Barley is known to improve the function of the spleen and expel excessive body fluid (diuretic), thus aiding to weight loss and relieving swelling. It also helps reduce hypertension and lower blood sugar. Barley is high in Vitamin A and contains phosphorus, magnesium, calcium, iron, sodium, potassium, zinc, niacin and folate. It contains both soluble and insoluble fibre and helps maintain a healthy colon and reduce cholesterol levels. So you can have barley water but make sure you make it at home and do not have the ready made one as it is full of sugar.