Category Archives: Nutrition

Super cool and its effects on the microbiome

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A terrific review (ED Rosen. NEJM 2016; 374: 885-7) explains how cool temperature can alter the microbiome and the implications of this finding.

Background: mammals have at least two types of adipose tissue: “the familiar (and all too abundant) white fat that stores calories, and brown adipose tissue that dissipates energy…studies of mice have identified several drivers of the appearance of beige fat cells in white fat pads, a process known as ‘browning.'”

Reviewed study: Chevalier et al. Cell 2015; 163: 1360-74.

“This new work shows that cold exposure, like dietary change, provokes alterations in the gut microbiota of mice.  Moreover, when cold-adapted flora are transferred to a germ-free animal, the recipient mouse loses fat mass and has improved insulin sensitivity…[they] are better able to defend their body temperature on being placed in the cold.”

  • “This new work shows that prolonged cold exposure induces a massive increase in the absorptive surface of the gut…cold causes a profound increase in the ratio of Firmicutes to Bacteroidetes”
  • “A companion article from the same group suggests that antibiotic therapy, which depletes gut microbiota, also induces browning and weight loss.”

My take: In totality, these studies demonstrate how multiple organs (in this case: adipose tissue and the gut) work together to face an environmental challenge.  Furthermore, changes in the gut microbiome may be important for therapeutic advantage in many disease states including obesity, type 2 diabetes, short bowel syndrome, irritable bowel syndrome and many others.  Now, that is cool.

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View from Walnut Street Bridge, Chattanooga

View from Walnut Street Bridge, Chattanooga

Detrimental Effect of Early Parenteral Nutrition in Critically-ill Children

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Ahead of publication: T Fizez et al. Early versus Late Parenteral Nutrition in Critically Ill Children. DOI: 10.1056/NEJMoa1514762

Link to quick take video summary (<2 minutes) : NEJM Quick Take on Parenteral Nutrition in Children

Abstract:

BACKGROUND

Recent trials have questioned the benefit of early parenteral nutrition in adults. The effect of early parenteral nutrition on clinical outcomes in critically ill children is unclear.

METHODS

We conducted a multicenter, randomized, controlled trial involving 1440 critically ill children to investigate whether withholding parenteral nutrition for 1 week (i.e., providing late parenteral nutrition) in the pediatric intensive care unit (ICU) is clinically superior to providing early parenteral nutrition. Fluid loading was similar in the two groups. The two primary end points were new infection acquired during the ICU stay and the adjusted duration of ICU dependency, as assessed by the number of days in the ICU and as time to discharge alive from ICU. For the 723 patients receiving early parenteral nutrition, parenteral nutrition was initiated within 24 hours after ICU admission, whereas for the 717 patients receiving late parenteral nutrition, parenteral nutrition was not provided until the morning of the 8th day in the ICU. In both groups, enteral nutrition was attempted early and intravenous micronutrients were provided.

RESULTS

Although mortality was similar in the two groups, the percentage of patients with a new infection was 10.7% in the group receiving late parenteral nutrition, as compared with 18.5% in the group receiving early parenteral nutrition (adjusted odds ratio, 0.48; 95% confidence interval [CI], 0.35 to 0.66). The mean (±SE) duration of ICU stay was 6.5±0.4 days in the group receiving late parenteral nutrition, as compared with 9.2±0.8 days in the group receiving early parenteral nutrition; there was also a higher likelihood of an earlier live discharge from the ICU at any time in the late-parenteral-nutrition group (adjusted hazard ratio, 1.23; 95% CI, 1.11 to 1.37). Late parenteral nutrition was associated with a shorter duration of mechanical ventilatory support than was early parenteral nutrition (P=0.001), as well as a smaller proportion of patients receiving renal-replacement therapy (P=0.04) and a shorter duration of hospital stay (P=0.001). Late parenteral nutrition was also associated with lower plasma levels of γ-glutamyltransferase and alkaline phosphatase than was early parenteral nutrition (P=0.001 and P=0.04, respectively), as well as higher levels of bilirubin (P=0.004) and C-reactive protein (P=0.006).

CONCLUSIONS

In critically ill children, withholding parenteral nutrition for 1 week in the ICU was clinically superior to providing early parenteral nutrition. (Funded by the Flemish Agency for Innovation through Science and Technology and others; ClinicalTrials.gov number, NCT01536275.)

More details:

Methods:

  • “In both study groups, enteral nutrition was initiated early and was increased in accordance with local guidelines. Both study groups also received intravenous micronutrients (trace elements, minerals, and vitamins) starting from day 2 and continuing until the enteral nutrition provided reached 80% of the caloric targets. Starting from the morning of day 8 in the pediatric ICU, supplementary parenteral nutrition was provided for patients in both groups who were not yet receiving 80% of the caloric target enterally.”
  • 45% of patients were less than 1 year of age

Discussion:

“Late parenteral nutrition resulted in fewer new infections, a shorter duration of dependency on intensive care, and a shorter hospital stay. The clinical superiority of late parenteral nutrition was shown irrespective of diagnosis, severity of illness, risk of malnutrition, or age of the child.”

My take:  The concept of providing early aggressive nutrition is NOT supported by this study; this study shows that early parenteral nutrition may be detrimental in critically-ill children.  This study echoes the results of a similar study in adults: Early versus late parenteral nutrition in critically ill adults

Springtime in my neighborhood

Springtime in my neighborhood

What happens with 98,500 IU/day of Vitamin A

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An interesting case report (LA Beste et al. NEJM 2016; 374: 73-8) reviews the presentation of a previously healthy 54 year old with ascites.  He initially indicated that he was taking 100 IU per day of vitamin A (his current dose), but later on directed questioning admitted that he had averaged 98,500 IU/day for prior 6 months.

The clinical-problem solving case reviews useful pointers about portal hypertension and in particularly noncirrhotic portal hypertension.  Vitamin A is a rare cause of noncirrhotic portal hypertension.

Other causes of noncirrhotic portal hypertension:

  • Prehepatic level: portal vein or splenic vein thrombosis, splanchnic arteriovenous malformation
  • Intrahepatic level: hepatic vasculitis, HIV infection, infiltrative disease, and medications
  • Posthepatic: Budd-Chiari syndrome, IVC obstruction, restrictive cardiac disease.
  • Worldwide, schistosomiasis is the most common reason.
  • When other causes have been excluded, idiopathic noncirrhotic portal hypertension may be diagnosed, “especially in patients with chronic infection, thrombophilia, and immunologic conditions such as SLE.”  In one series of 69 patients, the diagnosis of idiopathic noncirrhotic portal hypertension was delayed for more than a year in 25% of cases and 7% received an erroneous diagnosis of cryptogenic cirrhosis.

Other points:

  • When ascites is due to cirrhosis, other signs of liver disease are typically present, including jaundice and laboratory findings (low albumin, coagulopathy, hyperbilirubinemia) as well as absence of cirrhosis on biopsy.
  • Serum retinol levels poorly reflect total body stores of vitamin A (& was normal in this patient)
  • Vitamin A supplementation in appropriate doses can prevent blindness in areas where food stores are not secure.  But, consuming excessive doses can lead to being a case report.

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Mural, Old town San Juan

Mural, Old town San Juan

Excess Childhood Salt Intake Associated with Obesity

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A recent study (C Grimes et al. 24-h urinary sodium excretion is associated with obesity in a cross-sectional sample of Australian schoolchildren  British Journal of Nutrition  Volume  115 / Issue 06 / March 2016, pp 1071 – 1079) was summarized at AJP.com.au: Childhood salt intake linked to obesity.

An excerpt:

The study also found that in both four-to-seven-year olds and eight-to-12-year-olds, the prevalence of abdominal obesity was also higher in children with a higher intake of salt.

The recent findings published in the British Journal of Nutrition came from the SONIC (Salt and Other Nutrient Intakes in Children) study that measured salt intake in 666 primary schoolchildren aged four to 12 years….

“We found that 70% of Australian children are eating over the maximum amount of salt recommended for good health.

“In this study children were eating on average six grams of salt a day, which is over a teaspoon, and they should be aiming to eat about 4-5 grams a day.

”For every additional gram of salt children ate this was associated with a 23% greater likelihood of being overweight or obese. Such high intakes of salt are setting children up for a lifetime risk of future chronic disease such as high blood pressure and heart disease”

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Why GMO labels are a bad idea

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I was pleased to see the March 11 USAToday editorial: Our view: GMO Labels Feed Unwarranted Fears

Excerpt:

“Mandatory labeling …on balance it’s a bad idea. A key reason is that it validates the notion that genetically modified organisms (GMOs) are dangerous, which is simply not true.  Using science to make crops more resistance to drought or insects builds on the ancient practice of selectively breeding plants…Doing this in a lab at the genetic level makes it faster, more precise, and more effective.  But…harder for nonscientists to grasp…the European Union found that GMOs ‘are not per se more risky than…conventional plant breeding.’…75% to 80% of foods contain them.”

“The risk from mandatory labeling is the same as any action that ignores science and plays to unfounded fear.”

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Walnut Street Bridge

Walnut Street Bridge

Feeding Aversions -A Personal Journey

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A terrific article in NY Times Magazine explains the difficulties of feeding aversions and describes some of the approaches, including feeding tubes and behavior feeding programs.

Link: When Your Baby Won’t Eat

For families struggling with feeding problems and for feeding programs, this article is well worth the read.

By the Chattahoochee

By the Chattahoochee

“Supplements and Safety”

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There is a Frontline report (initially aired Jan 19th) on supplements.  A preview is available from the NY Times.

“Supplements and Safety” –link includes a 5 minute video on fish oil. Here’s an excerpt:

The Frontline documentary investigates large outbreaks of disease tied to tainted vitamins and fat-burning supplements, including one case in which a workout supplement was linked to more than 70 cases of liver damage. The company whose products were at the center of that outbreak, USPlabs, is among 117 companies and individuals that the Justice Department filed criminal and civil enforcement actions against last year…

Despite their popularity, some studies have found that roughly three-quarters of fish oil supplements on the market do not contain the amount of omega-3 fatty acids advertised on their labels. Some have also found that fish oil supplements are prone to becoming rancid.

Fish oil supplements are widely marketed as beneficial to cardiovascular health. But the film points out that such claims are debatable at best. A majority of clinical trials have found no evidence that they protect against heart disease, according to a study published in JAMA Internal Medicine in 2014.

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Mural in Old San Juan

Mural in Old San Juan

Systematic Review of Gluten Introduction

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A recent systematic review/meta-analysis (MI Pinto-Sanchez et al. J Pediatr 2016; 168: 132-43) identified 15 eligible studies among an initial search of 1982 studies.

Key findings:

  • There was a 25% increase in celiac disease risk with late (>6 months) vs recommended (4-6 months) gluten introduction.
  • There was no significant effect of breastfeeding or not breastfeeding.

The authors state there is no evidence on whether early introduction (<4 months) of gluten would affect the risk of celiac disease.  Late introduction (>6 months) is associated with increase risk of celiac disease.

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Isla Verde, San Juan

Isla Verde, San Juan

What We Should Not Worry About

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A few useful studies provide reassurances regarding exposures in the prenatal period and perinatal period that we should NOT worry about.

CN Bernstein et al. Clin Gastroenterol Hepatol 2016; 14: 50-7.

In this study with 1671 individuals with inflammatory bowel disease and 10,488 controls, “people with IBD were not more likely to have been born by cesarean section than controls or siblings without IBD.  These findings indicate that events of the immediate postpartum period that shape the developing intestinal microbiome do not affect risk for IBD.”

J Julvez et al. Am. J. Epidemiol. (2016) Full Text Link: doi: 10.1093/aje/kwv195. First published online: January 5, 2016 (thanks to Mike Hart for this reference)

For parents of autistic kids who avoid fish, this article provides information indicating that this is counter-productive.  ” Seafood consumption during pregnancy is thought to be beneficial for child neuropsychological development, but to our knowledge no large cohort studies with high fatty fish consumption have analyzed the association by seafood subtype.” The authors “evaluated 1,892 and 1,589 mother-child pairs at the ages of 14 months and 5 years, respectively, in a population-based Spanish birth cohort established during 2004–2008…” Key finding: “Consumption of large fatty fish during pregnancy presents moderate child neuropsychological benefits, including improvements in cognitive functioning and some protection from autism-spectrum traits.”

My take: We often worry about the wrong things.  These articles provide reassurance that mode of birth and consumption of seafood during pregnancy are things we should not worry about.

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Sleep Duration and Subsequent Obesity

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A provocative study from Brazil (CSE Halal et al. J Pediatr 2016; 168: 99-103) examined a cohort of 4231 infants and assessed sleep duration from 1-4 years of age.

Findings:

  • 10.1% of cohort had short sleep duration at any follow-up
  • At 4 years of age, 201 children (5.3%) were obese and 302 (8%) were overweight
  • Prevalence ratio for obesity/overweight was 1.32 among those who were ‘short-sleepers’

This study introduction notes that studies in adults have suggested an association between poor sleep and weight gain, “possibly through elevation of cortisol and gherlin levels, along with reduction in leptin levels, thereby leading to increased hunger and reduced energy expenditure.”

Normal sleep patterns: for infants 12-15 hours/day, & for toddlers 11-14 hours/day.  At night, average expected sleep is 12 hours at 1 year of age and 11 hours at 4 years of age.

My take: Looking at early sleep patterns helps reduce the likelihood of reverse causation.  This study and others shows an association with less sleep and increased likelihood of weight gain.  Why???

In same issue (AI Wijtzes et al. J Pediatr 2016; 168: 118-25) report that breakfast skipping at age 4 years is associated (ß =1.38) with a higher percent fat mass at age 6 years, though no associations were found with BMI or weight status.  This study involved prospectively collected data from 5914 children in the “Generation R Study” in The Netherlands.

Briefly noted: JA Emond et al. J Pediatr 2016; 168: 158-63. “Greater child commercial TV viewing was significantly associated with more frequent family visits to those fast food restaurants …toy collecting partially mediated that positive association.” This study involved 100 parents with children aged 3-7 in a rural community.

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This graphic identifies commercial entities influencing food choices

This graphic identifies commercial entities influencing food choices