Do gardeners live longer? Study of 475 participants found that frequent gardeners experienced slower declines in gait speed and slower telomere attrition between ages 79 and 90, and a 22% lower risk of death.
https://www.sciencedirect.com/science/article/pii/S027249442500372X
Most physicians don't even think about the thymus after childhood but now, a new paper published in Nature suggests that how well your thymus is functioning right now - whether in middle age, in your 60s, or your 70s - can predict with remarkable precision whether you will die from cancer, heart disease, metabolic disease, or pulmonary disease in the next 12 years. This is independent of age, sex, smoking history, and BMI.
Using a trained AI system, scientists analysed over 27,000 people and tracked who developed certain diseases and who died over a 12 year period. Those with high thymic health had:
The Mechanism: Inflammaging and Mitochondrial Dysfunction
Researchers measured 68 inflammation-related proteins in blood samples from 317 Framingham participants. People with worse thymic health showed elevated levels of inflammatory markers: IL-6, IL-18, VEGFA, and several pro-inflammatory chemokines. This is the molecular signature of inflammaging: the chronic, low-grade systemic inflammation that underlies most age-related disease.
They also tracked C-reactive protein (CRP) in over 1,150 people across 5–10 years. Chronically elevated CRP (≥3 mg/L) was independently associated with lower thymic health — not explained by age, sex, or smoking.
The picture that emerges is a vicious cycle: chronic inflammation accelerates thymic involution, fewer naive T-cells are produced, immune surveillance weakens, and inflammation climbs further. And sitting at the center of this cycle, increasingly, is mitochondrial dysfunction within immune cells themselves.
Mitochondrial dysfunction is recognized as a central hallmark of aging. Immune cells are especially energy-hungry. With age, mitochondria become less efficient. They produce less ATP, generate more reactive oxygen species, and accumulate damage to their DNA and membranes. In immune cells, mitochondrial dysfunction is associated with reduced functional adaptability and a shift toward chronic, low-grade inflammatory signaling that contributes to immunosenescence and inflammaging.
While researchers are still uncovering the full extent of mitochondria’s role in brain health, several strong connections have already been established. Beyond energy production, mitochondria support key aspects of cellular health that influence how brain cells operate.
Here are a few ways that mitochondrial dysfunction impacts brain health, beyond brain energy metabolism:
The good news is that recent research shows that individuals with stronger mitochondrial function tend to have better brain structure and experience less age-related cognitive decline.
A 2025 preclinical study published in iScience sheds light on how Urolithin A may support heart health.
Mitochondrial Dysfunction: A Hallmark of Cardiovascular Aging
The researchers began by confirming, through a review of prior data, that mitochondrial dysfunction is a hallmark of cardiac aging.
Cardiac Benefits of Urolithin A in Animal Models with Heart Disease
A heart attack was induced in one group of rats, while another group served as a healthy control. Among the heart attack rats, some received Urolithin A for two months, while others received no treatment. The results showed that two months of Urolithin A supplementation improved multiple measures of heart health, including:
In addition, Urolithin A helped correct defects in mitochondrial gene expression that are associated with heart failure.
Urolithin A Enhances Heart Function in Healthy Older Animals
The researchers also examined the effects of Urolithin A on cardiac function in older rodents without disease. They tested it in old mice (about 24 months old—representing a human in their 70s) and compared them with young mice (about 5 months old). The older mice were fed either their standard diet or a diet enriched with Urolithin A for two months.
The study found several key improvements in older mice that received Urolithin A supplementation:
While more human studies focused on heart outcomes are still needed, the findings reinforce the value of supporting mitochondrial health as we age.
Both improve muscle strength and have human RCT data. But they work at different levels of muscle biology and understanding that distinction changes how you think about using them
Creatine:
Urolithin A:
Are you currently taking either of these? And if so, what was the evidence that got it into your stack?
Estrogen's role in muscle health:
Research on the exact mechanisms of how estrogen impacts muscle health is still underway, but here is what is understood today:
What actually helps:
Strength training: Several studies have shown that strength training 2-3 times a week is sufficient to help maintain muscle strength and mass during this time, but post-menopausal women needed to complete 15 sets per exercise per week to stimulate muscle growth. Prioritize exercises that engage multiple muscle groups simultaneously to promote functional strength, endurance, and balance.
Nutrition: Research suggests that menopausal women should aim for a daily intake of 1.0 to 1.2 grams of protein per kilogram of body weight to maintain muscle mass. Also important are carbs for energy and recovery, healthy fats for inflammation, micronutrients for muscle function
Supplements: Creatine, Urolithin A, Vitamin D, Omega 3 fatty acids
For anyone who has gone through menopause: at what point did you notice the change in muscle recovery or strength, and what actually made a difference?
To most of us, skin looks like a simple protective covering. In reality, it is a metabolically active, energy-hungry organ. Beneath the surface, millions of cells are constantly dividing, differentiating, repairing DNA, producing collagen, and rebuilding the skin barrier. When mitochondria function efficiently, skin renewal and repair proceed smoothly. When they decline, the effects eventually become visible
Why Do Mitochondria Matter for Skin?
As we age, mitochondria accumulate damage. They become less efficient at producing energy and more likely to generate reactive oxygen species, molecules that can harm cellular structures. This combination creates cellular fatigue that eventually shows up in the mirror.
Together, these changes lead to:
What can be done to support your skin’s mitochondria:
How does the mitochondrial angle compare to other actives you've looked into (like retinol, vitamin C, peptides)? Does the science feel more or less convincing, or just different?
Mitochondria and Egg Quality
A single mature egg contains ~100,000 mitochondria, more than any other cell in the human body. Mitochondrial function in eggs is very closely related to fertility outcomes. Certain markers of mitochondrial health (mitochondrial DNA copy number and ATP levels) are associated with higher pregnancy success rates. On the other hand, inefficient mitochondria have been linked to infertility. Decline in mitochondrial performance is one of the primary reasons female egg quality declines with age.
On top of that, embryos with mitochondrial deficiencies often fail to implant. The data is so compelling that researchers have proposed using mitochondrial indicators as biomarkers for embryo selection in IVF.
Hormones
Mitochondria are the site for steroid hormone synthesis, involved in the synthesis and regulation of many different hormones, including estrogen, progesterone, and testosterone. If your mitochondria are underperforming, your hormones likely are too.
Mitochondria and Sperm Health
Every sperm cell carries dozens of tiny mitochondria. Research notes that a charged mitochondrial “battery” (normal membrane potential) is essential for human sperm motility and function. If mitochondrial energy output falters, sperm swim poorly, and fertility can suffer. Sperm with well-charged mitochondria show greater motility and a faster swimming speed.