Eating lots of fiber-rich fruits and breads may be one way to live longer without developing chronic diseases, an Australian study suggests.
Researchers followed about 1,600 adults aged 49 or older who didn't have any history of cancer, stroke or heart disease for a decade. They also surveyed participants about their fiber intake and eating habits.
At the end of the study, about 250 people had achieved what researchers called "successful aging," meaning they were still free of cancer and cardiovascular disease and also had no depression, disability, cognitive impairment, diabetes or other health problems.
People with the highest fiber intake were 79 percent more likely to age successfully than participants who consumed the lowest amount of fiber, the study found.
"We speculate that fiber might be reducing inflammation in the body, which is an important factor in a lot of these diseases and hence, could have a protective influence on health and protect against disease," lead study author Bamini Gopinath of the University of Sydney said by email.
Two other studies published this week, in the journals Circulation and The BMJ, linked whole-grain foods, which tend to be high in fiber, to lower risks for heart disease and cancer.
The Australian study set out to assess the role of sugary foods and fiber intake on aging. Researchers didn't find an association between healthy aging and how much carbohydrates or sugar people ate. They also didn't find a link between disease-free aging and what's known as the glycemic index, or how much foods can raise the levels of sugar in the blood.
There also was no difference in vegetable consumption between the people who aged successfully and those who did not.
Fibers from fruits, whole grain breads and cereals like rolled oats were associated with healthy aging, suggesting that the influence of dietary fiber on healthy aging may vary depending on the food sources it comes from, the authors conclude in the Journals of Gerontology Series A: Biological Science and Medical Science.
One limitation of the study is that the data on diet and disease were self-reported, relying on participants to accurately recall what they ate and whether they had been diagnosed with any medical problems, the authors note.
Even so, the findings add to a growing body of evidence suggesting that dietary fiber may influence health, said Nour Makarem, a nutrition researcher at New York University who wasn't involved in the study.
"There are number of mechanisms by which higher fiber intakes can contribute to successful aging," Makarem said by email.
"Fiber is associated with increased satiety and fiber food sources typically have low energy density, thereby reducing the risk of weight gain, obesity and associated chronic disease," Makarem noted. "Individuals with higher fiber intakes may also lead healthier lifestyles in general, which collectively contribute to improved health and successful aging."
While researchers did take some lifestyle factors into account, such as whether people smoked or maintained a healthy weight, they did not consider exercise or sleep habits.
"Research is pretty consistent that fiber in plant foods like whole grains, fruits, vegetables, legumes, nuts and seeds helps stave off all kinds of diseases," said Samantha Heller, a registered dietician in New York and author of The Only Cleanse.
"Going very low carb as a lifestyle is not necessary for most of us, nor is it the healthiest or the most realistic approach to a healthy diet," Heller, who wasn't involved in the study, said by email.