A recent new trend focusses on the potential health benefits of drinking coffee with lemon.

Proponents claim that the mix helps melt off fat and relieves headaches and diarrhea.

Since coffee and lemon each have multiple proven health effects, you may wonder whether drinking the two together offers any additional benefits.

This article reviews the evidence on coffee with lemon to either validate or debunk the claims.

Coffee and lemons are two common ingredients found in almost every kitchen.

Coffee — one of the most consumed beverages worldwide — is made by brewing roasted coffee beans (1).

In fact, about 75% of Americans report drinking it daily, and it’s sought after mainly due to its caffeine content, which stimulates the central nervous system and increases alertness and mood (1, 2, 3).

On the other hand, lemons are a fruit that belongs to the genus Citrus. They’re the third most produced citrus fruit in the world, after oranges and mandarins (4).

They’re a great source of vitamin C and antioxidants — along with many other beneficial plant compounds — which is why they have been used for centuries for their medicinal properties (4).

The coffee with lemon trend suggests mixing 1 cup (240 mL) of coffee with the juice of 1 lemon.

While some may think that it’s an unusual combination, others believe that the benefits outweigh the odd flavor — although science may disagree.

Summary

Coffee and lemon are two common ingredients with beneficial effects on your health. While some believe that mixing the two offers impressive benefits, science may disagree.

Both coffee and lemons have many proven health benefits, which are predominantly associated with their high content of antioxidants. These are molecules that protect your body from the harmful effects of excessive amounts of free radicals (5).

Here’s an overview of the benefits that each has to offer.

Evidence-based benefits of coffee

Roasted coffee beans contain over 1,000 bioactive compounds, but caffeine and chlorogenic acid (CGA) stand out as key active compounds with antioxidant capacity (6).

The two have been shown to activate pathways that protect against cancer growth, linking coffee to a reduced risk of several types of cancer, including liver, prostate, endometrial, breast, gastrointestinal, and colorectal cancer (6, 7, 8, 9).

Additionally, coffee has been associated with a reduced risk of type 2 diabetes, heart and liver disease, and depression, as well as Alzheimer’s and Parkinson’s disease (1, 6, 7, 10).

Lastly, its caffeine content is responsible for the drink’s energy-boosting effect, positive influence on endurance exercise performance, and ability to increase the number of calories you burn, resulting in weight loss (3, 11, 12, 13).

Evidence-based benefits of lemon juice

Lemons are a great source of vitamin C and flavonoids, both of which act as powerful antioxidants (14).

Both vitamin C and citrus flavonoids have been linked to a lower risk of specific cancers — namely esophagus, stomach, pancreas, and breast cancer (15, 16, 17, 18, 19).

Also, both compounds offer protection against heart disease, while vitamin C protects your immune system and helps fight infections (15, 19, 20, 21).

As you can see, coffee and lemons offer a wide range of benefits that protect your body from chronic ailments. Still, mixing the two doesn’t necessarily translate to a more potent drink.

Summary

Coffee and lemons contain plant beneficial compounds with cancer-fighting properties. They may also protect you against chronic conditions, such as heart disease and diabetes.

There are four main claims about the benefits of drinking coffee with lemon.

This is what science has to say about them.

Claim 1. It helps melt off fat

This notion is prevalent among various trends that involve the use of lemon, but ultimately, neither lemon nor coffee can melt off fat.

The only way to get rid of unwanted fat is either by consuming fewer calories or burning more of them. Thus, this claim is false.

However, studies show that coffee may help you lose some weight, which is why some people may experience a slight weight reduction upon consuming the drink.

Recent research has found that caffeine may stimulate brown adipose tissue (BAT), a type of metabolically active fatty tissue that decreases with age and can metabolize carbs and fats (12).

One test-tube and human study determined that caffeine from a standard 8-ounce (240-mL) cup of coffee can boost BAT activity, causing an increase in metabolic rate that leads to weight loss (12).

Similarly, older studies from the 1980s and 1990s explain that caffeine may increase your metabolic rate during the 3 hours after ingesting it, upping your burned calories up to 8–11% — meaning that you may burn an extra 79–150 calories a day (22, 23, 24).

That said, the potential weight loss effect may be due to the caffeine in coffee, not the mixture of coffee with lemon.

Claim 2. It eases headaches

Headaches and migraines have been ranked worldwide as major contributors to disability in those under 50 years old (25).

Hence, it’s common to find multiple home remedies for their treatment. Still, research is very divided when it comes to the use of coffee for this purpose.

One hypothesis suggests that the caffeine in coffee has a vasoconstrictor effect — meaning that it tightens your blood vessels — which reduces blood flow toward your head and relieves the pain (26).

Research also suggests that caffeine can amplify the effects of medication used for headaches and migraines (26, 27, 28).

Yet, another hypothesis believes that caffeine may act as a headache trigger for some, along with other beverages and foods, such as chocolate, alcohol, and citrus fruits like lemons (25).

Therefore, drinking coffee with lemon may either relieve or worsen a headache. And if it does help reduce pain, it would be again due to the caffeine in coffee, not the coffee and lemon drink itself.

Claim 3. It relieves diarrhea

This remedy calls for eating ground coffee with lemon instead of drinking it.

Still, there’s currently no evidence to support the use of lemon to treat diarrhea, and coffee stimulates your colon, which increases your need to poop (29).

Additionally, diarrhea causes a significant loss of fluids that can lead to dehydration, which coffee’s diuretic effect may worsen (30, 31).

Claim 4. It offers skin care benefits

Research suggests that both coffee and lemon’s antioxidant content may provide skin benefits, so there seems to be a shred of truth behind this claim.

On one hand, coffee’s CGA content is believed to improve blood flow and hydration in the skin.

Studies show that its consumption may reduce skin scaliness, improve smoothness, and reduce the deterioration of the skin barrier (32, 33, 34).

On the other hand, lemon’s vitamin C content may stimulate the production of collagen — a protein that provides your skin with strength and elasticity — and reduce skin damage caused by free radicals that originate from sun exposure (15, 35, 36).

However, you may still take advantage of these benefits by consuming coffee and lemons separately, as no evidence suggests that the effect is only exerted when the two are mixed.

Summary

Coffee seems to be responsible for most of the purported benefits of drinking coffee with lemon, though lemons also play an important role in the skin care claims. Yet, no evidence suggests that they should be consumed together for greater benefits.

As is the case with their benefits, the downsides of drinking coffee with lemon are due to the drawbacks of each ingredient.

For instance, evidence suggests that heavy coffee drinkers may become addicted to caffeine, which is recognized by the World Health Organization (WHO) as a clinical disorder (37).

Further studies also indicate that regular caffeine intake is linked to sleep disturbances and associated daytime sleepiness, as well as an increased risk of pregnancy loss (7, 38).

As for lemons, while generally uncommon, some people may be allergic to citrus fruits’ juice, seeds, or peels (39).

Summary

While coffee and lemon are two highly consumed ingredients, coffee may impair sleep, cause caffeine addiction, and increase the risk of pregnancy loss. Meanwhile, lemons may cause allergies in rare cases.

Coffee and lemons offer a wide range of health benefits, mostly due to their antioxidant contents.

However, there’s no evidence to support the claim that drinking coffee with lemon relieves diarrhea or causes fat to melt away.

As for the rest of the mixture’s proclaimed benefits, they can be obtained by consuming coffee or lemon juice separately. Thus, there’s no need to mix the two if you don’t feel like it.