Lemons and limes are some of the most popular citrus fruits in the world.

Lemons and limes are often used interchangeably for cooking purposes, but what about their health purposes? Are lemons and limes alike? Though they have a lot in common, they're also distinctly different in some ways.

These two fruits are well known for their acidity and sourness, which makes them useful in a variety of dishes, salads, soups and drinks.

Lemon and lime essential oils made from the rinds are often used for cosmetic and medicinal purposes. They're also included in many household cleaning products for their fragrance and antibacterial properties.

Many people often mistakenly think limes are just unripe lemons but that is not the case. Lemons and limes are two totally different citrus fruits but closely related.

Lemons grow on a small evergreen tree that is actually native to Asia. Limes are thought to be a hybridized fruit and actually come in several varieties from various parts of the world. Lemons and limes are now grown all over the world.

However, lemons — formally known as Citrus limon — are typically grown in moderate climates, while limes — or Citrus aurantifolia — grow better in tropical and subtropical regions.

Round vs Oblong

Lemons and limes definitely look different—if you look closely. Lemons are bright yellow and oblong, while limes tend to be smaller, rounder, and green. Some types of limes actually do turn yellow when ripe, but they do not turn into lemons.

Harvest

While limes are not unripe lemons, they are unripe limes and are harvested before they ripen. When harvested early and while still green, they have a rich, sour flavor and more citric acid. Once a lime is mature and yellow, they lose their acidity and their sour taste and become bitter.

Lemons are picked when ripe, yellow and mature.

Taste

Lemons and limes have a similar taste and are often used as substitutes for each other. But they do taste different. Lemons have a distinctly sour taste, while limes tend to be slightly more bitter but seem to have more flavor. Lemons contain about 2% sugar, while the bitter lime only contains 0.5% sugar. Limes tend to be more acidic than lemons. Some lemons, like Meyer lemons have a much mellower and sweeter taste.

Lemon vs Lime Nutrition

While neither lemons or limes have huge amounts of vitamins and minerals, both lemons and limes have generous amounts of vitamin C. Lemons win out here though, as they have substantially more vitamin C than limes do.

Ounce for ounce, (or gram for gram) lemons have more vitamin C. For example, 100 g of lime contains approximately 29mg of vitamin C, while 100g of lemon contains 53mg of vitamin C. In addition, they also have more potassium, vitamin A, vitamins B6 and folate.

Both lemons and limes have some great health benefits—let's take a look.

Strengthen Immunity

Lemons and limes contain a good amount of vitamin C, or ascorbic acid, which helps to strengthen the immune system, helping your body fight colds, flu, and other pathogens. Vitamin C helps to increase white blood cells, our little 'army' that fight off illnesses and infections.

Vitamin C is also a powerful antioxidant which helps prevent damage to the DNA of our cells, protecting and helping insure we have healthy cell reproduction. This review from the Annals of Nutrition & Metabolism shows that vitamin C helps reduce the duration and severity of respiratory tract infections.

Lemons and limes also fight inflammation. You can also keep your immune system strong by avoiding foods containing sugar or processed foods, eating probiotic rich foods and getting regular exercise.

Good for the Heart

Vitamin C is also valuable for the heart, helping you fight heart disease and lowering blood pressure. One study from the Harvard School of Public Health in Boston looked at the diets of 126,399 adults over a period of eight to 14 years and found that each serving of fruits and vegetables was associated with a 4 percent decreased risk of heart disease. It was found that the vitamin C-rich fruits and veggies, like lemons or limes had the biggest impact.

Another study published in the Journal of Nutrition and Metabolism in 2014 found daily consumption of lemons or limes was associated with a decrease in blood pressure, as well.

Prevents Kidney Stones

The citric acid in lemons or limes helps to prevent painful kidney stones. Lemons and limes are also slightly diuretic, helping to increase urine volume and cleanse the kidneys.

One small study published in the Journal of Urology treated 11 participants with lemonade therapy for nearly four years. Researchers found that stone formation dropped significantly, from an average of one kidney stone per year down to just 0.13 per year. And this study showed that treating kidney stone patients with lemon or lime juice increased urinary citrate levels and decreased the amount of calcium in the urine, suggesting that citric acid may be a potential alternative treatment for preventing kidney stones.