It is not exactly dinner table conversation, but the health of your colon has a huge impact on how you feel every day. One common problem is diverticular disease, where tiny pouches in the wall of the large intestine can sit there for years without causing any trouble.
By around age eighty, about seven in ten people in Western countries have these pouches in their colon, although only a minority ever develop serious inflammation. Recent evidence sends a simple message that might surprise you, since nuts and seeds are not the enemy and low-fiber diets are the real issue.
What diverticular disease actually is
Diverticular disease starts with diverticulosis, which means small bulges in the lining of the colon. When one of these pouches becomes inflamed or infected, doctors call it diverticulitis, and that is when symptoms usually appear.
These pouches form where the muscle wall is a little weak and pressure inside the bowel pushes outward over many years.
They often cluster in the last part of the large intestine, and many people only discover them during a colonoscopy or scan done for another reason.
Why fiber and modern diets matter
Fiber works like a natural softener for stool, soaking up water so poop passes more easily. When people eat very little fiber, stool becomes smaller and harder, the colon has to squeeze harder, and that extra pressure is thought to encourage weak spots in the wall to bulge outward into diverticula.
In the United Kingdom, official guidance suggests adults should eat around thirty grams of fiber a day, yet a major government nutrition survey from 2019 to 2023 found that most people fall well short of that target, with ninety six percent of adults and older teens not reaching it and living on low-fiber meals heavy on white bread, fast food, and packaged snacks instead of whole grains, beans, and vegetables instead.
Does this sound familiar when you think about your own dinner plate?
Nuts, seeds, and popcorn are back on the menu
For decades, people with diverticular disease were told to avoid nuts, seeds, popcorn, and even fruit skins, on the theory that small bits of food might get trapped in a pouch and trigger an infection.
Then a landmark study led by physician Lisa Strate, published in the journal JAMA, followed more than 47,000 male health professionals for eighteen years and found that people who ate nuts, corn, or popcorn regularly did not have a higher risk of diverticulitis or bleeding, and in some analyses frequent nut or popcorn eaters had a lower risk.
The United Kingdom’s National Institute for Health and Care Excellence, which writes official advice for theNational Health Service, now tells patients with diverticulosis that there is no need to avoid seeds, nuts, popcorn, or fruit skins unless a clinician gives specific personal reasons.
In practical terms, that means many people with this condition can put these foods back on their plate and focus instead on a high-fiber diet rich in fruits, vegetables, and whole grains.
Symptoms, treatment, and everyday prevention
Diverticular disease can be confusing because many people never feel a thing, while others have nagging discomfort. Typical mild symptoms include a dull ache in the lower left side of the abdomen that may get worse after eating and ease after a bowel movement, along with bloating, constipation, or diarrhea.
Diverticulitis is different and usually more intense, with constant abdominal pain, often on the lower left side, combined with fever, nausea, or a marked change in bowel habits. These signs should prompt urgent medical attention rather than a wait-and-see approach at home, because untreated infection can lead to abscesses or even a tear in the bowel.
The good news is that only a minority of people with diverticulosis ever develop diverticulitis, with recent reviews suggesting a range of about four to fifteen percent. Most uncomplicated attacks respond well to treatment, and habits like eating more fiber, drinking enough water, and staying physically active can lower the risk of flare ups.
The official statistics are available via GOV.UK.
