The Ultimate Science-Based Examination of Lemon Water

Lemon water is a big deal right now and it has been promoted as a miracle approach for weight loss and for promoting health in a variety of different ways.

Even though some of the hype is unrealistic, there really are some key lemon water benefits for health.

Lemons do contain important compounds for health and offer significant health benefits overall, some of which come from the compound limonene.

Lemon water offers a fantastic way to get lemons into the diet. Some choose to have it in hot water or warm water, often first thing in the morning in an attempt to speed up the metabolism and digestion.

Others drink lemon water throughout the day as a way to stay hydrated or simply because they like the taste.

With all the hype surrounding lemon water, it can be difficult to work out what is real and what isn’t. For example, claims range all the way to protection against cancer,  to getting rid of toxins and dramatic weight loss.

In this article, we’re going to have a look at these claims and work out the evidence behind them. 

Quite simply, lemon water is just the juice from lemons and water. Occasionally people choose to add in some lemon zest (rind from the lemon) also or other ingredients like a bit of ginger or a mint leaf.

How much lemon you include is largely based on how much you can tolerate.

For example, if you are trying lemon water for the first time, you probably don’t want to add too much lemon to it, as the taste can be a bit of a shock.

However, as time goes by, you will find it easier to drink the lemon water, which also means that you can add more lemon. Many people even find that they start to crave lemon water after a while. Certainly, it does have a unique taste and it is good for you at the same time.

A good place to start with lemon water is to include the juice from around half of a lemon into an 8 oz cup of water. From there, you can tweak the recipe based on your own preferences.

There are a number of significant nutrients in lemon that have been associated with improved health overall. Some of the key phytonutrients are discussed below and strongly contribute to lemon water benefits for health.

Vitamin C

One cup of lemon juice contains 187% of the recommended daily intake of vitamin C (1), compared to 207% for the same amount of orange juice (2).

While you might not drink a full glass of lemon juice at one time, having lemon water throughout the day would tend to get you close to this amount.

There has been a lot of study into vitamin C, and it is a highly effective nutrient, associated with improved cardiovascular health, immunity, eye health and reduced risk of some diseases (3,4).

Furthermore, vitamin C has an antioxidant function, helping to protect cells from damage caused by free radicals (5).

There are many ways to get vitamin C into your diet.

However, lemons are significant because they are lower in calories than most other fruit and have less sugar. This shouldn’t come as much of a surprise given how sour the fruit is.

For example, the graph below compares calories and vitamin C content for 100 grams of oranges and lemons (6,7).

As you can see, the vitamin C across the two fruits is very similar, gram for gram. However, an orange has many more calories.

Citric Acid

One of the key elements of lemons is citric acid.

Citric acid has been associated with preventing kidney stones, something that I will talk about in detail a little later on (8).

Hesperidin and Diosmin

Both hesperidin and diosmin are flavones.

This pair of compounds is common in citrus fruits in general (9,10).

They are antioxidants that have been associated with circulatory improvements (11,12,13).

Hesperidin has also been linked to lipid metabolism and the regulation of glucose (14), suggesting a role in improving hyperglycemia outcomes.

Antioxidants

Some of the compounds in lemons have also been linked to antioxidant roles, particularly citrus flavonoids (15).

Antioxidants are compounds that help to inhibit oxidation within the body. There has been growing interest in these compounds because of their ability to fight damaging compounds known as free radicals, which can contribute to health issues and disease development (16,17).

Flavonoids specific to lemon have been studied in rats, with researchers finding that these compounds had the potential to lower oxidative stress (18,19).

This outcome is highly significant, as it indicates that lemons may play a key role in decreasing disease risk.

However, animal studies are limited in how much they can tell us about compounds, and research in humans is needed before we know the full picture.

Nutritional Breakdown of Lemon Water

One of the key things to consider with lemon water is how much lemon you include.

This really varies from one person to the next, as everyone has different tolerances for the fruit.

A common approach is to squeeze half of a lemon into a cup of water (although some ambitious people use a full lemon). Ultimately, what you choose should be based on what you feel comfortable with, which might be less than this.

For the purposes of this discussion, I’m going to define lemon water as being one 8 oz glass of water with the juice from half of a lemon.

Lemon water made like this has a total of around 6 calories and around 18% of your vitamin C intake for the day (20).

If you wanted to hit your full amount of vitamin C per day this way, it would involve having six full glasses of lemon water in a day, which is pretty reasonable.

Calorie-wise, a glass of lemon water is pretty fantastic. It even contains fewer calories than most low-calorie drink packets and is much more natural at the same time.

Lemon water might seem like a bit of an odd choice.

After all, there are other ways to add lemon into the diet, and many recipes make use of lemon.

There are two main things that make lemon water stand out.

First of all, it is just lemon juice and water. This means that there are no additives or flavorings, and it barely has any impact on how many calories you are taking in or on your blood sugar.

Any other approach of including lemon in your diet would end up adding a lot of other things to your diet along the way.

Secondly, lemon water contains (surprise surprise) a decent amount of water. In fact, it tends to be mostly water.

Water – It Matters More Than You Think

Getting water into your diet is definitely a good thing, especially if you are trying to improve your health. In fact, the majority of the population may not drink enough water (21), and many people rely largely on soda and coffee, drinking actual water rarely.

Furthermore, water is an essential nutrient and plays many key roles within the body (22).

It may even help reduce the prevalence of headaches (23,24) as well as flushing your body and allowing nutrients to get where they are supposed to go.

Drinking enough water can be critical for preventing constipation and ensuring that your body processes food effectively (25).

Additionally, water has the potential to help satiate people (26), an approach that can potentially contribute to decreased food consumption (27,28).

Water is also key to preventing dehydration.

It is surprisingly easy for people to become dehydrated and many people don’t realize it.

Yet, dehydration can have many negative impacts, including impaired mental performance and cognitive function (29,30), as well as decreased physical performance (31).

Another important health behavior is eating adequate fiber.

Even though this isn’t directly related to lemon water, I want to touch on it briefly.

Many people don’t consume enough fiber and fiber can be quite hard on the body if you aren’t used to it. One of the key tricks for helping you digest the fiber in your diet is to make sure you are getting enough water.

This also means that as you increase the amount of fiber in your diet you should also increase your water intake to compensate.

Increased fiber and water can do wonders for your digestive system. This includes improving gut health and even decreasing the risk of cardiovascular disease (32).

If you find drinking plain water challenging (as many people do), then lemon water offers a good way of doing this.

In fact, even if there were no real health benefits from the lemon, lemon water would be worth it simply for the increased water intake.

Cardiovascular Health

The flavonoids in lemon play a significant role in regulating lipid metabolism through multiple mechanisms.

This role has the potential to help to decrease the risk of cardiovascular disease (33).

In fact, observational studies have suggested that the consumption of fruits and vegetables, in general, has been linked to decreased coronary heart disease risk (34). While this type of study does not show cause and effect, it is still a pretty important indication of the potential of fruits and vegetables for health.

In the case of lemon, vitamin C may be one of the key mechanisms for providing protection against cardiovascular disease (35).

Likewise, low levels of vitamin C can increase the risk of stroke (36,37).

Improving Iron Absorption

Iron deficiency is a significant problem and is very common in the United States (38) and throughout the world (39).

Women are particularly vulnerable to this deficiency because of their regular monthly cycles.

People are often deficient in iron because they aren’t getting enough in their diets. It is a challenging deficiency because many of the symptoms are not immediately noticeable, including fatigue, decreased performance and decreased immune function (40).

Lemon does contain a small amount of iron, but not really enough to make a difference in terms of health.

Instead, the citric acid, ascorbic acid and vitamin C in lemons can help to increase how much iron you absorb from other foods (41,42).

This can be critical for preventing iron deficiency.

This means that lemon water may be particularly important if you are taking an iron supplement or are eating a meal high in iron.

However, it is worth noting that the levels of compounds for iron absorption in lemons are not super high. So, a typical glass of lemon water may not contain enough of these compounds to significantly improve iron absorption.

If you're concerned about iron deficiency, you can take a look at this article from Mayo Clinic which offers details about how the deficiency is diagnosed and what you can expect. 

Preventing Kidney Stones

There have been some studies linking lemons to the prevention of kidney stone formation.

The argument for this effect is that compounds in lemons can stop urine from becoming too acidic, which in turn decreases the formation of kidney stones (43). Additionally, the approach can increase urine volume overall. This mechanism is one of the key reasons that potassium citrate is used to decrease kidney stone risk (44).

One study on the topic considered the impacts on supplementing with lemonade versus supplementing with lemonade along with potassium citrate.

The authors found that both approaches resulted in improved outcomes in the urine, indicating a decreased risk of stone formation. Of the two approaches, the combined therapy was more effective (45).

A second study also indicated that lemon juice could reduce the risk of stones being formed.

However, orange juice was more effective at this role (46).

Lemon juice has been suggested as an appropriate approach for people who cannot tolerate traditional therapeutic approaches for reducing stone formation (47,48), which suggests that it may also act as a general preventative measure.

Nevertheless, not all research has agreed with these outcomes (49), suggesting that further research is needed.

In general, the scent of lemon is considered to be energizing and uplifting.

For many people, this smell can help them to feel more energized and can help to improve their mood.

This may be one of the reasons why lemon water is so popular first thing in the morning. In fact, many people do claim that it helps them feel better, more energized and more ready for the day ahead.

Research even supports the ability of the smell of lemon to decrease both psychological and physical stress (50,51), and to improve mood (52).

The scent of lemon has also been linked to people becoming tired slower (53).

Some research has also indicated that the scent of lemon may act as in an antidepressant manner (54,55), although more research surrounding lemon and depression is needed. Dr. Axe also highlights this topic, talking about four essential oils that can help with depression.

Other Lemon Water Benefits

People often take lemon water specifically for health benefits, but the beverage has also been associated benefits for skin and for hair.

As is normally the case with hair and skin benefits, this area has not been the subject of significant research, so the benefits should be taken with a grain of salt.

The antioxidants in lemon are particularly relevant for skin, as is the vitamin C content.

These mean that lemon potentially has the ability to help repair damage to skin cells and potentially help with removing some blemishes and lines.

Some people also argue that drinking lemon water regularly can help in fighting acne and can assist in keeping the skin clear.

Likewise, lemon water may be able to help strengthen hair and prevent dandruff.

There are a lot of exaggerated claims out there about lemon water benefits. Actually, that is also true for pretty much any health product that you can imagine.

Many of these claims may have some kernel of truth, but that truth often gets exaggerated.

This is certainly the case with lemon water.

While lemon water does offer some significant health benefits, there are also some pretty major myths about it that don’t hold up to scrutiny.

Weight Loss

If you’ve heard of lemon water, you’ve probably heard it touted as a way to lose weight.

There is a lot of hype in this area and many people swear by lemon water as a weight loss aid.

But, does it actually work? The answer is a little bit yes and a little bit no.

Although it might shock some people, there isn’t much evidence that anything in lemons or in lemon water that directly contributes to weight loss.

There has been some indication that citrus flavonoids may help to suppress appetite (56), but the evidence for this perspective is limited.

Instead, the impact of lemon water is more based on behavior.

For the purposes of weight loss, lemon water is essentially water with a little bit of flavoring.

The flavoring from the lemon tends to make the water more appealing and this can often mean that people drink more water than they would otherwise.

If adding lemon to water makes you drink water more often or replace other drinks with lemon water, then yes, it probably would help you lose weight.

You would also lose weight by doing the same thing with normal water instead of lemon water (57).

Drinking water also acts as an appetite suppressant, which can be important for weight loss.

For example, one study tested this looking at changes in the consumption of water along with changes in body weight. The authors found that overall water consumption could help to promote weight loss (58).

Another study found similar outcomes when looking at weight loss as part of a hypocaloric diet intervention (59).

So, lemon water itself won’t miraculously help you to lose weight.

However, the additional flavor in the water can be enough to encourage you to drink more water, which in turn helps with weight loss.

It is certainly a better approach than using powdered drink mix, as the powders tend to be heavy in artificial ingredients and often contain sugar as well.

Detoxing

One topic that is often associated with both lemons and water is that of detoxing.

Detoxing has really become a big deal in recent years and there are thousands of different sites and products out there promoting the wonders of detox along with specific recipes or approaches for achieving it.

In general, detox approaches tend to focus on cutting out most foods from the diet and eating only specific ‘clean’ foods and supplements that are supposed to help remove toxins from the body.

Changing your pH

Perhaps the biggest myth surrounding lemons is something I call the pH myth or the alkaline diet myth. 

This focuses on the idea that you can change the overall pH of your body by moving away from foods that form acids and towards alkaline-forming foods.

Lemons are one of many foods that are considered to be alkaline-forming and they are often emphasized as a way of changing the pH of the body.

According to this type of diet, eating alkaline-forming foods can result in decreased risk of disease and greater overall health.

Protection against Cancer

Claims that any compound can protect against cancer are always borderline.

This is a very challenging area to study and most research is conducted on cell cultures, on animal models or using observational studies.

All of these approaches make it difficult to work out cause and effect in humans.

In the case of lemon, there has been some evidence that it may act to protect against cancer, but the evidence isn’t strong. An article on Snopes goes into this issue in further detail.

For example, one review study discussed theoretical pathways for action against cancer cells, including the antioxidant and antiproliferative (inhibits cell proliferation) properties of phytochemicals from citrus fruit (63).

Likewise, another study indicated that citrus flavonoids may protect against the carcinogenic properties of a compound associated with tobacco (64).

The potential of citrus flavonoids is an area that has been studied frequently (65), although more work is needed to know just how much potential these compounds actually hold.

Many studies associate the general abilities of lemon (or citrus fruit) to be an antioxidant and an anti-inflammatory agent with the ability to protect against cancer (e.g. 66). While this may be true, it also applies to a large range of different compounds beyond lemon.

One study did identify specific compounds in lemon, associated with inhibiting the development of tumors in cell cultures (67).

Collectively, these studies do indicate that components of lemon may play some role in protecting against cancer. However, how this applies to humans is less clear.

Even if these compounds were able to protect against cancer or slow down tumor development, it would probably take clinical levels of the compounds to make any significant difference.

This suggests that even if some of the compounds in lemons have anti-cancer impacts, drinking lemon water or even eating whole lemons frequently probably wouldn’t have any significant impact on your cancer risk.

How Much Lemon Water?

If you’re going to take anything for health, picking the right amount is critical.

This goes back to the old saying ‘everything in moderation’.

You want to be having enough to get lemon water benefits, but you don’t want to overdo it either. In the case of lemon water, you actually have two things to consider.

The first is how much lemon you are taking in and the second is how much water.

Of the two, most people will be more sensitive to taking in too much lemon. Lemon can be quite harsh, especially if you aren’t used to it.

However, too much water can also be an issue. In fact, despite common belief, there is relatively little research identifying how much water a person should be drinking in a day.

Even the ‘8 glasses of water rule’ doesn’t have a strong scientific basis and is more of a myth than anything (68).

It is also possible to drink too much water, which may have negative impacts on health (69).

As with many health topics, a single guideline for how much water you should drink is a major oversimplification.

For some people, eight glasses of water a day might be far too much, but for others, it might not be enough. Additionally, the approximation doesn’t take into account how much water you are getting from other parts of your diet, such as water-rich foods or other types of liquids.

The trick to figuring it out is to pay attention to your own body.

Even though some people claim otherwise, thirst is the most powerful indicator of when your body needs water. Research suggests that under normal circumstances we feel thirst before we are dehydrated (70).

This means that in most cases, you should be drinking when you are thirsty and not drinking when you are not.

There are special circumstances of course, such as people with kidney disease, problems with water retention and those engaging in strenuous activity. In those circumstances, it is important to learn how much water you should be drinking and go from there.

In the case of lemon water, your thirst should be the most significant guide to how much water to drink. This means that you shouldn’t down massive quantities because of the potential health benefits of lemon water.

Likewise, you should keep an eye out for any indications that you are having too much lemon juice, such as increased reflux or problems with your teeth.

Timing

For the most part, lemon water benefits come first from the water itself and second from the lemon. Because of this, the timing for when you drink lemon water is mostly about the water component.

One commonly quoted idea is to drink lemon water first thing in the morning. In concept, this approach is supposed to help increase digestion, resulting in improved energy throughout the day. There is some support for this perspective. 

In particular, most people don’t have any water during the night. So, having water when you wake up can be important for getting your body functioning correctly.

It’s also easy to become dehydrated overnight without really realizing it, so water first thing in the morning can help you to get rehydrated.

Some authors also suggest that drinking warm water first thing in the day can help. This is a topic that Wellness Mama discusses in more detail. 

Beyond this, the best timing for drinking lemon water really comes down to your own thirst.

As I mentioned earlier, thirst is a powerful indicator of when you should be drinking water. Under normal circumstances, you should be drinking water (or lemon water) whenever you are thirsty, and not when you aren’t.

There is a whole lot of debate about what temperature you should drink lemon water at. In fact, the debate extends to what temperature you should be drinking liquid at in general.

There are many of different perspectives out there, including drinking water cold, hot and warm, and various justifications for each perspective.

For example, warm water is supposed to help promote digestion and can help to ensure healthy bowel movements.

In contrast, cold water has been linked to weight loss and is thought to be particularly relevant when you are trying to cool down, such as from exercise or from a fever.

The argument for weight loss is that when you drink cold water, your body has to warm it, resulting in some calories being burnt.

However, the amount of calories actually used this way is so minimal that it is barely worth considering (80).

Some people even go so far as arguing that cold water is bad for health.

However, there is little research backing up the preference for warm water (and little research on the topic in general) and most of the information online is little more than hype. It’s unlikely that the temperature of water really makes much of a difference one way or the other, especially as we eat and drink things from a range of different temperatures (81).

Nevertheless, it may be worth trying out warm lemon water first thing in the morning as some advocates suggest.

There is certainly no health risk in either approach and you may find that warm water works well for your own needs. Additionally, having a hot drink in the morning can be an important way of relieving constipation (