A higher intake of saturated fatty acid is inversely associated with the presence of early age-related macular degeneration.
Saturated fatty acids are seen in food such as cheese, butter, red meat, ice cream, and some oils (e.g. coconut oil).
Age-related macular degeneration (AMD), at its early stages, is characterized by soft drusen. These yellow lesions on and around the macula are associated with the oxidation of lipoproteins secreted by retinal pigment epithelium (RPE). As such, it has been theorized that dietary fatty acids may influence the development of AMD. In fact, some studies have shown that the intake of n-3 polyunsaturated fatty acids (PUFA) and fish can reduce the risk of AMD. However, no studies have been done on an Asian population.
This is a cross-sectional study on the associations between dietary fatty acid and early AMD in a Japanese cohort from a larger metabolomics study. Data about food intake was analyzed using a short food frequency questionnaire (FFQ), with portion sizes for staple foods. Fundus photographs and grading were done by a masked assessor. Early AMD was defined as the presence of alarge drusen with a diameter >125 µm and/or an RPE abnormality within a specific radius with the fovea as a center. There should be no signs of late AMD, such as geographic atrophy or exudative AMD.
There were a total of 3988 participants included in the analysis, consisting of 1815 men (45.5%) and 2173 women (54.5%). The mean age was 62.4 years, and the mean total saturated fatty acid (SFA) intake was 11.6 grams. Results showed that there was a significant inverse association between SFA intake and early AMD in this study population. However, no association was found between intake of n-3 PUFA and the presence of early AMD.
It may be that the effect of SFA is U-shaped instead of liner, as SFA is known to increase total cholesterol levels, which predisposes to ischemic heart disease. However, it also can raise HDL-C levels, which provide an anti-atherogenic effect. Regardless, because of these findings, the study concluded that sufficient dietary fatty acid may be important in maintaining a healthy retinal homeostasis.
Sasaki, M., Harada, S., Tsubota, K., Yasukawa, T., Takebayashi, T., Nishiwaki, Y., & Kawasaki, R. (2020). Dietary Saturated Fatty Acid Intake and Early Age-Related Macular Degeneration in a Japanese Population. Investigative Ophthalmology and Visual Science, 61(3), 23. doi: 10.1167/iovs.61.3.23