Safely Boosting Fiber Intake: Essential Guide for Seniors

The word “fiber” used to conjure images of prunes or ads for Metamucil — not exactly sexy. But this nutrient is having a moment. It even has its own TikTok-driven trend, fibermaxxing: eating strategically to meet or exceed the recommended daily amount. The craze may have some real traction. On a recent call with investors, the CEO of PepsiCo called fiber “the next protein.” After a decade-plus of keto and other protein-focused diets, that’s quite a prediction. And the new Dietary Guidelines for Americans, released Jan. 7, recommend that we “prioritize fiber-rich whole grains” and “significantly reduce the consumption of highly processed, refined carbohydrates, such as white bread, ready-to-eat or packaged breakfast options, flour tortillas, and crackers.” The health benefits of eating fiber, which is found only in plants, are undeniable. Research has shown it can boost your health in numerous ways, including with gut health, heart disease, type 2 diabetes, weight management, inflammation, obesity and cancer prevention. Men over 50 should be aiming to eat 28 grams each day, and women 22. But right now, 97 percent of American men and 90 percent of women don’t eat the recommended daily amount. So jumping on the fibermaxxing bandwagon makes sense, right? Maybe not. “People forget that you have to adapt to fiber,” says Joanne Slavin, a registered dietitian and professor of food science and nutrition at the University of Minnesota. Though it’s not unusual for people on a plant-based diet to eat up to 75 grams of fiber a day, they don’t reach that level overnight. Your digestive system needs time to adjust, or you may experience bloating and pain. “Rather than fibermaxx, I’d like to get you to the recommended amount, which is probably doubling where you’re at,” says Slavin . Nutritionists also say it’s not just a matter of getting enough fiber — if your diet consists of mainly processed, low-fiber carbohydrates, taking a supplement won’t necessarily fill in the gaps. Different types do different things inside your body, so you need them all. And for some people, added fibers may even be harmful. Soluble and insoluble: the A team For years, dietary advice has focused on soluble and insoluble fibers. Most plants contain some of each but in varied ratios. For most people, Slavin says, eating normally provides a good mix: around one-quarter soluble, three-quarters insoluble .​ Soluble fibers dissolve in water in your intestine s, forming a gel that slows digestion and buys your body time to draw out nutrients. Once it reaches the large intestine, the gel can act as a prebiotic, providing food for good-for-you gut bacteria. Research has shown soluble fiber excels at lowering LDL cholesterol, known as the bad one, and helps control your blood sugar. Oatmeal gets its heart-protective properties from soluble fiber, and you’ll also find it in foods like citrus and stone fruits, carrots, broccoli and chia seeds. Insoluble fiber, on the other hand, doesn’t break down in your body. All that indigestible roughage helps keep you feeling full for longer and also keeps things moving through your system to prevent constipation. Berries, apples and pears with their skins, broccoli stems, green beans, whole grains and beans and legumes all have plenty. The thing is, even though research exists into how each type of fiber helps with specific conditions, some studies don’t distinguish between the two. After all, whenever you eat something with fiber, you’re getting both — along with other, less-studied types, not to mention all the other nutrients that come with plant foods. Ultimately, what matters may be the way the different types of fiber work together, which scientists are still researching. Resistant starch: the unsung fiber In basic terms, soluble fiber forms a gel-like substance in your digestive system, then feeds your gut bacteria. Insoluble fiber provides bulk that moves through you without breaking down. Resistant starch does a little of both, so it’s actually considered a fiber. Studies show it can help with blood sugar control. Like fiber, starch is a complex carbohydrate. It consists of long chains of glucose molecules, which takes time for your body to separate and access for energy. With many starches, that happens in your small intestine. But some starches are even slower to break down. Known as resistant starches, they go through your stomach and small intestine without being digested, just like insoluble fiber. Once resistant starch reaches your large intestine, however, it becomes prebiotic food for the friendly bacteria in your gut, which ferment it just like soluble fiber. Starches change with heat. Certain foods, like raw potatoes, contain one kind of resistant starch. Cooking makes that starch gel-like and easily digestible, which contributes to potatoes’ bad rep. Cool down cooked spuds, though, and the starch transforms again, into a different kind of resistant starch. That holds true for other starchy foods, like rice, pasta, white bread and beans. The cook-cool transformation into resistant starch only happens once, Slavin says. “If you throw the food into another recipe and use it, that doesn’t go away. It’s there forever.” So if you can, try to cook starchy foods a day or more ahead of time, refrigerate them and reheat as needed. Refined fibers have benefits, but maybe not what you expect Foods and supplements routinely tout added fiber on their labels, from the usual suspects like breakfast cereal to ice cream to soda. Sixteen types have been approved by the Food and Drug Administration. Many, but not all, are derived from plants. To gain FDA approval, the makers of these fibers had to prove they provide a health benefit — except it may not be the benefit you’re looking for. One of the most common added fibers is inulin, which is derived from chicory root. It helps with calcium absorption. “The FDA said, ‘Yep, that is a physiological benefit.’ Calcium is a nutrient of concern, so we will accept that as your physiological benefit,” Slavin says. “But it doesn’t have the other benefits of fiber. Even though I could get my recommended amounts of 28 grams of fiber, if I got it all as inulin, that would be a really bad idea.” Three more added fibers, inulin-type fructans, galactooligosaccharide and resistant maltodextrin, received approval for their calcium-absorption benefit. Another, polydextrose, qualified for its ability to help you reduce your caloric intake. Some of these added fibers do provide the expected benefits of fiber. Six types, including beta-glucan, psyllium, guar gum and pectin, help lower cholesterol. And arabinoxylan, alginate and certain resistant starches can help with your blood sugar control. Vishal Singh runs a lab at Penn State University that studies how added fibers affect our health. His research, conducted on mice, has found that some of these fibers may actually be harmful to people with, for example, irritable bowel syndrome. “Before going for a powdered fiber supplement,” Singh says, “you need to think twice and maybe consult with a dietitian.” Another reason to seek advice first: A health care professional can help you match a supplement to your needs. For example, if you’re looking to lower your cholesterol or deal with gastrointestinal issues. The right way to fibermaxx: get a good mix The good news in all this? You don’t have to seek out one type of fiber over another. “If I’m eating an apple, when you see the fiber composition, you will always find minimum two to three,” Singh says. “But the way fiber is available in the market as a supplement, it’s a single type. As a human being, we never consume a single fiber in fruit and vegetable form. That’s not natural.” A balanced diet featuring plenty of plant-based foods like fruits, vegetables and whole grains will give your body the fiber it needs, with myriad other benefits. Still, m ost of us know that already and aren’t getting enough. “That’s where the fibermaxxing comes in, I think, for a lot of people. It’s like, OK, I’m going to get this done,” Slavin says. “It kind of makes it more fun, rather than medicine.” If it gives you the push you need, go right ahead and fibermaxx. But maybe start with a mini-maxxing approach: Ease your way in, so your body can adjust.