COSMOS-Eye is an ancillary study of the COcoa-Supplement and Multivitamins Outcomes Study (COSMOS; NCT02422745). COSMOS is a randomized clinical trial of cocoa extract supplement (containing a total of 500 mg/d flavanols, including 80 mg (-)-epicatechins), and a standard multivitamin supplement to reduce the risk of cardiovascular disease and cancer among men aged 60 years and older and women aged 65 years and older. This ancillary study is being conducted among participants in COSMOS and will examine whether the cocoa extract supplement or the multivitamin supplement reduces the risk of cataract and AMD, two leading causes of visual impairment in US men and women.

COSMOS-Eye is an ancillary study of cataract and AMD utilizing resources and data from the COcoa-Supplement and Multivitamins Outcomes Study (COSMOS), a randomized, double-blind, placebo-controlled, 2x2 factorial trial of a high-quality cocoa extract supplement (Mars Symbioscience) and Centrum Silver multivitamin (Pfizer) in the prevention of cardiovascular disease and cancer among 12,000 women aged ≥65 years and 6,000 men aged ≥60 years.

Women will be recruited among active Women's Health Initiative (WHI) Extension Study participants, and men will be recruited among non-randomized respondents to the VITamin D and OmegA-3 Trial (VITAL). Women who responded but were not randomized into VITAL will also be included as well as other women and men who express interest in research being conducted at Brigham and Women's Hospital.

Participants will take three pills each day: two capsules that contain either cocoa extract or cocoa extract placebo, and one tablet that contains either multivitamin or multivitamin placebo. Participants will receive their study pills in convenient calendar packs via U.S. mail.

Participants also will be asked to complete short mailed questionnaires each year. The questionnaires ask about health; lifestyle habits, such as diet, physical activity, and smoking; use of medications and dietary supplements; family history of illness and new medical diagnoses including cataract and AMD.

Participants who report cataract or AMD will be asked to provide contact information for their eye doctor(s) as well as written consent to obtain the medical records. Eye doctors will be contacted by mail and asked to complete a cataract (or AMD) questionnaire or, alternatively, forward a complete copy of the patient's medical records pertaining to the diagnosis.

After the COSMOS trial began, an advanced method to analyze cocoa flavanols was accredited by AOAC International as a First Action Official Method of Analysis https://doi.org/10.1093/jaoacint/qsaa132). This updated method relies on a reference material (RM8403) recently standardized and made commercially available by the U.S. National Institute of Standards and Technology. While the actual cocoa flavanol content of the COSMOS intervention remained unchanged throughout the trial, the application of this new analytical method led to expected changes in how the total cocoa flavanol content is now reported. Applying AOAC 2020.05/RM8403 to the COSMOS intervention, the total cocoa flavanol content of the COSMOS intervention is now 500 mg/day. Reporting of (-)-epicatechin content remained unaffected. Going forward, we will therefore apply AOAC 2020.05/RM8403 and report that the COSMOS intervention tested 500 mg/day of cocoa flavanols, including 80 mg of (-)-epicatechin.

Participants in COSMOS who 1) report a diagnosis of cataract or AMD, or extraction of cataract, and 2) provide written consent to obtain the medical records for the reported endpoint, are eligible for this ancillary study.