Why Does Hair Thin With Age? New Research Explores the Role of Inflammation
As we get older, our hair often changes. It may become finer, less dense or take longer to grow.
While genetics and hormones are well-known influences on hair growth, scientists are increasingly interested in another factor: the environment surrounding our hair follicles.
A new study published in Aging Cell in 2026 has explored how age-related changes in the skin may affect hair growth.
What did the researchers discover?
Hair follicles are surrounded by a specialised layer of fatty tissue called dermal white adipose tissue. Far from simply providing cushioning, this tissue plays an active role in regulating hair growth.
The researchers found that ageing tissue produced increased amounts of a signalling molecule called MCP-1.
MCP-1 attracts immune cells known as macrophages. These cells normally play important roles in protecting and repairing our tissues, but their activity can change with age.
The study suggests that an accumulation of certain inflammatory macrophages around hair follicles may interfere with the normal hair growth cycle.
Can reducing this inflammation improve hair growth?
In animal studies, researchers found that reducing MCP-1 activity or altering macrophage populations encouraged hair follicles to enter the active growth phase, known as anagen.
They also observed changes in pathways involved in hair growth and pigmentation.
These findings suggest that the ageing immune environment surrounding hair follicles may influence their ability to regenerate.
What does this mean for people experiencing hair thinning?
This is early-stage research, and the findings have not yet been confirmed in humans.
Importantly, the study does not establish that inflammation is responsible for all age-related hair thinning, nor does it identify a new treatment for hair loss.
However, it adds to our growing understanding that hair growth is influenced by many interacting factors, including hormones, genetics, ageing, immune activity and the health of the surrounding scalp tissues.
Understanding your hair loss
Hair thinning can have several different causes, sometimes occurring together.
Although this research is still at an early stage, it highlights the complexity of hair follicle biology and the importance of understanding the different factors that influence hair growth.
Identifying the underlying cause of hair loss remains an important first step in determining which treatments, if any, may be appropriate.
Authored by Dr Gwen Adey
First published 12/11/2026
Research reference
Chen J, et al. (2026). MCP-1 From Aging Dermal Adipose Tissue Impairs Hair Follicle Cycling via Macrophage Recruitment: Implications for Age-Related Alopecia. Aging Cell.
