Linda F. Benedict, Lammi-Keefe, Carol, Durham, Holiday
Carol J. Lammi-Keefe, Holiday Durham and Ann H. Shaw
Quality of life in later years is associated with protection against agerelated changes to health status. While change with time is inescapable, lifestyle, such as diet, is known to delay the onset and extent of some changes. Age-related macular degeneration affects the eyesight of more than 14 percent of individuals 70-79 years of age, and it is the leading cause of blindness in the elderly. For adults between the ages of 60 and 75 years, one-third will develop age-related macular degeneration after 75 years of age. More women develop this disease than men, and they are more at risk over age 55.
Other factors that affect risk include race – with Caucasians more susceptible than African-Americans and Asians – smoking history, obesity, high blood pressure/hypertension, and a family history of age-related macular degeneration.
Lifestyle factors that may decrease risk for this debilitating disease include increasing the intake of dietary lutein. This plant pigment is found in dark green leafy vegetables, such as spinach, kale, collard greens and turnip greens, as well as broccoli.
More recently, evidence also points to increasing the consumption of coldwater marine fish – such as salmon, herring, mackerel, tuna and sardines – which contain DHA or docosahexaenoic acid.
It is known that DHA is preferentially transferred across the placenta to the developing fetus during pregnancy, essentially depleting women of DHA. But does this put women who have been pregnant at greater risk for developing macular degeneration? To answer this question we investigated the relationship between the number of pregnancies/babies and the risk for age-related macular degeneration. Underlining the hypothesis was the finding that intake of DHA during pregnancy is low in the United States.
Women in Baton Rouge who were 50 years of age and older and patients at private eye care facilities participated in our study. Information on their eye and physical health was collected. We found that women with age-related macular degeneration had given birth to more babies than women who had never been diagnosed with age-related macular degeneration. Women who were older and more overweight were also more likely to be diagnosed with age-related macular degeneration.
Based on our findings, some steps that women can take to protect against age-related macular degeneration include increased intake of foods that are good sources of both lutein – such as spinach, kale, and broccoli – and DHA, which is found in fish such as salmon, herring, mackerel, tuna and sardines. Women should also keep body weight within normal weight limits.
Supplementation with DHA found in cold-water marine fish during pregnancy may help protect the mother against development of age-related macular degeneration in later years. That is, while the consumption of DHA is recommended during pregnancy for infant brain and eye development, it is also recommended for protecting the mother against age-related macular degeneration in later years.
Carol J. Lammi-Keefe is the Alma Beth Clark Professor in the School of Nutrition and Food Sciences. Holiday Durham is an instructor at the Pennington Biomedical Research Center. Ann H. Shaw is an optometrist in Baton Rouge, La.
(This article was published in the fall 2013 issue of Louisiana Agriculture magazine.)