I found this and wondered is those of living LC are at risk, or does the 2 salads a day reduce diverticulosis?


https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3174080/

Abstract
Diverticular disease of the colon is among the most prevalent conditions in western society and is among the leading reasons for outpatient visits and causes of hospitalization. While previously considered to be a disease primarily affecting the elderly, there is increasing incidence among individuals younger than 40 years of age. Diverticular disease most frequently presents as uncomplicated diverticulitis, and the cornerstone of management is antibiotic therapy and bowel rest. Segmental colitis associated with diverticula shares common histopathological features with inflammatory bowel disease and may benefit from treatment with 5-aminosalicylates. Surgical management may be required for patients with recurrent diverticulitis or one of its complications including peridiverticular abscess, perforation, fistulizing disease, and strictures and/or obstruction.

EPIDEMIOLOGY
The incidence of diverticular disease has increased over the past century (2,5,6). Autopsy studies from the early part of the 20th century reported colonic diverticula rates of 2% to 10% (6). This has increased dramatically over the years. More recent data (5) suggest that up to 50% of individuals older than 60 years of age have colonic diverticula, with 10% to 25% developing complications such as diverticulitis. Hospitalizations for diverticular disease have also been on the rise. According to an American study evaluating hospitalization rates between 1998 and 2005 (2), rates of admission for diverticular disease increased by 26% during the eight-year study period. Similar trends have been observed in Canadian and European data over the same time period (5,7).

Diverticular disease has traditionally been believed to be a disease affecting the elderly (8). The prevalence of diverticular disease is as high as 65% by 85 years of age and estimated to be as low as 5% in those 40 years of age or younger (8). However, more recent literature has reported an increase in the incidence of diverticular disease among younger patients. For example, a large review of the Nationwide Inpatient Sample (NIS) of 267,000 admissions for acute diverticulitis between 1998 and 2005 (2) showed that the average age of patients decreased over the study period from 64.6 to 61.8 years. Incidence rates increased most dramatically among groups 18 to 44, and 45 to 64 years of age (incidence per 1000 population: 0.151 to 0.251, and 0.659 to 0.777, respectively). In contrast, incidence remained stable over the study period in persons between 65 and 74 years of age, and actually decreased in persons 75 years of age or older. Moreover, a very high incidence of diverticular disease in young patients was reported in a review of 238 patients admitted with diverticulitis to the surgical service at the Medical Center Hospital in San Antonio, Texas (USA) between 1981 and 1990 (9). In this review, 26% of patients were 40 years of age or younger. These patients had a more aggressive form of disease, requiring more surgical intervention than older patients, and they exhibited a five-fold increase in the risk of complications, such as fistula, compared with their older counterparts. Given the presumption of the low incidence of diverticular disease in young patients, nearly one-half of these patients were often misdiagnosed at presentation – most commonly with appendicitis.

Diverticular disease has long been regarded as a disease of western countries. The highest prevalence of this condition is in the United States, Europe and Australia, where approximately 50% of the population 60 years of age and older have diverticulosis (5,6). This common occurrence is in contrast to that in the developing world, where countries in Africa and Asia have prevalence rates of less than 0.5% (6,11,12). The western diet, particularly its deficiency in dietary fibre, has long been implicated as a causative factor for these geographical variations (6,13–16). This hypothesis was supported by a study that compared stool weight and transit time in 1200 individuals in the United Kingdom and rural Uganda (13). The United Kingdom subjects, who were shown to have lower fibre intake, had a transit time of 80 h and a mean stool weight of 110 g/day. This was significantly lower than in the Ugandan subjects, who had much shorter transit times (34 h) and greater mean stool weights (450 g/day). The prolonged transit time and small stool volumes were believed to predispose to diverticular disease by increasing intraluminal pressure. Moreover, there is growing evidence that the rates of symptomatic diverticular disease are on the rise because areas in the developing world are becoming increasingly westernized (14,15). For example, the rates of diverticular disease have increased among urban black populations of South Africa compared with rural black populations in the same country (14). The role of dietary fibre deficiency as a contributor to diverticular disease was further supported by a large prospective cohort study of more than 47,000 men who were followed over a four-year period (16). Dietary fibre intake was found to be inversely associated with the risk of developing diverticular disease, with an RR of 0.58 (95% CI 0.41 to 0.83; P=0.01).

In addition to the geographical variability in the prevalence of diverticular disease, there is significant variability in the location of diverticula within the colon in different regions of the world. In western countries, it has been well described that diverticulosis is primarily left sided, particularly involving the sigmoid colon (2,6–8). This is in contrast to findings in Asia, where right-sided diverticulosis dominates (17–19). In a review of 615 cases of diverticulosis detected on double-contrast barium enema examinations between 1975 and 1982 in Tokyo, Japan (17), 70% were right sided. Similar diverticular distribution has been shown in Hong Kong and Singapore (18,19). The reason for these differences remains unclear. Early hypotheses suggested that left-sided diverticula were acquired, whereas right-sided diverticula were more likely to be true diverticula and, thus, congenital (20,21). However, subsequent studies have shown that, similar to left-sided diverticula, the majority of right-sided diverticula are ‘false’ and are likely acquired (18,22). In fact, as Asian populations have begun to adopt a more westernized diet, the rates of diverticular disease have been shown to increase to the same extent noted in the west (17). This increase in diverticular disease, however, remains predominantly right sided. Factors other than deficiencies in dietary fibre are likely to play a role in the development of right-sided diverticulosis as demonstrated by studies that show that even with a high-fibre diet, the rates of right-sided disease are high. For example, a study from China (23) reported a diverticulosis rate of 62% in patients with high-fibre intake (greater than 14 g/day). More research is needed in this area to better identify potential causative factors.


In addition to the geographical variability in the prevalence of diverticular disease, there is significant variability in the location of diverticula within the colon in different regions of the world. In western countries, it has been well described that diverticulosis is primarily left sided, particularly involving the sigmoid colon (2,6–8). This is in contrast to findings in Asia, where right-sided diverticulosis dominates (17–19). In a review of 615 cases of diverticulosis detected on double-contrast barium enema examinations between 1975 and 1982 in Tokyo, Japan (17), 70% were right sided. Similar diverticular distribution has been shown in Hong Kong and Singapore (18,19). The reason for these differences remains unclear. Early hypotheses suggested that left-sided diverticula were acquired, whereas right-sided diverticula were more likely to be true diverticula and, thus, congenital (20,21). However, subsequent studies have shown that, similar to left-sided diverticula, the majority of right-sided diverticula are ‘false’ and are likely acquired (18,22). In fact, as Asian populations have begun to adopt a more westernized diet, the rates of diverticular disease have been shown to increase to the same extent noted in the west (17). This increase in diverticular disease, however, remains predominantly right sided. Factors other than deficiencies in dietary fibre are likely to play a role in the development of right-sided diverticulosis as demonstrated by studies that show that even with a high-fibre diet, the rates of right-sided disease are high. For example, a study from China (23) reported a diverticulosis rate of 62% in patients with high-fibre intake (greater than 14 g/day). More research is needed in this area to better identify potential causative factors.