This Type Of Fiber Does Something Unexpected Once It Reaches Your Gut
Could the fiber in your beans, oats, and potatoes have a connection to brain health in people with diabetes?
Researchers are exploring how resistant starch, a type of fiber that passes through the small intestine undigested, interacts with gut bacteria. When those bacteria break it down, they produce compounds that may help regulate inflammation and other processes linked to brain function.
A new mini review1 looks at whether this process could help explain the link between gut health and diabetes-related changes in memory and thinking.
About the review
The researchers pulled together existing human studies, feeding trials, and animal and cell research to explore how resistant starch might affect diabetes-related cognitive dysfunction (DACD).
This refers to changes in memory, focus, decision-making, and processing speed that can happen in people with diabetes. Blood sugar fluctuations, inflammation, and changes in blood flow to the brain may all play a role.
How resistant starch could influence brain health
Your small intestine doesn't fully break down resistant starch, which sets it apart from other types of starch.
Instead, it travels to your colon, where gut bacteria use it as food.
As those bacteria break down resistant starch, they produce substances called short-chain fatty acids. These compounds help support gut health and may also affect other parts of the body.
The review focuses on three:
- Acetate: Helps support other beneficial gut bacteria.
- Propionate: Plays a role in how your body manages metabolism and blood sugar.
- Butyrate: Provides fuel for the cells lining your colon and helps keep inflammation in check.
So, what does any of this have to do with your brain? Researchers think these compounds may help regulate inflammation and support communication between the gut and brain.
Previous research has also found links between changes in gut bacteria, short-chain fatty acid levels, and cognitive difficulties in people with diabetes.
Not all resistant starch works the same way. The type of food it comes from and how that food is prepared can affect how easily gut bacteria break it down, which influences how much of these compounds they produce.
RELATED READ: Follow This Guide To Get 30+ Grams Of Fiber Daily
Why more research is needed
Before we get too excited about the brain health connection, there's an important caveat.
Much of the evidence comes from animal and cell studies, which can't tell us whether eating resistant starch actually improves memory or protects against cognitive decline in people with diabetes.
Human studies have linked gut bacteria and short-chain fatty acids with cognitive health, but they haven't proven that resistant starch directly improves brain function. The review authors say more human trials are needed to test the idea.
How to get more resistant starch in your diet
Even if its brain benefits are still being investigated, resistant starch has other reasons to earn a place on your plate. It feeds beneficial gut bacteria and may help keep post-meal blood sugar more stable.
Some everyday sources include:
- Beans and lentils: Provide resistant starch, protein, and other types of fiber.
- Oats: Offer resistant starch alongside soluble fiber.
- Cooked-and-cooled potatoes: Cooling cooked potatoes increases their resistant starch content. Try them cold in a salad or reheated after cooling.
If you have diabetes, these foods can fit into a balanced eating pattern, but portion sizes and individual blood sugar responses still matter. And, of course, resistant starch isn't a replacement for prescribed medication or professional diabetes care.
The takeaway
Your gut bacteria have quite a job, and breaking down fiber is just one part of it. Resistant starch helps feed these microbes, which produce compounds researchers are now investigating for their possible brain health benefits.
For now, enjoy the beans, oats, and potatoes for what we already know they offer, while science catches up on the rest.