Health

3 Reasons to Prioritize Soluble Fiber if you have High Cholesterol

Health
February 7, 2026
10 min
Jenna Ehteshami, MS, MPH, RD, LD

When you have diabetes, managing your health often feels like a full-time job. You’re watching your glucose and may also be monitoring your blood pressure as well. But there is another vital metric to keep an eye on: your cholesterol.

People with diabetes are more likely to have high LDL ("bad") cholesterol and low HDL ("good") cholesterol. Insulin resistance causes the liver to overproduce fat and makes LDL particles smaller, denser, and more likely to clog arteries. At the same time, high levels of blood fats trigger a process that causes the body to break down and clear away HDL faster than normal.The good news is that two of the simplest tools in your kitchen - soluble fiber and water work together as a powerhouse duo to protect your heart. Now you may know that there are different types of fiber.  Both play a key role, but here is the distinction between them:

Soluble Fiber: the type of fiber that provides the most direct benefit for blood sugar and cholesterol levels because it helps carry cholesterol out of your body as waste and its gel-like consistency slows down the absorption of carbohydrates which helps with blood sugar spikes.  

High Soluble Fiber Foods

  • Oatmeal and oat bran
  • Beans (black, kidney, navy)
  • Lentils and peas
  • Apples and citrus fruits
  • Carrots and barley
  • Psyllium husk and flaxseeds
  • Avocados

Insoluble Fiber: doesn’t dissolve and passes through your system largely unchanged which is why it is beneficial for digestion.  It adds bulk to your stool and speeds up the passage of food through the stomach and intestines, making it a great defense against constipation.  Insoluble fiber also helps you stay fuller and more satisfied with meals and snacks which is helpful in weight management.

High Insoluble Fiber Foods

  • Whole wheat flour and wheat bran
  • Nuts and seeds
  • Beans and cauliflower
  • Green beans and potatoes (with skin)
  • Leafy greens (spinach, kale)
  • Fruit skins and root vegetable skins
  • Whole grains like quinoa and brown rice

Which one do you need?

For overall health, you need both. However when we talk about lowering cholesterol, that is the job of soluble fiber.  The good news is that most plant-based foods actually contain a mix of both types. For example, an apple has soluble fiber in the fleshy inside (pectin) and insoluble fiber in the skin (cellulose).

Here are three reasons why the soluble fiber/water combination should be at the top of your priority list to manage your high cholesterol.

1. Soluble Fiber Helps Carry Cholesterol Out of Your Body

Think of soluble fiber as a magnet for your digestive system. Unlike other nutrients, soluble fiber isn't fully absorbed by your body. Instead, as it travels through your intestines, it binds to bile acids (which are made of cholesterol) and holds onto them.

  • The Result: Instead of that cholesterol being reabsorbed into your bloodstream, it is carried out of your body as waste.

2. Soluble Fiber Slows the Absorption of Carbohydrates

For those managing diabetes, soluble fiber is a double-win. When it mixes with water, it turns into a thick, viscous gel-like substance. This gel coats the lining of your gut, which slows down how quickly your body digests food.

  • The Glucose Connection: Because digestion is slower, glucose (sugar) enters your bloodstream at a steady drip rather than a sudden influx.
  • The Metabolic Win: This helps prevent the post-meal "blood sugar spikes" that can damage blood vessels over time. By keeping your blood sugar stable, you reduce the oxidative stress that often contributes to heart disease.

3. Fiber Needs Water to Do Its Job

If fiber is the "broom," water is the "muscle power" that keeps everything moving. Many people increase their fiber intake but forget to increase their hydration, which can lead to bloating or constipation.

  • The Hydration Goal: Aim for at least 8 glasses of water a day. When you eat high-fiber foods like leafy greens, chia seeds, or beans, try to drink a full glass of water alongside them to ensure the fiber can effectively bind to cholesterol.
  • The Gelling Action: Soluble fiber literally cannot turn into that heart-healthy gel without sufficient water. Without hydration, fiber can sit heavily in your digestive tract, becoming more of a barricade than a highway.

How to Get Started

You don't need a complete pantry overhaul to see results. Start small with simple substitutes to things you already eat:

  • Add a tablespoon of ground flaxseed to your morning yogurt.
  • Swap white rice for lentils in your soup.
  • Carry a reusable water bottle to ensure you're hydrating throughout the day.

Increasing fiber too quickly can cause digestive upset. Aim to add about 5g of fiber per week until you reach your goal, and always keep your water intake high (at least 64 ounces per day) to match!