High saturated fat intake tied to poor low- and high-contrast visual acuity

Increased saturated fat intake in young adults appear to exert detrimental effects on high-contrast (HC) and low-contrast (LC) visual acuity (VA), according to a study.

The study included 64 apparently healthy young adults (mean age 21.6 years, 62.5 percent women). All participants completed a lifestyle questionnaire that detailed weekly physical activity (sedentary, active, and very active), the intake of fruits and vegetables per day (0–1 serving, 2–4 servings, and 5 or more servings), and the consumption of saturated fat per day (0–1 serving and 2–4 servings).

Best-corrected distance HC-VA and LC-VA were estimated using logMAR letter charts. Weight, height, and waist circumference (WC), as well as body mass index (BMI) and waist-to-height ratio (WHtR) measurements, were obtained. Additional measurements included systolic (SBP) and diastolic blood pressure (DBP), and cardiovascular risk (CVR; using the Framingham calculator).

The mean CVR of the cohort was normal (3.07 percent), and the spherical equivalent was −0.55 dioptres. Of the participants, 7.8 percent were underweight, 57.8 percent had normal weight (18.5 ≤ BMI < 25), 23.4 percent were overweight (25 ≤ BMI < 30), and 10.9 percent had obesity. A total of 23.4 percent participants had abdominal obesity (WHtR ≥ 0.5).

WHtR and BMI did not show any significant associations with HC-VA and LC-VA. Furthermore, the means of HC-AV and LC-AV did not significantly differ between the physical exercise groups and according to the daily intake of fruits and vegetables.

However, in the group of participants who consumed higher vs lower servings of saturated fat, the mean HC-VA was 0.03-logMAR worse (p=0.0474) and the mean LC-VA was 0.05-logMAR worse (p=0.0068).