Lab marker

PSA

Prostate-specific antigen

Men's most-discussed and most-controversial tumour marker — useful but only in the context of informed shared decision-making.

Strong relevance8 cited sourcesNo fasting€20–50 private; covered by most insurers on physician request.nutrition

What it measures

A serine protease produced almost exclusively by prostate epithelial cells. Elevated by prostate cancer but also by benign prostatic hyperplasia, prostatitis, recent ejaculation, urinary tract infection, and prostate manipulation (DRE, biopsy, cycling). Reported in ng/mL.

Reference context

2 guideline sources

Single PSA values are noisy — repeat after 4–6 weeks before action, and exclude transient causes (ejaculation, UTI, vigorous exercise). PSA velocity (rate of change) and PSA density (PSA / prostate volume on MRI) refine interpretation. The Stockholm3 test combines PSA with other biomarkers and kallikreins to reduce unnecessary biopsies; ERSPC follow-up confirmed mortality benefit at 16 years for organised screening.

Population context — consult guideline targets below

Mechanism

Why moving this marker matters

Prostate cancer cells leak PSA more freely than normal prostate tissue. Population screening has been shown to reduce prostate-cancer mortality (ERSPC, Göteborg) but at the cost of substantial overdiagnosis and overtreatment of indolent cancers that would never have caused harm. The evidence balance has been the subject of major guideline revisions over the past decade.

Guideline targets

What major guidelines recommend

Common reference (general adult action threshold)

Strong

>3 ng/mL → consider further evaluation (mpMRI, repeat testing). >4 ng/mL has been the historical biopsy threshold but is now considered too aggressive.

Age-adjusted reference (rough guide)

Moderate

<2.5 ng/mL under 50; <3.5 ng/mL 50–59; <4.5 ng/mL 60–69; <6.5 ng/mL 70+

How to measure

The test, where to get it, when to repeat

Method

Standard blood draw. Avoid ejaculation in the 48 hours before testing; avoid testing within 6 weeks of UTI, prostatitis, biopsy, or vigorous cycling.

Where

GP request, private lab, or organised screening programme (Germany: GKV from age 45 with DRE; UK: not offered routinely; US: shared decision-making from age 50, earlier with risk factors).

Typical cost

€20–50 private; covered by most insurers on physician request.

Fasting

Not required

When to test

USPSTF 2018
55–69male
Grade C (individual shared decision-making) for men 55–74. Grade D (recommend against) for men 70+. Strong emphasis on understanding overdiagnosis trade-off.
EAU 2024
50+male
Risk-adapted screening from age 50 (or 45 with family history / African ancestry). Multiparametric MRI before biopsy if PSA elevated.
ACS 2024
male
Shared decision-making from age 50; from 45 with elevated risk (family history, African American men).

Where to test

Independent labs offering this test

Healicus refers you to independent laboratories. You order from the lab; they take the sample, run it, and return your result on their own platform. Healicus never sees your value.

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Context

Reading the numbers

Caveats

PSA screening's benefits and harms balance differently for different men — informed discussion before testing is the standard of care, not optional. A PSA above threshold typically leads to mpMRI before biopsy in modern protocols; this has substantially reduced unnecessary biopsy rates.

Practices

What's been shown to influence this marker

Cohort meta-analyses (Liu 2011, Friedenreich 2016) show modest inverse association between regular physical activity and prostate cancer mortality — though not consistently with PSA values per se. Effect more pronounced for vigorous activity over 3+ hours/week.

Mediterranean dietary pattern adherence is associated with lower aggressive-prostate-cancer incidence in observational cohorts; effects on PSA itself are inconsistent.

Heavy alcohol use shows a modest dose-response association with aggressive prostate cancer; effect on PSA values is small.

Limit alcohol intake

Habit·Lancet pooled analysis (n=599,912): lowest mortality risk threshold is ~100 g/week — about 5-6 standard drinks total.

Strong evidence

Why

Wood et al. 2018 Lancet combined individual-participant data from 83 prospective studies (n=599,912 current drinkers in 19 high-income countries). Above ~100 g/week (about 5-6 UK standard units), all-cause mortality climbs in a dose-response manner. Below that threshold the curve is roughly flat — there is no protective effect. Reductions from heavier intake to ≤100 g/week could add up to 2 years of life expectancy at age 40.

How to do it

How

Track intake honestly for one week. If above threshold, set a weekly cap rather than a daily one (avoids the 'I'll catch up' trap). Several alcohol-free days per week is the simplest pattern. Sleep quality typically improves within 1-2 weeks of reduced intake.

Ideal for

Anyone currently drinking above ~100 g/week (≈one bottle of wine, six pints of beer, or a half-bottle of spirits).

Markers this may influence

Ferritin Triglycerides eGFR ALT GGT PSA Folate Iron studies Haemoglobin & CBC uACR Blood pressure AUDIT-C hsCRP

Caution: Sudden cessation in heavy drinkers can cause withdrawal — taper or seek medical guidance if you've been drinking heavily for years.

Evidence

Wood et al., Lancet 2018 — pooled analysis of 83 prospective studies (n=599,912 current drinkers)

Practising under

Mediterranean dietary pattern

Habit·Olive oil, fish, nuts, legumes, plants. The most-studied diet for cardiovascular and cognitive longevity.

Strong evidence

Why

The Mediterranean pattern — heavy on plants, olive oil, fish, nuts, legumes; moderate fish and dairy; light on red meat — has the strongest evidence base of any specific diet for long-term cardiovascular and cognitive outcomes. PREDIMED, the largest trial, showed ~30% reduction in major cardiovascular events vs. low-fat control.

Slot in your day

With a meal

How to do it

How

Olive oil as the primary fat. Plants at every meal. Fish 2–3× per week. Nuts daily (small handful). Red meat once a week or less. Wine optional, with food.

Sticking with it

Stock the kitchen for one week's pattern. Decisions live in the shopping list, not at mealtime.

Evidence

Estruch et al., NEJM 2018 (PREDIMED)

Zone 2 cardio

Habit·Conversational-pace cardio, 150+ minutes per week. Mitochondrial backbone of healthspan.

Strong evidence

Why

Zone 2 is the intensity at which you can still hold a conversation but a song would be a stretch — roughly 60–70% of max heart rate. Sustained Zone 2 work increases mitochondrial density, improves fat oxidation, and is the single most consistently associated exercise input with all-cause mortality reduction in cohort studies.

Slot in your day

Anytime

How to do it

How

Brisk walk, easy bike, slow jog. 30 minutes × 5 days, or 45–60 min × 3 days. The 'talk test' is the simplest gauge.

Ideal for

Anyone over 30; especially valuable as the foundation before adding higher-intensity work.

Sticking with it

Schedule it like a meeting. The session you 'fit in if there's time' is the session that doesn't happen.

Markers this may influence

Fasting insulin HOMA-IR Triglycerides eGFR Testosterone (total)HDL-C ALT PSA uACR Carotid intima-media thickness Push-up capacity Blood pressure Waist circumference VO₂max Heart rate variability (HRV)Resting heart rate ApoB HbA1c

Evidence

Lee et al., Lancet 2012

Practising under

Take to your physician

Worth discussing

Whether PSA screening makes sense for you given your age, family history, ethnicity, and personal values about overdiagnosis risk.
If PSA is elevated, what the workup path looks like (repeat, mpMRI, potentially biopsy) before assuming the worst.
If diagnosed with prostate cancer, whether active surveillance is appropriate for indolent disease (most early-stage cancers detected by screening qualify).

Sources

Cited literature

Edited by Carl Pöhl, MD · Healicus editorial

Last reviewed May 2026

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