New research supports earlier reports that link high consumption of dairy products to an increased risk of Parkinson's disease in men. These reports suggest that an ingredient or a possible contaminant may be responsible; calcium has been ruled out as a possible cause. The researchers reviewed data from the Honolulu Heart Program, which followed 7504 men aged 45 to 68 for 30 years. They monitored the development of Parkinson's disease and reviewed dietary intake. Of all the men involved in the study, 128 developed Parkinson's disease. The study authors found that the risk of developing the disease increased along with the increase in the amount of milk consumed each day. Big milk drinkers were 2.3 times as likely as non-milk drinkers to develop Parkinson's. The authors noted that, even among the highest consumers of milk, the risk of Parkinson's is very small. Over the course of a year, 6.9 cases of the disease might be expected among 10,000 non-milk drinkers, while 14.9 cases could be expected among 10,000 people who consumed more than 16 oz of milk per day. Further studies would be needed to establish a stronger link and to determine what ingredient is responsible for this pattern.
Ms. Farley is a freelance medical writer based in Wakefield, RI.