Whether they’re flavoring your fish or adding tartness to iced tea, lemons are one of the world’s most popular citrus fruits—and with good reason. Not only do they give foods and beverages a refreshing citrus kick, but lemons also make great skin care agents and cleaning aids and even have documented health benefits. So come with us as we explore all things lemon, from food to medicine and more!
Lemon Nutrition Facts
The yellow fruit we know as the lemon (Citrus limon) grows on a small evergreen tree that’s native to Southern Asia. While the exact origin of the first lemon tree is unknown, like most other citrus fruits, including oranges and grapefruit, lemons are actually hybrids of other naturally occurring species—in the case of lemons, this means citron and bitter orange, which is itself a hybrid of mandarin and pomelo.
Like other citrus fruits, lemons are rich in many important nutrients, including vitamin B6, vitamin C, thiamine, copper, iron, and even calcium. And just one fresh lemon contains a whopping 20% of the RDA of dietary fiber.
Lemons are also a great source of phytochemicals—biologically active compounds that help plants thrive and give them their characteristic taste, color, and smell—which are known to have benefits for us as well. For example, phytochemicals boost the immune system, reduce the effects of carcinogens, regulate hormones, and decrease oxidative stress, DNA damage, and inflammation, which can accelerate the aging process and lead to chronic disease.
Of the phytochemicals in lemons, some of the most important are polyphenols, such as various flavonoids and tannins, and terpenes, especially carotenoids. While new phytonutrients are being discovered all the time, some of the most studied lemon phytochemicals are:
Health Benefits of Lemons
With vitamins, minerals, fiber, and phytochemicals galore, you can bet that lemons have a long history of being used as medicine. In fact, they were discovered in the 18th century to cure scurvy—a disease of vitamin C deficiency that was the scourge of sailors. But even today studies continue to demonstrate the many health benefits of these tart yellow fruits.
A study published in the Annals of Internal Medicine involving over 100,000 individuals who were followed for 8 years found that participants with the largest intake of green vegetables and vitamin C–rich fruits (like lemons) had the lowest incidence of heart disease.
What’s more, studies have found that the dietary fiber in lemons—the majority of which is composed of a polysaccharide called pectin—may help lower cholesterol levels and regulate blood sugar and thus reduce the risk of both heart disease and type 2 diabetes.
Diabetes and Weight Loss
A rodent study published in the Journal of Clinical Biochemistry and Nutrition found that the polyphenols extracted from lemon peels significantly reduced weight gain and body fat accumulation as well as hyperlipidemia and hyperglycemia. These findings led researchers to conclude that lemon polyphenols may help prevent or improve obesity and insulin resistance—factors that are known to increase the risk of type 2 diabetes.
And another study in the journal Nutrition Research found that women who ate a low-calorie diet that included lemon juice experienced weight loss as well as decreased cholesterol and blood sugar levels.
Lemons are rich in an alpha hydroxy acid called citric acid, which in turn contains a type of salt called citrate. Studies have found that citrate binds to calcium and helps block the formation of kidney stones. In fact, drinking just half a cup of lemon juice diluted in water each day can increase the amount of citrate in urine and reduce kidney stone risk.
In addition to its effects on cholesterol and blood sugar, the pectin in lemons has been found in studies to increase levels of beneficial gut bacteria. Studies have also found that pectin helps strengthen the intestinal barrier and keep potential pathogens, including harmful bacteria, from entering the bloodstream.
Many of the phytochemicals in lemons are linked to immune system benefits. Quercetin, for example, has antiviral properties and is known for its ability to improve allergy symptoms by blocking histamine. And quercetin, pectin, lutein, and beta-carotene are all known to inhibit various cancers, including breast, prostate, lung, and colon cancers.
In addition, lemon rinds, from which lemon essential oil is extracted, are known to have potent antibacterial activity. For example, a study in the International Journal of Pharma and Bio Sciences found that lemon peel extract displayed significant antibacterial activity against a number of pathogenic bacteria, including Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, and Staphylococcus aureus.
Iron Deficiency Anemia
Because iron deficiency anemia is associated with low iron levels, people suffering from this condition may benefit from eating foods rich in vitamin C, which helps increase the absorption of iron. Not only are lemons a great source of this important vitamin, but they also contain citric acid, which is known to increase iron absorption as well.
By fighting free radicals and the oxidative stress they cause, lemon phytochemicals may contribute to healthy aging. A study in the journal Scientific Reports found that mice supplemented with lemon polyphenols throughout their lives had increased lifespans and decreased signs of cognitive decline. Similar findings have been documented in other studies as well.
The antioxidant properties of lemon flavonoids and carotenoids are also associated with decreased signs of skin aging. In fact, numerous studies have found that these phytochemicals can protect the skin from free radical damage caused by factors such as sun exposure and smoking and help reduce both wrinkles and skin cancer.
What’s more, the antibacterial properties of lemons make them a good choice for the treatment of acne prone skin—and the alpha hydroxy action of citric acid is great for removing dead skin cells.
Getting More Lemons in Your Diet
If you’re ready to add more lemon power to your diet, one of the easiest ways is simply combining the juice of half a lemon with a glass of water each morning. In fact, drinking lemon water is an ancient Ayurvedic technique that’s said to jump-start digestion and clear the digestive tract of toxins that may have built up overnight.
However, it’s important to remember that while the citric acid in lemons is great for preventing kidney stones, alkalizing the body, and removing dead skin cells, it’s also terrible for tooth enamel. So, to protect your teeth, be sure to use a straw (reusable, of course) or wash your mouth out with plain water afterward.
But drinking lemon water certainly isn’t the only way to get more lemons in your diet. Both lemon juice and lemon zest make great additions to everything from desserts and salad dressings to meat, poultry, and fish dishes.
And, for those who want to lift the spirit and increase attention span, there’s always lemon essential oil too. Not only is lemon oil known for its mood- and concentration-enhancing properties, but it also makes an effective insect repellant, disinfectant, degreaser, and glue remover—and you can even add it to homemade furniture polish and laundry detergent for a refreshing lemon scent!
However you choose to add more lemons to your life, be sure to look for organic whole lemons, lemon juice, and lemon essential oil. That way you can reap all the benefits without the possibility of any nasty pesticide residue.
As you can see, when it comes to fruit, it’s hard to find one with more benefits than the lemon. Whether you want to boost your mood and overall health or are looking for something nontoxic that can help you keep grease and bugs at bay, lemons have got you covered.