Don’t be confused about the pH of lemon juice and its effects on your body. Lemons and other citrus fruits have acidic juice. This means their pH is less than 7. Lemon juice pH is around 2.0, ranging between 2 and 3. This makes lemons less acidic (or more basic) than battery acid (sulfuric acid, pH=1.0) and slightly more acidic than apples (pH=3.0). Other foods with acidity comparable to lemon juice include vinegar and carbonated soft drinks.
Acids in Lemon Juice
Lemon juice contains two acids, but only one of them is a key player in the fruit’s acidity. Lemon juice is about 5-8% citric acid. Citric acid is a weak acid and accounts for the tart flavor of lemons. Lemons also contain ascorbic acid or vitamin C. A 100-gram serving of lemon juice contains 38.7 milligrams of vitamin C. This is 43% of the daily recommended allowance of the nutrient, but it’s not a significant factor in lemon juice pH.
Lemon Juice pH and Your Body
Eating lemons and drinking their juice may increase the risk of tooth decay. The acid in lemon juice attacks tooth enamel, plus lemons contain a surprisingly high amount of natural sugars. While including lemons as part of a healthy diet is fine, dentists typically warn patients against sucking on lemons.
Vitamin C-rich foods, such as lemon juice, aid in the absorption of some minerals. Specifically, citrus fruits help the body absorb iron.
While lemons are acidic, they have an alkalinizing effect once digested and metabolized. In other words, the by-products of lemon juice digestion tend to increase pH. Drinking lemon juice doesn’t significantly affect the pH of blood. Researchers estimate you’d need to eat the equivalent of 8 kilograms (18 pounds) of citrus fruit to increase blood pH by just 0.2! Part of the reason the body’s pH resists change is because the kidneys filter out excess acids and bases and excrete them as urine. Lemon juice increases urine pH and may help prevent the formation of some types of kidney stones.
References
- Bonjour, J.P. (October 2013). “Nutritional disturbance in acid-base balance and osteoporosis: a hypothesis that disregards the essential homeostatic role of the kidney.” Br J Nutr 110(7):1168-77. doi:10.1017/S0007114513000962
- Fenton, T.R., Lyon, A.W. (October 2011). “Milk and acid-base balance: proposed hypothesis versus scientific evidence.” J Am Coll Nutr. 30(5 Suppl 1):471S-5S. doi:10.1080/07315724.2011.10719992
- Koeppen, B.M. (December 2009). “The kidney and acid-base regulation.” Adv Physiol Educ. 33(4): 275-81. doi:10.1152/advan.00054.2009
- Penniston, K.L.; Nakada, S.Y.; Holmes, R.P.; Assimos, D.G. (2008). “Quantitative Assessment of Citric Acid in Lemon Juice, Lime Juice, and Commercially-Available Fruit Juice Products.” Journal of Endourology. 22 (3): 567–570. doi:10.1089/end.2007.0304
- Rauf, A.; Uddin, G.; Ali, J. (2014). “Phytochemical analysis and radical scavenging profile of juices of Citrus sinensis, Citrus anrantifolia, and Citrus limonum.” Org Med Chem Lett. 4: 5. doi:10.1186/2191-2858-4-5