All articles tagged with #cohort study
A large Harvard-affiliated cohort study found that consuming at least one sugar-sweetened beverage per day was linked to a 2.45-fold higher risk of gastric cancer compared with consuming less than one per month, with higher fructose intake tied to greater risk; the study is observational and cannot prove causation, and findings need replication across diverse populations.
A Swedish analysis of two large cohorts (82,009 participants) over 20 years links higher dietary nitrite intake to greater colorectal cancer risk in men (HR 1.23 for highest vs lowest quintile; p-trend = 0.05), strongest for distal colon cancer (about 50% higher). No association with nitrate or in women. Men reported higher nitrite exposure partly from meat, while women mostly from vegetables. Limitations include self-reported diet and possible confounding; more research is needed to understand why men are affected.
A 10-year Norwegian cohort of 1,324 middle-aged and older adults measured iohexol-based GFR and found that higher habitual protein intake (mean 1.2 g/kg/d) was not associated with faster GFR decline, accelerated decline, or incident CKD, suggesting protein restriction may not prevent CKD. Limitations include FFQ-based protein estimates and lack of 24-hour urinary urea validation.
A long-running UK study of 2,759 people from the 1946 birth cohort tracked income and hardship across adulthood and found that persistent low income and financial hardship were associated with poorer verbal memory and processing speed at age 53 and greater brain shrinkage by ages 69–71, even after accounting for childhood factors. The links were stronger in men, those from disadvantaged backgrounds, and APOE risk carriers. Interestingly, memory decline from 53 to 69 appeared slower for those with prior hardship, likely because they started from a lower baseline. While the study can’t prove causation, it suggests reducing chronic financial hardship could help protect brain health and potentially reduce dementia risk.
In a Swedish nationwide cohort of 184,266 adults with autoimmune hypothyroidism, starting liothyronine (LT3) in combination with levothyroxine (LT4) was linked to a 43% higher risk of any psychiatric morbidity (adjusted HR 1.43) versus LT4 alone, with similar increases for affective/anxiety (HR 1.44) and psychotic morbidity (HR 1.46). The associations held across sexes and ages under 75, and were especially elevated for psychotic morbidity among women and those under 30. Limitations include retrospective design and potential confounding; authors note LT3 use may reflect emerging mental-health issues rather than causation.
A long-term study of about 40,000 adults over 15 years links regular egg consumption with a lower risk of developing Alzheimer’s disease. Participants aged 65+ who ate at least one egg daily, five days a week, had up to a 27% lower risk than those who rarely or never ate eggs; even modest intake showed protection. Nutrients in eggs such as choline, omega-3s, lutein, and zeaxanthin are proposed as contributing factors. The study emphasizes eggs can be part of a balanced diet, though findings are observational, and funding included support from the American Egg Board.
A large observational study using Adventist Health Study-2 linked eating eggs at least five times weekly with up to 27% lower odds of an Alzheimer’s diagnosis versus no egg consumption, echoing prior findings that modest egg intake may support brain health as part of a balanced diet. The study cannot prove causation and may reflect overall healthy lifestyle patterns; nutrients in eggs (such as choline, lutein/zeaxanthin, omega-3s, and B12) could plausibly support brain function, but more diverse populations and mechanistic research are needed. Moderation and context are advised.
A Danish nationwide cohort study of more than 4 million adults found that longer antidepressant use is associated with an increased risk of sudden cardiac death, with adjusted hazards of 1.41 for 1–5 years and 1.74 for six or more years; current users face the highest risk, though the study cannot prove causality due to its observational design and potential residual confounding. The findings suggest a time-dependent risk across antidepressant subclasses, and further research is needed to clarify causality and mechanisms.
A BMJ Medicine analysis of two large cohorts finds that both total physical activity and the variety of activities independently correlate with longer life. Walking and other activities show strong associations, with benefit peaking around 20 MET-hours per week, while those engaging in a broader range of activities have about a 19% lower risk of all-cause mortality after adjusting for total activity. Limitations include self-reported data and a largely White sample, making the findings observational rather than causal.
A large cohort study of 461,586 adults followed for a median of 13.4 years found a J-shaped relationship between coffee consumption and mood/stress disorders: two to three cups per day were linked to the lowest risk of anxiety and depression, while five or more cups were associated with higher risk. The pattern held across ground, instant, and decaf coffee and was more pronounced in men. Because the study is observational, it cannot prove causality, and genetic caffeine metabolism did not significantly alter the associations; researchers suggest bioactive coffee compounds may help calm brain circuits related to mood and stress.
A VA-led cohort study of 606,434 U.S. veterans with type 2 diabetes found that GLP-1 medicines (including Ozempic, Wegovy, Mounjaro, and Zepbound) are associated with a lower risk of developing substance use disorders across alcohol, opioids, nicotine, cocaine, cannabis and other substances—and with fewer hospitalizations, overdoses, and deaths among veterans who already have an addiction. The study also notes a 25% reduction in suicidal ideation. As observational research, it cannot prove causation, and results may reflect greater health engagement; randomized trials are underway, and GLP-1s are not yet approved as addiction treatments.
A pooled analysis of 1.8 million adults from nine prospective cohorts across the UK, US, Taiwan, and India found diet‑related differences in cancer risk. Compared with meat eaters, poultry eaters had a lower prostate cancer risk; pescatarians had lower colorectal, breast, and kidney cancer risks; vegetarians had lower risks of pancreatic, breast, prostate, kidney cancers and multiple myeloma but a higher risk of oesophageal squamous cell carcinoma; vegans had a higher risk of colorectal cancer. The authors caution that results may not generalize and could be influenced by residual confounding and misclassification in diet groups.
In a three-year Japanese cohort, older adults who ate cheese at least weekly showed a 24% lower risk of dementia (hazard ratio 0.76) versus those who rarely/never ate cheese, based on 3,957 matched pairs from nearly 8,000 participants. The association remained after adjusting for overall diet quality but remains observational and not causal. Most cheese consumed was processed, and researchers note potential biological pathways (e.g., vitamin K2, gut-brain axis) while acknowledging limitations such as baseline-only intake data and dementia measured via long-term care records.
A large UK cohort study of about 10,930 people followed from childhood found that higher ADHD traits at age 10 are linked to more physical health problems and disability by midlife (age 46). Those with elevated ADHD traits had 14% higher odds of two or more conditions (including migraine, back pain, cancer, epilepsy, diabetes) and 42% reported two or more health problems versus 37% with lower trait scores; associations were partly explained by mental health issues, higher BMI, and smoking, with stronger effects in women. The findings emphasize the need for better ADHD recognition, ongoing health monitoring, and accessible support across adulthood.
A Harvard Chan School of Public Health study of more than 111,000 adults over 30 years found that people who perform a variety of exercise types—beyond just increasing total activity—had about a 19% lower risk of premature death, with benefits seen across activity levels. Limitations include self-reported data and a predominantly white health-professional cohort.