**5. Conclusions**

This case-control study provides insights on the role of dietary factors in EOD risk. In particular, our findings suggest a detrimental effect on EOD risk due to a high intake of cereals, dairy products, and some types of sweets. Conversely, the intake of some types of fish, vegetables, dry fruits, and chocolate alongside moderate coffee consumption appear to be beneficial. Finally, our study indicates that an increasing adherence to the Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND) may decrease EOD risk.

**Supplementary Materials:** The following are available online at http://www.mdpi.com/2072-6643/12/12/3682/s1. Supplemental Table S1: Clinical diagnosis of early-onset dementia cases; Supplemental Table S2: Food and beverages mean (standard deviation (SD)) intake and number (%) of consumers in the study population. Early-onset dementia (EOD); Supplemental Table S3: Food and beverages mean (standard deviation (SD)) intake and number (%) of consumers according to the EOD subtype. Early-onset Alzheimer's dementia (EO-AD) and early-onset frontotemporal dementia spectrum (EO-FTD); Supplemental Table S4: Odds ratio (OR) and 95% confidence intervals (CI) for early-onset dementia (EOD), early-onset Alzheimer's dementia (EO-AD), and early-onset frontotemporal dementia spectrum (EO-FTD) for increasing tertiles of food and beverage intake; Supplemental Figures S1–S10: Spline regression analysis of risk of early-onset Alzheimer's dementia (EO-AD) for an increasing intake of food: Cereals and cereal products (1); meats and meat products (2); milk, dairy products, and eggs (3); fish and seafood (4); vegetables (5); mushrooms, legumes, and potatoes (6); fresh and dry fruits (7); sweets, chocolate, cakes, etc. (8); oils and fats (9); beverages (10). The black line indicates the odds ratio for dementia risk; the dash gray lines are 95% confidence limits; the reference line at 1.0 with black spikes indicates the distribution of intake of participants. Note: Spline analysis was not possible for offal and most beverages due to a few subjects reporting consumption which is different from the null value (tea, red, white, aperitif wines and beers, spirits and soft drinks); Supplemental Figures S11–S20: Spline regression analysis of risk of early-onset frontotemporal dementia spectrum (EO-FTD) for an increasing intake of food: Cereals and cereal products (1); meats and meat products (2); milk, dairy products, and eggs (3); fish and seafood (4); vegetables (5); mushrooms, legumes, and potatoes (6); fresh and dry fruits (7); sweets, chocolate, cakes, etc. (8); oils and fats (9); beverages (10). The black line indicates the odds ratio for dementia risk; the dash gray lines are 95% confidence limits; the reference line at 1.0 with black spikes indicates the distribution of intake of participants. Note: Spline analysis was not possible for offal and most beverages due to a few subjects reporting consumption which is different from the null value (tea, red, white, aperitif wines and beers, spirits, fruit juices, and soft drinks); Supplemental Figure S21: Spline regression analysis of risk of early-onset Alzheimer's dementia (EO-AD) for increasing adherence to the Greek-Mediterranean (GM) diet, Dietary Approaches to Stop Hypertension (DASH) diet, and Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND) diet. The black line indicates the odds ratio for dementia risk; the dash gray lines are 95% confidence limits; the reference line at 1.0 with gray bars shows the distribution of dietary pattern scores; Supplemental Figure S22: Spline regression analysis of risk of frontotemporal dementia spectrum (EO-FTD) for increasing adherence to dietary patterns. Greek-Mediterranean (GM) diet, Dietary Approaches to Stop Hypertension (DASH) diet, and Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND) diet. The black line indicates the odds ratio for dementia risk; the dash gray lines are 95% confidence limits; the reference line at 1.0 with gray bars shows the distribution of dietary pattern scores.

**Author Contributions:** Conceptualization, A.C., T.F., and M.V.; data curation, T.F., G.A., C.G., (Caterina Garuti), M.M., and S.C.; formal analysis, G.A., T.F., and M.V.; participant recruitment, A.C., M.C., C.G. (Caterina Garuti), C.G. (Chiara Galli), M.T., G.V., and G.Z.; writing—original draft, G.A., T.F., and M.V.; writing—review and editing, all authors. All authors have read and agreed to the published version of the manuscript.

**Funding:** This study was supported by the grant "Dipartimenti di Eccellenza 2018–2022, MIUR, Italy" awarded to the Department of Biomedical, Metabolic and Neural Sciences of the University of Modena and Reggio Emilia, and by a grant from the Airalzh ONLUS & Coop Italia.

**Acknowledgments:** We are grateful to all the patients and their families for participating in this study. We also thank Martha Clare Morris who was the lead creator of the MIND pattern and originally inspired the analysis of the effect of dietary patterns in this research.

**Conflicts of Interest:** The authors declare no conflict of interest.
