Drinking up to five cups of caffeinated coffee a day is generally safe for most adults and may be associated with a reduced risk of several cardiovascular diseases, according to a new scientific statement from the American Heart Association (AHA).
The document was published on July 20, 2026, in the scientific journal Circulation. Its authors analyzed the results of studies on the effects of caffeine on blood pressure, cholesterol levels, heart rhythm, and the risk of stroke, coronary heart disease, heart failure, and type 2 diabetes.
For most adults, consuming up to 400 mg of caffeine per day is considered safe. This corresponds to approximately three to five standard cups of black coffee, each about 240 ml. However, the actual caffeine content can vary significantly depending on the type of coffee beans and the method of preparation.
According to the AHA, drinking two to four cups of coffee a day is associated with a lower risk of heart disease, stroke, and heart failure. In some studies, the lowest risk of coronary heart disease was observed in people who drank two to three cups a day.
Regular consumption of coffee without sugar, syrups, or cream is also associated with a reduced risk of developing type 2 diabetes. However, researchers emphasize that the benefits may be due not only to caffeine but also to other bioactive compounds in coffee that possess antioxidant and anti-inflammatory properties.
Adding large amounts of sugar, sweet syrups, cream, and other additives can reduce the beverage’s potential benefits. The authors of the review also do not recommend extending the findings about coffee to energy drinks. High doses of caffeine and the additional ingredients in energy drinks can raise blood pressure and increase the risk of heart rhythm disturbances.
The method of coffee preparation also matters. Unfiltered coffee—including espresso, French press coffee, and Turkish coffee—contains cafestol, which may contribute to an increase in levels of so-called “bad” cholesterol. When a paper filter is used, the content of this substance is significantly reduced.
However, experts do not consider five cups to be a one-size-fits-all recommendation for everyone. The response to caffeine depends on age, genetics, metabolic rate, medications taken, and overall health. For some people, even a small amount of coffee can cause a rapid heartbeat, anxiety, high blood pressure, or sleep disturbances.
Most of the data analyzed comes from observational studies, so while they show an association, they do not prove that coffee itself directly prevents disease. The American Heart Association notes the need for additional randomized controlled trials.
Source: ScienceAlert
Thanks to Ukraine’s participation in the POLARIN project under the Horizon Europe program, two new international research projects are launching at the “Akademik Vernadsky” station and on the icebreaker “Noosphere,” according to the National Antarctic Scientific Center (NASC).
“At the ‘Vernadsky’ station, researchers will study the aerosol-mediated dispersal of microbial communities in polar regions as part of the MICROAIRPOLAR project. The second project—TRICUSO-FLOATS—is dedicated to monitoring carbon in the Southern Ocean; for this project, six argon buoys equipped with a range of sensors will be deployed from aboard the icebreaker ‘Noosphere,’” the NANC stated in a press release on Tuesday.
Specifically, as part of the MICROAIRPOLAR project, which is being carried out by scientists from the Autonomous University of Madrid (Spain) and Northumbria University (United Kingdom), special MicroAirCollector equipment will be installed at three stations in the Arctic and three in Antarctica to collect samples of microorganisms from the air. Scientists will conduct genetic analysis to determine exactly what the wind carries into the polar regions and will track the trajectories of air masses and the movement of bacteria in the Arctic and Antarctic, as well as between them.
As part of the second project—TRICUSO-FLOATS, carried out by scientists from the National Oceanography Center (United Kingdom), the Norwegian Research Center, and Sorbonne University (France)—carbon monitoring will be conducted in the Southern Ocean. To this end, six argon buoys equipped with a range of sensors will be deployed from the Noosphere to measure total alkalinity and dissolved inorganic carbon content, which will help quantify how much carbon the Southern Ocean absorbs.
Both studies will begin during the next Antarctic season, which starts in late 2026.
The NASC also notes that POLARIN brings together 64 polar research infrastructures belonging to organizations from around the world. MICROAIRPOLAR and TRICUSO-FLOATS are the first winning projects to gain access to the “Vernadsky” and “Noosphere” stations as part of POLARIN.
“For Ukraine, such initiatives represent an opportunity to participate in cutting-edge scientific research and to be an active member of the global polar community,” the NASC concludes.
Surgeons and engineers at the University of California, San Diego, have used remotely controlled humanoid robots to perform surgery on live animals for the first time as part of a preclinical study.
This was not autonomous surgery: the surgeons controlled all of the robots’ movements from a console. However, the experiment marked an important step forward for medical robotics, as humanoid robots had not previously been used to perform full-scale surgical procedures on living subjects.
According to UC San Diego, two surgeries were performed as part of a preclinical trial, the results of which were published on July 8 in the journal *Nature*. In one case, the surgery was performed by a “human-robot” team: a humanoid robot operated under the surgeon’s control, while a human assisted. In the second case, the procedure was performed by two humanoid robots working side by side. Both surgeries were performed on pigs.
Ars Technica notes that the robots performed two invasive gallbladder removal surgeries on live pigs.
The robots are called Surgie. Unlike specialized surgical systems, such humanoid systems are more compact and can potentially be used in standard operating rooms without major renovations. UC San Diego notes that Surgie is about 5 feet tall and weighs about 60 pounds, whereas traditional robotic surgical platforms can weigh around 1,800 pounds and require a large team to set up.
According to one of the study’s senior authors, Professor Michael Yip, remotely controlled and, in the future, autonomous humanoid robots could expand access to surgical care in regions where there is a shortage of doctors and specialized infrastructure. Researchers at the University of California, San Diego, believe that such systems could be useful in rural hospitals, field medical settings, disaster zones, and other locations where it is impossible to quickly deploy a full-fledged surgical center.
However, the researchers emphasize that the technology is still far from clinical application in humans. During the operations, the robots had to be recalibrated several times, which caused the procedures to take longer than when using specialized surgical systems. Another issue is the delay between the surgeon’s movements at the console and the robot’s movements, which is particularly important for future remote surgeries.
The main significance of the experiment lies not in the fact that robots replaced surgeons, but in the fact that a humanoid robot was tested in a real surgical setting for the first time. Researchers view the immediate future of such systems primarily as assistants: they can help in the operating room, hand instruments, perform physical tasks, and eventually take over part of tele-surgical procedures.
For the medical technology market, this could open up a new niche between traditional surgical robots and versatile humanoid platforms. If such systems become sufficiently precise, safe, and affordable, they could lower the barriers to robotic surgery in small hospitals and resource-limited countries.
According to the Interfax-Ukraine Culture project, nearly 40% of Ukrainians attend cultural events once every six months or less, most often at movie theaters, according to the “Culture in Ukraine” study by Research.ua, which was presented by the Ministry of Culture of Ukraine on Thursday in Kyiv.
Specifically, when asked about the frequency of attending cultural events, 37% of respondents said they attend such events once every six months or less, 26%—once every few months, 30%—once a month or more often, and 7% noted that they do not attend cultural events.
Among the main sources of cultural news in 2025 were social media (75%) and messaging apps (65%), specifically: Telegram is a source of cultural news for 58% of respondents, Facebook – 51%, Instagram – 46%, and YouTube – 42%.
Among the most popular formats for cultural events are movie theaters (66% of respondents), music concerts (42%), and theater performances (40%).
Regarding barriers to attending cultural events: lack of funds (54% of respondents), lack of time (42%), lack of events nearby (26%), and lack of company (17%).
The survey was conducted December 22–30, 2025, via online interviews; the sample consisted of 2,000 respondents; the survey covered the adult urban population of Ukraine in all regions, excluding temporarily occupied territories.
https://interfax.com.ua/news/culture/1171698.html
Walking and other simple body movements may promote fluid circulation in the brain and potentially help it eliminate metabolic waste, according to a study published in the journal *Nature Neuroscience*.
A team of scientists studied brain movement in awake mice using high-speed two-photon microscopy. The researchers found that during movement, the brain shifts slightly within the skull, and this process is closely linked not to breathing or heart rate, but to the contraction of abdominal muscles during movement.
According to the study’s authors, the contraction of abdominal muscles creates mechanical pressure that is transmitted to the brain via vascular connections between the abdomen, spine, and central nervous system. The scientists describe this mechanism as a kind of “hydraulic” connection: body movement and muscle tension can trigger micro-movements of the brain and influence the movement of cerebrospinal and interstitial fluid.
Simulations have shown that such gentle brain movement may facilitate the removal of cerebrospinal fluid from brain tissue into the subarachnoid space. The authors emphasize that the direction of this flow differs from that observed during sleep, when the so-called glymphatic system—associated with clearing the brain of metabolic waste—is more active.
The popular science publication ScienceDaily, citing this study, notes that the contraction of abdominal muscles during movement may aid the circulation of cerebrospinal fluid, meaning that simple physical activity could potentially be linked to maintaining brain health. One of the study’s authors, Patrick Drew, explained that body movement may be an important physiological mechanism that affects the brain through a mechanical connection with the abdominal cavity.
However, the study does not prove that walking directly “cleanses” the human brain or treats neurological diseases. The study was conducted on mice, and conclusions regarding humans require further research. However, it demonstrates a possible biological mechanism through which routine physical activity may be beneficial not only for the heart, blood vessels, and muscles, but also for fluid exchange processes in the brain.
This is important for medicine and the wellness market because walking remains one of the most accessible ways to maintain health. Unlike complex workouts, it requires no equipment, special conditions, or high physical fitness. If future studies confirm a similar mechanism in humans, regular walking could gain another scientific rationale as a tool for preventing cognitive decline and maintaining normal brain function.
The study also notes that brain movement during walking has a very small amplitude—we are talking about microscopic displacements that cannot be felt. However, it is precisely these mechanical oscillations that may be sufficient to influence the movement of fluid in brain tissues.
The key conclusion of the study is that the brain is not completely isolated from the rest of the body, as was often previously thought. It is mechanically linked to the body’s movements, and contractions of the abdominal muscles during walking and other activities may be part of a system that helps move fluids within and around the brain.
Watching short videos before bed may not only impair sleep quality but also contribute to daytime fatigue. This is the conclusion reached by researchers in China who studied the link between problematic short-video consumption and symptoms of insomnia among college students, according to a study published in the journal Personality and Individual Differences.
The authors analyzed data from 6,691 students in central China. The survey was conducted twice at three-month intervals: participants answered questions about their short-video viewing habits, sleep difficulties, daytime fatigue, mood, and reduced productivity.
The study revealed a bidirectional relationship: excessive use of short-form video platforms predicted an increase in sleep problems three months later, but the reverse effect was even stronger. People who felt tired, lethargic, or had a worsened mood during the day due to poor sleep were more likely to lose control over their video viewing and use it as a way to quickly relieve tension or boredom.
According to the researchers, daytime fatigue acts as a kind of “bridge” between insomnia and problematic use of digital platforms. Lack of sleep reduces self-control and the ability to resist instant gratification, while short videos offer a simple and almost effortless form of emotional release. As a result, a person may start watching videos again in the evening, fall asleep later, and feel even more tired the next day.
The authors note that short-video platform algorithms reinforce this cycle: a personalized feed holds the user’s attention, and the user often underestimates how much time they have already spent watching. Difficulty falling asleep proved to be a particularly significant factor, as it can trigger a persistent habit of delaying sleep.
For businesses and the digital services market, this study is important because it highlights not only the power of engaging algorithms but also the growing demand for digital well-being. Apps, educational platforms, employers, and healthcare services will increasingly take into account the impact of nighttime screen time on users’ productivity, mental health, and quality of life.
The researchers emphasize that the problem is not simply a matter of “weak willpower.” When a person sleeps poorly and feels tired during the day, their ability to control impulses decreases, and digital entertainment becomes the most accessible way to achieve short-term relief.
