High intake of ultra-processed food is associated with dementia in adults: a systematic review and meta-analysis of observational studies.

"table 1 description of studies included in the systematic review ( n = 10) publication source of data and study design (follow up) population (age/sex) dementia diagnosis exposure (via nova unless otherwise stated) adjustment outcome dearborn-tomazos et al 2019 [ ] atherosclerosis risk in communities (aric) prospective cohort (20 years) 15792 males/females mean age 54 6 years icd-9 and icd-10 criteria for dementia western dietary pattern: moderate: 2^0 tertile high: 3^0 tertile age sex education race-field centre total calories apolipoprotein e e4 status alcohol use smoking activity level bmi total cholesterol coronary heart disease hypertension diabetes stroke dementia: moderate 1 01 (0 91-1 13) and high intake 1 06 (0 92-1 22) had no significant association dobreva et al 2022 [ ] uk biobank retrospective cohort (11 4 years) 249511 males/females mean age 62 icd-9 and icd-10 criteria for dementia processed meats: moderate: 3^0 quintile high: 5^0 quintile age sex townsend deprivation score age left education household income physical activity smoking status weekly alcohol units loneliness depression bmi cholesterol diabetes hypertension cardiovascular events major dietary changes dementia: moderate 0 83 (0 72-0 95) and high intake 1 07 (0 88-1 30) had no significant association feng et al 2020 [ ] china health and nutrition survey retrospective cohort (18 years) 8236 males/females mean age 62 98 years cognitive screening item: telephone interview for cognitive status (< 7) fast-food ssbs salty snacks: moderate: no data high: high intake age sex smoking drinking ethnicity education levels married status regions gross family income hypertension diabetes death bmi and physical activity mci: high intake increased the risk from 28% to over twofold fast-foods2 40 (1 76-3 28) ssbs1 28 (1 02-1 61) salty-snacks1 52 (1 17-1 96) filippini et al 2020 [ ] newly-diagnosed patients referred to the cognitive neurology network of modena province case-control 108 males/females mean age 65 years dsm-v criteria for dementia pizza salty snacks processed meats sweets chocolates cakes pastries ice cream ssbs: moderate: 2^0 tertile high: 3^0 tertile sex age educational attainment and energy intake dementia: moderate and high intake had no significant association moderate intake: pizza and salty snacks0 33 (0 11-0 84) processed meats0 51 (0 18-1 47) sweets chocolates cakes etc 1 47 (0 50-4 38) ssbs1 67 (0 38-7 40) high intake: pizza and salty snacks0 33 (0 11-0 84) processed meats0 94 (0 35-2 54) sweets chocolates cakes etc 2 61 (0 82-8 34) ssbs0 62 (0 18-2 18) fu et al 2022 [ ] tianjin elderly nutrition and cognition cohort (tencc) cross-sectional 4457 males/females mean age 67 6 years petersen criteria (5 out of 5 of the criteria needed) processed foods dietary pattern: moderate: 2^0 quartile high: 4^0 quartile sex age educational level income marital status bmi pa hypertension diabetes hyperlipidemia gs smoking status drinking status and total energy intake mci: moderate intake 1 32 (0 97-1 79) had no significant association high intake 1 39 (1 03-1 88) increased by 39% li et al 2019 uk biobank prospective cohort (10 years) 72083 males/females mean age icd-10 criteria for dementia moderate: 2^0 quartile high: 4^0 quartile age sex education level total daily intake smoking alcohol intake physical activity bmi sleep duration cardiovascular disease family history of dementia healthy diet score dementia: moderate intake 1 02 (0 80-1 31) had no significant association high intake 1 44 (1 12-1 85) increased the risk by 44% pearson et al 2016 [ ] regards prospective cohort (6 8 years) 18080 males/females mean age 64 8 years six-item screener (sis) (shifting from intact cognitive function to impaired cognitive function (a score <= 4)) southern dietary pattern: moderate: 3^0 quintile high: 5^0 quintile age race sex region total energy intake income education physical activity smoking status bmi hypertension diabetes cardiovascular disease and depressive symptoms mci: moderate 1 07 (0 81-1 33) and high intake 1 16 (0 93-1 45) had no significant association ylilauri et al 2022 [ ] kuopio ischaemic heart disease risk factor study (kihd) prospective cohort (22 years) 2497 males aged 42-60 years icd-8 icd-9 and icd-10 criteria for dementia processed red meats: moderate: 2^0 quartile high: 4^0 quartile age baseline examination year energy intake education years pack-years of smoking bmi diabetes leisure-time physical activity coronary heart disease use of lipid-lowering medication intakes of alcohol fibre sum of fruits berries and vegetables and dietary fat quality dementia: moderate 1 06 (0 79-1 44) and high intake 1 12 (0 79-1 57) had no significant association zhang et al 2021 [ ] uk biobank retrospective cohort (8 years) 493888 males/females mean age 56 5 years icd-9 and icd-10 criteria for dementia processed meats: moderate: 2^0 quartile high: 4^0 quartile age gender ethnicity socioeconomic status educational level region bmi physical activity smoking status typical sleep duration stroke history family history of dementia and dietary factors including total consumption of vegetables and fruits total fish tea and coffee and alcohol dementia: moderate intake 1 13 (1 02-1 25) increased the risk by 13% high intake 1 67 (1 41-1 98) increased the risk by 67% miao et al 2021 [ ] framingham heart study (fhs) retrospective cohort (19 years) 2664 males/females mean age 53 7 years dsm-iv criteria for dementia ssbs: moderate: 2^0 tertile high: 3^0 tertile age sex hypertension smoking bmi diabetes dementia: moderate intake 1 53 (1 21-1 93) increased the risk by 53% high intake 2 80 (2 24-3 50) increased the risk over twofold the outcome column represents the odds ratio or relative risk calculated by the authors of the original included studies icd international classification of diseases dsm diagnostic and statistical manuscript of mental disorders supplementary table s4 shows the quality of evidence as reported by the nos."

"Declarations Conflicts of interestNone of the authors of the current review had any conflict of interest. Conflicts of interest None of the authors of the current review had any conflict of interest."

"Funding No grant support was received in the generation of this study. No additional individual or funding source was needed for writing assistance."

"The protocol for this review was registered on PROSPERO (CRD42023388363). Methods: We performed a systematic review and meta-analysis of all records registered on Ovid Medline and Web of Science from inception until December 2022 [PROSPERO (CRD42023388363)]. Studies that assessed UPF consumption in adults, determined according to NOVA, and that reported dementia (Alzheimer’s disease, vascular dementia and mild cognitive impairment) determined by clearly stated diagnostic criteria (including formal assessment of dementia or use of diagnostic codes) were included. The association between UPF consumption and dementia was assessed using random-effects meta-analysis, controlling for confounding variables. Study quality was assessed using the Newcastle Ottawa Scale and evidence credibility evaluated using the NutriGrade system."