Michael O’Riordan
December 27, 2013
LEEDS, UK — Aside from keeping you “regular,” eating fiber also appears to be good for your heart. A new review has shown that increased consumption of dietary fiber is associated with a significantly lower risk of CVD and CHD.
For every 7 g of dietary fiber eaten daily—which can be achieved by eating two to four servings of fruits and vegetables or a serving of whole grains plus a portion of beans or lentils—the risks of CVD and CHD were each lowered by 9%, according to a new meta-analysis published December 19, 2013 in BMJ[1].
“Lower risk of cardiovascular disease was also seen with greater intakes of insoluble, cereal, fruit, and vegetable fiber,” write Diane Threapleton (University of Leeds, UK), a PhD student, and colleagues. “In addition, reduced risk for CHD was associated with greater intake of insoluble fiber and fiber from cereal or vegetable food.”
A cardioprotective effect of dietary fiber was first suggested in the 1970s, and numerous studies have attempted to investigate the link, including the effects of fiber on CV risk factors.
In the present meta-analysis, Threapleton et al analyzed 22 cohort studies that reported total dietary-fiber intake, fiber subtypes, and fiber from food sources and CVD or CHD events. CVD events included CHD along with fatal and incident stroke. Five studies suggested that each 7-g/day increase in insoluble fiber lowered the risk of CVD and CHD by 18%, respectively. Fiber consumption from cereals lowered the risk of CVD and CHD, as did fiber from vegetables. Fiber sourced from fruit lowered the risk of CVD only.
Putting these results in perspective, Dr Robert Baron (University of California, San Francisco) gets straight to the point in his editorial, “Eat More Fiber”[2]. Although the study is limited by the potential for confounding—there is the possibility of an association between high fiber intake and other healthy behaviors—”clinicians should enthusiastically and skilfully recommend that patients consume more dietary fiber,” writes Baron. This includes a mix of soluble and insoluble fiber and fiber from multiple food sources, he adds.
Although the evidence for recommending higher fiber intake comes from “imperfect evidence,” including observational studies and expert opinion, the updated meta-analysis by Threapleton et al increases confidence in the recommendation, writes Baron.
The study was funded by the UK Department of Health. Threapleton reports that her PhD studentship receives funding from Kellogg’s. Baron reported no relevant financial disclosures.
References
- Threapleton DE, Greenwood DC, Evans CE, et al. Dietary fiber intake and risk of cardiovascular disease: systematic review and meta-analysis. BMJ 2013; 347:f6879. Available at: http://www.bmj.com.
- Baron RB. Eat more fiber. BMJ 2013; 347:f7401. Available at: http://www.bmj.com.