Cortisol, prunes and the social media effect: overview
- Cortisol is a normal, essential hormone that follows a daily rhythm, not a toxin that can be ‘detoxed’ through a single food, drink or supplement
- Fibre, not cortisol, is where the real evidence and the commercial opportunity sit, with UK intake still running well below the 30g daily recommendation
- The underlying trend of stress resilience, better sleep and nutrient-dense eating is likely to outlast the hashtag itself, reinforced by rising GLP-1 use and shoppers wanting more from every bite
The hashtag #cortisoldetox has racked up close to 800 million views on TikTok, while #HowToReduceCortisol and #CortisolLevels have pulled in more than 140 million views between them, according to Cam Hostinar, a psychology professor at UC Davis.
Scroll for long enough and you’ll find ‘cortisol face’, ‘cortisol belly’ and endless promises that a single drink or supplement can flush the hormone out for good.
None of that is quite how cortisol works, but the fascination is changing what people put in their trolleys.
Fibre has become the trend riding alongside it, not because it lowers cortisol directly, but because of its role in gut health, which social media has increasingly linked to stress and mood. That’s given rise to fibremaxxing, a trend that’s been viewed 150 million times on TikTok and has pushed searches for gut health and high-fibre foods up by as much as 5,000% over five years, according to Google Trends.
In the UK, 47.5% of shoppers say they’ve actively tried to increase their fibre intake in the past three months, according to survey data from Attest, even though average UK fibre intake still sits at around 20g a day, well short of the 30g recommendation, according to the UK government and FSA’s joint National Diet and Nutrition Survey.
The pivot towards fibre and ‘cortisol-friendly’ eating looks like an obvious commercial opportunity for an industry that’s spent years chasing protein. Naturally nutrient-dense foods, from wholegrains to dried fruit, are finding new audiences among shoppers who’d never have picked them up a few years ago.
Euromonitor International data shows more than a quarter of UK shoppers now closely read nutrition labels before they buy, a habit that would have seemed niche a decade ago. Retailers are responding in kind, with high-fibre product claims growing at a compound annual rate of 5.4% between 2020 and 2025, according to Innova Market Insights, as brands scramble to meet a wave of interest that shows little sign of slowing.
It’s worth noting, too, that the fibre trend isn’t purely a social media phenomenon.
Survey data from Attest found that 52% of UK consumers haven’t actually seen the fibre buzz on platforms like TikTok, with only 7.3% saying social media directly motivated their shift towards eating more of it. The behaviour change looks broader and steadier than a single viral hashtag, even if cortisol content is what’s grabbing the headlines.
But there’s a catch and it’s one that dietitians keep repeating: cortisol itself isn’t the villain the algorithm makes it out to be.
“Cortisol is an essential hormone, not a toxin that needs to be eliminated,” says Dr Annamaria Acquaviva, dietitian and Italian nutrition consultant for the California Prune Board
Getting shoppers past that misconception, while still capturing their genuine appetite for better food, is where the real opportunity lies.
Cortisol, decoded
Cortisol is best known as the body’s built-in response to acute stress, working alongside adrenaline to prepare for a demanding moment before settling back down once it passes. But it’s a lot more than a stress signal: it’s a steroid hormone made by the adrenal glands that regulates energy metabolism, blood glucose, immune function, inflammation, blood pressure and the sleep-wake cycle.
Under normal circumstances, it follows a circadian rhythm, peaking shortly after waking and declining gradually through the day, helping the body know when to be alert and when to wind down.
Problems arise not because cortisol exists, but when chronic stress, poor sleep or circadian disruption throw that rhythm off course, keeping levels elevated for longer than they should be. That’s the process scientists actually study, and it’s a good deal less dramatic than a single puffy-faced TikTok clip suggests.
Cortisol isn’t the enemy
“Cortisol is more like a fire alarm than a fire itself, essential when activated at the right time, problematic only when it never switches off,” explains Dr Acquaviva.
Under normal conditions, she notes, cortisol follows a circadian rhythm, peaking in the morning and declining across the day as it helps regulate energy metabolism, blood glucose, immune function and sleep.
The trouble starts when every symptom gets pinned on ‘high cortisol’. “From abdominal fat and fatigue to sugar cravings, poor sleep or bloating”, everything is automatically attributed to the hormone, even though “these symptoms are non-specific and may have many different causes”.
She’s equally sceptical of the idea that cortisol can be “detoxed, flushed out or rapidly lowered through a drink, supplement or single food ingredient. Cortisol itself is not the enemy. The goal is not to eliminate it, but to preserve a healthy circadian rhythm and an appropriate physiological response to stress.”
She also cautions manufacturers to start with science and regulation rather than marketing narratives, warning that even technically accurate wording can create a health halo if shoppers come away believing a product can treat stress, anxiety or hormonal imbalance.
Fibre’s real job
If cortisol itself can’t be eaten away, fibre still has a genuine, if less dramatic, part to play.
Dr Acquaviva describes a gut-brain connection where bacteria in the gut communicate constantly with the brain, shaping mood, energy, sleep and the body’s response to stress. “Fibre helps nourish these beneficial bacteria and support a healthier gut environment,” she says, which is why interest in fibre-rich foods has grown alongside the wider gut health conversation.
Fibremaxxing is, at its simplest, a conscious effort to increase daily fibre intake, and dietitians broadly view the trend positively given that various surveys put the proportion of UK adults missing the 30g daily recommendation anywhere between 90% and 96%, depending on the dataset.
Dr Acquaviva is careful to stress that whole foods do more heavy lifting than isolated ingredients ever could. “Naturally nutrient-dense foods such as prunes, which provide fibre together with important vitamins, minerals and bioactive compounds, can therefore help support the microbiota, contribute to overall diet quality and encourage more balanced and mindful eating habits,” she says.
Dried prunes remain the first whole fruit to receive a European Food Safety Authority health claim, giving retailers a genuinely evidence-backed option to sit alongside the newer fibre-forward launches crowding supermarket shelves.
Beyond the hashtag
Cortisol’s moment on social media probably won’t last forever and Dr Acquaviva doubts it needs to. “The word ‘cortisol’ may eventually lose some of its current social media appeal, but the needs behind the trend are unlikely to disappear,” she says.
What’s driving the conversation, in her view, is a longer-term hunt for stress resilience, better sleep and steadier energy, needs that will keep shaping food choices long after the hashtag fades.
There’s a second force reinforcing that shift: the rise of GLP-1 medications. Figures from University College London suggest 1.6 million UK adults have used weight-loss medications in the past year, which is changing how much nutritional value people expect from every bite. “As appetite decreases and portion sizes become smaller, every bite becomes nutritionally more important,” says Dr Acquaviva, pointing to smaller, nutrient-dense formats as the format most likely to meet that demand.
Esther Ritson-Elliott, director of international marketing and communications for the California Prune Board, sees the two trends converging on the same shopper. “Online conversations around cortisol and wellness are contributing to broader changes in consumer attitudes towards food, with shoppers becoming increasingly focused on balanced nutrition and overall diet quality.”
Consumers, she adds, are “looking for foods that offer fibre, nutritional value and convenience, and which fit with more mindful eating habits.”
Brands promising to “beat cortisol” with a single ingredient, however, risk the health halo outrunning the evidence. Gut health, fibre and genuinely nutrient-dense whole foods are the more durable opportunity, one that doesn’t depend on cortisol staying fashionable at all.
As Ritson-Elliott puts it, shoppers are simply looking for food that fits how they already want to eat, and that’s the trend worth building for, long after the hashtags have moved on.
Formulating with prunes
The common thread of the humble prune, itself simply a dried plum, is multifunctionality: simultaneously reducing sugar or fat, boosting fibre and extending shelf life. The California Prune Board supplies this versatile ingredient to manufacturers in several forms, including paste, purée, butter, juice concentrate and powder, giving formulators flexibility across categories rather than a single application.
Prune purée is commonly used to replace sugar, fat or eggs in cakes, muffins, cookies and bread, with research showing it can cut fat content by nearly a quarter while adding moisture, natural sweetness and shelf life. Prune concentrate performs a similar binding role in snack bars and energy bars, reducing the need for added syrups.
Paste and purée offer natural sweetness and a soft, workable texture for fillings and fruit-based bars, giving formulators an alternative to refined sugar-heavy recipes.
Powder suits dry applications such as baking mixes, seasoning blends and beverage powders, contributing fibre without adding moisture to the formulation.
Juice concentrate can be incorporated into juices, smoothies and yoghurts to add natural sweetness, colour and fibre, functioning as a clean label alternative to synthetic additives.
Studies:
Alufer L, Tsaban G, Rinott E, et al. Long-term green-Mediterranean diet may favor fasting morning cortisol stress hormone: the DIRECT-PLUS clinical trial. Front Endocrinol (Lausanne). 2023;14:1243910.
Cryan JF, O’Riordan KJ, Cowan CSM, et al. The microbiota-gut-brain axis. Physiol Rev. 2019;99(4):1877-2013.
Lassale C, Batty GD, Baghdadli A, et al. Healthy dietary indices and risk of depressive outcomes: a systematic review and meta-analysis of observational studies. Mol Psychiatry. 2019;24(7):965-986.
Blundell J, Finlayson G, Axelsen M, Flint A, Gibbons C, Kvist T, et al. Effects of once-weekly semaglutide on appetite, energy intake, control of eating, food preference and body weight in subjects with obesity. Diabetes Obes Metab. 2017;19(9):1242-1251.
European Parliament and Council of the European Union. Regulation (EC) No 1924/2006 on nutrition and health claims made on foods. Off J Eur Union. 2006;L404:9-25.
