Health Institute Carlos III

A global analysis of data from more than 232 million people shows that the rise in obesity has slowed or stabilised in some high-income countries since the 1990s among children and adolescents, and, a decade later, among adults. In Spain, this stabilisation or even a slight decline is also observed. In most low- and middle-income regions, the prevalence of obesity continues to increase and, in some cases, has already surpassed that of more developed economies. The study, published in Nature, included 4,050 studies covering the period from 1980 to 2024 across 200 countries.

Repeated cloning cannot be sustained indefinitely in mammals, according to the findings of a twenty-year study on mice conducted in Japan. Serial cloning of mice led to an accumulation of lethal DNA mutations that affected birth rates from the 27th generation onwards, with the 58th generation being the last, according to the article published in Nature Communications, showing that sexual reproduction is necessary to prevent large-scale genetic mutations.

A study published in The Lancet Oncology shows that age-adjusted breast cancer mortality has declined from 1990 to 2023, even though the number of cases has increased. In Spain, the mortality rate for this disease fell by almost 42% during this period, reflecting the success of screening, diagnosis and treatment in high-income countries, according to the article's data. Although incidence and mortality rates will remain stable, the authors predict that population growth and ageing will increase the number of breast cancer cases and deaths between now and 2050.

According to the newspaper El País, the Catalan Regional Government has reported a case of swine flu —not swine fever, which is caused by another virus and does not affect humans— in an 83-year-old person in the province of Lleida. The newspaper points out that, as the patient had no contact with pigs that could transmit the virus, they may have been infected by another person.

According to the Ministry for Ecological Transition and Demographic Challenge, masses of African air with varying concentrations of surface dust are expected to reach the Canary Islands and the Iberian Peninsula on Wednesday. Health authorities in different provinces have recommended avoiding outdoor physical exercise or activities that require effort, especially for vulnerable groups such as children, pregnant women, the elderly and the sick.

Measles cases in Europe and Central Asia fell in 2025 compared with 2024, according to preliminary data reported by 53 countries in the World Health Organization (WHO) European Region. This decline aligns with the preliminary figures published this week by the European Centre for Disease Prevention and Control (ECDC). According to the WHO, countries in Europe and Central Asia reported 33,998 measles cases in 2025, representing a decrease of nearly 75 % compared with the 127,412 cases recorded in 2024. In Spain, however, the number of cases has increased, as shown by data from the Carlos III Health Institute. A few weeks ago, the WHO announced that Spain had lost its measles-free status.

A study published in The BMJ suggests that the incidence of autism spectrum disorder (ASD) is comparable between boys and girls. The study included a sample of more than 2.7 million people born in Sweden between 1985 and 2020 who were followed from birth to a maximum age of 37. More than 78,000 were diagnosed with ASD. It was observed that boys are usually diagnosed between the ages of 10 and 14, five years earlier than girls. By the age of 20, the proportion of diagnoses is almost equal between the sexes. Before the age of 10, the ratio is 3:1 in favour of boys.

In 2022, approximately four out of every 10 new cancer cases worldwide were due to modifiable risk factors, primarily tobacco or alcohol consumption and infections, including those caused by the human papillomavirus or H. pylori bacteria. These are some of the conclusions of a global study led by the World Health Organisation (WHO) and its International Agency for Research on Cancer (IARC), published in Nature Medicine. In Spain, 41.8% of cancer cases in men are attributed to modifiable external factors, compared to 26.1% in women, with smoking remaining the main factor (28.5% and 9.9%, respectively). The analysis is based on data from 185 countries.

A study published in PLOS Biology analysed whether supplementation with zinc, serine and branched-chain amino acids —valine, isoleucine and leucine— improves autism-related symptoms in three mouse models. These nutrients are believed to regulate synaptic formation and activity. The results show that the combination of the three nutrients, at low doses for seven days, improved affected brain traits —such as hyperactivity and hyperconnectivity of the amygdala— and the social behaviour of the animals. Individual supplementation did not show such improvements. 

Viruses that cause avian influenza are capable of replicating at temperatures higher than a typical fever, according to a study in in vitro models and mice. ‘Fever-resistant replication could help explain why avian viruses and pandemic influenza viruses with avian PB1 cause more severe disease in humans,’ the authors write in the journal Science.