Does coffee intake raise cortisol levels in healthy adults, particularly those with anxiety, hypertension, or adrenal hyperactivity?

Does Coffee Affect Cortisol Levels?

Yes, coffee acutely raises cortisol levels in healthy adults, but this effect is substantially blunted with regular daily consumption, and moderate intake (3-5 cups/day) does not pose cardiovascular or metabolic harm in most individuals. 1, 2

Acute Effects in Non-Regular Users

Coffee consumption causes robust cortisol elevation in people who do not regularly consume caffeine:

• A single dose of caffeine (equivalent to 2-3 cups of coffee) increases ACTH by 33% and cortisol by 30% within 60 minutes in caffeine-naive individuals 3
• The cortisol response occurs through central nervous system stimulation of the pituitary-adrenocortical axis, triggering ACTH release 3
• This acute cortisol elevation is similar in magnitude to stress-induced cortisol responses 4

Tolerance Development with Regular Use

The cortisol response to coffee is substantially reduced—but not completely eliminated—in people who consume caffeine daily:

• After 5 days of regular caffeine intake (300-600 mg/day), the cortisol response to the first morning dose is abolished 4
• However, cortisol levels still rise with subsequent doses later in the day (1:00 PM and after), indicating incomplete tolerance 4
• Habitual caffeine users show heightened cortisol reactivity specifically when exposed to psychosocial stress, suggesting the adrenal axis remains primed 5
• Regular caffeinated coffee consumption prevents the normal physiological decline in cortisol throughout the day, maintaining elevated levels compared to decaffeinated coffee or water 6

Interaction with Stress and Anxiety

Coffee amplifies cortisol responses when combined with mental stress or exercise:

• Caffeine taken before mental stress further increases cortisol levels beyond stress alone (p=0.011), with similar effects in men and women 7
• Caffeine consumed before exercise elevates cortisol in both sexes, even though exercise alone does not 7
• In individuals with anxiety-related traits (such as rumination), habitual caffeine use may mask the typical blunted cortisol response seen in depression-risk populations 5

Clinical Implications for Specific Populations

Patients with Hypertension

• The American College of Cardiology recommends limiting caffeine to <300 mg/day in patients with hypertension and avoiding it entirely in those with uncontrolled hypertension 1, 8
• Despite acute cortisol rises, moderate coffee consumption (3-5 cups/day) is not associated with increased cardiovascular disease risk in most healthy adults 2

Patients with Anxiety

• Coffee's cortisol-elevating effects may exacerbate anxiety symptoms, particularly in non-habitual users 4, 7
• Consider limiting intake to <300 mg/day (approximately 3 cups) or switching to decaffeinated coffee, which provides cardiovascular benefits without cortisol elevation 1, 2

Suspected Adrenal Hyperactivity

• When evaluating for Cushing syndrome or other hypercortisolism states, patients should abstain from caffeine for at least 5 days before cortisol testing to avoid false elevation 4
• Caffeine-induced cortisol elevation can confound diagnostic interpretation of 24-hour urinary cortisol or salivary cortisol measurements 9, 4

Practical Algorithm for Coffee Consumption

For healthy adults without hypertension or anxiety:

• Safe limit: ≤400 mg/day (3-5 cups) 1
• Optimal cardiovascular benefit: 3-4 cups/day 1
• Cortisol elevation occurs but tolerance develops with regular use 4

For patients with hypertension:

• Limit to <300 mg/day (approximately 3 cups) 1, 8
• Avoid entirely if blood pressure is uncontrolled 8

For patients with anxiety or panic disorders:

• Consider limiting to 1-2 cups/day or switching to decaffeinated options 1
• Monitor for symptom exacerbation, as cortisol amplification with stress may worsen anxiety 7, 5

For diagnostic workup of adrenal disorders:

• Require 5-day caffeine abstinence before cortisol testing 4
• Document caffeine intake history when interpreting cortisol results 4, 6

Key Caveats

• Decaffeinated coffee provides cardiovascular benefits without cortisol elevation, making it a suitable alternative for cortisol-sensitive populations 2, 6
• The cortisol response varies by timing: tolerance develops to morning doses but persists with afternoon consumption 4
• Women may have different metabolic responses to caffeine-induced cortisol elevation, particularly after meals and exercise 7
• Caffeine does not acutely affect appetite, energy intake, or inflammatory markers despite raising cortisol 6