Fruit juice is a poor alternative to breast milk or infant formula as it contains only carbohydrate and vitamins

At what age can an infant first drink juice? Only when he or she is old enough to drink from a cup. This rules out the first six months of life, when breast milk ought to be the only food. Fruit juice is a poor alternative to breast milk or infant formula because it contains only carbohydrate and vitamins, and little else. When juice partially replaces milk or formula, it results in lowered intake of protein, fat, vitamins, and minerals such as iron, calcium, and zinc. Studies show that infants who drink juice excessively grow up to be short and malnourished. Older children who binge on juice tend to be obese.

Wherever possible, children should have whole fruit instead of fruit juice. Even mashed fruit is better than juice. Children between the ages of 1 and 6 years should have no more than 120 – 180 ml of 100 %, no-sugar-added juice per day. Older children, up to 18 years, should limit themselves to 240 – 360 ml per day. Drinking from a cup is messier than drinking from a bottle, but it is better for the teeth.

When a child sips juice from a bottle or goes to bed drinking from one, it exposes teeth to sugars for longer duration. This promotes development of dental caries.

During an episode of gastroenteritis, parents often give their children juice in liberal amounts when they should actually be withholding it. During gastroenteritis, the intestines have a lowered capacity to absorb carbohydrate. Juice contains 10 – 15 gm of carbohydrate per 100 ml, most of which is unabsorbed and remains in the bowel. The unabsorbed carbohydrate in the bowel drains water from the body just as salt sprinkled on chopped vegetables draws water. This process, called osmotic diarrhoea, worsens existing diarrhoea.

Infants with diarrhoea need electrolytes, and juice does not have enough to qualify as therapy. The little sodium in juice is just not enough to replace losses in diarrhoea, where the stool contains 20 to 40 mEq/L of sodium.

Oral Rehydration Solution contains carbohydrate (2.5-3 g per 100 ml) and sodium (40 to 45 mEq/L) in just the right amounts and should be the preferred fluid in gastroenteritis. Drinking juice instead of ORS may lower the blood levels of sodium- a condition called hyponatremia.