With dietary carbohydrates currently languishing in unpopularity -witness the rise of the low carb diets like South Beach and Atkins, low-carb foods and gluten-free everything- a new study from the University of Sydney in Australia suggests that eating one kind of carb, fibre, is a key factor in healthy aging.
The study followed 1,609 healthy adults aged 49 over a period of 10 years and found that participants with the highest fibre intake in their diets were 79 per cent more likely to “age successfully,” defined as the absence of disability, depressive symptoms, cognitive impairment, respiratory symptoms and chronic diseases such as cancer and coronary artery disease.
“Consumption of dietary fiber from breads/cereals and fruits independently influenced the likelihood of aging successfully over 10 years,” say the study’s authors, whose work was published in The Journals of Gerontology – Medical Sciences.
“These findings suggest that increasing intake of fiber-rich foods could be a successful strategy in reaching old age disease free and fully functional.”
Fibre is a form of carbohydrate that cannot be broken down by the body and instead passes through the system undigested. Found in whole grains, vegetables and legumes, fibre works to regulate blood sugar levels and to counteract trends to obesity -unlike simple carbohydrates which increase blood glucose and dietary glycemic loads. Scientists have long spoken of the benefits of a high-fibre diet but some of the effects are still not fully understood- research has yet to show, for example, whether the other elements in fruits, vegetables and legumes (so-called co-passengers with fibre) create much of the health-providing properties of fibrous foods. Further, the viscosity and fermentability of fibre foods may turn out to be the primary health drivers, as well.
Researchers combed data from the Blue Mountains Eye Study conducted in a suburban Australian population west of Sydney to conclude that in comparison to other factors examined such as total carbohydrate intake, total fibre intake, glycemic index, glycemic load and sugar intake, a high fibre intake turned out to make the biggest difference in successful aging. They saw suboptimal aging to be associated with participants who had a lower dietary consumption of fibrous foods and these foods are often missing in low carb diets.
The key to the connection between health aging and fibre, say the researchers, may lie in fibre’s ability to help with chronic inflammation, a trait commonly associated with aging and with deteriorating metabolic function. “These epidemiological data suggest that lifestyle interventions increasing the intake of fiber-rich foods could be a successful strategy in reaching old age disease free and fully functional,” say the study’s authors.
Lead author Bamini Gopinath from the Institute for Medical Research says that the research opens up new avenues for study. “There are a lot of other large cohort studies that could pursue this further and see if they can find similar associations. And it would also be interesting to tease out the mechanisms that are actually linking these variables,” says Gopinath.
The Canadian Heart and Stroke Foundation recommends a daily fibre intake of between 21 and 38 grams a day. Currently the average Canadian daily intake is about 14 grams.