Oxygen, clearance, and what keeps a cell working well

“Cellular health” gets used constantly—on supplement labels, in longevity podcasts, on skincare shelves—and it is rarely defined. It is worth defining, because it is not a vague wellness concept. It is a specific set of properties, most of which can be measured, and understanding them changes what you bother spending money on.

The Basic Idea

Every tissue in your body is only as healthy as the cells that compose it. Skin, muscle, brain, liver—all of them are populations of cells doing their jobs, replacing themselves on different timelines, and either keeping pace with damage or slowly losing ground to it.

A cell in good health is doing four things well:

• Producing energy efficiently: Its mitochondria are working, and it has the oxygen and substrate to run them.
• Clearing what it no longer needs: Damaged proteins, spent organelles and metabolic byproducts are broken down and removed rather than accumulating.
• Communicating accurately: It hears hormonal and chemical signals and responds appropriately.
• Renewing on schedule: Dividing and repairing often enough to maintain the tissue, without dividing so often that errors accumulate.

Almost everything marketed as a longevity intervention is claiming to improve one of those four. It is a useful filter: ask which one, and ask how it is supposed to get there.

Mitochondria and the Energy Question

Mitochondria convert nutrients and oxygen into ATP, the molecule that powers essentially everything a cell does. They are also where a good deal goes wrong first.

As mitochondria age they become less efficient and generate more reactive oxygen species—byproducts that damage nearby proteins, membranes and DNA. This is not automatically catastrophic. Cells have antioxidant systems built to handle a baseline level of it.

The problem is a slow drift: efficiency falls, oxidative byproducts rise, and the two trends compound over years. Muscle and skin are both relatively energy-hungry tissues, which is part of why exercise capacity and skin quality tend to decline gradually rather than falling off a cliff.

Oxygen: The Supply Side

Mitochondrial energy production is aerobic. Oxygen is the final electron acceptor at the end of the chain, and without enough of it reaching the cell, the whole process backs up—the cell falls back on glycolysis, which yields a fraction of the ATP and leaves lactate behind.

Anywhere oxygen delivery is chronically marginal, cellular function is marginal too. It is one of the more underrated inputs in this entire conversation.

The limitation is almost never the air. If your resting oxygen saturation is 97 to 99 percent, you are not short of oxygen at the lungs. The weak links sit downstream, in delivery and utilisation: cardiac output, capillary density in the tissue, haemoglobin and iron status, diffusion distance from capillary to cell, and the health of the endothelium lining the vessels.

This is why an oxygen canister does very little and why cardiovascular fitness does a great deal.

What Genuinely Improves Delivery

Aerobic training increases cardiac output, capillary density and mitochondrial density together—it improves both the supply line and the machinery at the end of it.

VO2 max is among the strongest predictors of all-cause mortality in the epidemiological literature, which is striking for what is essentially a measure of how well you move oxygen.

Correcting iron deficiency matters where it exists. Treating obstructive sleep apnoea is one of the largest single interventions available to anyone who has it: repeated nocturnal drops in oxygen drive oxidative stress, endothelial dysfunction and systemic inflammation, night after night, and it remains badly underdiagnosed.

Hyperbaric Oxygen

Pressurised hundred percent oxygen dissolves oxygen directly into plasma, raising tissue oxygen levels well beyond what breathing alone achieves.

The evidence is strong for defined medical indications—non-healing and diabetic wounds, radiation tissue injury, carbon monoxide poisoning, decompression illness.

The longevity claims rest on a much smaller literature: a handful of small trials in older adults reporting changes in telomere length, senescent cell counts and cognitive measures, generally short, generally without proper control groups.

Interesting, plausible, not established.

It is also a significant commitment of time and money and carries real if uncommon risks, including barotrauma and transient changes in vision.

More Is Not Linearly Better

This is the part usually left out. Cells evolved to operate within a range, and sustained hyperoxia increases reactive oxygen species rather than reducing them.

Some of the most robust mitochondrial adaptations actually come from intermittent mild oxygen stress—the mechanism behind altitude and interval training, which upregulates the cell’s own hypoxia-response machinery.

The goal is efficient delivery and use, not maximum saturation.

Topical oxygen treatments sit at the other end of this: oxygen does not meaningfully diffuse into skin from a spray or a mask, and what people are responding to is the hydration, the vasodilation and whatever serum was applied alongside it.

Clearance: Autophagy and Senescence

Autophagy is the cell’s internal recycling system, breaking down damaged proteins and organelles so their components can be reused. It runs harder during periods of energy restriction, which is much of why fasting research keeps returning to this pathway. When it slows, damaged components accumulate and efficiency falls.

Senescence is what happens when a cell stops dividing but does not die. It is not purely harmful—it is partly a brake on damaged cells replicating—but senescent cells secrete inflammatory signalling molecules that affect the tissue around them.

A few are normal; an accumulation, which happens with age, contributes to the chronic low-grade inflammation researchers call inflammaging.

Skin shows both at once. Fibroblasts with reduced autophagic efficiency produce collagen and elastin less effectively, while senescent fibroblasts secrete enzymes that degrade the collagen already there.

Less built, more broken down—which presents as thinning, laxity and slower healing.

Cells do not need rescuing. They need supply, clearance, and conditions that let them do the work themselves.

Detoxification: What the Word Actually Means

Few words have been abused more thoroughly. Underneath the marketing there is real, specific physiology, and it is worth knowing what it is, because the real version and the sold version have almost nothing in common.

The liver does the chemistry in two phases. Phase I enzymes transform fat-soluble compounds into reactive intermediates. Phase II then conjugates those intermediates—attaching molecules through glucuronidation, sulfation, methylation, acetylation or glutathione binding—which makes them water-soluble and safe to excrete.

The intermediates produced between the two phases are often more reactive than the original compound, which is why the phases need to be in balance rather than either one simply “boosted.”

Then the rest of the system removes them. Water-soluble products leave through bile into the gut or through the kidneys into urine. Fibre binds bile in the intestine so its contents are carried out rather than reabsorbed further down.

The lymphatic system clears interstitial fluid and immune debris, driven largely by muscle contraction and breathing rather than by any pump of its own. Sweat plays a minor role for most compounds, whatever the sauna marketing suggests.

Why This Is a Cellular Story and Not Just a Liver Story

The load these systems handle is mostly generated internally—hormone metabolites, ammonia from protein metabolism, aldehydes from lipid peroxidation, the byproducts of ordinary energy production.

Glutathione, the workhorse of phase II conjugation, is also the principal antioxidant inside the cell. Clearance capacity and oxidative stress handling are, to a large extent, the same system. Deplete it in one direction and you have less of it in the other.

What Actually Supports It

Adequate protein, because conjugation runs on amino acids including glycine, cysteine and glutamine.

Cruciferous and allium vegetables, which supply sulphur compounds and activate the Nrf2 pathway that upregulates the body’s own antioxidant enzymes.

Fibre, to carry bile-bound compounds out rather than allowing reabsorption.

Enough water for renal clearance.

Moderating alcohol, which consumes both NAD+ and glutathione.

Sleep, during which the brain’s glymphatic clearance is most active.

Movement, which is what drives lymphatic flow in the first place.

What Does Not

Juice cleanses, detox teas and similar protocols do not increase hepatic conjugation capacity; the teas are frequently laxatives or diuretics, and what they produce is fluid and electrolyte loss rather than clearance.

Foot pads have no plausible mechanism.

Sauna has genuinely good cardiovascular observational data behind it and is well worth doing, but the benefit almost certainly comes from heat adaptation and cardiovascular conditioning rather than from excreting anything meaningful in sweat.

Lymphatic massage moves fluid and feels good; it is not removing toxins in the sense implied.

The honest summary is that you do not need to run a detox. You need to avoid impairing systems that already run continuously, and give them the substrate they require.

Signalling: Cells Listening to Each Other

Cells receive constant chemical instruction—hormones, growth factors, cytokines—and a healthy cell responds accurately.

Insulin sensitivity is the everyday example: a responsive cell hears insulin and takes up glucose. When that degrades you get insulin resistance, which itself drives oxidative stress and inflammation elsewhere.

This matters because most repair is signal-dependent. Growth factors tell fibroblasts to build collagen; cytokines tell immune cells where to work.

If the signalling is noisy or the receptors are less responsive, repair that should happen automatically starts happening late, or incompletely.

Where the Evidence Thins Out

A great deal of longevity marketing takes real mechanisms—senescence, autophagy, mitochondrial function, glutathione—and attaches them to products with far less human evidence than the underlying biology implies.

NAD+ precursors, senolytics, glutathione injectables and mitochondrial support formulas are legitimate areas of active research. Few have the large, long-term human trial data that would justify the confidence with which they are sold.

It is entirely reasonable to find the category interesting and to remain sceptical of specific claims at the same time.

The Practical Takeaway

Good cellular health is not a number or a supplement. It is the sum of how efficiently your cells make energy, how well oxygen reaches them, how completely they clear their own waste, how accurately they respond to signals, and how well they balance renewal against overuse.

The largest levers are unglamorous and mostly free: aerobic fitness, treating disordered sleep, adequate protein and fibre, plants with sulphur compounds in them, sensible alcohol intake, daily movement, and sun protection.

Treatments and supplements work best layered on that foundation—never as a substitute for it.

Cells do not need rescuing. They need supply, clearance, and the right conditions.

Ready to learn more about supporting your cellular health? Book a consultation with Remedē Longevity & Aesthetics.

Written for Remedē Longevity & Aesthetics. General information only, and not medical advice—individual suitability is determined at consultation.