Category Archives: Nutrition

Holes in the fiber theory

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Since the 1970s, it has been accepted that diverticular disease is related to low fiber intake and the Western diet.  Problem is that this might not be right (Gastroenterology 2012; 142: 205-10).  In this observational cross-sectional study (n=2104), low dietary fiber was not associated with diverticulosis; just the opposite.  High fiber intake, after adjusting for other factors, had an adjusted prevalence ratio of 1.3.  Due to the nature of the study, there may be potential bias that would not be present with a prospective study, especially with regard to dietary recall.  An editorial in the same issue (pg 205-07) lists three other studies; two of these also could not demonstrate a protective effect of fiber.  In addition to these findings, this study did not find an association between fat, red meat, physical activity and diverticulosis.

Although these data throw a big question mark regarding the pathogenesis of diverticular disease, this does not mean you should throw away your fiber bars quite yet.  Although low fiber may not cause diverticular disease, several large prospective studies have been completed which convincing show an association with lower complications/hospitalizations among individuals with higher fiber intake.  In addition, increased fiber in the diet has been shown to lower cardiovascular complications.

Additional references:

  • -Br Med J 1971; 2: 450-54.  Seminal article on diverticular disease and association with Western countries with low fiber intake.
  • -Am J Clin Nutr 1994; 60: 757-64.  Prospective study showing benefits of fiber in preventing diverticular complications (n=47,888); RR=0.58 for developing symptomatic diverticulitis.
  • -BMJ 2011; 343: d4131.  EPIC study, n=47,033, showing benefit of fiber in reducing hospitalizations due to diverticular dz over 12yrs (0.59 RR)
  • -NEJM 1999; 340: 169. fiber does not decrease Colon Ca risk.
  • -NEJM 2000; 342: 1149 & 1159. fiber does not decrease risk of recurrent adenomas.
  • -Am J Clin Nutr 2000; 70: 1433-1438. Fiber lowers cholesterol & can decrease risk of heart attack by 15%.

More evidence that breastfeeding improves cognitive development

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A large cohort study from the United Kingdom with 11,101 term infants and 778 preterm infants shows improved cognitive development when infants are breastfed.  J Pediatr 2012; 160: 25-32.  There have been a number of previous studies as well that have shown that breastfed children have an IQ that is ~5 points higher than nonbreastfed children; however, when adjustment for confounders, especially maternal education, this effect is weaker.  Since this is an observation study (randomized blinded study would be impossible), it is difficult to control for all variables.  Nevertheless, prolonged breastfeeding, more than 2 months in preterm and more than 4 months in term infants, is associated with higher cognitive development.

Additional references:

  • Am J Clin Nutr 199; 70: 525-35.
  • BMJ 2006;  333: 945.
  • Arch Gen Psychiatry 2008; 65: 578-84.
  • Paediatr Perinat Epidemiol 2003; 17: 81-90.

Other refences:

  • J Pediatr 2009; 155: 421.  Breastfeeding may have possible protective effect from developing inflammatory bowel disease.  Review of multiple studies.
  • J Pediatr 2002; 141: 764.  Breastfeeding may protect against obesity.
  • BMJ 2007; 335: 815-20.  Longer time of breastfeeding does not reduce allergy/asthma. n=17,046 pairs of mother-infant (13,889 followed up at age 6.5yrs)