Day: August 6, 2022

Early Europeans drank milk for thousands of years before they evolved the ability to fully digest it as adults, scientists say.

New results published in the journal Nature suggest that being able to digest the lactose in milk wasn’t usually much of an advantage for ancient people in Europe. Instead, the new study suggests that famine and disease made lactose intolerance deadly.

The new discovery challenges the long-standing assumption that dairy farming spread through ancient populations alongside the genetic quirks that prevent adults from losing the ability to digest lactose.

Like other young mammals, human children produce an enzyme called lactase that breaks down lactose. The gene for lactase usually turns off in adulthood because aside from humans, adult mammals don’t drink milk.

Without lactase, lactose from milk ends up feeding gut microbes that produce gas, which can cause uncomfortable digestive problems.

“You’ll get some cramps. You’ll get some diarrhea. Might fart a bit more. It might be unpleasant for you,” said geneticist Mark Thomas of University College London, who led the genetics work for the new study. “It might be embarrassing, but you’re not going to die.”

But when our ancient ancestors suffered through plagues or famines, getting diarrhea from drinking milk was probably more than just uncomfortable, the authors suggest.

“Then we’re talking about a life-threatening condition,” Thomas said.

About one-third of people alive today have a genetic variant that keeps their lactase gene from turning off. This trait has evolved independently multiple times in the ancestors of people now living in parts of Africa, the Middle East, South Asia and Europe.

Scientists long assumed that lactase persistence evolved alongside the spread of dairy farming, which happened over a few thousand years beginning around 7000 BC.

However, earlier studies revealed that lactase persistence was vanishingly rare in Europe until about 3,000 years ago. But after that, it took only a few thousand years for the trait to become widespread — the blink of an eye in evolutionary time.

Why this trait would evolve so quickly was a mystery.

“Lactase persistence has been under enormous amounts of natural selection over the last eight to ten thousand years … more than any other part of the genome in Europeans,” said Thomas. “It was, for a very long period of time, the one trait upon which life and death pivoted more than any other. … It’s insane. It just defies explanation.”

Searching for an explanation, the authors sought to reconstruct the history of milk use in the region over the past 9,000 years. They examined fat residues left on more than 7,000 pottery shards collected at 550 archaeological sites across Europe.

“When people were cooking … fat liquefies and then penetrates into the pores of the pottery,” said organic geochemist and study co-author Mélanie Roffet-Salque of the University of Bristol. “It’s quite stunning, really. But thousands of years later when archaeologists excavate a piece of pottery that had been discarded and then we analyze the pottery, it’s still there.”

The pottery shards showed that milk consumption was widespread across most of Europe for thousands of years before most Europeans became lactose tolerant.

Studying health data on modern Britons, the researchers didn’t find any evidence that drinking milk hurts the health of modern adults who don’t produce lactase.

Surprisingly, using data on ancient population fluctuations to approximate when and where ancient Europeans dealt with famine and disease, the researchers found that sickness and hunger might explain the evolution of lactase persistence better than milk consumption.

Famine could have forced ancient people to drink more milk than usual as other food sources ran out. And both malnutrition and disease could have made lactose-induced diarrhea very dangerous. Severe diarrhea can kill — it is still the second leading cause of death for children under 5 worldwide.

Shevan Wilkin, a biomolecular archaeologist at the University of Zurich who reviewed the new paper, said the research was an important step forward but that she’s not necessarily convinced that famine and disease alone can explain the evolution of lactase persistence.

“The reason I don’t know if I think they’re right, I also don’t know if I think they’re wrong, is before 2,000 years ago, there were absolutely times of famine,” Wilkin said.

Thomas said he’d like to see similar studies done in Africa, where lactase persistence evolved independently three different times. Wilkin agreed, noting that Europe is over-studied, and that future research should focus on other regions, including central Asia, where people drink lots of milk despite lacking a genetic variant that keeps lactase from turning off in adults.

“I think it’d be really interesting to apply this [in] multiple places,” said Wilkin. “It’s just such a cool and ambitious undertaking, and I think it’s really going to spur a ton of new studies.”
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Scientists say that climate change is increasing the likelihood of lightning strikes across the United States, after lightning struck at a square near the White House, leaving three people dead and one more in critical condition. 

The hot, humid conditions in the U.S. capital on Thursday were primed for electricity. Air temperatures topped out at 34 degrees Celsius, 3 C higher than the 30-year normal maximum temperature for August 4, according to the National Weather Service. 

More heat can draw more moisture into the atmosphere, while also encouraging rapid updraft, two key factors for charged particles that lead to lightning. A key study released in 2014 in the journal Science warned that the number of lightning strikes could increase by 50% in this century in the United States, with each 1 C of warming translating into a 12% rise in the number of lightning strikes. 

Fast-warming Alaska has seen a 17% rise in lightning activity since the cooler 1980s. And in typically dry California, a siege of 14,000 lightning strikes during August 2020 sparked some of the state’s biggest wildfires on record. 

Beyond the United States, there is evidence that lightning strikes are also shooting up in India and Brazil. 

Bolts rarely hit people

But even as lightning strikes increase, being hit by one is still extremely rare in the United States, experts say. Roughly 40 million lightning bolts touch down in the country every year, according to the U.S. Centers for Disease Control and Prevention, with the odds of being struck at less than 1 in a million. 

Among those who are hit, about 90% survive the ordeal, the CDC says. The country counted 444 deaths from lightning strikes from 2006 through 2021. 

The two men and two women struck by lightning on Thursday while visiting Washington’s Lafayette Square, just north of the White House, were not so lucky when a bolt hit the ground during a violent afternoon thunderstorm. 

The lightning hit near a tree that stands meters from the fence that surrounds the presidential residence and offices across from the square, which is often crowded with visitors, especially in the summer months. 

All four victims suffered life-threatening injuries and were taken to area hospitals. Two later died: James Mueller, 76, and Donna Mueller, 75, from Janesville, Wisconsin, the Metropolitan Police Department said. 

“We are saddened by the tragic loss of life,” the White House said in a statement on Friday. “Our hearts are with the families who lost loved ones, and we are praying for those still fighting for their lives.” 

Later Friday a third victim, a 29-year-old male, was pronounced dead, the Metropolitan Police Department said. Further details on the victim were being withheld until the person’s family could be notified. 

Because heat and moisture are often needed to make lightning, most strikes happen in the summer. In the United States, the populous, subtropical state of Florida sees the most people killed by lightning. 
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As a sex worker and adult film actor, Roc was relieved when he was among the first Spaniards to get a monkeypox vaccine. He knew of several cases among men who have sex with men, which is the leading demographic for the disease, and feared he could be next. 

“I went home and thought, ‘Phew, my God, I’m saved,’ ” the 29-year-old told The Associated Press. 

But it was already too late. Roc, the name he uses for work, had been infected by a client a few days before. He joined Spain’s steadily increasing count of monkeypox infections that has become the highest in Europe since the disease spread beyond Africa, where it has been endemic for years. 

He began showing symptoms: pustules, fever, conjunctivitis and tiredness. Roc was hospitalized for treatment before getting well enough to be released. 

Spanish health authorities and community groups are struggling to check an outbreak that has killed two young men. They reportedly died of encephalitis, or swelling of the brain, that can be caused by some viruses. Most monkeypox cases cause only mild symptoms. 

Spain has confirmed 4,942 cases in the three months since the start of the outbreak, which has been linked to two raves in Europe, where experts say the virus was likely spread through sex. 

The only country with more infections than Spain is the much larger United States, which has reported 7,100 cases. 

Global count

In all, the global monkeypox outbreak has seen more than 26,000 cases in nearly 90 countries since May. There have been 103 suspected deaths in Africa, mostly in Nigeria and Congo, where a more lethal form of monkeypox is spreading than in the West. 

Health experts stress that this is not technically a sexually transmitted disease, even though it has been mainly spreading via sex among gay and bisexual men, who account for 98% of cases beyond Africa. The virus can be spread to anyone who has close, physical contact with an infected person, their clothing or bed sheets. 

Part of the complexity of fighting monkeypox is striking a balance between not stigmatizing men who have sex with men, while also ensuring that both vaccines and pleas for greater caution reach those currently in the greatest danger. 

Spain has distributed 5,000 shots of the two-shot vaccine to health clinics and expects to receive 7,000 more from the European Union in the coming days, its health ministry said. The EU has bought 160,000 doses and is donating them to member states based on need. The bloc is expecting another 70,000 shots to be available next week. 

To ensure that those shots get administered wisely, community groups and sexual health associations are targeting gay men, bisexuals and transgender women. 

In Barcelona, BCN Checkpoint, which focuses on AIDS/HIV prevention in gay and trans communities, is now contacting at-risk people to offer them one of the precious vaccines. 

Pep Coll, medical director of BCN Checkpoint, said the vaccine rollout is focused on people who are already at risk of contracting HIV and are on preemptive treatment, men with a high number of sexual partners and those who participate in sex with the use of drugs, as well as people with suppressed immune responses. 

But there are many more people who fit those categories than doses, about 15,000 people just in Barcelona, Coll said. 

The lack of vaccines, which is far more severe in Africa than in Europe and the U.S., makes social public health policies key, experts say. 

Contact tracing more difficult

As with the coronavirus pandemic, contact tracing to identify people who could have been infected is critical. But, while COVID-19 could spread to anyone simply through the air, the close bodily contact that serves as the leading vehicle for monkeypox makes some people hesitant to share information. 

“We are having a steady stream of new cases, and it is possible that we will have more deaths. Why? Because contact tracing is very complicated because it can be a very sensitive issue for someone to identify their sexual partners,” said Amós García, epidemiologist and president of the Spanish Association of Vaccinology. 

Spain says that 80% of its cases are among men who have sex with men and only 1.5% are women. But García insisted that will change unless the entire public, regardless of gender or sexual orientation, grasps that having various sexual partners creates greater risk. 

Given the dearth of vaccines and the trouble with contact tracing, more pressure is being put on encouraging prevention. 

From the start, government officials ceded the leading role in the get-out-the-word campaign to community groups. 

Sebastian Meyer, president of the STOP SIDA association dedicated to AIDS/HIV care in Barcelona’s LGBTQ community, said the logic was that his group and others like it would be trusted message-bearers with person-by-person knowledge of how to drive the health warning home. 

Community associations that represent gay and bisexual men have bombarded social media, websites and blogs with information on monkeypox safety. Officials in Catalonia, the region including Barcelona that has over 1,500 cases, are pushing public service announcements on dating apps Tinder and Grindr warning about the disease. 

But Meyer believes fatigue from the COVID-19 pandemic has played a part. Doctors advise people with monkeypox lesions to isolate until they have fully healed, which can take up to three weeks. 

“When people read that they must self-isolate, they close the webpage and forget what they have read,” Meyer said. “We are just coming out of COVID, when you couldn’t do this or that, and now, here we go again. … People just hate it and put their heads in the sand.”
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