Coffee and lemon: fact-checking the TikTok trend

TikTok trend

If you're familiar with TikTok, you've probably seen your fair share of "lose weight fast!" life-hack trends circulating the social media platform. Adding lemon in your coffee is one that has become especially popular - #LemonCoffee is gathering millions of views.

The drinking coffee with lemon weight loss hack is presented as a miracle fat-burning concoction that can make your weight loss journey much easier. Supposedly, there are other health benefits too; influencers and other TikTok users are also promoting drinking coffee and lemon together to relieve diarrhoea, soothe headaches, and even improve skin.

But can it actually work? We take a look at the evidence behind the claims.

What does coffee and lemon do?

There's no evidence that drinking coffee and lemon together has any significant health benefit but there is research on the individual ingredients. Clare Thornton-Wood, registered dietitian and British Dietetic Association (BDA) member, highlights the benefits of the individual items:

• Coffee - In moderation, caffeine in coffee can assist with memory, concentration, and energy levels.

• Lemon - Lemon, much like other citrus fruit, is a good source of vitamin C, which is important for a healthy immune system.

Does coffee and lemon help you lose weight?

There is no evidence for this.

Losing weight - or burning fat - only happens by consuming fewer calories than you need in a day, or burning off any excess calories," says Thornton-Wood.

Always be wary of claims that a particular drink or food can help to resolve a person's weight loss struggles easily and quickly.

The coffee and lemon trend may be a case of adding one plus one and deciding it equals four. Thornton-Wood points out that caffeine has been reported to be appetite surpressing, although study results are often mixed, and more research is needed¹. Lemon water is also a popular diet hack, but only because the lemon itself provides flavour to the calorie-free water.

Does coffee and lemon relieve diarrhoea?

Brace yourself! This version of the trend involves eating ground coffee with lemon, as opposed to drinking coffee with squeezed lemon juice. Not only is it not for the faint-hearted, its not for those with diarrhoea - it will actually make the condition worse.

There is no evidence that lemon can help relieve diarrhoea and coffee actually results in looser stools (poo). "Caffeine can also stimulate bile production which can also lead to diarrhoea," says Thornton-Wood.

Does coffee and lemon help with headaches?

"Caffeine is added to some pain relief medications to increase the effectiveness and speed with which they work," says Thornton-Wood. "However, there’s no evidence that lemon is needed in this combination."

Also, whilst a cup of coffee can help some, for others it brings on headaches and migraines². "Caffeine narrows the blood vessels in the brain and when these expand again this can sometimes cause pain. This can be a particular problem if you regularly consume caffeine and then stop."

Does coffee and lemon improve your skin?

There is some limited evidence that coffee and lemon individually contain antioxidants that promote good skin health. The vitamin C in lemon may stimulate the production of collagen, a protein that increases your skin’s elasticity and strength³. When drunk in moderation, the antioxidant in coffee, called caffeic acid, may also boost collagen levels⁴.

"However, these benefits are not related to consuming coffee and lemon together, and consuming fruit and vegetables and staying hydrated will provide similar benefits," cautions Thornton-Wood.

Downsides of coffee and lemon

If you're going to try the coffee and lemon trend, the best thing you can do for your health is to drink in moderation and continue to follow a nutrient-rich diet.

Always remember that too much coffee and lemon can damage your health. Thornton-Wood warns that:

• The caffeine in coffee triggers the release of adrenaline, the 'fight or flight' hormone. In high doses, this can make you feel jittery.

• This also blocks the adenosine receptors in the brain. Adenosine promotes sleep and builds up gradually in the body throughout the day, leading to us feeling sleepy as we get closer to night-time. If the receptors are blocked, we struggle to sleep. Caffeine can also interfere with our natural sleep-wake cycle - circadian rhythm.

• Lemon contains citric acid which has the potential to damage your tooth enamel. You need to avoid cleaning your teeth immediately after consuming as it softens the enamel of the teeth (demineralisation) making it easy to brush some of the protective enamel away.

Further reading

1. Schubert et al: Caffeine, coffee, and appetite control: a review.

2. Nowaczewska et al: The ambiguous role of caffeine in migraine headache: from trigger to treatment.

3. Pullar et al: The Roles of Vitamin C in Skin Health.

4. Chung et al: Role of caffeic acid on collagen production in nasal polyp-derived fibroblasts.