Whole grain, bran and cereal fibre consumption and CVD: a systematic review

Abstract

Whole grain intake is associated with lower CVD risk in epidemiological studies. It is unclear to what extent cereal fibre, located primarily within the bran, is responsible. This review aimed to evaluate association between intake of whole grain, cereal fibre and bran and CVD risk. Academic databases were searched for human studies published before March 2018. Observational studies reporting whole grain and cereal fibre or bran intake in association with any CVD-related outcome were included. Studies were separated into those defining whole grain using a recognised definition (containing the bran, germ and endosperm in their natural proportions) (three studies, seven publications) and those using an alternative definition, such as including added bran as a whole grain source (eight additional studies, thirteen publications). Intake of whole grain, cereal fibre and bran were similarly associated with lower risk of CVD-related outcomes. Within the initial analysis, where studies used the recognised whole grain definition, results were less likely to show attenuation after adjustment for cereal fibre content. The fibre component of grain foods appears to play an important role in protective effects of whole grains. Adjusting for fibre content, associations remained, suggesting that additional components within the whole grain, and the bran component, may contribute to cardio-protective association. The limited studies and considerable discrepancy in defining and calculating whole grain intake limit conclusions. Future research should utilise a consistent definition and methodical approach of calculating whole grain intake to contribute to a greater body of consistent evidence surrounding whole grains.

Differential associations betweena prioridiet quality scores and markers of cardiovascular health in women: cross-sectional analyses from TwinsUK

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Dietary Fibre from Whole Grains and Their Benefits on Metabolic Health

“…It is widely accepted that it is through their high dietary fibre levels that these whole grain products play a very important role in the prevention and alleviation of NCDs. The term ‘whole grain products’ refers to products that are made with a relative proportion of bran, germ and endosperm tissue equal to what would naturally occur in intact grains [ 4 ].…”

Whole grain intake compared with cereal fibre intake in association to CVD risk factors: a cross-sectional analysis of the National Diet and Nutrition Survey (UK)

“…These methods have the potential to misestimate true whole grain intake, which confounds results and makes it difficult to accurately determine if findings can be attributed specifically to whole grains. We recently reviewed existing observational studies exploring whole grains, bran and cereal fibre and the risk of CVD and CVD-related outcomes (15) . We found that when studies defined whole grains as including the germ, endosperm and bran in their natural proportions, results were stronger and less likely to be attenuated after adjusting for individual whole grain components such as cereal fibre intake, potentially due to poorer-quality non-whole grain foods weakening any associations.…”