Several common foods and drinks can raise cortisol, your body’s primary stress hormone. Caffeine is the most well-documented trigger, but high-sugar drinks, salty foods, alcohol, and even licorice can push cortisol higher through different mechanisms. Some raise it directly by stimulating your adrenal glands, while others work indirectly by promoting inflammation or blocking the enzymes that normally clear cortisol from your system.
Caffeine Has the Strongest Direct Effect
Of all dietary triggers, caffeine produces the most reliable and immediate cortisol spike. A standard cup of coffee containing 80 to 120 mg of caffeine can raise cortisol roughly 50% above baseline levels. Tea, with its lower caffeine content of 20 to 60 mg per serving, produces a milder bump of about 20%. Energy drinks and caffeinated sodas fall somewhere in between, boosting cortisol by around 30%.
This happens because caffeine stimulates the signaling chain that runs from your brain to your adrenal glands, triggering a fresh release of cortisol. The effect is strongest in people who don’t drink caffeine regularly. If you’re a daily coffee drinker, your body partially adapts, though the cortisol response never disappears entirely. Timing matters too: caffeine consumed in the morning stacks on top of your natural cortisol peak, which is already at its highest in the first hour after waking.
Sugar-Sweetened Drinks and High-Fructose Corn Syrup
Sodas, fruit-flavored drinks, and other beverages sweetened with high-fructose corn syrup can dysregulate your stress hormone system. High fructose intake raises levels of corticosterone (the animal equivalent of cortisol, commonly used in lab studies) and disrupts the feedback loop between your brain and adrenal glands. This means the system that normally keeps cortisol in check stops working as precisely as it should.
High-fructose corn syrup also promotes insulin resistance, blood sugar swings, and oxidative stress, all of which place additional demand on cortisol production. The combination of a direct hormonal effect and these metabolic disruptions makes sugary drinks one of the more impactful dietary sources of cortisol elevation, particularly with regular consumption over weeks and months.
Salty Foods Raise Cortisol More Than Expected
A high-salt diet has a surprisingly potent effect on stress hormones. Research from the University of Edinburgh found that mice on a high-salt diet had resting cortisol levels 75% higher than normal. Even more striking, when those mice encountered a stressful situation, their hormonal stress response was double that of mice eating a standard diet.
The mechanism runs through the brain itself. Excess salt intake increased the activity of genes responsible for producing proteins that control the body’s stress response system. This suggests that loading up on salty processed foods, cured meats, chips, and canned soups doesn’t just affect blood pressure. It may fundamentally change how reactive your stress system is, making you hormonally more responsive to everyday stressors.
Alcohol, Especially Binge Drinking
Alcohol is a potent activator of cortisol release. Even a single episode of heavy drinking triggers a significant spike, and the pattern of drinking matters. Binge drinkers show consistently higher cortisol levels compared to moderate drinkers, along with measurable reductions in brain volume in areas involved in memory and impulse control, including the hippocampus and prefrontal cortex.
These brain changes aren’t just a side note. The hippocampus plays a key role in shutting off cortisol production once a stressful event has passed. When it shrinks, cortisol stays elevated longer than it should. This creates a cycle where drinking raises cortisol, cortisol damages the brain regions that regulate it, and the body becomes less capable of returning to a calm baseline.
Trans Fats and Inflammatory Foods
Industrially produced trans fats, found in some fried foods, packaged baked goods, and margarine, drive up inflammation in ways that feed into cortisol production. A 16-week randomized trial in women found that a diet high in industrial trans fats increased TNF-alpha, a key inflammatory signaling molecule, by 12% compared to controls. Related inflammatory markers rose significantly as well.
This matters because chronic low-grade inflammation and cortisol exist in a feedback loop. Inflammatory molecules signal the brain to produce more cortisol as part of the body’s damage-control response. While the trans fat study didn’t measure cortisol directly, the activation of this inflammatory pathway is one of the established routes through which diet raises stress hormone levels over time. Many countries have banned or restricted trans fats in food manufacturing, but they still appear in some processed products.
Licorice: A Unique Mechanism
Real licorice root (not the artificially flavored candy) raises cortisol through a mechanism entirely different from anything else on this list. It doesn’t cause your body to produce more cortisol. Instead, it blocks the enzyme that breaks cortisol down. Compounds in licorice root inhibit an enzyme called 11-beta-hydroxysteroid dehydrogenase, which is responsible for deactivating cortisol after it has done its job. With that enzyme suppressed, cortisol accumulates in the body and stays active longer.
This is potent enough that licorice root has actually been studied as a treatment for people with abnormally low cortisol. But for anyone with normal or already elevated levels, regular consumption of licorice tea, licorice supplements, or European-style licorice candy made with real licorice extract can push cortisol into a range that causes symptoms like high blood pressure, water retention, and low potassium.
Artificial Sweeteners and Food Additives
Several common food additives appear to disrupt the stress hormone system. Aspartame, sucralose, and saccharin have all been linked to dysregulation of the brain-to-adrenal-gland signaling chain that controls cortisol. Long-term aspartame use may increase cortisol levels and oxidative stress, contributing to insulin resistance over time. Sucralose has been shown to trigger stress responses in liver cells in animal studies, generating reactive oxygen species and promoting inflammation.
MSG (monosodium glutamate) also appears to alter this same hormonal axis, alongside changes to neurotransmitter production. These effects tend to emerge with chronic, daily exposure rather than a single serving. The broader concern with ultra-processed foods is that they combine multiple cortisol-raising ingredients, sugar, salt, artificial sweeteners, and inflammatory fats, into a single product, creating a cumulative effect that whole foods simply don’t produce.
What About Low-Carb and Keto Diets?
Very low-carbohydrate diets have a complicated relationship with cortisol. In the short term, drastically cutting carbs can raise cortisol because the body needs to generate glucose from other sources, a process that relies partly on cortisol. This is one reason some people feel wired or have trouble sleeping in the first week or two of a ketogenic diet.
Over longer periods, however, the picture shifts. An 8-week study in obese men found that a very low-calorie ketogenic diet actually decreased salivary cortisol compared to baseline, possibly by reducing cortisol-binding proteins in the blood. The initial rise appears to be a transitional stress response that resolves as the body adapts to burning fat for fuel. If you’re following a keto or low-carb diet and notice anxiety, poor sleep, or feeling “on edge” in the early weeks, elevated cortisol is a likely contributor, and it typically settles on its own.
Dehydration as a Hidden Factor
Not eating something can raise cortisol too. Losing just 3% of your body weight in water, which can happen during intense exercise, a hot day without adequate fluids, or simply forgetting to drink, triggers a measurable rise in cortisol. Research shows that cortisol climbs progressively as dehydration worsens from 3% to 7% body mass loss, and your habitual hydration status influences how reactive your cortisol system is to stress in general. People who are consistently under-hydrated tend to have a larger cortisol spike when faced with a stressful situation compared to those who drink enough fluids throughout the day.