Medical Bulletin 05/September/2026

Always Exhausted? Study Identifies Common Link Across Five Health Conditions

Chronic exhaustion may have a deeper biological connection across several unrelated illnesses, according to new research linking five conditions through shared cellular pathways.

A study published in the Journal of Translational Medicine found that long Covid, post-traumatic stress disorder (PTSD), rheumatoid arthritis, myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and multiple sclerosis may disrupt similar biological systems, despite having different triggers.

Researchers from the University of East Anglia and Oxford BioDynamics in the UK found that genes linked to these conditions were connected to common networks involved in immune and inflammatory responses, energy production inside cells, metabolism, stress responses and hormone signalling.

The findings could help explain why people affected by viral infections, psychological trauma or autoimmune disease can develop similar, disabling fatigue.

Instead of looking only at individual genes, researchers examined how genes interact in the three-dimensional structure of DNA. They used Oxford BioDynamics’ EpiSwitch Orion platform, which analyses how DNA folds and how different regions come into contact to regulate gene activity.

The analysis combined previously published genomic data on long Covid, PTSD, rheumatoid arthritis and multiple sclerosis with earlier three-dimensional genomic data from people with ME/CFS. No new patient samples were collected for this analysis.

Interestingly, researchers found little direct overlap between individual genes across the five conditions. However, when those genes were examined as part of biological networks, strong similarities emerged.

Researchers said this network-level connection suggests that different triggers may disturb the same systems responsible for energy production, immune regulation and cellular resilience.

The study does not prove that these conditions have the same cause or that one biological pathway explains all fatigue. Further research will be needed to confirm these findings in patients and determine whether the shared pathways could lead to diagnostic tests or treatments.

REFERENCE: Hunter, E., et al. (2026). Beyond genes: EpiSwitch® and Orion platform-powered 3D genome architecture biomarkers reveal shared biology across ME/CFS, long COVID, PTSD, rheumatoid arthritis, and multiple sclerosis. Journal of Translational Medicine. DOI: 10.1186/s12967-026-08874-9

Vitamin B12 Levels in Parents May Influence Birth Defect Risk in Babies: Study

New research highlights the importance of vitamin B12 levels in both parents around conception for a future child.

A study published in the Annals of Internal Medicine found that higher vitamin B12 levels in mothers and fathers were associated with a lower prevalence of birth defects in their children.

Researchers from Fudan University in China analysed 3,032 couples whose blood samples were collected within four months before conception. They measured vitamin B12 and red blood cell folate levels. The team also examined data from 17,765 women tested during early pregnancy, at four months or earlier.

The researchers found that birth defect prevalence decreased as maternal B12 levels increased. A similar association was observed among fathers, although the relationship became weaker once paternal B12 levels reached moderately high concentrations. Congenital heart defects accounted for a large proportion of the birth defects recorded.

Vitamin B12 is essential for DNA production, nerve function and healthy red blood cells. It is found in foods including meat, fish, poultry, eggs and dairy products. Because many birth defects develop during the earliest weeks of pregnancy, nutrition before conception may be important for both parents.

The study also found that higher maternal red blood cell folate levels after conception were associated with a lower predicted prevalence of birth defects, supporting the importance of adequate folate during early pregnancy.

Researchers said fathers may influence a child’s health through more than inherited genes. Nutrition can affect epigenetic processes and one-carbon metabolism, which involves vitamin B12 and folate.

However, the findings show an association rather than proving that higher B12 directly prevents birth defects. Further research is still needed to determine whether improving B12 levels before conception can reduce risk and how these findings could influence preconception care in humans.

REFERENCE: Hongyan Chen, Xiaotian Chen, Yi Zhang, et al. Periconception Parental Red Blood Cell Folate, Vitamin B12, and Birth Defects in Offspring: A Prospective Cohort Study. Ann Intern Med.; 2026; doi:10.7326/ANNALS-25-05243

Coffee, Tea Consumption Linked to Dementia Risk, Study Examines Amount You Drink

Moderate caffeine intake in midlife may be linked to a lower risk of dementia in later life, according to a perspective published in npj Dementia.

The article reviewed evidence from prospective studies, meta-analyses and experimental research, suggesting that moderate coffee and tea consumption may offer benefits than very low or high intake. However, researchers stressed that the evidence does not prove caffeine prevents dementia.

One prospective cohort study found an 18% lower dementia risk with 2-3 cups of caffeinated coffee and a 14% lower risk with 1-2 cups of tea. Among people aged 75 or younger, the association was stronger. Another study suggested that genetic differences in caffeine metabolism may influence the relationship. People with a slower-metabolising CYP1A2 variant showed lower dementia risk with higher coffee consumption, while fast metabolisers did not show the same benefit and could have increased risk at high doses.

UK Biobank data from 8,715 adults aged 60-85 linked moderate coffee and tea consumption with slower declines in cognitive abilities, including fluid intelligence. However, higher coffee intake was associated with more visual memory errors.

Researchers proposed several possible mechanisms. Caffeine blocks adenosine receptors, increasing neural activity and potentially supporting complex brain-network function. Coffee and tea compounds may reduce oxidative stress and neuroinflammation. Some research, however, has linked caffeine or coffee consumption with reduced brain grey matter, although the significance of this remains still uncertain today.

The authors highlighted that genetics, age, beverage preparation and ingredients such as milk and sugar could influence caffeine’s effects. They noted that South Asian populations require further study because tea is commonly consumed with milk and sugar.

Importantly, most evidence remains observational, with possible confounding, measurement errors and reverse causality. Randomised trials testing whether caffeine can prevent dementia are still lacking.

REFERENCE: Balakrishnan, R., Subbarayan, R., & Shrestha, R. (2026). Midlife window: Moderate caffeine consumption and reduced dementia risk. Npj Dementia, 2(1), 79. DOI: 10.1038/s44400-026-00134-3, https://www.nature.com/articles/s44400-026-00134-3