Fiber: The health factor that almost everyone underestimates
Your gut works day and night, controls your immune system, and influences your metabolism. Yet, in everyday life, it often gets too little of what it urgently needs for its work: fiber. It is precisely fiber that determines how well your digestion functions, how stable your blood sugar remains, and how resilient your body really is. Fiber is not a minor player—they are a central health factor.
Find out now how strongly they affect your well-being, your energy, and even your long-term disease risk.
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Table of contents
Fiber – the heroes for the gut
Fiber is plant-based components of our diet that our body cannot digest. And that is precisely their great advantage. While sugars, fats, and proteins are broken down in the small intestine, fibers continue on to the colon. There, they play a key role: they are food for the gut bacteria. These microorganisms—several trillion in number—together form the so-called gut flora, a highly complex ecosystem that is now considered central to our health.
The gut bacteria process the fiber, among other things, into short-chain fatty acids. These metabolic products have an effect anti-inflammatory, strengthen the intestinal mucosa and contribute to harmful germs and substances being less likely to enter the body. At the same time, they influence the immune system, because about 70 percent of our immune cells are located in the gut. A diet rich in fiber is thus not only a digestive aid but also a kind of daily training for our immune system.
What types of fiber are there?
There are roughly two types of dietary fibers that have different effects. They are distinguished between:
soluble dietary fibers that swell in the intestine and form gel-like substances
insoluble dietary fiber that increases stool volume and stimulates bowel movement
Both forms are important - and both are often lacking in modern diets.
What does science say – how helpful are dietary fibers?
In the overview study1 by Veronese et al. (2018), 18 meta-analyses from almost 300 observational studies were examined to see how fibers affect our health. The results show that people who consume more dietary fibers have
a lower overall mortality
less likely to die from or develop cardiovascular diseases
a lower risk for certain types of cancer, stroke, and type 2 diabetes.
Another study2 published in the Nutrition Journal also shows that just 5 grams more soluble fibers per day could contribute to a reduction in blood pressure by 0.54 mmHg systolic and 0.28 mmHg diastolic.
The researchers attribute the positive effects of dietary fibers to multiple interacting mechanisms: fibers not only improve glucose and fat metabolism, can lower cholesterol and blood pressure, and have anti-inflammatory effects, but they also promote the gut microbiome, satiety, and weight control, thus reducing the risk of cardiovascular diseases and diabetes.
Micronutrients and Fiber: Plant Power for Health
In the EPIC study3, which involved over 500,000 participants in Europe, it was shown that a higher intake of fruits, vegetables, and fiber is associated with a lower risk for certain types of cancer. The protective effect was particularly clear for colorectal cancer, where both fruits and vegetables, as well as fiber, reduce the risk. Fiber alone was also associated with a reduced risk of liver cancer.
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The data is convincing, but hardly anyone reaches the recommended 30 to 50 grams of fiber per day. Our diet is often characterized by highly processed foods, white flour products and sugar – all low in fiber. The consequences are gradual: sluggish digestion, bloating, cravings, weight gain or a feeling of fatigue after eating. Fiber can counteract this naturally: they increase stool volume, stimulate bowel movement, and slow down the absorption of sugar into the bloodstream. Soluble fibers found in vegetables and fruits form a kind of gel in the intestines, slowing down digestion. The rise in blood sugar levels is slower, cravings become less frequent, and the feeling of satiety lasts longer. Many people report having more energy and noticeably a better gut feeling after just a few weeks.
You can't tolerate fiber?
Who has eaten a low-fiber diet for years and suddenly integrates large amounts of whole grains, legumes, or seeds, often experiences bloating or an uncomfortable feeling of fullness. This is not a sign that fiber is not tolerated but an adjustment of the intestinal flora. A slow increase and adequate drinking – ideally 1.5 to 2 liters of water daily – help the intestine to adapt.
More Fiber in Everyday Life - Here’s How to Succeed:
Fiber can be easily integrated into everyday life. Often small changes have a big impact:
A breakfast with oatmeal and berries instead of white bread rolls
Whole grain bread instead of toast
Legumes as a side dish or meat substitute
Fruit with skin
a spoonful of flaxseed in yogurt or salad
A simple rule of thumb: The more natural and plant-based a food is, the higher its fiber content usually is. Variety plays an important role, as different fibers promote different types of bacteria in the gut.
Our list: High-fiber foods at a glance
Soluble fiber (pectin, beta-glucan, inulin) | Insoluble fiber (cellulose, lignin) |
Fruit: Apple, berries, citrus fruits | Whole grain products: bread, rice, wheat bran, oat bran |
Vegetables: Artichokes, Carrots, Leeks, Tomatoes, Onions, Asparagus | Vegetables: Potatoes, carrots, spinach, sweet potato, Brussels sprouts |
Legumes: lentils, beans, peas, chickpeas | Legumes |
Grains, like barley and oatmeal | Nuts |
Together | Flaxseed, sesame |
Mushrooms | Berries |
„If you want to tackle just one change that really makes a difference, increase your daily intake of micronutrients and fiber.“
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Dunja Rieber
Nutritionist
Conclusion
Fiber is a simple health booster – and you have the chance to turn it on every day. With simple, everyday dietary choices, you can do something good for your gut, enhance your well-being, and reap long-term health benefits that go far beyond digestion. Let your gut bacteria work for you – for more energy, a stronger immune system, and a better quality of life.
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Veronese N, Solmi M, Caruso MG, Giannelli G, Osella AR, Evangelou E, Maggi S, Fontana L, Stubbs B, Tzoulaki I. Dietary fiber and health outcomes: an umbrella review of systematic reviews and meta-analyses. Am J Clin Nutr. 2018 Mar 1;107(3):436-444.
2)Ghavami A. et al. Effect of soluble fiber on blood pressure in adults: a systematic review and dose-response meta-analysis of randomized controlled trials. Nutr J. 2023 Oct 13;22(1):51.
3)Bradbury KE, Appleby PN, Key TJ. Fruit, vegetable, and fiber intake in relation to cancer risk: findings from the European Prospective Investigation into Cancer and Nutrition (EPIC). Am J Clin Nutr. 2014 Jul;100 Suppl 1:394S-8S.
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