Whole-grain products and whole-grain types are associated with lower all-cause and cause-specific mortality in the Scandinavian HELGA cohort

Abstract

No study has yet investigated the intake of different types of whole grain (WG) in relation to all-cause and cause-specific mortality in a healthy population. The aim of the present study was to investigate the intake of WG products and WG types in relation to all-cause and cause-specific mortality in a large Scandinavian HELGA cohort that, in 1992 -8, included 120 010 cohort members aged 30-64 years from the Norwegian Women and Cancer Study, the Northern Sweden Health and Disease Study, and the Danish Diet Cancer and Health Study. Participants filled in a FFQ from which data on the intake of WG products were extracted. The estimation of daily intake of WG cereal types was based on country-specific products and recipes. Mortality rate ratios (MRR) and 95 % CI were estimated using the Cox proportional hazards model. A total of 3658 women and 4181 men died during the follow-up (end of follow-up was 15 April 2008 in the Danish sub-cohort, 15 December 2009 in the Norwegian sub-cohort and 15 February 2009 in the Swedish sub-cohort). In the analyses of continuous WG variables, we found lower all-cause mortality with higher intake of total WG products (women: MRR 0·89 (95 % CI 0·86, 0·91); men: MRR 0·89 (95 % CI 0·86, 0·91) for a doubling of intake). In particular, intake of breakfast cereals and non-white bread was associated with lower mortality. We also found lower allcause mortality with total intake of different WG types (women: MRR 0·88 (95 % CI 0·86, 0·92); men: MRR 0·88 (95 % CI 0·86, 0·91) for a doubling of intake). In particular, WG oat, rye and wheat were associated with lower mortality. The associations were found in both women and men and for different causes of deaths. In the analyses of quartiles of WG intake in relation to all-cause mortality, we found lower mortality in the highest quartile compared with the lowest for breakfast cereals, non-white bread, total WG products, oat, rye (only men), wheat and total WG types. The MRR for highest v. lowest quartile of intake of total WG products was 0·68 (95 % CI 0·62, 0·75, P trend over quartiles , 0·0001) for women and 0·75 (95 % CI 0·68, 0·81, P trend over quartiles , 0·0001) for men. The MRR for highest v. lowest quartile of intake of total WG types was 0·74 (95 % CI 0·67, 0·81, P trend over quartiles , 0·0001) for women and 0·75 (95 % CI 0·68, 0·82, P trend over quartiles , 0·0001) for men. Despite lower statistical power, the analyses of cause-specific mortality according to quartiles of WG intake supported these results. In conclusion, higher intake of WG products and WG types was associated with lower mortality among participants in the HELGA cohort. The study indicates that intake of WG is an important aspect of diet in preventing early death in Scandinavia.

Whole-grain intake and total, cardiovascular, and cancer mortality: a systematic review and meta-analysis of prospective studies

“…We used a random-effects model (29), which considers both within-and between-study variation to calculate the summary risk estimates. For studies that separately reported results by sex (17) or CVD subtype (17, 18) (IHD and stroke) without presenting overall estimates, we pooled the results with a fixed-effects model and included the combined results in the main analyses to maintain the correct df for heterogeneity tests. We conducted stratified analyses to explore the potential sources of heterogeneity according to geographic region, sex, duration of follow-up, methods for exposure assessment, the types of intake (whole-grain products compared with whole grain), quality scores, exclusion of prevalent disorders at baseline, and adjustment for potential confounders.…”

“…If the highest category was open ended, we assumed the width of the interval to be the same as in the second-highest category. Three studies from 2 publications (17,26) reported the amount of whole-grain intake, and the other included studies reported the amount or frequency of whole-grain products. According to recent recommendations by Ross et al (32), we converted the intake of whole-grain products into the intake of whole grain as follows: for studies (14,15,19,21,23,24) reporting the frequency of whole-grain products, the intake was converted into the amount of whole grain by using 16 g as a serving size, and for studies (13,20,25) in which whole-grain products were reported in grams, the weights were multiplied by 0.57 (28 g of wholegrain products approximates 16 g of whole grain) to estimate the intake of whole grain.…”

“…Most of these reports were excluded because the exposure or outcome of interest was not relevant to the topic studied. The Iowa Women's Health Study; the Nurses' Health Study; and the Diet, Cancer and Health study had 4 (15,(38)(39)(40), 3 (26, 41, 42), and 2 (17, 43) overlapping publications, respectively, and we included the reports (15,17,26) with the largest number of events. One report (44) was excluded because the association was investigated in participants with heart failure.…”

“…Excluding 2 studies (20, 21) that involved only IHD death, the summary RR was 0.82 (95% CI: 0.79, 0.85), with no heterogeneity (I 2 = 0%). The summary RRs were 0.75 (95% CI: 0.69, 0.83) for IHD mortality [Supplemental Figure 2A; 7 studies (15-21)] and 0.96 (95% CI: 0.75, 1.22) for stroke mortality [Supplemental Figure 2B; 4 studies (15,(17)(18)(19)]. …”

High Fiber Fat and Protein Contents Lead to Increased Satiety Reduced Sweet Cravings and Decreased Gastrointestinal Symptoms Independently of Anthropometric Hormonal and Metabolic Factors

“…There is a strong evidence for that intake of breakfast cereals and regular meals are associated with better well-being and metabolic control and less gastrointestinal symptoms [10,40]. By eating breakfast, important cereals are ingested, which are associated with overall healthier life style habits and lower mortality [41,42]. Thus, intake of breakfast and regular meals may per se, independent of dietary content, be of importance for healthy habits and lower prevalence of gastrointestinal symptoms [10].…”