How the body ages, and what genuinely slows it

Last reviewed: 7 May 2026

Anti-ageing is one of the most lucrative and least honest corners of the supplement industry. The real biology of ageing is genuinely interesting, and the things that slow it are less glamorous than the marketing makes out. This piece covers the biology — including the specific molecular process of glycation and AGEs that sits under so much of visible skin ageing.

What ageing is

At the cellular level, ageing is the accumulation of damage faster than the body can repair it. Several processes run in parallel:

Oxidative damage — free radicals damaging cell membranes, proteins and DNA over time (covered in detail in our antioxidants guide).
Chronic low-grade inflammation — "inflammageing" is a real term in the longevity literature.
Glycation and AGEs — the specific mechanism where sugars in the bloodstream bind to proteins and form advanced glycation end-products. AGEs stiffen collagen and elastin, which is a major driver of visible skin ageing.
Telomere shortening — the protective caps on chromosomes getting slightly shorter with each cell division.
Mitochondrial decline — the energy-producing organelles in cells becoming less efficient over time.
Stem-cell pool depletion — the reserve cells that repair tissues running lower with age.
Hormonal shifts — oestrogen, testosterone, growth hormone, thyroid function all changing.

Different tissues age at different rates. Skin shows visible change because it's on the outside. Bones lose density slowly. Muscle mass declines predictably without strength training. Cognition changes differently again. The common thread across all of them is that lifestyle inputs influence the rate — in both directions.

The three biggest modifiable levers

Decades of longevity research keep pointing to the same three things:

1. Movement — specifically strength and cardio combined. Sedentary living accelerates muscle loss (sarcopenia), bone loss (osteopenia → osteoporosis), cardiovascular decline and metabolic decline in parallel. Strength training 2–3 times a week and regular cardio is not a vanity intervention — it is the most mechanically powerful anti-ageing tool anyone has identified. The LIFTMOR trial showed 8 months of supervised resistance and impact training raised lumbar spine BMD by ~3% in postmenopausal women with low bone mass.^[1]

2. A plant-forward Mediterranean-style eating pattern. Vegetables, fruit, whole grains, legumes, olive oil, oily fish, nuts and seeds. Lower in ultra-processed food, added sugar and excess alcohol. The PREDIMED trial (n≈7,447) found that a Mediterranean diet supplemented with extra-virgin olive oil or nuts cut major cardiovascular events by roughly 30% over 4.8 years compared with a low-fat control.^[2]

3. Sleep, social connection, stress management. Boring, non-negotiable. Chronic under-sleeping, social isolation and chronic stress all show up as ageing accelerants in the research. Emotional health is physical health at ageing scales.

Nothing sold in a bottle replaces any of these three.

AGEs — the glycation mechanism explained

Advanced glycation end-products form when blood sugars (particularly glucose and fructose) bond to proteins in tissues. The reaction is non-enzymatic — it happens automatically whenever sugar and protein coexist. Once formed, AGEs are essentially permanent and they cross-link collagen and elastin fibres together, making them stiff and brittle.

What this looks like visibly:

Skin — reduced elasticity, deeper lines, that particular "glycated" complexion that high-sugar-diet individuals develop over decades.
Blood vessels — stiffer arteries, rising blood pressure.
Kidney and retinal capillaries — the reason diabetic complications hit these tissues.
Cartilage — joints losing resilience.

What drives AGE accumulation:

Chronic high blood sugar — the biggest single driver. Type 2 diabetes dramatically accelerates AGE formation; prediabetes and insulin resistance contribute.
High-temperature cooking with sugar — deep frying, grilling with sugar-based marinades, caramelising, browning. These generate dietary AGEs that you then absorb.
Excess dietary sugar and fructose — particularly from sweetened drinks.
Smoking — generates large quantities of AGEs directly.

What reduces it:

Lower-glycaemic eating pattern.
Gentler cooking methods — steaming, poaching, stewing, using moisture rather than dry high heat.
Limited smoking and limited sugar.
Adequate vitamin C, vitamin E, selenium and zinc — the authorised-claim antioxidants.^[3]

Skin ageing specifically

Skin ageing is a combination of intrinsic (genetic programming) and extrinsic (sun, pollution, smoking, diet) drivers. The extrinsic side — photoageing especially — accounts for the majority of visible change in people with meaningful UV exposure.

The inside-out side of skin ageing is where nutrition and supplementation matter:

Daily SPF — the single highest-ROI intervention for skin ageing. Nothing in a capsule outranks it.
Collagen peptides — covered in detail in our collagen and when to start guides. An 8-week RCT in 69 women aged 35–55 found that 2.5–5 g/day of specific collagen peptides significantly improved skin elasticity vs placebo.^[4]
Vitamin C — contributes to normal collagen formation for normal skin function (authorised claim). Also a strong antioxidant.
Vitamin A — contributes to maintenance of normal skin (authorised claim).
Vitamin E — protects cells from oxidative stress (authorised claim).
Zinc — contributes to maintenance of normal skin, hair and nails (authorised claim).
Biotin — for hair and nails specifically.
Omega-3 EPA and DHA — the inflammatory-modulation side of skin physiology.
Ceramides, squalane and fat-soluble vitamins delivered orally — our LipidCell covers this angle.

Our full beauty-vitamins guide walks through the inside-out nutrient map across skin, hair and nails.

Bone and muscle ageing

Both respond to inputs far more than people appreciate.

Strength training — twice a week minimum, progressive loading. Protects bone density and muscle mass simultaneously.
Adequate daily protein — 1.0–1.5 g/kg for most adults, up to 1.6–2.0 g/kg for older adults and athletes.
Vitamin D — contributes to maintenance of normal bones and normal muscle function (authorised claims). Most UK adults need a winter supplement (10 µg/day).^[5] Our D3+K2 covers this.
Vitamin K2 (MK-7) — contributes to maintenance of normal bones (authorised claim). Included in our D3+K2.
Calcium — from dairy, leafy greens, fortified plant milks, sardines.
Collagen peptides — a 12-month trial in postmenopausal women with reduced BMD reported gains at lumbar spine and femoral neck with 5 g/day of specific peptides.^[6]

Brain ageing

Cognitive decline is not inevitable at the rate many fear. Active interventions:

Cardio exercise — raises BDNF, improves cerebral blood flow, protects hippocampal volume in ageing brains.
Omega-3 DHA — contributes to maintenance of normal brain function and normal vision at 250 mg daily (authorised claims).
B-vitamins — especially B12, folate, B6. Homocysteine biology matters for vascular-cognitive health.
Ongoing cognitive engagement and social connection — not supplements, but the most consistent non-pharmacological findings in ageing research.

Hormonal changes

Menopause specifically drives accelerated changes in skin, bone and body composition that are not purely "ageing" but hormonal. This needs a doctor-led conversation rather than a supplement answer. We cover the nutritional side in our upcoming menopause skin guide; hormonal treatment is a medical question.

What supplements to skip

"Anti-ageing complexes" that blend 20+ ingredients at sub-clinical doses.
Mega-dose single antioxidants (see the antioxidants article for why).
Unregulated "NAD+ boosters" and similar longevity-branded products with thin clinical bases at human doses.
Hormone-adjacent supplements (DHEA, pregnenolone etc.) without medical supervision.

The rational stack remains small and boring: B-complex, vitamin D, magnesium, omega-3, and targeted additions for the specific tissue focus (collagen peptides for skin/joints, LipidCell for skin barrier, bioavailable curcumin for broader polyphenol coverage).

In practice

The body ages because damage accumulates faster than repair. The rate of accumulation is heavily influenced by what you do with movement, food, sleep, stress and sunlight. The interventions with real research behind them are unglamorous: strength training twice a week, a Mediterranean eating pattern, seven-plus hours of sleep, not smoking, SPF every morning, and a small sensible supplement baseline covering the authorised-claim nutrients most likely to be under-delivered. The "anti-ageing supplement" market is mostly selling fantasy at a premium; the biology is real, but the effective tools for it are unglamorous.

References

Watson SL, Weeks BK, Weis LJ, et al. High-Intensity Resistance and Impact Training Improves Bone Mineral Density and Physical Function in Postmenopausal Women With Osteopenia and Osteoporosis: The LIFTMOR Randomized Controlled Trial. J Bone Miner Res. 2018;33(2):211–220. PubMed: 28975661
Estruch R, Ros E, Salas-Salvadó J, et al. Primary Prevention of Cardiovascular Disease with a Mediterranean Diet Supplemented with Extra-Virgin Olive Oil or Nuts. N Engl J Med. 2018;378(25):e34. PubMed: 29897866
European Commission. EU Register of Nutrition and Health Claims Made on Foods. ec.europa.eu
Proksch E, Segger D, Degwert J, et al. Oral supplementation of specific collagen peptides has beneficial effects on human skin physiology: a double-blind, placebo-controlled study. Skin Pharmacol Physiol. 2014;27(1):47–55. PubMed: 23949208
Scientific Advisory Committee on Nutrition. SACN Vitamin D and Health Report (2016). gov.uk
König D, Oesser S, Scharla S, et al. Specific Collagen Peptides Improve Bone Mineral Density and Bone Markers in Postmenopausal Women — A Randomized Controlled Study. Nutrients. 2018;10(1):97. PubMed: 29337906