Health Benefits of Lemon

Lemons are a type of citrus fruit that derive from the flowering plant Rutaceae. Lemon water is simply the juice from lemons mixed with water. 

Lemons are high in vitamin C, fiber and various beneficial plant compounds. Here are the health benefits of lemons:

1. Support heart health

Lemons are a good source of vitamin C. One peeled lemon provides about 53 mg of vitamin C, which is almost 60% of the reference daily intake (RDI). 

Vitamin C reduces the risk of heart disease and stroke. In addition, the fiber compounds in the pith (white exterior) of lemons could also lower some risk factors for heart disease.

A review of 14 studies found that an average increase of 10 mg of flavonoids (which found in lemons and lemon peels and have antioxidant properties) per day reduced heart disease risk by 5%.

2. Help manage weight

Lemons are often promoted as a weight loss food. The soluble pectin fiber in them expands in the stomach, which may help you feel full for longer.

But because lemon juice (or lemon water) contains no pectin, lemon juice drinks will not promote fullness in the same way.

3. Prevent kidney stones

Citric acid may help prevent kidney stones by increasing urine volume and increasing urine pH, creating a less favorable environment for kidney stone formation.

Just a half cup (4 ounces or 125 ml) of lemon juice daily may provide enough citric acid to help prevent stone formation in people who have already had them.

However, more well-conducted studies are needed to confirm whether lemon juice affects kidney stone formation.

4. Protect against anemia

Lemons contain some iron. But they primarily prevent anemia by improving the absorption of iron from plant foods as iron from plant sources (non-heme iron) does not absorb as easily. This absorption can be improved by consuming vitamin C and citric acid.

5. Reduce cancer risk

As a matter of fact, a healthy diet rich in fruits and vegetables can help prevent some cancers.

What is more, it was found that flavonoid intake is associated with a reduced risk of several types of cancer.  And vitamin C may bolster the growth of white blood cells, which help eliminate mutated cancer cells.

In addition, lemon peel (see below) may also have several cancer-fighting properties. Lemon peels are an excellent source of terpenes such as D-limonene (a compound that gives lemon its characteristic aroma). The primary health benefits of terpenes revolve around some impressive anticancer effects – both in prevention and possibly treatment. Specifically, D-limonene reduced the expression of breast tumor cyclin D1 (cyclin D1 is one of the frequently overexpressed proteins and one of the commonly amplified genes in breast cancer).

One test-tube study also found that D-limonene helped kill stomach cancer cells. Similarly, a 52-week study in rats noted that different concentrations of D-limonene inhibited stomach cancer by increasing the death rate of the mutated cells.

Nevertheless, lemon peel should not be considered a treatment or cure for cancer. Human research is needed.

6. Improve digestive health

Lemons contain about 10% carbohydrates, mostly soluble fiber and simple sugars. The main fiber in lemons is pectin, a form of soluble fiber.

Soluble fiber can improve gut health and slow the digestion of sugars and starches. These effects may result in reduced blood sugar levels.

However, to get the benefits of fiber from lemons, you need to eat the pulp. People who drink lemon juice without the pulp will miss out on the benefits of fiber.

Lemon peel

While the pulp and juice are used the most, the peel tends to be discarded. However, studies have determined that lemon peel is full of bioactive compounds that may provide numerous health benefits.

Besides fighting cancer as mentioned above, research shows that lemon peel also has many other health benefits because of its fiber, vitamin and antioxidants.

Lemon peel packs a high amount of fiber and vitamin C, providing 9% of the DV in only 1 tablespoon (6 grams). It also has small amounts of calcium, potassium and magnesium.

Additionally, it has other health benefits as well:

1. May support oral health

Dental cavities and gum infections are widespread oral diseases caused by bacteria like Streptococcus mutans. In one study, researchers identified four compounds in lemon peel that have powerful antibacterial properties and effectively fight common oral-disease-causing bacteria.

2. High in antioxidants

Lemon peel is high in antioxidants, including D-limonene and vitamin C. 

Intake of flavonoid antioxidants like D-limonene is linked to a reduced risk of certain conditions, such as heart disease and type 2 diabetes.

Animal studies also show that D-limonene increases the activity of an enzyme that helps reduce oxidative stress. Oxidative stress is associated with tissue damage and accelerated aging.

Additionally, the vitamin C in lemon peel acts as a powerful antioxidant and likewise promotes immune health.

A review of 82 studies found that 1–2 grams of vitamin C per day reduces the severity and duration of the common cold by 8% in adults and 14% in children.

Vitamin C also accumulates in phagocytes, a type of cell that ingests harmful compounds.

3. Have antimicrobial and antifungal properties

In a test-tube study, it was found lemon peel significantly harmed and reduced the growth of antibiotic-resistant bacteria.

Another test-tube study showed that lemon peel extract fought a drug-resistant fungus that causes skin infections.

Despite these promising findings, human studies are needed.

4. May promote heart health

In a study in mice with obesity, D-limonene lowered blood sugar, triglyceride and LDL (bad) cholesterol levels, while increasing HDL (good) cholesterol.

A 4-week study in 60 children with excess weight noted that supplementing with lemon powder (containing peel) led to reductions in blood pressure and LDL cholesterol.

The pectin in lemon peels may also reduce cholesterol levels by increasing the excretion of bile acids, which are produced by the liver and bind to cholesterol.

5. May treat gallstones

Some studies suggest that D-limonene may help treat gallstones — hard deposits that can develop in the gallbladder.

In a study in 200 people with gallstones, 48% of those injected with a D-limonene solvent experienced complete gallstone disappearance, suggesting that this treatment could be an effective alternative to surgery.

But more studies are needed.