital in Beijing and another in the city of Hangzhou, he added.

"Hopefully the second-phase trial will be completed in the latter half of 2021, and the third-phase clinical trial may start at the end of that year, which will involve thousands of volunteers in a trial to test the effectiveness of the vaccine to protect people against HIV," Shao said.

Washington, Jul 19 (AP/UNB) — The Environmental Protection Agency rejected a key legal challenge Thursday to a pesticide linked to brain damage in children, saying environmental groups had failed to prove that a ban was warranted.

The agency's defense of continued use of the widely used bug-killer chlorpyrifos could set the stage for a pivotal federal court decision on whether to overrule the EPA and force the agency to ban it.

"To me, this starts the clock on the use of chlorpyrifos on food crops in the US," said former senior EPA attorney Kevin Minoli.

Scientists say studies have shown that chlorpyrifos damages the brains of fetuses and children. The pesticide has been used nationally on dozens of food crops, but California — the nation's largest agricultural state — and a handful of other states have recently moved to ban it.

The agency said the environmental groups had failed to prove that the pesticide wasn't safe.

Last summer, a three-judge panel of the 9th Circuit Court of Appeals ordered the EPA to ban all sales of the pesticide. The court decided to reconsider that ruling with a slate of 11 judges, who gave the EPA until this month to respond to the environmental groups' arguments for banning chlorpyrifos.

The EPA under the Obama administration had initiated a ban, but the agency reversed that decision shortly after President Donald Trump took office.

The EPA defense Thursday showed that "as long as the Trump administration is in charge, this EPA will favor the interests of the chemical lobby over children's safety," said Ken Cook, head of the Environmental Working Group environmental advocacy organization.

In a statement, the EPA said it was separately speeding up a regular agency review of the pesticide's continued use, and expected a decision on that well ahead of a 2022 deadline.

The EPA said it also was talking with chlorpyrifos makers about further restrictions on how farmers use the pesticide.

New York, Jul 18 (AP/UNB) — U.S. overdose deaths last year likely fell for the first time in nearly three decades, preliminary numbers suggest.

The Centers for Disease Control and Prevention on Wednesday posted data showing nearly 68,000 drug overdose deaths were reported last year. The number may go up as more investigations are completed, but the agency expects the tally will end up below 69,000.

Overdose deaths had been climbing each year since 1990, topping 70,000 in 2017.

The numbers were celebrated by the U.S. secretary of health and human services. "Lives are being saved, and we're beginning to win the fight against this crisis," Alex Azar wrote in a tweet.

But the overdose death rate is still about seven times higher than it was a generation ago.

"We're still in a pretty sad situation that we need to address," said Rebecca Haffajee, a University of Michigan researcher.

Researchers do not believe this is the start of a dramatic decline. Data from the first months of this year likely will show that the decrease is not gaining steam, said Farida Ahmad of the CDC's National Center for Health Statistics.

The improvement was driven by a drop in deaths from heroin and prescription painkillers. Those falls were offset somewhat by continuing growth in deaths involving a different opioid, fentanyl, as well as other drugs such cocaine and methamphetamines. Overdose deaths often involve more than one drug.

The improvement is not uniform: Some states seem to be making dramatic progress, while deaths continue to rise in others. The preliminary CDC data suggested deaths last year were down by as many as 1,000 or more in Ohio and Pennsylvania — each seeing declines of about 20%. Meanwhile, deaths increased by about 17% in Missouri, which had more than 200 additional deaths.

It can take months for authorities to complete toxicology tests and other elements of a death investigation involving drugs. And some states report faster than others. The CDC is expected to report more complete data later this year.

The current overdose epidemic has killed more people than any other in U.S. history, and it had been on a soaring trajectory. From 2014 to 2017, overdose deaths jumped by 5,000 or more each year.

Experts trace the epidemic's origins to 1995 and the marketing of the prescription painkiller OxyContin. It was meant be safer and more effective than other prescription opioids, but some patients got hooked and found they could crush the tablets and snort or inject them to get high.

Gradually, many turned to cheaper street drugs such as heroin and fentanyl. In 2015, heroin began causing more deaths than prescription painkillers or other drugs. In 2016, fentanyl and its close cousins became the biggest drug killer, and in 2018 they were involved in about 46% of the reported overdose deaths, according to the preliminary CDC data.

Strategies to reduce drug overdose deaths have included tougher policing, treatment program expansions, policies to limit opioid painkiller prescriptions and wider distribution of the overdose-reversing drug naloxone.

Haffajee and other researchers are trying to figure out what measures are most responsible for the slight improvement.

"It's complicated because there are so many policies going on, and as an evaluator it's very hard to separate them out and determine which is working," she said.

Valerie Hardcastle, a Northern Kentucky University administrator who oversees research and other work on local health issues, has seen the overdose epidemic play out in her region, near Cincinnati. She believes a major factor is Narcan, a nasal spray version of naloxone, that has been widely distributed through the efforts of philanthropists and local, state, and federal officials.

"It's fantastic that we have fewer deaths, don't get me wrong," she said. "But I'm not sure it's an indication that the opioid problem per se is diminishing. It's just that we have greater availability of the drugs that will keep us alive."