An international team of astronomers has discovered the remnant of an ancient collection of stars that was torn apart by our own galaxy, the Milky Way, more than two billion years ago.

A new blood test demonstrated remarkable promise in discriminating between persons with and without Alzheimer’s disease and in persons at known genetic risk may be able to detect the disease as early as 20 years before the onset of cognitive impairment, according to a large international study published today in the Journal of the American Medical Association (JAMA) and simultaneously presented at the Alzheimer’s Association International Conference.

• A woman’s eggs may be able to choose which sperm to accept
• Chemical signals released by the eggs ‘attract’ certain sperm
• This means that egg-sperm chemical dynamics may make particular egg-sperm combinations work better

People have certain qualities they look for in a mate, and now a new study finds that a woman’s eggs may be choosy about sperm, too.

Researchers said the findings offer new insight into human reproduction – showing that eggs will not accept just any sperm, and actually have more say in the union than previously recognised.

In the moments just before fertilisation, there is a chemical “conversation” between an egg and sperm, explained John Fitzpatrick, an associate professor at Stockholm University, in Sweden, and leader of the new study.

“The chemical signals released from eggs allow sperm to change their swimming behaviour,” Fitzpatrick said. “Sperm swim straighter and move towards the egg when they are exposed to the chemical signals. In other words, eggs are releasing sperm-guidance chemicals, like a trail of bread crumbs leading the sperm to the egg, and this can influence fertility.”

Chemicals draw sperm in

Based on the new findings, a woman’s eggs use those signals preferentially, to better attract sperm from certain men.

The researchers arrived at that conclusion after studying samples of sperm and follicular fluid from couples undergoing infertility treatment. Follicular fluid surrounds eggs and contains the chemicals that draw sperm in.

It turned out that follicular fluid from any one woman was better at attracting sperm from certain men, versus others. And the egg’s preferences did not always match with the woman’s choice of mate.

It’s not clear whether there could be any practical implications for addressing infertility, Fitzpatrick said.

“But,” he said, “about one-third of cases of infertility don’t have a clear cause. We weren’t considering how chemical signals might influence egg-sperm interactions and infertility before. Our work helps open the door to consider this in the future.”

The findings were published online on 10 June in the journal Proceedings of the Royal Society B.

Vying for the fittest sperm

Dr Natan Bar-Chama is president of the Society for Male Reproduction and Urology, in Birmingham, Alabama. He cautioned that the findings are based on a small number of couples, and a statistical finding in a study does not always translate into actual physiology.

That said, the existence of such a process makes sense, according to Bar-Chama. The implication, he said, is that right up to the last moment, the egg is vying for the most fit sperm.

But it’s not clear how important that “final filter” is in a couple’s chances of having a baby, Bar-Chama said.

“This is one step, and its impact has yet to be determined,” he said.

Fitzpatrick said that in the context of infertility treatment, the effects of the egg’s chemical signals may, in fact, be minimal. “This is because eggs and sperm are treated very well under clinical in-vitro fertilisation protocols and given every chance to produce viable embryos,” he explained.

Few sperm ‘make it’

Plus, Bar-Chama pointed out, during infertility treatment sperm are often injected directly into eggs – in a process called intracytoplasmic sperm injection (ICSI).

But could bypassing that final chemical interaction between eggs and sperm have consequences? Again, Bar-Chama pointed to all the steps that are taken to ensure the most viable embryo is implanted.

“I think all the data we have on (the health of) ICSI babies speaks for itself,” he said.

But eggs’ chemical attractants may be more critical during natural fertilisation, according to Fitzpatrick. On average, the study found, when follicular fluid was being “more attractive” in its chemical signals, about 18% more sperm swam for their goal. And that could be “pretty important”, Fitzpatrick said.

“Our best estimates are that only a few hundred sperm make it to the egg,” he noted. “And only around 10% of these sperm are able to fertilise an egg at any given time.”

Of course, couples presumably get together without a clue of their egg-sperm compatibility. And no one is saying these egg-sperm chemical dynamics are likely to make or break the chances of conceiving.

“Instead, it may make particular egg-sperm combinations easier to fertilise,” Fitzpatrick said. “We still have a long way to go before we can say this definitely, but it is certainly a possibility.”

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• In midlife, smoking diabetes and hypertension can reduce cognitive skills in middle age
• Modifying behaviours can help modify or prevent this decline
• This emphasises the need to educate people on healthy lifestyle choices earlier in life

Your thinking skills may be at risk of declining in midlife if you smoke or have high blood pressure or diabetes, a new study suggests.

Heart disease risk factors – especially high blood pressure and diabetes – have become more common in midlife, the study authors noted.

“We found those two risk factors, as well as smoking, are associated with higher odds of having accelerated cognitive [mental] decline, even over just a short span of five years,” said lead author Dr Kristine Yaffe. She’s a professor of psychiatry, neurology and epidemiology at the University of California, San Francisco.

“It’s encouraging to know that there are behaviours people can modify in midlife to help prevent the steepest declines in thinking and memory as they age,” she said in a news release from the American Academy of Neurology.

Obesity and cholesterol less risky

For the study, Yaffe’s team collected data on nearly 2 700 people, average age 50, whose memory and thinking were tested at the study’s start and five years later.

After five years, 5% had mental decline, including 7.5% of people with high blood pressure, 10% of those with diabetes and nearly 8% of smokers.

After age, race, education and other factors were considered, smokers were 65% more likely to have accelerated mental decline. Those with high blood pressure were 87% more likely and those with diabetes had nearly triple the risk, the researchers said.

“Surprisingly, people who were considered obese and those with high cholesterol did not have a greater risk of cognitive decline,” Yaffe said.

People who had one or two of the risk factors were nearly twice as likely as those with none to have midlife mental decline. Three or more risk factors nearly tripled the risk, the findings showed.

“Most public health prevention efforts focus on older adults, but our study suggests the need to look at cognitive performance across a person’s life span,” Yaffe said. “Middle-aged adults who have one or more cardiovascular risk factors like smoking, high blood pressure and diabetes may be people we should be monitoring and educating on healthy lifestyle choices earlier in life.”

The findings were recently published online in the journal Neurology.

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A committee says moving NHS patients into care homes without Covid tests was an “appalling error”.

• Glaucoma is the leading cause of blindness in the United States
• A low-carbohydrate diet might offer some protection against this disease
• Patients with a genetic makeup of primary open angle glaucoma will likely benefit most from this kind of diet

Glaucoma strikes many people as they age, but what if a simple dietary change could lower your risk?

New research suggests it can: Scientists found a low-carbohydrate diet might protect you against the vision-robbing disease.

The researchers analysed data from 185 000 female nurses and male health professionals, aged 40 to 75, who took part in three large studies in the United States conducted between 1976 and 2017.

Leading cause of blindness

Throughout the studies, the participants provided information about their diet and health.

Maintaining a long-term diet low in carbohydrates and high in fat and protein from vegetables was associated with a 20% lower risk of primary open angle glaucoma (POAG) with early paracentral visual loss, according to the study published online recently in the journal Eye.

Glaucoma is the leading cause of blindness in the United States and POAG is the most common type of glaucoma. Patients typically have few or no symptoms until the disease progresses and they lose their peripheral vision.

“A diet low in carbohydrates and higher in fats and proteins results in the generation of metabolites favourable for the mitochondrion-rich optic nerve head, which is the site of damage in POAG,” explained co-corresponding study author Dr Louis Pasquale, deputy chair for ophthalmology research at Mount Sinai Health System, in New York City.

Advantage of low-carb diet

“It’s important to note that a low-carbohydrate diet won’t stop glaucoma progression if you already have it, but it may be a means to preventing glaucoma in high-risk groups,” he explained in a Mount Sinai news release. “If more patients in these high-risk categories – including those with a family history of glaucoma – adhered to this diet, there might be fewer cases of vision loss.”

Previous research has shown that a low-carbohydrate/high-fat (keto) diet may protect against neurologic disorders, the study authors noted.

“This was an observational study and not a clinical trial, so more work is needed, as this is the first study looking at this dietary pattern in relation to POAG,” Pasquale said. “The next step is to use artificial intelligence to objectively quantify paracentral visual loss in our glaucoma cases and repeat the analysis,” he explained.

“It’s also important to identify patients who have a genetic makeup of primary open angle glaucoma who may benefit from a low-carbohydrate diet,” he added. “This dietary pattern may be protective only in people with a certain genetic makeup.”

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Getting too little or too much sleep may worsen asthma in adults, a new study finds.

Researchers asked nearly 1 400 adults, 20 and older, with self-reported asthma about their sleep habits.

About one-quarter said they slept five hours or less a night (short sleepers), 66% slept six to eight hours a night (normal sleepers), and 8% slept nine or more hours a night (long sleepers).

Short sleepers were more likely to be younger and non-white, while long sleepers were more likely to be older, female and smokers, according to the study published recently in the Annals of Allergy, Asthma and Immunology.

Inadequate sleeping patterns

“Disturbed sleep in an asthma patient can be a red flag indicating their asthma isn’t well-controlled,” said Dr Gailen Marshall, an allergist and journal editor-in-chief.

The study warns that “consequences can be expected when sleep patterns are chronically inadequate”, Marshall said in a journal news release.

Compared to normal sleepers, short sleepers had: a higher risk of an asthma attack, dry cough and an overnight hospitalisation during the past year; significantly worse health-related quality of life, including poor physical and mental health and inactivity due to poor health; and more frequent general healthcare use during the past year.

Compared to normal sleepers, long sleepers were more likely to have some activity limitation due to wheezing, but no other significant differences.

“Previous research revealed that poor sleep quality has a negative effect on asthma symptoms in adolescents,” study author Faith Luyster said.

Good asthma management

“Our study shows that adults with asthma are equally affected by too little [or sometimes too much] sleep. Compared to normal sleepers, short and long sleepers had a higher proportion of people who reported having an asthma attack in the past year (45% vs. 59% and 51% respectively) and had more days with impaired health-related quality of life. Impaired quality of life was characterised by more days of poor physical and mental health,” Luyster said.

Marshall said the study adds solid evidence to the practice of asthma patients discussing sleep issues with their allergist. Those discussions can help determine if they need to change their asthma plan to achieve adequate sleep as a component of overall good asthma management.  

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The test could spot the disease at the earliest stage before symptoms appear, studies suggest.

The government is to plough millions into research into why ethnic minorities are at increased risk.