French nutrition expert Laurent's research confirms that long-term, excessive milk consumption causes its casein to metabolize into cysteine, which deposits on artery walls, easily leading to arteriosclerosis and coronary heart disease. It also contains 5% lactose, which is broken down into galactose by lactase in the body. Excessive galactose deposits in the lens, causing protein denaturation and leading to cataracts. Experts recommend that 250 milliliters of milk per day is most appropriate.