Raising fibre in wheat flour and white bread
What it found
Modelling of UK diet data suggests that raising the fibre in white flour by 50% would add about 1 gram of fibre a day to people's diets.
Lab tests suggest the extra fibre slows starch digestion and glucose release.
What they found
Studies in people
Fibre intake rise
The model predicted fibre intake would rise by 1.41 g a day for males and 1.04 g a day for females. The share of men reaching the fibre target would rise from 11.3% to 15.6%, and women from 5.7% to 7.4%.
Animal and lab studies
Starch digestion in lab
In lab tests, bread made from a high-fibre wheat released glucose more slowly than bread from a standard UK wheat. Adding arabinoxylan or beta-glucan to bread also slowed starch breakdown.
Other findings
Fibre in white flour
White flour contains about 4% fibre by dry weight, and about half of that is arabinoxylan. The amount of arabinoxylan varies about two-fold between wheat varieties, and most of that variation is genetic.
Bread quality and cost
The authors say higher-fibre wheat can be grown without affecting crop yield or production costs. They also say the changes in dough viscosity and water absorption fall within the range millers and bakers already see.
Consumer acceptance
The authors believe the extra fibre can be added without changing appearance, flavour, texture or mouthfeel. They note some shoppers may still avoid bread labelled as higher fibre because of a negative image of fibre.
What the authors conclude
“Despite the encouraging results discussed above, it is clear that further research is required to validate the approach and explore any potential beneficial effects on health.”
Also in their conclusions
- They say further research is needed to confirm the benefits in people and to understand how arabinoxylan works.
- They advise that raising fibre in white flour should be part of wider changes in diet needed for better health.
- They suggest labelling the fibre content in the usual way rather than marketing it, to reach people who prefer white bread.
How it was done
Most people eat less fibre than recommended, and white bread remains the dominant type of bread in many countries. The authors wanted to see whether boosting the fibre in white flour could raise fibre intake without changing how bread looks, tastes or is made.
They used UK National Diet and Nutrition Survey data from 3558 people to model what would happen if white flour had 50% more fibre and wholemeal flour had 20% more. They also looked at lab studies of bread made from a high-fibre wheat variety compared with a standard UK variety.
What it can’t tell you
- The intake figures come from a model of what people eat, not from a trial where people actually ate the higher-fibre bread.
- The effects on starch digestion come from lab tests, so it is not yet known whether the same happens in people.
- The paper does not show whether the small rise in fibre intake would lead to better health outcomes.
Who paid
- Funding
- Funded by Biotechnology and Biological Sciences Research Council (from the PubMed record).
- Conflicts
- The authors report no conflicts of interest to declare that are relevant to the content of this article.
- Authors work at
- London School of Hygiene & Tropical Medicine, UK; Aberystwyth University, UK
The paper
- Title
- Increasing fibre in white flour and bread: Implications for health and processing
- Type
- Study
- Evidence
- Studies in people · animals · lab
- Summarised from
- Full text
- Cite
- Shewry PR, Joy EJM, De La Revilla LS, Hansen A, Brennan J, Lovegrove A (2023). Increasing fibre in white flour and bread: Implications for health and processing. Nutrition bulletin. doi:10.1111/nbu.12648Free full textPubMed 37904716DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error