Fiber, the edible part of plants that resist digestion, has been suggested to lower risks of heart disease, diabetes and obesity, and certain cancers, as the substance reduces blood cholesterol levels, improves blood glucose levels, lowers blood pressure, promotes weight loss, reduces inflammation and binds to potential cancer-causing agents to promote excretion.  Yikyung Park, from the National Cancer Institute (Maryland, USA), and colleagues analyzed data from 219,123 men and 168,999 women enrolled in the National Institutes of Health-AARP Diet and Health Study. Participants completed a food frequency questionnaire at the beginning of the study in 1995 and 1996, and causes of death were determined by linking study records to national registries. Participants' fiber intake ranged from 13 to 29 grams per day in men and from 11 to 26 grams per day in women. Over an average of nine years of follow-up, 20,126 men and 11,330 women died. Fiber intake was associated with a significantly decreased risk of total death in both men and women—the one-fifth of men and women consuming the most fiber (29.4 grams per day for men and 25.8 grams for women) were 22% less likely to die than those consuming the least (12.6 grams per day for men and 10.8 grams for women). As well, the risk of cardiovascular, infectious and respiratory diseases was reduced by 24% to 56% in men and 34% to 59% in women with high fiber intakes. Dietary fiber from grains, but not from other sources such as fruits, was associated with reduced risks of total, cardiovascular, cancer and respiratory disease deaths in men and women. Reporting that: “Dietary fiber may reduce the risk of death from cardiovascular, infectious, and respiratory diseases,” the researchers urge that: “Making fiber-rich food choices more often may provide significant health benefits.”