May Edition

Methodology

Thirty healthy adults were randomly put into one of three groups for 8 days. The first group was instructed to eat following the original ProLon diet. The second group was instructed to follow a lower-starch variant of the diet called FMD2. And the third group ate normally.

Both FMD protocols involve 5 days of significant calorie restriction (starting at roughly 1,100 kcal and dropping to 700-800 kcal on days 2-5), followed by a return to normal eating. Blood was drawn before the start of the trial to establish a baseline, then again at days 4 and 6, and finally 48 hours post-diet to measure fasting glucose, insulin resistance, ketones, and autophagy activity in white blood cells.

Clinical Implications

Both FMD groups showed significant improvements in weight, fasting glucose, insulin, and insulin resistance by day 6, whereas the control group’s insulin resistance actually increased. On autophagy, the ProLon group showed a meaningful increase in cellular cleanup activity by day 6, persisting two days after returning to normal eating. The FMD2 group showed a similar trend, but delayed. The authors note this is the first human trial to directly measure autophagic flux during and after FMD, rather than relying on gene expression proxies (measures used to infer the activity of a gene without directly measuring the gene’s protein output).

The study’s limitations are worth noting: only 30 participants, only one FMD cycle, and industry sponsorship by L-Nutra (the maker of ProLon). Larger independent trials are needed to confirm these findings.

Velocity Takeaway:

This adds meaningful human evidence to an area of study that has largely focused on animal models. Plus, it shows that true, strict fasting is not necessary to induce an increase in autophagy. A short, periodic dietary intervention appears effective at activating cellular cleanup mechanisms while also improving metabolic markers. If you have been curious about ProLon or similar protocols, the data increasingly suggest something real is happening at the cellular level, though one small pilot study is just the beginning of that case.

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Emerging:

This Immune Organ May Be the Secret to a Longer Life

Summary

A new study published in Nature used an artificial intelligence (AI) tool to evaluate the thymus, a small organ in your chest. The study found that people with healthier thymus glands had lower rates of cancer and heart disease, and they lived longer.

The thymus is the organ that trains your immune system’s T cells, which fight infections and cancer. Most doctors have assumed the thymus becomes useless after puberty. This study says otherwise.

Methodology

Researchers developed an AI program that analyzed routine chest CT scans (the same type of imaging many adults already receive for lung cancer screenings) to measure the health of each person’s thymus. They applied this tool to data from two large studies: the National Lung Screening Trial (25,031 participants) and the Framingham Heart Study (2,581 participants). Participants were followed for up to 12 years.

Clinical Implications

People with healthier thymus glands had significantly lower rates of death from all causes, lower rates of lung cancer, and lower rates of death from heart disease over a 12-year period. This suggests the thymus is not simply an inactive relic of childhood development, but a meaningful contributor to health and longevity throughout adulthood. Because the AI tool works on standard CT scans that many adults already receive, thymic health could potentially become part of routine health assessments without any additional testing.

Velocity Takeaway:

This study is a landmark piece of research because it uses a brand-new AI tool to reveal something doctors never realized: that the thymus continues to affect your health throughout your adult life. The connection between a healthier thymus and lower cancer and cardiovascular mortality is both striking and clinically meaningful.

That said, this is an observational study that shows an association, not a direct cause-and-effect relationship. No proven interventions exist yet to improve or maintain thymic function in adults, though thymic regeneration research is an active and exciting emerging area. What this study definitively establishes is that the thymus is a biomarker worth watching. At Velocity, we will be monitoring the developing science on thymic health closely as this field matures.

Experimental:

Your Organs Are Not All Aging at the Same Rate: A New Study Mapped Each One Separately

Summary

A study published this year in npj Aging used imaging data from over 70,000 participants to generate separate biological age estimates for seven different organs: brain, heart, kidneys, liver, pancreas, spleen, and eyes. The central finding is that these organs age largely independently of each other. How old your heart looks biologically tells you relatively little about your brain, and neither tells you much about your kidneys or pancreas.

By “biological age,” we mean how quickly organs are aging on a molecular level, as opposed to how many years the whole body has aged.

Methodology

Researchers trained AI models on MRI and eye imaging data. For each organ, the AI model produced a biological age estimate and compared it to the person’s actual age, calculating a gap score. A positive gap means the organ is aging faster than average; a negative gap means it is aging more slowly than expected.

Clinical Implications

The gap scores were meaningfully predictive of future disease. Accelerated brain aging was linked to a 49% higher risk of Alzheimer’s disease per year of age gap. Accelerated heart aging was associated with a 12% higher annual mortality risk. Accelerated kidney aging was tracked with approximately a 19% higher risk of chronic kidney disease per year. Accelerated aging across the brain, heart, and pancreas together was associated with higher rates of type 2 diabetes, suggesting that metabolic disease leaves a systemic fingerprint rather than affecting just one organ.
Critically, the organ-aging patterns were largely independent of one another. Protecting your heart does not necessarily protect your brain. Strong metabolic markers do not necessarily indicate that your kidneys are also aging slowly. You could have the heart and pancreas of a 30-year-old, but the brain of a 70-year-old.

Velocity Takeaway:

The results of this study make it clear that there can be no single number or “score” that reveals a person’s “biological age,” as many online wellness trends have claimed. Each organ system runs on its own timeline, and a comprehensive approach to health monitoring, one that looks across multiple systems rather than leaning on one or two metrics, is the only approach that reflects how aging actually progresses.