Cutting carbs can increase risk of diabetes and other diseases, experts warn

Australians risk increasing their chances of developing diabetes, cardiovascular disease and colon cancer if they cut quality carbohydrates high in cereal fibre from their diets, experts say.


A group of leading international and Australian experts say the evidence on the health benefits of eating whole grains is "unequivocal" and those who avoid them are increasing their risk of disease.


In a bid to increase the consumption of whole grains, the International Carbohydrate Quality Consortium (ICQC) - a group of about 30 nutrition academics, epidemiologists and scientists - has released a consensus report on their health benefits.


The report follows two days of discussions in Italy in September between ICQC members, including US physician Professor Walter Willett at Harvard University's School of Public Health.


Professor Jennie Brand Miller from the University of Sydney's Charles Perkins Centre and School of Life and Environmental Sciences - one of three Australian members of the consortium - says unfortunately there is a "very noisy" group trying to convince people to completely cut carbohydrates.


"We think that the current environment is giving the general public the impression that all grains are best avoided when in fact the research is very clear that when you include whole grain it is associated with lower risk of cardiovascular disease, diabetes and of weight gain," Professor Miller told AAP.


"The science is unequivocal when it comes to diabetes and cardiovascular disease."


Fruit and vegetables contain fibre but the cereal fibre found in whole grains is most closely associated with reduced colon cancer risk, Prof Miller added.


"There are many positive studies showing that a lack of cereal fibre is associated with increased risk of colon cancer," she said.


A whole grain retains its original form, with the bran, germ and endosperm remaining. Many products, in particular bread, remove the bran and germ.


"The bran layer is where all the micronutrients are concentrated, so it does not make sense to throw out the bran," Prof Miller said.


One body of thought is that when people consume carbohydrates without fibre it quickly raises insulin levels and the insulin stimulates the growth of mutant cells, such as colon cancer cells.


"Insulin is this anabolic hormone that doesn't distinguish between good cells and bad cells, so the insulin is increasing the multiplication of mutant cells and sort of acting like fertiliser," explained Prof Miller.


When you ingest the whole grain, she says, the body benefits from the "full compliment of micronutrients and antioxidants" like Vitamin E and C, which help slow down the process of free radicals.


The report also supports consuming whole grains for weight control among the overweight and obese and calls for multifaceted efforts to increase whole grain consumption.