The global market for functional drinks now commands £115bn annually, promising everything from focus to gut health, yet national experts and regulatory bodies in the UK are raising serious questions about these claims. These brightly packaged cans and bottles, marketed with slogans like “Fuel your focus” and “Find your calm,” often lean heavily on sweetness, artificial flavouring, and aggressive marketing rather than proven benefits. In the UK, this market generates £100m in sales each year, with a quarter of consumers now seeking functional benefits from their drinks, a significant rise from 13% in 2024.
The Global Market's Grip
One out of every four new food and drink launches now makes a functional benefit claim, according to Mintel. Influencers promote them, podcasters are sponsored by them, and even public figures like Gillian Anderson have launched functional drink brands. These products contain added vitamins, minerals, botanical ingredients such as ashwagandha and ginseng, and compounds like caffeine or CBD. Some are enriched with collagen, protein, fibre, or probiotics, creating a perception of health that often lacks robust scientific backing.
Consultant dietitian Sophie Medlin, from City Dietitians, acknowledges that these drinks “do offer more than other regular soft drinks do.” However, she doesn't encourage people to start drinking them. Medlin notes that while some consumers use them to swap from less healthy options or as an alcohol alternative, others, who previously avoided soft drinks, now believe functional drinks are a worthwhile addition to their diets. This highlights a concerning shift in consumer behaviour, driven by marketing rather than genuine nutritional need.
National Standards Under Threat
Health claims on foods, drinks, and supplements are tightly controlled in the UK, a crucial defence for our citizens. Despite this, some brands have already faced censure from the Advertising Standards Authority (ASA). Last year, a complaint against Trip was upheld after its ads suggested the drink could reduce stress and promote calm. Also last year, Myota was censured for illegally suggesting a food product could have medicinal effects when promoting its metabolic booster drink. Producers can legally make health and nutrition claims only about specific ingredients, meaning vitamins like C, D, or B12 often carry the weight of broad health promises on labels. A product containing just 15% of an adult’s recommended daily allowance of B12 per 100ml can claim to reduce tiredness, support neurological functioning, and help the immune system, regardless of other unproven ingredients.
Gopi Chandratheva, a registered nutritionist working in the NHS, points out that many functional drinks add numerous vitamins and minerals in small amounts, creating a health perception without significantly impacting overall nutrient intake. For example, Huel’s Daily Greens drink, marketed with 41 vitamins, minerals, and superfoods, provides less than 20% of daily requirements for several key nutrients. Celsius, another popular brand, contains nearly 300% of the RDA for vitamin B7 and well over 100% for several other B vitamins, raising questions about unnecessary over-supplementation.
The Cost to Our Health and Wallets
Experts warn against the uncritical consumption of these products. Medlin states there's insufficient research on clinically significant doses of adaptogens and other natural products, and no long-term studies exist on daily consumption. The variability of ingredients like mushrooms, depending on their origin and growth, makes it difficult to ascertain meaningful effects. Chandratheva cautions that mixing multiple adaptogens, nootropics, vitamins, minerals, and stimulants or relaxants might not be wise, as these drinks contain bioactive compounds that could interact with medications. She warns that other added ingredients can often outweigh any perceived benefits. Medlin suggests that any felt benefit is likely from ingredients like caffeine, not the expensive, unproven additions.
Concerns extend to specific ingredients. The Food Standards Agency in 2023 lowered its recommended daily intake limit for CBD to 10mg from 70mg, following new evidence linking long-term use to liver damage and thyroid disease. While some evidence supports CBD for anxiety, most consumer drinks contain small doses, with human trials for anxiety typically using much higher amounts, from 150mg to 600mg. Popular brands like Goodrays and Trip contain only 10mg per can. Electrolyte drinks, heavily promoted on social media, are often unnecessary for healthy individuals. Medlin confirms that if you're drinking enough water and eating a normal diet, electrolytes aren't needed, and their popularity could lead to excessive salt intake, exceeding the UK guidance of 6g per day. Cadence and Na11, for instance, contain 1.25g of salt per 330ml can.
Protein and collagen waters are also under scrutiny. Medlin classifies these as ultra-processed foods, advising that people needing more protein should get it from whole foods, not drinks with numerous additives. Research on collagen products remains limited, with little high-quality evidence to support claims about joint, skin, hair, or nail benefits. Most functional drinks avoid sugar, instead using artificial sweeteners like sucralose or erythritol. Medlin, as a gut-health dietitian, expresses concern about sweeteners, noting their detrimental effect on gut bacteria and their tendency to train palates to crave more sweet flavours. Caffeine also carries risks; some energy drinks contain 200mg per can, far exceeding the 30-50mg in a cup of tea. Chandratheva warns that excessive caffeine can cause anxiety, poor sleep, and in rare cases, fatal heart arrhythmia. The NHS advises against caffeine for babies and young children, and the government is consulting on a ban for under-16s in England. This national focus on protecting the health of our youth is paramount.
While functional drinks with added fibre or live probiotics are considered less problematic, even these can trigger symptoms for individuals with irritable bowel syndrome due to ingredients like inulin. Dr. Daniel Lamport, a psychologist at the University of Reading, concludes that while functional foods have a place, a robust evidence base for many wellbeing and cognition claims is lacking. Ultimately, he stresses, there is no substitute for a fibre-rich, fruit-and-vegetable-rich, whole-foods diet—a clear message for our people to prioritize genuine nutrition over marketing hype. The integrity of our national health and consumer trust demands nothing less. The pandemic era, now in its sixth year, saw this new breed of self-optimisation-obsessed functional drink truly take off, further highlighting the need for vigilance against misleading claims.