1.3. Diet Scoring

A list of all food groups and the consumption frequencies used for scoring can be found in the Supplementary data (Tables S1–S3). For all diets, food items that did not fall in any of the listed food groups were discarded. MIND dietary adherence was calculated using the number of servings per food group outlined by Morris et al, 15 giving MIND scores out of a maximum of 15 for each participant.

For the OMeDi scoring, food groups were binned as specified by Trichopoulou et al, 5 and the ratio of monounsaturated to saturated fat intake was calculated using FETA. 14 Participants who consumed below the sex‐specific median for dairy and meat were given a score of 1 for the category or 0 for the remaining categories. Ethanol intake (g/day) was estimated by multiplying the relevant FFQ items by the following ethanol contents: wine, 15 g/glass; beer, 14.4 g/half pint; ports/liqueurs, 10 g/glass; and spirits, 9.2 g/shot. A score of 1 was assigned for consumption between 5 and 25 g/day for women and between 10 and 50 g/day for men. Food group scores were then summed to give the OMeDi score out of a maximum of 9.

For the GMeDi scoring, food groups were scored out of 5 according to Panagiotakos et al. 6 Ethanol intake (g/day) was quantified as described above and scored out of 5. Accurate quantification of olive oil intake was not available; instead, a score of 3 points was added to the total score if olive oil was the primary cooking oil used by the participant. All categorical scores were then summed to give the GMeDi score out of a maximum of 53.

All dietary tertiles were assigned in a manner that optimized PD participant distribution (Table S4).