Heat Shock Proteins – Part 2: What the Main Ones Actually Do

Four Main Areas of Action

Across the board, most HSPs are involved in:

1. Protein maintenance – Helping other proteins fold correctly, stay functional, or get recycled.

2. Inflammation regulation – Turning down overactive immune responses and boosting anti-inflammatory processes.

3. Cell survival and repair – Preventing cell death, especially in times of heat, oxygen deprivation, or stress.

4. Cardiovascular and metabolic protection – Supporting the heart, blood vessels, and energy production systems.

Now let’s break down the individual players.

HSP27 – Inflammation Regulator and Vascular Protector

What it does:HSP27 helps stabilise the cell’s internal structure and blocks damaging proteins from triggering inflammation and cell death. It’s known to interact with the immune system, especially under cardiovascular stress.

What the science says:

• Elevated in rats under heart stress; improves oxygen flow in heart cells (Zou et al., 1998).

• Lower in damaged human arteries, higher in healthier vascular tissue (Martin-Ventura et al., 2006).

• Blocks release of inflammatory cytokines like IL-1, while boosting anti-inflammatory IL-10 (Bruey et al., 2000).

Health benefits when activated:

• Reduced inflammation

• Improved heart and blood vessel health

• Protection from atherosclerosis and oxygen-starved heart tissue

• Better resilience under oxidative or metabolic stress

HSP70 – Heart Helper and Muscle Repair Chief

What it does:HSP70 is a large chaperone protein that refolds damaged proteins and prevents them from clumping. It’s also heavily involved in protecting heart muscle, supporting the immune system, and reducing damage during high stress.

What the science says:

• Higher levels linked to reduced atrial fibrillation after cardiac surgery (Chen et al., 2005).

• Improves calcium handling in heart cells, reducing risk of cell death from calcium overload (Zhang et al., 2003).

• Elevated after sauna or heat stress, especially with repeated exposure (Kregel, 2002).

Health benefits when activated:

• Improved cardiac resilience and reduced risk of heart rhythm issues

• Faster muscle repair and recovery

• Enhanced immune defence

• Reduced likelihood of protein aggregation and cell death

HSP60 – Mitochondrial Mechanic with an Immune Twist

What it does:HSP60 operates mainly inside mitochondria, the powerhouses of the cell. It maintains energy-producing enzymes and helps manage the stress response. But when released outside cells, it can also trigger immune responses — for better or worse.

What the science says:

• Refolds mitochondrial proteins damaged by oxidative stress (Pockley et al., 2004).

• Can signal danger to the immune system when circulating freely — a double-edged sword depending on the situation.

Health benefits when activated (in balance):

• Improved mitochondrial function

• Better cellular energy production

• Enhanced stress resilience

• May play a role in cellular renewal and metabolic health

HSP90 – Hormone Stabiliser and Stress System Manager

What it does:HSP90 supports the structure and function of key signalling proteins — including hormone receptors, enzymes, and other regulators. It ensures proper stress response, immune activity, and cell survival. In cancer, unfortunately, it can also protect tumours — hence why it’s a drug target.

What the science says:

• Maintains stability of steroid hormone receptors and other key proteins (Trepel et al., 2010).

• Overexpressed in some cancers, helping cancer cells survive.

• Targeted by cancer drugs to destabilise tumours.

Health benefits when activated (in the right context):

• More stable hormone regulation (cortisol, estrogen, testosterone)

• Stronger and more coordinated stress response

• Immune system balance

• Nervous system resilience under chronic stress

HSP110 – Backup Support for Extreme Stress

What it does:HSP110 partners with HSP70 to stop proteins from clumping under extreme conditions like sepsis, stroke, or heat shock. It’s a late responder in the stress cascade and offers deeper protection when the heat is really on.

What the science says:

• Assists HSP70 in protecting cells during extreme thermal stress (Yamagishi et al., 2000).

• Prevents large-scale protein aggregation, especially in brain and liver tissue.

Health benefits when activated:

• Protection against high-intensity or prolonged stress

• May support recovery from major trauma, fever, or heat stroke

• Additional protein rescue capacity in extreme cellular damage

A Note on the Limits of Current Knowledge

While these health benefits are real and supported by published studies, it’s still early days. Much of the research has been done in animals or under controlled lab conditions. Human physiology is complex, and sauna, cold, exercise, fasting, and illness all interact differently with HSP systems.

We know enough to say they’re beneficial — but we’re still learning how much is optimal, what the long-term effects are, and how different people respond over time.

Final Thoughts

Each HSP has its own speciality, but together they form a team that protects your cells, repairs your systems, and keeps you functioning under pressure. Activating these proteins — through controlled stress like sauna or exercise — may help build deeper resilience across the board: immune, cardiovascular, metabolic, and neurological.

That’s the real win.Not just feeling good when you step out of the sauna.But knowing your body’s quietly adapting, one heat stress at a time.