Carcinogenicity and regulation of caramel colorings.

2- and 4-methylimidazoles are present as contaminants in caramel colorings manufactured with ammonia catalysts. Both contaminants have been shown to induce cancer in animals and may be present in caramel colorings in amounts that exceed federal guidelines. California requires warning notices on products that could lead to consumption of more than 30 micrograms per day. The US Food and Drug Administration should bar the use of excessively contaminated caramel coloring in food.

Liquorice and hypertension.

Glycyrrhetinic acid, the active constituent of liquorice, inhibits renal IIbeta-hydroxysteroid dehydrogenase. This allows cortisol to stimulate mineralocorticoid receptors, which can result in hypertension and hypokalaemia. Treatment options are based on pathophysiological understanding.