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- Ketogenic diet, by replacing glucose with ketones as an energy source, lessens alcohol cravings among people with alcohol use disorders.
- Omega-3 fatty acids reduce the risk of cardiovascular disease-related death by up to 23 percent, especially in people with high triglyceride levels.
- Women see a 24 percent drop in premature death risk with just 140 minutes of weekly activity – half the time men need for similar benefits.
- Aging undermines the brain's capacity for maintaining working memory, with subtle declines in neuron activity and connectivity in the prefrontal cortex.
Losing weight can mean losing lean tissue along with fat, an increasing concern as muscle mass and strength tend to decline with age. A clinical trial tested whether creatine could improve that balance, both alongside a training program and without structured exercise.
Researchers recruited 73 adults aged 45–65 for a 12-week trial, with 64 completing the study. Participants first chose whether to join an exercise program, then were randomly assigned within each group to creatine monohydrate (5 grams twice daily) or placebo. Exercisers completed supervised resistance and aerobic training three times weekly while following a diet that aimed to reduce calories by 300–500 per day.
- Among adults exercising and dieting, lean mass increased by 1.27 kilograms (2.80 pounds) with creatine over 12 weeks, compared with 0.14 kg (0.31 lb) with placebo.
- Among adults not participating in the structured exercise and diet program, lean tissue increased by 1.10 kg (2.43 lb) with creatine, versus a 0.16-kg (0.35-lb) decrease with placebo.
- During the exercise and diet program, maximum leg-press strength increased more with creatine than placebo: 54.82 kg (120.86 lb) versus 25.85 kg (56.99 lb).
- Among adults not participating in the structured exercise and diet program, maximum bench-press strength increased by 4.02 kg (8.86 lb) with creatine, compared with a 2.96-kg (6.53-lb) decline with placebo.
- During the exercise and diet program, body-fat percentage fell significantly more with creatine than placebo: 3.24 versus 1.87 percentage points.
Creatine increases muscle stores of phosphocreatine, which rapidly replenishes energy during forceful contractions. That extra reserve could improve lifting performance even without structured training and, with regular exercise, help muscles sustain the work that drives adaptation. This may become increasingly relevant with age, as muscle mass and strength decline and weight loss can further reduce lean tissue. Creatine can also increase body water, so some of the increase in lean tissue may reflect changes in hydration rather than muscle growth.
Creatine is not a substitute for exercise, but it may still help both alongside training and without a structured exercise program. Benefits that do not depend on structured training become increasingly relevant with age, when illness or limited mobility may make exercise harder to maintain.
Low testosterone is often viewed as a consequence of getting older. A study examined how body fat compared with age in accounting for differences in testosterone levels among adult men.
The analysis drew on nationally representative US health survey data collected from 2011 to 2016. It included 4,984 men aged 20 to 59, each with a single blood measurement of total testosterone. Researchers compared statistical models relating testosterone to age alone with models that also included body fat or waist circumference.
- Within every age decade studied, men with testosterone below the commonly used 300 ng/dL cutoff for low testosterone had a higher total body-fat percentage than those with levels at or above it.
- Including an adiposity marker alongside age explained about 18–20% of the variation in testosterone levels, compared with just 2.5% for age alone.
- After accounting for age, predicted testosterone fell from about 500 to 300 ng/dL as waist circumference increased from 80 to 120 cm, from about 900 to 250 ng/dL as body fat rose from 5% to 45%, and from about 700 to 230 ng/dL as visceral fat area increased from below 50 to above 300 cm².
- A simple waist measurement explained differences in total testosterone about as well as measuring visceral fat with a body scan.
Fat tissue contains aromatase, an enzyme that converts testosterone into estradiol, a form of estrogen. Greater conversion can lower testosterone while strengthening estradiol's signal to the brain and pituitary to reduce testosterone production. Inflammation and insulin resistance associated with excess body fat can further interfere with testosterone regulation. Low testosterone can in turn promote fat gain, making the relationship potentially two-way, but the study could not determine how much each pathway contributed.
Body composition can provide useful context when interpreting a low testosterone result in men. However, confirming a clinical disorder requires repeat measurements together with an assessment of symptoms.
AI-designed drugs could open a new path toward treatments that slow or reverse aspects of human aging. Researchers investigated whether rentosertib, developed to treat idiopathic pulmonary fibrosis (a lung-scarring disease), could also affect age-related biological changes.
Researchers analyzed blood samples from 42 adults with an average age of 67 and idiopathic pulmonary fibrosis who completed a randomized, double-blind trial. Participants received rentosertib at 30 mg once daily, 30 mg twice daily, or 60 mg once daily, or placebo, for 12 weeks alongside usual treatment. Six "aging clocks" converted blood-protein patterns at the start and at weeks 2, 4, and 12 into biological age estimates. Four clocks used protein patterns that tend to differ between younger and older people to predict chronological age. The other two based their age estimates on protein patterns associated with a higher or lower risk of death.
- All six clocks showed lower biological-age estimates during rentosertib treatment, while placebo estimates changed little or increased.
- At week 4, age estimates fell by 2.7–3.5 years more with 60 mg once daily than with placebo across the four clocks trained to predict chronological age. Neither of the two clocks trained to predict mortality risk showed a clear effect with this dosing schedule.
- The 30 mg twice-daily dose produced the most consistent reduction in estimated biological age across the different clocks and follow-up visits.
- Age estimates largely plateaued between weeks 4 and 12.
Rentosertib inhibits TNIK, an enzyme involved in several cellular processes, including cell signaling. Analysis of the blood proteins suggested lower activity in several growth-factor and nutrient-sensing pathways after treatment. These signals are essential for normal cell function, but when they remain highly active, they can promote processes linked to aging. Dampening them could therefore help explain the younger age estimates.
Rentosertib offers an early glimpse of how AI-designed drugs might be used to target human aging and disease. However, in this study, the younger biological age estimates could not distinguish a broader effect on aging from biological changes caused by treating lung fibrosis.
