Adopting and maintaining a healthy lifestyle could prevent up to 60% of inflammatory bowel disease (IBD) cases, making it a feasible option for future preventive strategies, according to US researchers.
The findings, published in the journal Gut, are based on analysis of two large studies looking at the health of thousands of nurses and other health professionals.
“We confirm that a substantial proportion of the risk of Crohn’s disease and ulcerative colitis can be prevented by modifying lifestyle risk factors”
Study authors
Diagnoses of IBD, which includes Crohn’s disease and ulcerative colitis, have been increasing worldwide, the study authors noted, and the condition currently affects about 1.3 million adults in Europe.
Previous research has linked IBD risk to various lifestyle factors, they said, but it was unclear whether adopting and maintaining a healthy lifestyle might reduce the risk of developing it in the first place.
To investigate further, they analyzed data from participants from the Nurses’ Health Study, the Nurses’ Health Study II, and the Health Professionals Follow-up Study.
The Nurses’ Health Study enrolled 121,700 nurses, ages 30-55, from 11 US states in 1976, while the Nurses’ Health Study II supervised 116,429, ages 25-55. Age 42, from 15 states in 1989.
Meanwhile, the Health Professionals Follow-up Study included 51,529 male physicians, ages 40 to 75, from across the US in 1986.
The researchers created modifiable risk scores (MRS) for each participant based on established modifiable risk factors for IBD, to estimate the proportion of cases that could have been prevented.
Risk factors included body mass index (BMI); of smoking; non-steroidal anti-inflammatory drugs; physical activity; and the daily intake of fruit, fiber, vegetables, polyunsaturated fatty acids and red meat.
The researchers then calculated the proportion of preventable cases if an overall healthy lifestyle was adopted and maintained.
A healthy lifestyle included a BMI between 18.5 and 25, never smoking, and a maximum of one alcoholic drink per day for women or two for men.
In addition, it included at least eight daily servings of fruits and vegetables, less than half a serving of red meat, at least 25 g of fiber per day, two weekly servings of fish, and half a daily serving of nuts or seeds.
During the follow-up period of the three trials, 346 cases of Crohn’s disease and 456 cases of ulcerative colitis were reported.
“Lifestyle modification may be an attractive target for future IBD prevention strategies”
Study authors
Based on the MRS scores, the researchers estimated that a low MRS could have prevented 43% and 44.5%, respectively, of Crohn’s disease and ulcerative colitis cases.
Similarly, maintaining a healthy lifestyle could have prevented 61% of Crohn’s disease cases and 42% of ulcerative colitis cases.
The researchers then applied their scoring systems to data from three large European studies to validate their findings.
This suggested that a low MRS and maintenance of a healthy lifestyle could have prevented, respectively, 44-51% and 49-60.5% of Crohn’s cases, and 21-28% and 47%-56.5% of ulcerative colitis cases.
The study authors said: “In six cohorts from the US and Europe, we confirmed that a substantial proportion of the risk of Crohn’s disease and ulcerative colitis can be prevented by lifestyle risk factor modification or adherence to a healthy lifestyle.
“Further prospective intervention studies are needed to determine if lifestyle modification is effective for the primary prevention of IBD, particularly in a population at high risk and younger onset disease,” they said.
However, the researchers acknowledged that their study was observational and therefore could not establish causes.
“A key assumption of our findings is that the relationship between lifestyle factors and the development of IBD is causal,” they said.
“Although this has not yet been established, several lines of evidence support a critical role for environmental and lifestyle factors in the development of IBD,” they stated.
“Lifestyle modification may be an attractive target for future IBD prevention strategies,” the researchers from Massachusetts General Hospital in Boston added.
“This may be of particular relevance to high-risk groups, such as first-degree relatives of IBD patients, who have an estimated 2% to 17% lifetime risk of developing the disease.”
Source: news.google.com