Eating to beat stress: How your diet can help blunt cortisol this holiday season

December is peak stress season for many, and nutrition scientists say what you eat can shape how the body handles the pressure. With busy days, disrupted routines and late-year deadlines, stress can spike, but dietary choices may help soften the body’s response. Diet shapes how the body manages blood sugar, inflammation, sleep and appetite—factors that determine whether stress leaves you feeling depleted or resilient. Public health nutritionist Dr Emma Derbyshire of the Health and Food Supplements Information Service notes that eating regularly, prioritising protein and fibre, and choosing foods that support steady energy can blunt the body’s stress response rather than amplify it. She stresses that breakfast is particularly important: those who skip it are more likely to experience early-morning stress."

The most important meal of the day – oats or eggs

Starting the day with a balanced breakfast appears to support healthier cortisol rhythms. Research suggests skipping breakfast can raise levels of the stress hormone cortisol, while meals containing protein help blunt excessive stress responses. Eggs provide high–quality protein and essential amino acids, while oats offer slow–release carbohydrates that help stabilise blood sugar—both important for cortisol regulation. Oats are also a great source of soluble fibre, which feeds beneficial gut bacteria and supports a microbiome that communicates with the brain to regulate stress responses. Fortified cereals and eggs can help boost vitamin D intake, which is crucial for the immune system and stress response.

Oily fish such as mackerel, salmon and sardines are a great source of omega–3 fats, which have been shown to lower markers of stress and inflammation. A 2011 study from Ohio State University, published in Brain, Behavior, and Immunity, found omega–3 supplementation reduced cortisol and inflammatory responses during periods of psychological stress. Omega–3s act as anti‑inflammatory agents, helping blunt stress hormone production. However, oily fish intake in the UK falls well below recommended levels. Guidelines advise adults to eat two portions of fish per week, one of which should be oily, with a portion about 140 grams or the size of a small tin. Latest figures, published in the Food and Nutrition Sciences Journal, show adults up to age 64 consuming only around 5 grams of fish per day. Dr Derbyshire adds that taking an omega‑3 or fish oil supplement can be a sensible form of self‑care to top up vital levels in the diet.

Oranges, kiwis, berries and other vitamin C sources

Vitamin C plays a direct role in adrenal health and has been shown to help people return to baseline cortisol levels more quickly after acute stress. Controlled trials cited in the literature indicate higher vitamin C intake can blunt cortisol responses during stressful tasks. Kiwi, oranges and berries are rich sources and easy to add to breakfasts or desserts during the holidays. Berries, in particular, provide flavonoids with antioxidant properties that help reduce oxidative stress, which can trigger cortisol release.

Dark leafy greens provide magnesium and folate

Leafy greens such as spinach, kale and chard offer magnesium and folate, nutrients linked to nervous system regulation. Low magnesium levels have been associated with heightened stress responses, while folate supports neurotransmitter production tied to mood regulation.

Alcohol in moderation and its effects on cortisol

The question of alcohol is nuanced. An occasional glass of wine may lower perceived stress briefly, but physiologically it raises cortisol levels, especially when consumed in the evening. Studies show alcohol can disrupt the normal evening drop in cortisol, impairing sleep and potentially worsening next‑day stress. Dr Derbyshire cautions that moderation is key and pairing alcohol with a healthy meal can help reduce cortisol spikes.

What drives stress hormones beyond diet

While certain foods can help balance cortisol levels, others can cause spikes, particularly those that rapidly affect blood sugar or stimulate the nervous system. Sugary and highly processed foods like pastries, white bread and pasta can trigger rapid blood sugar fluctuations, prompting the body to release cortisol to stabilise glucose. Beyond diet, sleep quality, chronic psychological stress, excessive caffeine, blood‑sugar swings and limited daylight exposure remain significant drivers of elevated stress hormones, especially in winter. Getting natural light early in the morning is cited as crucial for setting cortisol at appropriate levels for the day ahead.

Putting it into practice amid a busy season

Experts say the practical takeaway is straightforward: eat regularly, prioritise protein and fibre, and include foods that support stable energy and mood. Breakfast should be a focal point to help regulate cortisol from the outset of the day. Alongside mindful portions and balanced meals, incorporating omega‑3–rich fish a couple of times weekly, vitamin C–rich fruit, leafy greens, and mindful limits on alcohol may collectively support a calmer stress response. While dietary changes are not a substitute for broader stress management—such as sleep hygiene, daylight exposure, and reasonable workload planning—they can be a meaningful piece of the puzzle for people navigating December’s demands.