A new study found eating a diet plentiful in fruit, vegetables and fatty fish, such as the Mediterranean diet, can help protect from an eye disease that erodes central vision.
Accumulating evidence shows the consumption of a poor diet is a major contributing factor to a leading cause of blindness — age-related macular degeneration (AMD).
European researchers found that following the Mediterranean diet (MedDiet) reduced the risk of late-stage AMD by 41 percent in people who were free of an advanced stage of the disease at the beginning of the study.
A MedDiet is an energy-unrestricted eating plan that focuses on nutrient-rich foods such as fruits, vegetables, legumes, nuts, olive oil and fish. Eating food rich in those nutrients may help to preserve ocular health.
AMD is a degenerative illness that causes a loss of central vision, which impairs the performance of everyday tasks like reading and driving. Only a few studies have examined the MedDiet’s effect on AMD; some indicate it has value only for certain types or certain stages of the disease. However, when these findings are considered with the results from the latest research, the evidence clearly shows the diet can help prevent the disease.
In the study published in the journal Ophthalmology, food frequency questionnaires from approximately 5,000 people were examined. The participants were enrolled in two previous research projects: the Alienor Study, which explored the link between eye disease and nutrition in senior adults, and the Rotterdam Study, which assessed disease risk in people age 55 and older.
Individuals in the Alienor Study were seen every two years within a four-year period, and individuals in the Rotterdam Study were evaluated and given food questionnaires to complete every five years within a 21-year period.
Data analysis showed that participants who closely adhered to the MedDiet had a 41 percent lower likelihood of developing AMD compared to those who didn’t adhere to the diet.
Interestingly, the researchers discovered that none of the elements of the diet, such as fruits or vegetables, lowered the risk of late AMD alone. Instead, it was the entire diet that reduced the likelihood of the disease.
“A MedDiet is an energy-unrestricted eating plan that focuses on nutrient-rich foods such as fruits, vegetables, legumes, nuts, olive oil and fish,” coauthor Benedicte Merle told Olive Oil Times. “It also limits the consumption of unhealthful foods such as red and processed meats, along with salty industrialized products.
“The macula, the central part of the retina, is very rich in omega‑3 polyunsaturated fatty acids, as well as the pigments of lutein and zeaxanthin. Omega‑3 fatty acids within the macula have neuroprotective actions, in addition to properties that prevent the abnormal growth of blood vessels. Thus, they help prevent degenerative retinal diseases such as AMD. Lutein and zeaxanthin play an important role in protecting vision by filtering the blue light that is toxic to the retina,” Merle said.
“Omega‑3 fatty acids are contained in oily fish, such as tuna and salmon, while lutein and zeaxanthin can be found in orange-red fruits and in green leafy vegetables such as spinach, kale, pumpkins, broccoli, corn, oranges and berries. Our body is not able to synthesize omega‑3 fatty acids, lutein and zeaxanthin, so they have to be provided by our diet. Therefore, eating food rich in those nutrients may help to preserve ocular health.”
Just how much fruits, vegetables and fatty fish should people consume for optimal health? Olive Oil Times put the question to nutritionist Kelsey Peoples of The Peoples Plate in Ramsey, New Jersey.
“Components of a MedDiet certainly create the perfect storm for a healthy body,” she said. “They are consistent with the 2015 Dietary Guidelines, which recommend about 2 cups of fruit and 2.5 cups of vegetables each day for a typical 2,000-calorie diet. The guidelines emphasize the importance of consuming a variety of colors to ensure consumption of a wide range of nutrients. Eating about one to two portions of fatty fish each week can help provide healthy fats and protein. Together, all these protective dietary factors will help keep cells in peak shape and promote long-term health.”