Lactic Acid (Lactate): Function, Formation and Importance
Lactic acid (lactate) is an organic acid produced naturally in the body during energy metabolism. It plays a key role in muscle physiology, diagnostics, and food production.
Things worth knowing about "Lactic acid"
Lactic acid (lactate) is an organic acid produced naturally in the body during energy metabolism. It plays a key role in muscle physiology, diagnostics, and food production.
What is Lactic Acid?
Lactic acid (chemical name: 2-hydroxypropanoic acid; its salts and esters are called lactate) is an organic acid that occurs naturally in the human body and in many foods. It is primarily produced during anaerobic metabolism, when body cells need to generate energy without a sufficient supply of oxygen. Lactic acid is also widely used in the food and pharmaceutical industries.
Formation and Mechanism of Action
In the human body, lactic acid is mainly produced in muscle cells. When muscles require more energy than aerobic (oxygen-dependent) metabolism can supply, cells switch to anaerobic glycolysis. In this process, glucose is broken down without oxygen, producing lactate as a metabolic byproduct.
- Aerobic metabolism: With sufficient oxygen, glucose is fully broken down into carbon dioxide and water – highly efficient but relatively slow.
- Anaerobic metabolism: When oxygen is limited (e.g., during intense physical exercise), lactic acid is formed as an intermediate product – fast, but less energy-efficient.
The lactate produced is transported via the bloodstream to the liver and heart muscle, where it can be converted back into glucose or used directly for energy production. This process is known as the Cori cycle.
Lactic Acid in Sports and Physical Exercise
During intense physical activity, blood lactate concentrations rise significantly. The lactate threshold (also called the anaerobic threshold) marks the exercise intensity at which lactate production exceeds the rate at which the body can clear it. Beyond this threshold, lactate accumulates in the blood, contributing to sensations of muscle fatigue and the characteristic burning feeling in working muscles.
Contrary to a widespread belief, lactic acid itself does not cause delayed onset muscle soreness (DOMS). DOMS results from micro-tears in muscle tissue and is a separate physiological process.
Lactate Measurement in Diagnostics
In clinical medicine, blood lactate levels are measured to assess various conditions. Elevated lactate levels (hyperlactatemia) may indicate insufficient oxygen delivery to tissues, as seen in conditions such as shock, severe infection (sepsis), or heart attack.
- Normal range: approximately 0.5 – 2.2 mmol/L at rest
- Lactic acidosis: Markedly elevated lactate levels (above 5 mmol/L) can lead to dangerous acidification of the blood, a condition known as lactic acidosis, which requires intensive medical treatment.
Lactic Acid in Food
In food production, lactic acid is generated by lactic acid bacteria (lactobacilli), which ferment sugars into lactic acid, naturally preserving foods. Well-known examples include:
- Yogurt, cheese, and buttermilk
- Sauerkraut and fermented vegetables
- Sourdough bread
- Miso and other fermented products
As a food additive, lactic acid is listed as E 270 on product labels, where it functions as a preservative and acidulant.
Lactic Acid in Medicine and Pharmaceuticals
Lactic acid and its salts (lactates) are used in a variety of medical applications:
- Infusion solutions: Lactated Ringer solution and similar electrolyte solutions are used in emergency medicine and for treating fluid deficits.
- Dermatology: Lactic acid is a common ingredient in skincare products and chemical peels, as it is an alpha-hydroxy acid (AHA) that promotes skin renewal and has moisturizing properties.
- Biodegradable plastics: Polylactic acid (PLA) is used for medical implants and sutures because it is broken down by the body over time.
References
- Silbernagl, S. & Despopoulos, A. (2018). Color Atlas of Physiology, 8th edition. Thieme Publishers.
- Brooks, G. A. (2018). The Science and Translation of Lactate Shuttle Theory. Cell Metabolism, 27(4), 757–785. DOI: 10.1016/j.cmet.2018.03.008.
- World Health Organization (WHO) & Food and Agriculture Organization (FAO): Codex Alimentarius – Food Additives (E 270 Lactic Acid). Available at: https://www.fao.org/fao-who-codexalimentarius/en/
Most purchased products
For your iron balance
Specially formulated for your iron balance with plant-based curry leaf iron, Lactoferrin CLN®, and natural Vitamin C from rose hips.
For your universal protection
As one of the most valuable proteins in the body, lactoferrin is a natural component of the immune system.
For Healthy Oral Flora & Dental Care
Formulated lozenges with Dentalac®, lactic acid bacteria, and Lactoferrin CLN®The latest entries
3 Posts in this encyclopedia categoryHereditary diseases
Cabozantinib
Entrectinib
Most read entries
3 Posts in this encyclopedia categoryMagnesiumcarbonat
Calorie content
Cologne list
Related search terms: Lactic acid