To prevent heart disease, Americans should embrace this underrated carb
Well, most of us.
One plant-based substance used to haunt our television screens, popping up in commercials for everything from cheerful sounding powder supplements to dessert-like energy bars. Many of these ads danced coyly around a point of this nutrient — which doubles as a type of carbohydrate.
If you eat fiber, you’re more likely to have regular bowel movements.
But despite the bygone marketing, Americans are not still getting nearly enough dietary fiber. A study presented last week at the virtual Nutrition 2021 Live conference confirmed this, assessing the fiber intake of those with diabetes and those without. That’s an issue because fiber does more than help us use the restroom: The carb reduces the risk of disease.
The study looked at people with diabetes, who are at a higher risk for heart disease, and without. “I was surprised to first to find that adults with diabetes, were more likely to meet the recommendations — although the most was 11 percent in females with diabetes, which is still incredibly poor,” lead author Derek Miketinas tells Inverse. Miketinas is an assistant professor of nutrition and food sciences at Texas Woman’s University.
Turns out, there’s much more to this nutrient than blissful bathroom time — and we’re better off forgoing the processed, packaged versions of fiber and choosing to consume it naturally.
SCIENCE IN ACTION — As a nutrient, dietary fiber itself is surprisingly tricky to demystify.
“It’s not like another nutrient ...”
Fiber is a carbohydrate that, for the most part, passes through our digestive system and isn’t broken down. Because it’s not absorbed by the body, there’s no way to quantify it within our bodies as we can for something like vitamin C, which is measured in our blood. This makes it hard for scientists to make precise daily intake recommendations.
“Dietary fiber and its role in human health are complex,” Miketinas says.
“It's not like another nutrient, that once you take it, it becomes a part of the uptake by the body. This is something that acts in conjunction with other nutrients, perhaps in the context of meals.”
Regardless, the U.S. Department of Agriculture pushes a daily recommendation of 14 grams of fiber per 1,000 calories consumed, based on the amount that’s been observed to reduce the risk of coronary heart disease.
- For females, this looks like about 28 grams for a 2,000 calorie diet
- For males, this is about 35 grams on a 2,500 calorie diet
Very, very few of us are hitting those marks.
The study found that, among those without diabetes, only 8 percent of women and only 4.3 percent of men were meeting their daily fiber intake. People with diabetes fared slightly better, but not by much — 11.5 percent of women and 8.6 percent of men in the study hit the mark.
Researchers zoomed in on those with diabetes because they are at a higher risk for heart disease, which fiber can help prevent.
Miketinas and colleagues used data from 14,640 adults who were part of a long-term survey called the National Health and Nutrition Examination Survey to establish how much dietary fiber a representative sample of Americans was really getting.
They used an advanced statistical method, along with a 24-hour recall of food eaten. This was in place of another kind of questionnaire that asks people to recall food habits over long periods of time, Miketinas said. Using this approach over the other helped researchers control for errors and more accurately estimate participants’ actual intake of fiber.
HOW THIS AFFECTS LONGEVITY — Though we’ve come to associate dietary fiber with “cleaning out your insides,” a growing body of research suggests it can do much more than that.
“... dietary fiber promotes fullness and satiety between meals.”
We know from past studies dietary fiber can contribute to the prevention of cardiovascular disease — the number one cause of death in the United States — by lowering LDL cholesterol (or “bad” cholesterol). It can also be helpful in weight management for those whose health could benefit from it, Miketinas says.
“It’s not enough to supplement dietary fiber and achieve weight loss,” says Miketinas. “You have to create an energy deficit somehow. That could be achieved with a high fiber diet, because dietary fiber promotes fullness and satiety between meals.”
And while this study did not investigate the long-term health effects of dietary fiber, that’s just what the team plan on doing next.
Miketinas already knows what they’d do: First, they’d look at intake and “cardiometabolic outcomes” like levels of cholesterol, blood lipids, and measurements of glycemic control and inflammation.
“The goal for the next step is to assess the relationship between these outcomes and dietary intake across adults with diabetes, pre-diabetes, and without diabetes,” Miketinas says.
WHY IT'S A HACK — This finding — all Americans should increase their dietary fiber intake —isn’t exactly a new idea, but the statistical analysis the team used gets at more accurate estimates of just how we’re doing overall.
How we can get more daily fiber? Supplements aren’t necessarily the answer, Miketinas says. It’s harder to evaluate their effectiveness, and besides, fiber through whole foods is the easiest and cheapest way to go.
“It's nothing sexy,” Miketinas says. “It's what dietitians, physicians, and other professionals have been trying to get people to do for decades: To just eat a well-balanced diet rich in fruits, vegetables, whole grains, low fat, nonfat dairy, nuts and seeds, lean protein, fish.”
In another study by his team that was presented at the same nutrition conference, researchers hone in on one kind of fiber that’s less well-known but potentially important: resistant starch.
It’s a kind of fiber that, according to John’s Hopkins Medicine, is hard to break down in the small intestine but is fermented in the large intestine. This feeds “good bacteria” and benefits gut health. It’s a kind of starch that doesn’t break down into glucose, can keep us full, and may not cause as much gas or bloating as other fibers.
Plantains, green bananas, peas, beans, lentils, and whole grains (especially oats and barley) all contain high fiber in the form of “resistant starch.” Meanwhile, there are many other high-fiber foods that, chances are, you could eat more of:
- Nuts and seeds, particularly chia seeds, almonds, and popcorn
- Berries, especially raspberries and blackberries
- Collard greens
- Dark chocolate
- Sweet potatoes
So sit back, relax, and enjoy some dietary fiber. Not just for your digestions’ sake, but for your heart’s too.
HACK SCORE OUT OF 10 — 🌾🌾🌾🌾🌾🌾🌾🌾/10 - Fiber One? Fiber won.