**3. Results**

In Table 1 basic socio-demographic, lifestyle, and clinical characteristics of the participants based on the type of oil are presented. Exclusive culinary olive oil users were more likely to be older (*p* < 0.001), male (*p* < 0.001), physically active (*p* < 0.001), and to have higher adherence to the Mediterranean diet (*p* < 0.001), and they were less likely to have hypertension (*p* = 0.001) compared to non-culinary users of olive oil and/or non-exclusive users.

Moreover, type of oil consumption was directly correlated with age (*r* = 0.15, *p* < 0.001); therefore, a stratified analysis based on the median value of participants' ages was applied. Participants were divided into two categories, namely one including those aged 50–70 years as compared to those aged ≥70 years old. Table 2 shows that among those aged 50–70 years old, exclusive culinary olive oil users were more likely to be physically active (*p* < 0.001), to have higher levels of adherence to the Mediterranean diet (*p* < 0.001), and less likely to have hypertension (*p* = 0.001). Accordingly, among those aged ≥70 years, exclusive culinary olive oil users were more likely to be physically active (*p* < 0.001), smokers (*p* = 0.002), to have higher level of adherence to the Mediterranean diet (*p* < 0.001) and higher levels of SAI (*p* < 0.001), and they were less likely to have hypertension (*p* = 0.01).

After adjusting for age, gender, and smoking habits, the "Non-exclusive culinary use of olive oil" category in comparison to the "No culinary use of olive oil" category was not significantly associated with SAI levels (*p* = 0.114); only "Exclusive culinary use of olive oil" vs. "No culinary use of olive oil" was significantly associated with SAI (*p* = 0.001) (Table 3). For individuals older than 70 years, there was a positive relationship between "Exclusive culinary use of olive oil" (vs. "No culinary use of olive oil") and beneficial SAI levels (b ± SE: 0.38 ± 0.15, *p* = 0.01), meaning that people older than 70 years old who consumed exclusively olive oil had higher SAI levels compared to those without any culinary use of olive oil; no significant association was observed for individuals in the 50–70 years old category (*p* = 0.51). It is noteworthy that "Non-exclusive culinary use of olive oil" (vs. "No culinary use of olive oil") was not significantly associated with SAI levels either in the overall study sample or among the aforementioned age-specific strata (All *p* > 0.05).


**Table 1.** Socio-demographic, lifestyle, and clinical characteristics of the participants based on All and the category type of dietary fat consumption.

Data are presented as mean values and SD or frequencies. *p*-values derived from analysis of variance (ANOVA) for continuous variables or the chi-square test for the categorical variables. *p* 0: comparisons between groups; *p* 1 : comparisons between "No culinary use of olive oil" and "Non-exclusive culinary use of olive oil"; *p* 2: comparisons between "Non-exclusive culinary use of olive oil" and "Exclusive culinary use of olive oil"; *p* 3: comparisons between "Exclusive culinary use of olive oil" and "No culinary use of olive oil"; after correcting for the inflation of Type-I error with the Bonferroni rule. BMI is body mass index, CVD is cardiovascular disease, SAI is successful aging index.


**Table 2.** Clinical and lifestyle characteristics of the participants, by age and type of culinary fat.

Values are presented as percent (%) or mean ± standard deviation. *p* 0: between 50–70 years old and over 70 years old comparisons, *p* 1: between 50–70 and over 70 for "No culinary use of olive oil" category, *p* 2: between 50–70 and over 70 for "Non-exclusive culinary use of olive oil" category, *p* 3: between 50–70 years old and over 70 years old for "Exclusive culinary use of olive oil" category, BMI = body mass index; SAI = successful aging index. *p*-values derived from Pearson's chi-square test for categorical variables and from Pearson's *t*-test for continuous variables. \* *p*-value < 0.05 for the comparisons vs. "No culinary use of olive oil" category; † *p*-value < 0.05 for the comparisons vs. "Non-exclusive culinary use of olive oil" category and *× p*-value < 0.05 for the comparisons vs. "Exclusive culinary use of olive oil" category; after correcting for the inflation of Type-I error with the Bonferroni rule.


**Table 3.** Results from linear regression models (b ± SE) that evaluated the association between (a) "Non-exclusive culinary use of olive oil" category vs. "No culinary use of olive oil" category (independent variable) or (b) "Exclusive culinary use of olive oil" category vs. "No culinary use of olive oil" category (independent variable), and successful aging index (dependent outcome).

b: unstandardized B-coefficient, SE: Standard Error; \* Adjusted for age, sex, smoking habits; \*\* Adjusted for sex and smoking habits.
