Dietary Fat Quality (DFQ) Indices and Breast Cancer Risk:Report from a Large-Scale Case-Control Study

Although several studies have assessed the relationships between breast cancer (BC) and total fat intake andfat types, relative proportions of fatty acids assessed through indices are not known to be associated with BC.Several fat quality indices have been published to aid the evaluation of DFQ in relation to health consequences.In ۱۹۹۱, Ulbricht and Southgate (۱۵), proposed the atherogenicity index (AI) and thrombogenicity index (TI),which consider the ratio of subclasses of SFAs to MUFAs and PUFAs. Subsequently, in ۱۹۹۶, Mitchellet al.introduced Cholesterol-Saturated Fat Index (CSI). Later, in ۲۰۰۸, Ding et al proposed that the lipophilic index(LI), might be an innovative tool for evaluating fatty acids, which could be used to determine the mean fluidityof fatty acids either consumed in the diet or present in biological samples, into an index. Until now, to ourknowledge, AI, TI, LI, Σω-۳/Σω-۶ ratio, h/H, PSR or CSI have not been studied for the association with BC inthe Middle Eastern population. This study investigates the association between dietary fat quality (DFQ)indices and odds of BC among women.This hospital-based case-control study assessed ۴۶۴ women with pathologically confirmed BC during the past year and ۴۹۸ apparently healthy controls of similar age and residence. Dietary intake was assessed using a validated food frequency questionnaire (FFQ) and DFQ indices were calculated by formula. We calculated DFQ indices based established protocols as detailed below:Polyunsaturated fatty acids/saturated fatty acids ratio (PSR)=PUFAs: SFAs ratio. Atherogenicity index (AI)=(l۲:۰+(۴ x l۴:۰)+۱۶:۰) / (Σω-۶ PUFA +Σ ω-۳ PUFA + ΣMUFA ω-۹), where ۱۲:۰=lauric acid,۱۴:۰=myristic acid, ۱۶:۰=palmitic acid, Σω-۶ PUFA=sum of omega-۶ polyunsaturated fatty acids, Σω-۳ PUFA=sum of omega-۳ polyunsaturated fatty acids, and ΣMUFA ω-۹=sum of omega-۹ monounsaturated fatty acidsThrombogenic index (TI)=[(۱۴:۰+۱۶:۰+۱۸:۰) / [(۰.۵ΣMUFA)]+(۰.۵Σω-۶ PUFA)+(۳ Σω-۳ PUFA)+(Σ ω-۳ PUFA / Σω-۶ PUFA)]; where ۱۴:۰=myristic acid, ۱۶:۰=palmitic acid, ۱۸:۰=stearic acid, MUFA= monounsaturated fatty acids, Σω-۶ PUFA=sum of omega-۶ polyunsaturated fatty acids, Σω-۳ PUFA=sum of omega-۳ polyunsaturated fatty acids.Σω-۳ / Σω-۶ ratio = where Σω-۳=sum of omega-۳ PUFAs, Σω-۶=sum of omega-۶ PUFAs.Dietary lipophilic index= The lipophilic index of dietary intake was computed by multiplying the intake of each fatty acid (in grams) by its specific melting point (°C), adding the products, and then dividing by the total of fatty acid intake (in grams).Dietary lipophilic index (LI)=Σ[Fatty acid (g) i×Melting point (°C)i] / ΣFatty acid (g) i.Cholesterol/saturated fat index (CSI)The Cholesterol-Saturated Fat Index (CSI) has potential as a dietary self-monitoring tool and enables patients to monitor their progress toward a cholesterol-lowering.The likelihood of BC was evaluated across quartiles of specific DFQ indices scores [atherogenicity index (AI), thrombogenic index (TI), hypo- and hypercholesterolemic fatty acids ratio (h/H), omega-۳ to omega-۶ polyunsaturated fatty acids ratio (Σω-۳/Σω-۶), polyunsaturated fatty acids/saturated fatty acids ratio (PSR), dietary lipophilic index (LI), Cholesterol/saturated fat index (CSI)].

کلیدواژه ها:

Dietary fat quality ، Breast cancer ، Dietary fat ، case-control