Dogs Share Our Mortality Markers
Dogs may be doing more than stealing our couch space—they may also share our biochemical roadmap to mortality. In a longitudinal analysis from the Dog Aging Project, researchers examined 133 plasma metabolites in 937 companion dogs. After adjusting for age, sex, weight, creatinine, and genetic relatedness, an estimated 17% of the metabolites were associated with all-cause mortality, with 23 meeting the study’s statistical significance threshold. During an average 2.6 years of follow-up—a much speedier mortality window than the 8.0 to 22.5 years of average follow-up in the human studies—104 dogs died. Across 5 independent human studies, mortality associations for overlapping metabolites were condorant with those in dogs 64% of the time, with agreement strengthening among metabolites closely associated with mortality. Data pooled from 9 human studies showed a similar pattern across 93 metabolites. Higher pseudouridine, N2, N2-dimethylguanosine, and homocitrulline as well as lower deoxycarnitine and homoarginine tracked with mortality in both species, with several linked to renal function and potentially shared aging biology. Apparently, man’s best friend has been quietly moonlighting in geroscience between walks.
Source: The Journals of Gerontology
Cardio Gives Brain Fog a Workout
Aerobic exercise may give the postmenopausal brain a little extra pep in its step. In a post hoc analysis, researchers examined 93 cognitively healthy women aged 20 to 67 years with below-average cardiovascular fitness who were randomly assigned to aerobic exercise or stretching and toning 4 days per week for 6 months. They noted that 38% of the participants were postmenopausal. Women in the aerobic group progressed to 45-minute workouts at 75% of maximal heart rate. Postmenopausal women who performed aerobic exercise showed greater improvements in executive function—including skills involved in planning, task switching, resistance to interference, inhibition, and mental flexibility—compared with those doing stretching and toning and premenopausal women. Differences emerged at 3 months and remained at 6 months, and the association persisted after accounting for age, education, and baseline cognition and in an analysis examining age as a moderator. Menopausal status did not alter exercise effects on processing speed, episodic memory, working memory, attention, or language; estradiol did not significantly change or correlate with cognitive improvement. The small secondary analysis could not fully separate age from menopause or examine perimenopause, so larger trials still have some sweating to do—but executive function apparently brought its gym shoes.
Source: Journal of Alzheimer’s Disease
Rom-Coms Get a Reality Check
Rom-coms may be putting a little extra sparkle on our ideas about love, but personality still gets top billing. In a cross-sectional study, researchers surveyed 646 Brazilian adults with a mean age of about 30 years, 73% of whom were women and 60% of whom were in a relationship, about their movie preferences, romantic beliefs, personality, and relationship satisfaction. Watching more romantic comedies per week was associated with stronger beliefs in soul mates, idealized relationships, love at first sight, and love conquering obstacles. Still, rom-com exposure and preference added just 2% to 4% to the variance in romantic beliefs, while personality, emotional investment, gender, and age explained up to 23%, with romanticism stealing the scene as the strongest predictor. Romantic beliefs were also associated with greater relationship satisfaction, particularly beliefs in “one and only” love and idealization, although weekly rom-com consumption showed a negative direct association with satisfaction. Overall, rom-com type was not significantly associated with relationship satisfaction. The cross-sectional, self-reported data could not determine whether rom-coms created romantics or whether romantics simply reach for the remote. With just 3.4% watching at least 3 rom-coms per week, this cast was hardly bingeing. So, for now, the grocery store meet-cute in the dairy section can keep its suspiciously perfect timing.
Source: Trends in Psychology
The Skinny on Tea and Weight
Tea may have found a cozy little seat at the obesity-management table, but it is not exactly arriving with a prescription pad. A recent review explored how white, green, oolong, black, and dark teas differ in processing and how their bioactive compounds might tinker with digestive enzymes, fat oxidation, thermogenesis, inflammation, gut microbes, and bile-acid signaling. While green tea has enjoyed the most clinical attention, the scale is unlikely to swoon. A meta-analysis in women with overweight or obesity found average reductions of 1.23 kg in body weight and 3.46 cm in waist circumference, a bit shy of the 5% or greater weight loss commonly considered clinically meaningful. Evidence for other tea varieties also remains more limited and frequently preclinical. In a 6-month trial, 3 cups of black tea daily produced small improvements in weight and waist measures at 3 months, but the benefits did not stick around at 6 months. Poor polyphenol bioavailability and differences in processing, dosing, and brewing further muddy the teapot. Concentrated extracts also warrant caution: supplemental epigallocatechin-3-gallate doses of 800 mg per day or more have been associated with elevated liver enzymes, and drinking tea with iron-containing meals can inhibit nonheme iron absorption. Unsweetened tea can happily join the obesity-care ensemble—just don’t expect the beverage to outshine diet and exercise.
Source: International Journal of Molecular Sciences
The intersection of medicine and the unexpected reminds us how wild, weird, and wonderful science can be. The world of health care continues to surprise and astonish.
