longevitywatch
HomeBiomarker
Biomarker

HbA1c

Also: glycated hemoglobin
Last scientific update: jun 2026

HbA1c is a blood value that reflects your average blood sugar over the past 2 to 3 months. It is the standard measure to detect and follow diabetes and prediabetes.

HbA1c at a glance

WhatAverage blood sugar over 2 to 3 months
ImportancePredicts risk, even below the lineModerate
LowerableYes, with lifestyleModerate
AimBelow the prediabetes threshold

HbA1c is the best measure of your average blood sugar and a useful early warning, also for prediabetes.

29 studies4 answersupdated jun 2026
Evidence per claim
Useful to spot prediabetes early
View evidence →
Moderate
Limiting blood sugar spikes can be worthwhile
View evidence →
Moderate
A walk after eating lowers the spike
View evidence →
Moderate
A glucose monitor is not needed for everyone
View evidence →
Preliminary
Practical use

For whom

People who want to know their diabetes risk, from middle age or with overweight.

Not for whom

Continuous glucose monitoring is usually not needed for healthy people.

Usual dose

Have HbA1c tested by your GP; with prediabetes repeat after lifestyle changes.

Key caveats

Single values fluctuate; the trend matters more than one reading.

What we know, and don't

Known

Good measure of average blood sugar
Predicts risk even below the diabetes line
Can be lowered with lifestyle

Not yet

The ideal target per person
Whether spikes harm non-diabetics
The added value of continuous monitoring for healthy people
Common misconceptions
"Only diabetics need to know HbA1c."
Incomplete. It also warns early for prediabetes.Moderate evidence
"Measuring well once is enough."
False. The trend over time says more.Moderate evidence
How HbA1c connects
Conditions
Data sources

· MeSH D006442

Newsletter

Stay in the loop

Every two weeks, the most notable longevity research in your inbox. No hype.