A quick scroll through TikTok reveals thousands of people taking on the ‘chia seeds challenge’ blissfully unaware that their lives could be at risk.
The trend involves drinking a cup of water containing two tablespoons of chia seeds for anything from seven to 40 consecutive days – with devotees claiming it’s helped them shed substantial amounts of weight with minimal effort.
Chia seeds are highly hydrophilic, meaning they can absorb up to 27 times their weight in liquid, and form a thick gel when submerged in water.
On TikTok, some users call the chia seeds and water drink ‘tadpole water’ because of its appearance and texture. It is said to encourage weight loss by acting as a natural laxative.
While their absorbent properties make them a versatile ingredient, perfect for thickening smoothies, making chia pudding or acting as an egg substitute, they can also absorb water from the digestive tract and cause a blockage.
If eaten raw and chased down with a glass of water, the seeds could cause choking – or even suffocation – because they can create a life-threatening obstruction in the throat.
It might sound like an urban legend, but in 2014 an unidentified man presented at a North Carolina hospital unable to swallow – and chia seeds were the cause.
Dr. Rebecca Rawl, MD, who helped treat the patient said that the mass became like plasticine.
She told Time: ‘It got to be this sort of almost Play-Doh-like consistency, very hard in terms of a liquid but also sort of soft.’
None of her usual tools worked at dislodging the blockage, so she had to use an endoscope, usually used on infant patients to slowly chip away at the congealed lump until it was small enough to push down into the stomach.
She added: ‘It was labour-intensive.
‘Generally, vegetative matter and seeds at least can get broken down and slide through.
‘The popularity of chia seeds is growing, and I think this will come up more frequently.’
But it’s not only the upper end of the digestive tract which can fall foul to an unexpected lump of gelatinous chia seeds.
When swallowed dry, nutritionists have warned that the seeds can lead to severe abdominal pain, constipation, bloating and gas.
Registered nutritionist Monica Kranner told the Daily Mail: ‘Some viral claims don’t mention that chia can cause digestive discomfort if increased too quickly or taken without enough fluid.
‘They can support weight management because they’re fibre-rich and may increase fullness, which can help some people reduce overall calorie intake.
‘But they’re not a weight-loss tool on their own, and they still contain calories, so very large amounts won’t help.’
While many online videos tout chia as a magic wand for ‘weight-loss transformations, nutritionist GQ Jordan is sceptical.
‘Chia seeds aren’t a detox, a cure-all, or a shortcut to fat loss,’ she said.
‘They’re supportive as part of an overall balanced diet, but they won’t override poor nutrition, irregular meals or low fibre intake elsewhere.’
And Sophie Bertrand, a registered nutritionist and co-author of Forking Wellness, told the Daily Mail that while chia seeds are sometimes hailed as a super food, people should be wary of any single food being labelled a ‘magic solution’.
‘Chia seeds are often over-hyped online, but they do offer genuine benefits for satiety, digestive health, and glucose regulation. That said, no single food is a magic solution.
‘As a nutritionist, I strongly advocate for personalised nutrition. The way individuals digest and respond to foods can differ significantly.
‘Sustainable health outcomes, including weight management, depend on overall dietary pattern, physical activity, sleep, and metabolic health, not individual “superfoods”,’ she said.
GQ Jordan warned people with swallowing difficulties, significant digestive conditions, or known seed allergies to be cautious.
This is because chia seeds are high in dietary fibre, containing around 10 grams of fibre in a 28-gram serving. Eating them in excess can cause abdominal discomfort.
‘Anyone prone to bloating may want to start with a small amount and build gradually,’ she added.
Often found in the health food section of supermarket aisles, chia seeds can be black or white in colour, with no nutritional difference between them.
When it comes to how to eat them safely, GQ Jordan said that a small serving provides a meaningful amount, which can support digestion, bowel regularity, blood sugar stability and cholesterol management.
They also provide alpha-linolenic acid (ALA), a plant-based omega-3, along with some protein, which contributes to fullness and overall nutrient intake rather than acting as a primary protein source.
Most recently, new research found that eating chia seeds could be the key to protecting the brain and body against the harmful effects of eating ultra-processed foods.
