Skip to main content
. 2023 Oct 11;10:1218538. doi: 10.3389/fnut.2023.1218538

Table 1.

Baseline characteristics of the included studies.

Study ID Study design Country Follow-up duration Study Population Sample Size Case/Intervention, n Control, n Male, n (%) Age, mean (SD) Education, mean (SD), years ApoE-ε4, n (%) Diet assessment/intervention instructions BMI, mean (SD), kg/m2 MeDi Score, mean (SD)
Anastasiou et al. 2017 (48) Cross-sectional Greece No follow-up Adults over the age of 64 years 1,803 1st quartile: 416
2nd quartile: 432
3rd quartile: 470
4th quartile: 485		 No control 1st quartile: 108 (26.0)
2nd quartile: 145 (33.6)
3rd quartile: 218 (46.4)
4th quartile: 256 (52.8)		 1st quartile: 73.9 (5.9)
2nd quartile: 73.3 (6.0)
3rd quartile: 72.3 (6.7)
4th quartile: 72.5 (5.8)		 1st quartile: 6.7 (4.4)
2nd quartile: 7.1 (4.5)
3rd quartile: 8.1 (4.9)
4th quartile: 8.7 (4.9)		 N/A FFQ 1st quartile: 29.4 (5.0)
2nd quartile: 29.3 (5.0)
3rd quartile: 28.6 (4.4)
4th quartile: 28.7 (4.3)		 N/A
Bajerska et al. 2014 (53) Cross-sectional Poland No follow-up Elderly people aged 60 years or older with high risk of metabolic syndrome, living in rural area 87 Group 1: 46
Group 2: 41		 No control Group 1: 15 (17.0)
Group 2: 16 (18.0)		 Group 1: 69.0 (7.0)
Group 2: 72.0 (6.0)		 N/A N/A FFQ Group 1: 30.0 (5.5)
Group 2: 29.3 (4.7)		 N/A
Berr et al. 2009 (16) Prospective cohort France 1 to 4 years Adults aged 65 years and over and not institutionalized 6,947 Moderate use of olive oil: 2,772
Intensive use of olive oil: 2,599		 1,576 Case:

  • moderate use: 1,099 (20.5)

  • intensive use: 1,017 (18.9)

Control: 639 (40.5)		 N/A N/A Total: 1365 (19.7) FFQ N/A N/A
Fischer et al. 2018 (23) Prospective cohort Germany 10 years Urban dwelling adults (75 years or older) who sought primary care 2,622 2,622 No control Case: 910 (34.7) 81.2 (3.4) N/A 551 (21.0) FFQ 25.9 (3.3) N/A
Galbete et al. 2015 (49) Prospective cohort Spain 8 years Adults over 55 years at the time of the baseline assessment 823 low MeDi score: 275
middle MeDi score: 435
high MeDi score: 113		 No control Low MeDi score: 73
Middle MeDi score: 72
High MeDi score: 74		 Low MeDi score: 61.6 (6.1)
Middle MeDi sore: 61.9 (5.8)
High MeDi score: 62.5 (6.2)		 N/A Low MeDi score: 51 (18.6)
Middle MeDi score: 89 (20.5)
High MeDi score: 19 (16.8)		 FFQ 1.3 (8.2) N/A
Martínez-Lapiscina et al. 2013 (22) RCT Spain 6.5 years Men (aged 55–80) and women (aged 60–80) living in the community. Free from CVD but with an elevated vascular risk 268 MeDi+EVOO: 91
MeDi+Nuts: 88		 89

  • Intervention: MeDi+EVOO: 38 (41.8)

  • MeDi+Nuts: 35 (39.8)

Control: 47 (52.8)		 Intervention:

  • MeDi+EVOO: 67.18 (5.61)

  • MeDi+Nuts: 67.33 (5.96)

Control: 67.52 (5.67)		 Intervention:

  • MeDi+EVOO: 8.87 ± 2.08

  • MeDi+Nuts: 8.57 ± 2.84

Control: 8.75 (3.34)		 MeDi+EVOO: 12 (13.2)
MeDi+Nuts: 17 (19.3)
Control: 14 (15.7)		 Two interventions with MeDi (supplemented with either EVOO or a variety of nuts) contrasted against a control (low-fat diet) Intervention:

  • MeDi+EVOO: 28.68 (3.6)

  • MeDi+Nuts: 28.83 (3.2)

Control: 29.12 (3.5)		 N/A
Mazza et al. 2018 (50) RCT Italy 1 year Individuals aged 65 and older, living in the community, without debilitating disease, literate and having an MMSE score of over 20 110 55 55 N/A Intervention: 70 (4)
Control: 70 (4)		 Intervention: 11 (5)
Control: 11 (5)		 N/A Intervention: MeDi plus extravirgin olive oil, 20–30 g/day
Control: MeDi		 Intervention: 28.8 (4)
Control: 28.0 (5)		 Intervention: 33 (3)
Control: 33 (3)
Psaltopoulou et al. 2008 (4) Prospective cohort Greece 6 to 13 years Those aged 60 and above, residing in the Attica region 732 732 No Control Case: 257 (35.1) N/A N/A N/A FFQ N/A Men: 5.0 (1.7)
Women: 4.5 (1.6)
Tsolaki et al. 2020 (51) RCT Greece 12 months Elderly patients with mild cognitive impairment aged from 60 to 80 50 Group 1 (Greek high phenolic early harvest EVOO): 18
Group 2 (Greek moderate phenolic EVOO): 16		 16 Intervention:

  • Group 1: (14.0)

  • Group 2: 5 (10.0)

Control: 3 (6.0)		 Intervention:

  • Group 1: 68.5 (6.8)

  • Group 2: 70.8 (8.1)

Control: 70.1 (6.0)		 Intervention:

  • Group 1: 11.3 (2.8)

  • Group 2: 8.9 (3.7)

Control: 10.6 (4.6)		 Intervention:

  • -Group 1: 12 (66.7)

  • -roup 2: 12 (75)

Control: 5 (31.3)		 Intervention:

  • Group 1: Greek early harvest EVOO (50 mL/day) plus MeDi guidelines

  • Group 2: Greek EVOO (50 mL/day) plus MeDi guidelines

Control: only the MeDi instructions		 N/A N/A
Valls-Pedret et al. 2012 (52) Cross-sectional Spain No follow-up Men (aged 55–80) and women (aged 60–80), living in the community, no CVD history but were diagnosed with diabetes or 3+ cardiovascular risk factors 447 447 No control 214 (47.9) 66.9 7.18 Total: 79 (17.8) FFQ 28.5 N/A
Talhaoui et al. 2023 (54) Cross-sectional MOROCCO No follow-up Moroccan elderly subjects from 3 elderly care homes in
Rabat, Kenitra, and Sidi Kacem, plus one center in Sidi kacem		 151 151 No control 90 (59.6) N/A N/A N/A FFQ N/A Cognitively normal: 29.9 (4.4)
Cognitively impaired: 28.2 (4.1)

RCT, randomized clinical trial; MeDi, Mediterranean diet; EVOO, extra virgin olive oil; CVD, cardiovascular disease; MMSE, Mini–mental state examination; FFQ, food frequency questionnaire; N/A, not available; SD, Standard deviation.