WORLD – High intake of dietary fiber and whole grains has been associated with reduced risk of non-communicable diseases, according to a series of systematic reviews and meta-analyses published in The Lancet.
The study, commissioned by the World Health Organization show that people who eat higher levels of the products have lower rates of non-communicable diseases compared to those who eat lesser amount.
Results of the analyses have suggested a 15-30% decrease in all-cause and cardiovascular related mortality when comparing people who eat the highest amount of fibre to those who eat the least.
Eating fibre-rich foods also reduced incidence of coronary heart disease, stroke, type 2 diabetes and colorectal cancer by 16-24%, with the impact translating into 13 fewer deaths and six fewer cases of coronary heart disease.
Higher intake of dietary fiber was associated with lower bodyweight and cholesterol, compared with lower intakes.
Focus should be increasing intake for greater protection
While it is recommended that one should eat at least 25g to 29g or more of dietary fibre a day in order to unbolt the health benefits that come along, reports indicate that most people worldwide consume less than 20 g of dietary fibre per day.
UK Scientific Advisory Committee on Nutrition in 2015 recommended an increase in dietary fibre intake to 30 g per day.
In the US, fibre intake among adults averages 15 g a day and in the UK, only 9% of adults manage to reach the 30g per day target.
Rich sources of dietary fibre include whole grains, pulses, vegetables and fruit.
“Previous reviews and meta-analyses have usually examined a single indicator of carbohydrate quality and a limited number of diseases so it has not been possible to establish which foods to recommend for protecting against a range of conditions,” said corresponding author of the report, Professor Jim Mann, the University of Otago, New Zealand.
“Our findings provide convincing evidence for nutrition guidelines to focus on increasing dietary fibre and on replacing refined grains with whole grains.
This reduces incidence risk and mortality from a broad range of important diseases.”
The research revealed that for every 8g increase of dietary fibre eaten per day, total deaths and incidences of coronary heart disease, type 2 diabetes and colorectal cancer decreased by 5-27%, while protection against stroke, and breast cancer also increased.
Consuming 25g to 29g each day was adequate but the data suggest that higher intakes of dietary fibre could provide even greater protection.
The meta-analysis of clinical trials involving whole grains showed a reduction in bodyweight, a reflection of the health benefits of dietary fiber contained in them.
The study also found that diets with a low glycaemic index and low glycaemic load provided limited support for protection against type 2 diabetes and stroke only. Foods with a low glycaemic index or low glycaemic load may also contain added sugars, saturated fats, and sodium that limits their health benefits.
The authors however, noted that high intakes might have ill-effects for people with low iron or mineral levels, for whom high levels of whole grains can further reduce iron levels.
They also note that the study mainly relates to naturally-occurring fibre rich foods rather than synthetic and extracted fibre, such as powders, that can be added to foods.