Intermittent fasting not associated with lower glaucoma risk among older adults
Key takeaways:
- Skipping breakfast did not reduce risk for glaucoma among older adults.
- All methods of glaucoma diagnosis were associated with older age and Black, Latino or Hispanic identity.
Older adults who participated in time-restricted fasting by skipping breakfast were not at reduced risk for glaucoma compared with individuals who did not fast, according to a study published in Journal of Glaucoma.
Intermittent fasting, which consists of extending the typical time between meals, has become increasingly popular in recent years “owing to its ability to result in significant weight loss and protective effects against metabolic diseases,” Marlow Schulz, BS, MD candidate at University of Washington School of Medicine, and colleagues wrote.
Previous studies have demonstrated the potential protective effect of intermittent fasting against ophthalmologic diseases such as age-related macular degeneration.
This inspired the researchers to perform a retrospective, cross-sectional study using data from the National Health and Nutrition Examination Survey — which, the researchers said, is well-suited to assess glaucoma due to its inclusion of older individuals of various races and ethnicities — to reveal the association between intermittent feeding and glaucoma diagnosis.
The analysis included 7,081 participants aged 40 years or older (mean age, 61.6 years; 50.5% women; 21.4% Black; 22.9% Hispanic or Latino) and enrolled in NHANES from 2005 to 2006 (n = 3,056) or 2007 to 2008 (n = 4,025).
The researchers defined intermittent fasting as skipping breakfast on both days NHANES participants were interviewed (n = 946; 13.4%), whereas the nonfasting group included individuals who reported any other breakfast pattern in one of the interviews (n = 5,248; 74.1%). The only significant difference in characteristics between the two groups was that individuals in the fasting group were younger (mean age, 55.54 years vs. 57.33 years).
The researchers based glaucoma diagnosis on participant self-report (n = 482; 6.8%), cup-to-disc (CDR) greater than or equal to 0.6 in at least one eye at initial grading (n = 549; 7.8%) or expert clinical judgments of gradable images (n = 343; 6%).
When considering all forms of diagnosis, glaucoma was associated with older age (P < .001) and Black or Hispanic or Latino race/ethnicity (P = .004). Conversely, glaucoma diagnosis was not associated with fasting status.
The researchers described several limitations to this study, noting that participants may have skipped breakfast on interview days by chance and not habitually.
“Although intermittent fasting has been associated with various health benefits, including ocular health, our study did not find a statistically significant association between intermittent fasting by skipping breakfast and the risk of glaucoma,” Schulz and colleagues wrote.
Perspective
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This study found no evidence to indicate that intermittent fasting protects against glaucoma.
Conducted by Schulz and colleagues at the University of Washington, the study analyzed NHANES data from 7,081 participants aged 40 years and older. Intermittent fasting was defined as skipping breakfast on consecutive interview days, and glaucoma diagnoses were assessed through self-report, cup-to-disc ratios and expert clinical evaluations.
Key findings revealed no statistically significant association between intermittent fasting and reduced glaucoma risk. These results highlight the enigmatic nature of glaucoma, emphasizing that intermittent fasting, though popular for its weight loss and metabolic health benefits, does not appear to offer direct protective effects against glaucoma.
Limitations of the study included potential misclassification of fasting habits and reliance on cross-sectional data. While prior studies have suggested benefits of intermittent fasting for some conditions like age-related macular degeneration, it is conceivable that different methods of intermittent fasting could still produce a decrease in glaucoma risk.
As doctors we must keep an open mind to natural approaches and encourage healthy habits. This study underscores the need for further research into targeted prevention strategies for high-risk populations.
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