I've talked a bit in previous posts about the link between stress, and diseases such as autoimmune disease, type 2 diabetes heart disease, allergies, depression, dementia, and cancer
It's estimated around 80% of chronic disease is related to dysregulated activation of the stress system!
One of the main reasons for this is thought to be due to how stress affects levels of inflammation
Chronic inflammation underpins many health issues (in particular those listed above)
And chronic stress is shown to increase systemic inflammation - as measured by markers in the blood (CRP, lL6 etc)
Acute stress increases inflammation as a defence response - helping the body fight off infection and heal from injury
It does this mostly via cortisol (stress hormone) as well as adrenaline and noradrenaline These hormones increase levels of pro inflammatory cytokines (inflammatory chemicals) in the circulation, as well as alte activity of white blood cells (in particular t cells, the cells that regulate the inflammatory pathways)
Normally when the stress goes away, these levels return to normal
If stress becomes chronic however, the pathways stay 'switched on', causing inflammation in the body, which over time can cause disease
They can also be up regulated - meaning they create a cascade effect, where the presence of cytokines leads to the release of more and more
Studies have shown that stress is a risk factor for heart disease and this risk can be measured by a test called high sensitivity CRP. Even children who have high levels of stress have an increased risk of heart disease as adults
Stress also increases rates of autoimmune disease, dementia, and mental illness due to a similar pathway
Cancer patients with higher levels of stress have lower survival rates and higher rates of metastases (spread), and stress is a risk factor for developing several types of cancer
Even response to infections and vaccines are affected by stress levels - people under chronic stress catch viral infections more often, and vaccines may be less effective if given when you are stressed!
Fortunately reducing stress can reduce inflammation and risk of disease - see my previous posts