Say, "NUTS" to Diverticulosis by Robert Fusco, MD

What is diverticulosis?
Diverticulosis is a condition, rather than a disease. It affects the large intestine, or colon. The inner wall of a normal colon is strong and the inner surface is relatively smooth. A colon affected by diverticulosis has weak spots in the wall that bulge outward - much like a hollow bubble forming on a worn inner tube. The openings of these out-pouches, or "pockets" can readily be seen during a colonoscopy exam.

A single pocket is called a diverticula and the presence of these pockets on the colon is termed diverticulosis. When these pouches are inflamed or infected, it is called diverticulitis. When diverticula begin to hemorrhage, that is not an infection, but rather simply, bleeding diverticulosis.

Who gets diverticulosis?
Diverticulosis is a common condition affecting both men and women. Since diverticulosis takes so long to develop, it usually appears later in life. It affects over 50 percent of those over age 60. Occasionally it occurs in much younger individuals where it is usually a more aggressive problem.

Avoiding seeds, nuts, corn...
Even before I entered medical school in 1969, doctors have been advising their patients with diverticulosis to change their diet in two ways:

1. Consume more dietary fiber
   
2. Avoid foods with seeds, nuts, corn, and popcorn
   

Doctors have known for years that there was reasonably good evidence to support the first recommendation. Population studies have shown that a high fiber diet is helpful.

However, doctors have also known that no scientific studies had been done to actually prove that avoiding seeds, nuts, and corn was helpful. This suggestion was based on the supposed notion that foods containing seeds, nuts, or popcorn could become lodged in the hollow pockets in the colon and cause an irritation. This irritation might lead to a full-blown case of infection, or diverticulitis. It was just good "common sense" and for decades millions of patients with diverticulosis have been told to avoid these foods. In the past 30 years, I have given that advice to many.

Turning that diet upside down
Well, finally, someone has taken the time and effort to set the record straight and this new research has turned this advice upside down. Since 1986, medical researchers at the University of Washington and Harvard Medical School have been studying the diet and health of over 47,000 professional men. After over two decades of follow-up, they reported their findings at Digestive Disease Week, an annual international conference of gastroenterologists that I recently attended. Surprisingly, their research found that men who frequently ate popcorn, corn, seeds, or nuts had a 28% DECREASE in the risk of diverticulitis and bleeding diverticulosis compared to those who avoided these foods. This is exactly the opposite of what was expected.

Eat more fiber
I believe this advice is still sound. Most health experts agree that the lack of fiber and bulk in the diet is the major cause of chronic constipation and diverticular disease in this country. As our foods are becoming more highly refined, more of us are suffering from symptoms of diverticular disease. Once diverticula have formed there is no way to reverse the process. The pouches are there for the rest of your life.

Chances are you are not getting enough fiber in your diet. In fact, most people in the United States average only 10 to 15 grams of dietary fiber a day. Most dietitians, however, use 25 - 35 grams of fiber a day as the minimum benchmark for a high-fiber diet.

Adding fiber and bulk to your diet helps promote regular bowel function and is very important in controlling and minimizing this disease. Foods rich in fiber, such as bran cereals, whole wheat breads, a variety of beans, and fresh fruits and vegetables help keep the stools soft and bulky. We all should make an effort to include more fiber, or roughage, in our diet. But, don't be too enthusiastic. That is, do not add too much fiber too soon. Otherwise, troublesome side effects, such as increased gas and bloating, may occur. The golden rule regarding fiber is to go slow. Start with small amounts and gradually increase the extra fiber in your diet.

If you have diverticulosis ... what about nuts?
So, unexpectedly, this long-term Harvard research study has shown that frequent popcorn, corn, seed, and nut consumption actually reduces the risk of diverticulitis or bleeding. If you have diverticulosis and have been religiously avoiding eating tomatoes, cucumbers, corn, nuts, popcorn and similar foods, you should feel liberated - but don't go crazy. You might consider slowly adding some of these foods back into your diet. I don't suggest making any major changes too quickly, but the truth is that there is no longer any scientific evidence to avoid any of these foods. In fact, we now have good evidence to suggest that eating more of these foods may be helpful. If you have any questions, ask your doctor.

What Diverticulosis Looks Like
This is an example of what the doctor sees during a colonoscopy exam. The colon was thoroughly cleaned out with a special laxative solution the night before. In this patient, you see a normal healthy lining. The walls are smooth and delicate blood vessels can be seen within.	This patient's colon has extensive "pockets" which are readily visible along the wall of the colon. They are hollow and protrude outside the colon. Here you see the inner openings of many of these pockets. Since there is no bleeding or inflammation, this is a case of simple diverticulosis, not diverticulitis.