Diverticulosis is common and affects us as we age. Thirty-five percent of 50-year-olds in the U.S. are affected and, for those over the age of 60, approximately 58 percent are affected. Many will never experience symptoms.
Diverticular disease is a weakening of the lumen, or wall of the colon, resulting in the formation of pouches or out-pocketing referred to as diverticula. Diverticula may be attributable to pressure from constipation. Its mildest form, diverticulosis may be asymptomatic.
Symptoms can include fever and abdominal pain, predominantly in the left lower quadrant in Western countries, or the right lower quadrant in Asian countries. It may need to be treated with antibiotics.
Diverticulitis affects 10 to 25 percent of those with diverticulosis. Diverticulitis is inflammation and infection, which may lead to a perforation of the bowel wall.
If a rupture occurs, emergency surgery may be required. As of 2010, about 200,000 are hospitalized for acute diverticulitis each year, and roughly 70,000 are hospitalized for diverticular bleeding.
How do you prevent diverticular disease and its complications? There are modifiable risk factors, including fiber intake, weight and physical activity.
In terms of fiber, a prospective study published in the British Medical Journal extolled the value of fiber in reducing diverticular disease risk. It showed a 31 percent risk reduction among those who were vegetarian. This was part of the EPIC trial, involving over 47,000 people living in Scotland and England.
More intriguing, participants who had the highest fiber intake saw a 41 percent reduction in diverticular disease. Those participants in the highest fiber group consumed over 25.5 grams per day for women and over 26.1 grams per day for men, whereas those in the lowest group consumed less than 14 grams per day.
Though the difference in fiber between the two groups was small, risk reduction was substantial.
Another study, which analyzed data from the Million Women Study, a large-scale, population-based, prospective UK study of middle-aged women, confirmed the correlation between fiber intake and diverticular disease and further analyzed the impact of different sources of fiber.
The authors’ findings were that reduction in the risk of diverticular disease was greatest with high intake of cereal and fruit fiber.
Most Americans get about 16 grams of fiber per day. The Institute of Medicine recommends daily fiber intake for those over 50 years old of 25-26 grams for women and 31-38 grams for men. Interestingly, their recommendations are lower for those over 50 years old.
Can you imagine what the effect is when people consume at least 40 grams of fiber per day? This is what I recommend for my patients. Some foods that contain the most fiber include nuts, seeds, beans and legumes. In a 2009 study, men who consumed the most nuts and popcorn saw a protective effect from diverticulitis.
Obesity puts patients at a much higher risk of complications. In the large, prospective male Health Professionals Follow-up Study, body mass index played a significant role, as did waist circumference.
Those who were obese had a 78 percent increased risk of diverticulitis and a greater than threefold increased risk of a diverticular bleed compared to those who had a BMI in the normal range.
Those whose waist circumference was in the highest group had a 56 percent increased risk of diverticulitis and a 96 percent increased risk of diverticular bleed.
Physical activity is also important for reducing diverticular disease risk, although the exact mechanism is not yet understood. In a large prospective study, those with the greatest amount of exercise were 37 percent less likely to have diverticular disease compared to those with the least amount.
Jogging and running showed the most benefit. When the authors combined exercise with fiber intake, there was a dramatic 256 percent reduction in disease risk.
Thus, preventing diverticular disease is based mostly on lifestyle modifications through diet and exercise.