By: Rachel Neifeld, RD, CDN

Most pregnant women know that fiber is a very important part of their diet, but now that we can easily find high fiber granola bars, yogurts, and juices, do we still need to get some fiber from fruits and vegetables?

The answer is yes! This is because the type of fiber found in fruits, vegetables, and whole grains offers benefits which added fiber cannot provide. These include decreased risk of heart disease, type two diabetes, and some types of cancers. When packaged foods claim to be a “good source of fiber” and to “aid in digestive health,” this doesn’t mean they provide all the same benefits of naturally fiber-containing foods.   

This is because added fiber is extracted from a plant or manufactured in a lab which causes it to lose many of the heart-healthy and anti-cancer benefits that it possessed when packaged in its original form. Added fibers are safe for pregnant and breastfeeding women, but be sure to look at labelsto see where the fiber is coming from and what effects it can have.

Maltodextrin and polydextrose are types of added fiber that are manufactured in a lab. Maltodextrin is chemically processed to be resistant to digestive enzymes which may be helpful for people with diabetes as it does not turn into sugar in the bloodstream, thus helping to keep blood sugar levels in check. Unlike other added fibers, though, it does not help to relieve constipation. Polydextrose is a reduced calorie bulking agent made by combining dextrose (corn sugar) with the sugar alcohol, sorbitol- a low-calorie sweetener that can be helpful for people with diabetes due to its slow absorption rate. Products with more than 15 grams of polydextrose carry a mild warning label stating that sensitive individuals may experience a laxative effect from excessive consumption. Inulin, oat hull, and wheat fibers all come from plants. 

Inulin, composed of a long chain of sugars (mostly fructose), is usually extracted from the chicory root and is digested by “good” bacteria in the gut which is why products containing its claims that it can “aid in digestive health.” The studies on whether inulin helps reduce cholesterol and blood sugars are not clear, and the extent to which inulin benefits health in humans is not well understood either. Oat hull fiber and wheat fiber are insoluble fibers which may prevent constipation but do not lower blood sugars or cholesterol. Some other isolated fibers include oat fiber and sorghum fiber which can also perform some of the same functions as dietary fiber when it comes to preventing constipation and helping create a feeling of fullness.

The research suggests that certain added fibers can help with constipation, control blood sugar rise in people with diabetes, and possibly increase healthy gut bacteria in the case of inulin, but none have been shown to have the cardiovascular and cancer-fighting benefits which naturally fiber-containing foods possess. Though it doesn’t hurt, added fiber doesn’t necessarily erase the sugar and sodium that many processed, packaged foods contain- not to mention that when fiber is added to a product such as a calorie-dense granola bar, it no longer has the benefit of aiding in calorie control like many naturally fiber-containing foods do.

Why settle for obtaining just some of fibers health benefits when you can get the whole package? Strive to get most of your fiber from whole grains, fruits, vegetables, beans, and legumes which come with vitamins, minerals, and antioxidants included!

Sources

1. Center for Science in the Public Interest: CSPI.org
2. Whole Grain Council: Wholegraincouncil.org
3. Dietary Guidelines for Americans 2010: Health.gov