Milk and citrus fruits are both healthy foods, each rich in essential nutrients. However, when combined, chemical reactions can occur that affect digestion and the absorption of beneficial substances. This combination is often encountered in various recipes or drinks, but specialists draw attention to the possible negative effects on the stomach and metabolism.
What happens in the body when you combine milk with citrus fruits
When citrus juice (lemon, orange, grapefruit, etc.) comes into contact with milk, the high acidity causes the proteins in milk, especially casein, to coagulate. This phenomenon is similar to the process of cheese making, but in the stomach, it can lead to the formation of clumps that are difficult to digest. As a result, digestion is hindered, and symptoms such as bloating, heartburn, or even diarrhea may occur.
Why this combination is contraindicated
- Digestive issues Coagulated milk under the action of citric acid is harder to digest, causing bloating, gas, and abdominal discomfort.
- Risk of diarrhea Some individuals may experience diarrhea due to the formation of indigestible protein clumps.
- Reduced nutrient absorption Acidity can affect the bioavailability of calcium and other minerals in milk.
- Gastric irritations Individuals with gastritis or reflux may experience aggravated symptoms.
- Adverse reactions in children The sensitive stomachs of children may be more affected by this combination, leading to colic and stomach upset.
Scientific studies and research
A study published in Journal of Dairy Science showed that citric acid causes rapid precipitation of casein, forming hard-to-digest particles. Researchers explained that these clumps can persist in the stomach longer than regular milk proteins, prolonging the digestive process.
Another study conducted by Food Chemistry demonstrated that adding lemon juice to milk reduces calcium bioavailability by up to 30%. This decrease has direct implications for bone and dental health, especially in individuals who frequently consume the combination.
Additionally, researchers in India analyzed the effect of traditional drinks made with milk and citrus on digestion. The results showed that, although some recipes are based on this mixture, it is recommended only after the milk is heated and transformed into cheese (paneer), not in its raw state.
In International Journal of Food Sciences and Nutrition, an article highlighted that the acidity of orange juice added to milk can increase the risk of gastric irritations in individuals with digestive sensitivity.
More recently, a study published in Nutrients (2021) drew attention to the interaction between dairy proteins and vitamin C, which can modify their molecular structure, reducing the beneficial effects of both milk and citrus fruits.
Contraindications
- Individuals with gastritis, ulcers, or gastroesophageal reflux should avoid the combination.
- Young children and the elderly are more prone to digestive disturbances.
- Individuals with lactose intolerance may experience exacerbated symptoms.
- Pregnant women and those who are breastfeeding should consume milk and citrus separately to avoid digestive discomfort.
Sources
- Journal of Dairy Science Effect of citric acid on casein coagulation
- Food Chemistry Impact of acidic juices on calcium bioavailability in milk
- International Journal of Food Sciences and Nutrition Acidic fruit juices and their interaction with dairy proteins
