What Your Poop Can Tell You About Your Risk Of Alzheimer's

Constipation can be frustrating, not to mention pretty uncomfortable. Lack of fiber in your diet, not enough exercise, dehydration, certain medications, and issues with your intestinal functions are some of the reasons you could be constipated. You're also more likely to be constipated as you get older, according to Johns Hopkins Medicine.

Although being occasionally constipated is common, chronic constipation occurs when you don't have regular bowel movements for several weeks. Chronic constipation can result in complications such as swollen veins or torn skin in your anus or stool that gets stuck in your intestines (via Mayo Clinic). Researchers are also looking into how chronic constipation might influence your cognitive health as you age. A 2023 preliminary study presented at the Alzheimer's Association International Conference found that people who had infrequent bowel movements were more likely to experience cognitive decline. The researchers believe this connection between chronic constipation and cognitive health might have something to do with the balance of bacteria in your gut.

The study tracked more than 110,000 people over several years, asking them about the frequency of their bowel movements and whether they had complaints about their cognition. The researchers also used psychological tests to objectively measure cognitive decline and DNA sequencing to test the health of the bacteria in their gut. The results showed that people who had less frequent bowel movements (one every three or more days) had the cognitive age of people three years older. Those with infrequent bowel movements were also more likely to report problems with their memory and thinking over time.

The study also found that the types of bacteria living in their gut were related to bowel movement frequency and cognitive function. People with less frequent bowel movements not only had a decline in cognitive function, but they also had fewer bacteria that produce butyrate, which is good for the gut and brain health. However, those who had more frequent bowel movements (more than twice a day) had more of certain bacteria that can cause inflammation in the gut.

"Our body systems are all interconnected," said Heather M. Snyder, Ph.D., Alzheimer's Association vice president of medical and scientific relations, in a press release. "When one system is malfunctioning, it impacts other systems. When that dysfunction isn't addressed, it can create a waterfall of consequences for the rest of the body."

When you poop, your body is eliminating waste and other substances that could be harmful to your body. If you're not regular, your body could respond with inflammation, hormonal imbalances, and mental health problems. Your gut is often called the "second brain" because it helps regulate digestion, immunity, and mood. Having regular bowel movements is a good indicator of a balanced gut microbiome. Your gut might also be linked to your brain health.

Another 2023 study presented at the Alzheimer's Association International Conference used stool samples and brain scans from 140 middle-aged people to see if there was a link between gut bacteria and the presence of certain proteins associated with Alzheimer's disease. The study found that people with more of these proteins had fewer Butyricicoccus and Ruminococcus bacteria in their gut. Butyricicoccus and Ruminococcus are bacteria that produce butyrate, which is believed to have protective effects on the brain. The people with more of these brain proteins associated with Alzheimer's also had more of the Cytophaga and Alistipes bacteria.

An occasional bout of constipation might go away after a day or two, but chronic issues with your digestive health could lead to problems with your body absorbing the nutrients it needs. Sugar, processed foods, and alcohol can wreck the balance of bacteria in your gut, causing symptoms such as brain fog and irritability.

It's the good bacteria that produce the brain-protective butyrate after they feed on the soluble, fermentable fibers in your diet. You'll find these fermentable fibers in fruits, vegetables, legumes, and whole grains (via Cleveland Clinic). Resistant starches, which can be found in overnight oats, cooked and then cooled rice, and green bananas, will also feed the good bacteria in your gut to produce more butyrate (via Healthline).

It's a good idea to be aware of the frequency of your bowel movements to signal the health of your gut. "You know what your normal bowel function is. If you're outside of it, your body will tell you what it's lacking or what you have too much of," dietitian Sheila Vo tells MD Anderson Cancer Center.