A five-year study conducted at the University of Eastern Finland found that higher-than-recommended doses of vitamin D reduced the risk of atrial fibrillation in older men and women. Atrial fibrillation is a common arrhythmia associated with an increased risk of stroke, heart failure, and mortality. The study involved 2,495 participants aged 60 or older (men) and 65 or older (women) who were randomly assigned to placebo or two vitamin D3 supplementation groups. Those taking 40 micrograms per day had a 27% lower risk, and those taking 80 micrograms per day had a 32% lower risk of atrial fibrillation compared to the placebo group. However, further confirmation is needed before recommending higher vitamin D doses for preventing atrial fibrillation.

Regular physical activity may help protect against cognitive decline in older adults, but this benefit may be compromised if individuals do not get enough sleep, as per a study by UCL researchers. The research, published in The Lancet Healthy Longevity, followed 8,958 individuals aged 50 and over in England for 10 years, examining the relationship between sleep, physical activity, and cognitive function. Participants who were physically active but had short sleep durations (less than six hours) experienced faster cognitive decline compared to those who engaged in less physical activity. The study underscores the importance of considering both sleep and physical activity in maintaining cognitive health as we age.

Schizophrenia, a psychiatric disorder with adult onset, is influenced by both environmental factors and genetics. A study published in Cell Genomics reveals a correlation between schizophrenia and somatic copy-number variants (mutations occurring after genetic material is inherited). The research examined genotype-marker data from over 20,000 blood samples, identifying two genes, NRXN1 and ABCB11, associated with schizophrenia when disrupted in utero. NRXN1, linked to schizophrenia before, was now associated with somatic, not inherited, mutations. ABCB11, known for encoding a liver protein, was unexpectedly found to be expressed in specific dopamine-carrying neurons related to schizophrenia drug targets. This study expands the understanding of psychiatric disorders and opens new avenues for research into acquired mutations’ roles in various disorders.

Scientists have discovered that differences in gut bacteria are linked to the development of juvenile idiopathic arthritis (JIA) in children, even years before symptoms appear. The research analyzed stool samples from one-year-old children participating in a long-term study. Children with gut bacteria known to cause inflammation were nearly seven times more likely to develop JIA, while those with bacteria promoting a healthy gut lining were reduced. The findings offer potential for early disease risk indicators and alternative approaches for JIA treatment. Researchers aim to understand how these bacteria contribute to the disease and explore microbial differences associated with other childhood conditions. 

New research from the University of Exeter, Exeter Clinical Research Facility, and the University of Bristol reveals that obesity risk genes can heighten feelings of hunger and lack of control overeating. However, the study suggests that practicing dietary restraint, such as both flexible strategies (conscious eating and smaller servings) and rigid approaches (calorie counting), can mitigate the effects of these genes by up to half. The research, conducted on 3,780 adults from two UK cohorts, found that high genetic risk scores were associated with higher BMI due to increased disinhibition and hunger. By understanding these gene influences, restraint-based interventions could be developed to address obesity risk in genetically susceptible individuals. 

New findings from the University of California, Berkeley suggests that deep-sleep brain waves at night play a role in regulating the body’s sensitivity to insulin, improving sugar control the following day. The combination of two brain waves, sleep spindles and slow waves, increases the body’s sensitivity to insulin, leading to lower glucose levels. This discovery could potentially be used as a therapeutic treatment for individuals with high sugar or Type 2 diabetes. Additionally, these deep-sleep brain waves could serve as an indicator of a person’s next-day sugar levels, making them a valuable tool for mapping and predicting sugar control. The research, published in Cell Reports Medicine, reveals a new role for deep-sleep brain waves in managing sugar and complements previous studies that showed their role in learning and memory. The researchers analyzed sleep data from 600 individuals and found that the coupling of deep-sleep brain waves predicted next-day glucose control better than sleep duration or quality.

A major study in Sweden has found a connection between specific gut bacteria and the development of coronary atherosclerotic plaques, which can lead to heart attacks. The study analyzed gut bacteria and cardiac imaging in nearly 9,000 participants without previously known heart disease. The researchers discovered that certain oral bacteria, particularly from the Streptococcus genus, were associated with an increased occurrence of atherosclerotic plaques in the small arteries of the heart when present in the gut. The study also found that the same bacteria were linked to levels of inflammation markers in the body. The findings highlight the need for further research on the relationship between gut bacteria and cardiovascular health.

A study in Neurology suggests that limited social contact in older people may increase the risk of brain shrinkage and damage in dementia-affected areas. However, the study does not prove causation. It highlights the concern of social isolation among seniors and proposes that supporting social connections could potentially prevent brain atrophy and dementia. The research involved nearly 9,000 participants, revealing lower brain volume and memory-related area volume in those with the least social contact. Factors like age, diabetes, smoking, and exercise were considered, and socially isolated individuals had more white matter lesions. Symptoms of depression partly explained the relationship. Prior studies indicate that exposure to socially stimulating groups might reverse brain volume and cognitive declines in older people. Notably, this study focused on older Japanese individuals, so generalization to other populations requires further research.

A recent study from the University of York has found that quality sleep can help protect against depression and anxiety, particularly during periods of chronic stress like the COVID-19 pandemic. Researchers analyzed data from over 600 participants and discovered that high-quality sleep and positive coping strategies, such as reframing negative situations, were associated with better mental health outcomes. The study emphasizes the importance of addressing both sleep quality and coping strategies when dealing with prolonged stress. The findings highlight the significant role sleep plays in managing chronic stress and reducing symptoms of depression and anxiety.

A study on UK healthcare workers compared cellular and humoral immune responses to SARS-CoV-2 vaccination by ethnic group. Results showed that, in an infection naïve cohort, both humoral and cellular immune responses were stronger in South Asian healthcare workers than in White healthcare workers. The differences were most pronounced in the early period following vaccination. The study was funded by UK Research and Innovation and conducted using baseline data from two immunological cohort studies in Leicester, UK. Further research is needed to understand the underlying mechanisms, whether differences persist with further exposure to the vaccine or virus, and the potential impact on vaccine effectiveness.