Fiber and cholesterol – why is oats the heart’s best friend?

Fiber is a fundamental pillar of nutritional recommendations, but its importance is particularly emphasized when the goal is to manage blood cholesterol levels. In particular, soluble fiber – and its most well-known form, oat beta-glucan – has proven to be an effective means of lowering LDL cholesterol, or "bad cholesterol." This article delves into how fiber affects cholesterol, the difference between soluble and insoluble fiber, and why oats are one of the best nutrients for heart health.

Fiber is indigestible carbohydrate from plant parts that the body cannot break down in the small intestine.Fiber is divided into two main types:

• Soluble fiber: forms a gel in the intestines, binds bile acids, and slows down nutrient absorption. Particularly beneficial for managing cholesterol and blood sugar levels.
  
  

• Insoluble fiber: increases stool bulk, speeds up bowel movement, and prevents constipation. Has little effect on cholesterol.
  
  

Both are important, but from a cholesterol perspective, soluble fiber is crucial.

Soluble fiber – particularly beta-glucan, which is obtained from oats and barley – binds bile acids in the intestines that the body needs to digest fats. When bile acids are excreted with stool, the liver must use blood cholesterol to produce new bile acids.

As a result:

• Blood LDL cholesterol decreases
  
  

• HDL cholesterol remains the same or increases
  
  

• Triglycerides may also decrease slightly
  
  

The effect is particularly noticeable in individuals with elevated LDL.

Beta-glucan is a soluble fiber found particularly in oats and barley.Its effectiveness is based on a gel-like composition that:

• Prevents the absorption of cholesterol and bile acids
  
  

• Balances blood glucose levels
  
  

• Slows down stomach emptying and increases the feeling of fullness
  
  

Studied effect:
Just 3 grams of beta-glucan per day can lower LDL cholesterol by 5–10 %. The effect increases with daily use and as part of a varied diet.

1. Oatmeal
1.5 dl of oats = approx. 2 g of beta-glucan

2. Oat drink and yogurt
Check the packaging for fiber content. Good products contain 1–3 g of beta-glucan per serving.

3. Oat flakes
Less processed than flakes – rich in beta-glucan.

4. Barley pearl varieties
Contain nearly as much beta-glucan as oats.

5. Beta-glucan powders and supplements
Particularly suitable for situations where a daily dose needs to be ensured easily.

Recommendations for adults:

• Women: at least 25 g/day
  
  

• Men: at least 35 g/day
  
  

• Soluble fiber: about 5–10 g/day, of which 3 g of beta-glucan to achieve cholesterol effects
  
  

Most Finns fall short of these recommendations – the average intake is about 20 g per day.

Tips for increasing fiber intake:

• Replace white bread with whole grain bread
  
  

• Eat oatmeal or bran daily in your smoothie
  
  

• Add beans, lentils, and vegetables to every meal
  
  

• For a snack, have a fruit or a handful of nuts
  
  

Fiber has many other health benefits beyond cholesterol management:

• Improves gut function
  
  

• Stabilizes blood sugar levels
  
  

• Aids in weight management
  
  

• Reduces the risk of type 2 diabetes and colorectal cancers
  
  

• Promotes the activity of beneficial gut microbes
  
  

Therefore, it is advisable to systematically increase fiber intake in the diet, even if cholesterol levels are normal.

Fiber – and especially oat beta-glucan – is an effective and natural way to lower cholesterol. Even small changes, such as eating oatmeal or adding oat products, can lead to measurable health benefits. A fiber-rich diet also supports weight management and blood sugar balance, making it an excellent choice for a heart-friendly lifestyle.