Dietary Fiber Linked to Lower Risk of Heart Disease and Cancer

A study found that a high con­sump­tion of fiber-rich foods, which are sta­ples of the Mediterranean diet, offers pro­tec­tion from non-com­mu­ni­ca­ble dis­eases.

The fiber con­tent of fruits, veg­eta­bles, beans and whole grains appears to reduce the death rate from heart dis­ease, dia­betes and col­orec­tal can­cer.

“Our find­ings pro­vide con­vinc­ing evi­dence for nutri­tion guide­lines to focus on increas­ing dietary fiber and on replac­ing refined grains with whole grains,” Professor Jim Mann, the author of the study from the University of Otago in New Zealand, said. ​“This reduces inci­dence risk and mor­tal­ity from a broad range of impor­tant dis­eases.”

The review, pub­lished in The Lancet, exam­ined data from 58 clin­i­cal tri­als involv­ing 4,635 par­tic­i­pants, as well as 185 obser­va­tional stud­ies that related to 135 mil­lion per­son years. Researchers looked at the inci­dence of and the death rate from car­dio­vas­cu­lar dis­ease, coro­nary heart dis­ease and stroke, along with Type 2 dia­betes and var­i­ous can­cers tied to obe­sity. The clin­i­cal tri­als and stud­ies spanned nearly 40 years.

Results revealed the advan­tages of eat­ing at least 25 to 29 grams of dietary fiber per day. The high­est fiber intakes were asso­ci­ated with a 15 to 30 per­cent reduc­tion in death rate from car­dio­vas­cu­lar dis­ease and all causes, com­pared to the low­est fiber intake.

Consumption of fiber-rich foods was also tied to a 16 to 24 per­cent decreased inci­dence of stroke, coro­nary heart dis­ease, col­orec­tal can­cer and Type 2 dia­betes. In addi­tion, higher fiber intake was linked to health­ier cho­les­terol and body weight, com­pared to lower fiber intakes.

Every 8‑gram increase of daily dietary fiber con­sump­tion was con­nected with a five to 27 per­cent reduc­tion in the inci­dence of and death rate from coro­nary heart dis­ease, col­orec­tal can­cer and Type 2 dia­betes. Protection from stroke and breast can­cer also rose. While con­sum­ing 25 to 29 grams daily was suf­fi­cient, the data indi­cated that a higher intake would offer even more pro­tec­tion.

Each 15-gram increase of daily dietary whole grains was con­nected to a two to 19 per­cent decline in the inci­dence of and death rate from coro­nary heart dis­ease, col­orec­tal can­cer and Type 2 dia­betes. Higher con­sump­tion of whole grains was tied to a 13 to 33 per­cent decrease in non-com­mu­ni­ca­ble dis­ease risk. Whole grains con­sump­tion was also linked to a lower body weight.

The World Health Organization com­mis­sioned the study to guide the devel­op­ment of new dietary fiber rec­om­men­da­tions for opti­mal health. Another goal of the study was to iden­tify what types of car­bo­hy­drates pro­vide the most pro­tec­tion from weight gain and non-com­mu­ni­ca­ble dis­eases.

Most peo­ple around the world con­sume con­sid­er­ably less fiber than what health experts advise. In 2015, the U.K. Scientific Advisory Committee on Nutrition advo­cated rais­ing the rec­om­mended dietary fiber intake to 30 grams per day; how­ever, a mere nine per­cent of U.K. adults con­sume this amount. Fiber intake in the U.S. is also lack­ing, as the aver­age adult intake is 15 grams per day.

“The health ben­e­fits of fiber are sup­ported by over 100 years of research into its chem­istry, phys­i­cal prop­er­ties, phys­i­ol­ogy and effects on metab­o­lism,” Mann said. ​“Fiber-rich whole foods that require chew­ing and retain much of their struc­ture in the gut increase sati­ety and help weight con­trol and can favor­ably influ­ence lipid and glu­cose lev­els. The break­down of fiber in the large bowel by the res­i­dent bac­te­ria has addi­tional wide-rang­ing effects includ­ing pro­tec­tion from col­orec­tal can­cer.”

High-fiber foods are plen­ti­ful in a host of phy­tonu­tri­ents that sup­port health, a fact that begs the ques­tion: how much of the ben­e­fits found in the study are due to fiber, and how much are due to phy­tonu­tri­ents? Mann told Olive Oil Times that while the nutri­ent-dense foods are extremely health­ful, fiber pro­duces pos­i­tive well­ness effects inde­pen­dent of the other con­stituents.

“Of course you are cor­rect in sug­gest­ing that fiber-rich foods are high in a num­ber of other poten­tially pro­tec­tive con­stituents,” he said. ​“However, the dose-response rela­tion­ship between dietary fiber and pro­tec­tion against a num­ber of impor­tant dis­eases sug­gests that fiber itself is a very impor­tant fac­tor con­tribut­ing to the pro­tec­tion.”

• The Lancelet


• Science Daily