The Boston Globe (7/8, Satija) reported that a study published in the July issue of Ophthalmology detailed the influence of genetics and environment on the development of age-related macular degeneration (AMD). Researchers “looked at over 200 male pairs of identical twins” in which some twins both had the disease but at different stages, or only one twin did. The study found that heavy smoking was correlated with more advanced AMD, whereas eating foods high in betaine and methionine correlates with slower development of disease. “A previous study of identical and fraternal twins…found that genetics explained between 46 and 71 percent of the severity of the disease, while environmental factors explained between 19 and 37 percent.”