Regular consumption of leafy greens such as lettuce, kale spinach and chard could reduce ones risk of developing open-angle glaucoma, according to results of a study published January 14 in JAMA Opthalmology. The lead researcher was Jae H. Kang, ScD, of Brigham & Women’s Hospital and Harvard Medical School.
An analysis by Dr. Kang and her colleagues found nitrate-rich foods such as leafy greens can cut risks of regular glaucoma by 20-30% for most people and by as much as 40-50% for individuals with early paracentral (central) visual field loss.
Their study followed earlier research that indicated Nitric oxide (NO) is involved with both glaucoma and ocular blood circulation. Nearly 80% of NO is obtained by the body from leafy greens, the authors of this study declared.
Two groups were studied – 121,700 females in the Nurses’ Health Study, between 1984-2012, from when the women were 30-35 years of age, and 51,529 men in the Health Professionals Follow-up Study, which ran between 1986 and 2012, starting when the subjects were between 40-75 years of age. More than 85% of the participants were monitored every 2 to 4 years through mailed questionnaires that explored their health, diet and disease status. The women’s questionnaire consisted of 126 queries; The men’s contained 131.
In preparing to do the analysis, the researchers eliminated participants affected by diseases that could cause them to alter their diet, as well as individuals younger than 40 – the age at which one’s risk for developing glaucoma noticeably increases. The records of 63,893 women and 41,094 men were included in the analysis, which represented 1,678,713 person-years of follow-ups.
In the nearly 105,000 analysis subjects, 433 were found during the analysis to have early paracentral vision field loss, and 835 suffered from peripheral vision field loss.
Sub groups had consumer greater or lesser amounts of leafy greens, and the detailed break-down of the analysis indicated that “higher dietary nitrate and green leafy vegetable intake was associated with a lower POAG (primary open-angle glaucoma) risk, particularly with early paracentral vision field loss as a diagnosis.”