Category Archives: Nutrition

Fresh Fruit Study

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A study from China has shown benefits associated with increased fresh fruit intake (H Du et al. NEJM; 2016; 374: 1332-43). Abstract Link: Fresh Fruit Consumption and Major Cardiovascular Disease in China

Study methods: 512,891 adults recruited from 2004-2008.  Prospective cohort.

Results: 18% of participants consumed fresh fruit daily.  This group had lower systolic blood pressure (by 4 mm Hg), lower glucose (by 0.5 mmol/L) (both with P<0.001).  The adjusted hazard ratio for cardiovascular death was 0.6 (CI 0.54-0.67), 0.66 for major coronary event, 0.75 for ischemic stroke, and 0.64 for hemorrhagic stroke.

Limitation: Fruit consumption was correlated with socioeconomic status and this may have affected findings even after adjustment due to residual confounding.

My take: While fruit consumption has not been proven to cause better health, daily fruit consumption is associated with better outcomes.

Related blog post: Eat your veggies…if you don’t want to get sick | gutsandgrowth

Savings with veggies

 

Goldilocks and Gluten

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A recent study (CA Aronsson et al. Clin Gastroenterol Hepatol 2016; 14: 403-09, editorial 410-12) suggests that how much gluten is given may be another important factor rather than looking at the timing with regard to the development of celiac disease (CD).

In this 1-to-3 nested case-control study with 146 cases of CD and 436 controls, the authors indicate that a larger intake of gluten than controls increased the likelihood of celiac disease.  Specifically, children receiving large amounts of gluten (>5 g/day) during their first 24 months had a 2.6-fold increased risk of CD compared to those who consumed lower quantities.

The associated editorial notes that the total amount of gluten intake was only marginally increased in CD cases versus all control patients (OR 1.05) and that the association was decreased when individuals with first-degree relatives with CD were excluded.  In addition, this high consumption increased the risk after the first 2 years of life, rather than during this period of high consumption.

Does this make sense? Not to me.  These findings need to be replicated in other studies to determine if gluten exposure is like Goldilocks: too little, too much –>just right.

My take: For now, I think sticking with the timing of gluten exposure (recommended at 4-6 months) rather than the quantity is worthwhile.

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Plumbism in Flint

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A brief commentary (DC Berlinger NEJM 2016; 1101-3) provides a succinct summary of the medical story from Flint.

Historical:

  • Lead exposure has been known to be a hazard since the 1st century: Dioscorides “observed in his De Materia Medica that ‘lead makes the mind give way.'”
  • In 1723, an industrial hygiene act in the colonies prohibited the use of lead in the apparatus to distill rum due to being “unwholesom.”
  • “Water doesn’t receive as much attention as paint…but,…our word ‘plumbing’ derives from the Latin for lead, and lead poisoning is often called ‘plumbism.'”
  • The past 40 years, the U.S. has had dramatic reductions in blood lead levels.  This is “one of the cardinal public health success stories.”
  • Lead in water poses unique problems because “it rarely originates in the source water.  Rather, the problem usually lies near the point of consumption.”

“There is no safe level of lead, particularly for children”

Flint:

  • In 2014, “the city began taking its water from the Flint river rather than Lake Huron.”  This was expected to save ~$100 per day; now, the cost of repairing infrastructure is estimated to be as high as $1.5 billion.  Yet the Flint river water was “19 times as corrosive,” leading to more lead in the water.
  • The incidence of blood lead concentrations above the reference value of 5 mcg/dL rose from 2.4% to 4.9% from 2013 to 2015.  “The increase was greatest, from 4.0% to 10.6%, among children in neighborhoods with the highest lead concentrations.”
  • Disadvantaged children already are at increased risk due to houses more likely to be in poor repair.  In addition, they are at increased risk from higher levels of lead in solid/dust and lead paint.
  • “In coming years, parents will undoubtedly wonder, with anxiety and even guilt, whether their children’s every developmental stumble stems from this episode.”

My take (borrowed from author): “We have the knowledge required to redress this social crime…what we lack is the political will to do what should be done.”

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Gibbs Gardens

Gibbs Gardens

Which kids who aspirate need a gastrostomy tube?

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While some may think all children who aspirate should have a gastrostomy tube, a recent study (ME McSweeney et al. J Pediatr 2016; 170: 79-84) indicates a more selective approach is appropriate.

This retrospective review of 114 patients (2006-2013) compared patients fed by gastrostomy tube (g-tube) and those who were fed orally.  In their introduction, the authors note, “there has been a practice shift at many institutions away from g-tube placement and more toward continuing to feed children with aspiration orally.”  All patients in the study had aspiration and/or penetration with thin liquids and/or nectar thick liquids on a videofluoroscopic swallow study (VFSS).

There were 61 who aspirated only thin liquids and 53 who aspirated thin and nectar thick liquids.  All patients were divided into two groups: a g-tube group which did not have a preoperative trial of thickened feeds and an orally-fed group.  Patients who had a fundoplication or post-pyloric feeds were excluded from this study.

Key findings:

  • There were no significant differences in admissions among those who aspirated thins compared with those that aspirated thin & nectar thick liquids.
  • Patients fed by gastrostomy were hospitalized more frequently (median 2 times compared to once with orally-fed) and for longer duration (median 24 days compared with median 2 days for orally-fed)
  • No differences in total pulmonary admissions were noted between gastrostomy-fed and orally-fed group

The authors advocate a trial of oral feeding in all children cleared to take nectar or honey thick liquids prior to g-tube placement.

 

While the authors note that g-tube placement did not result in fewer pulmonary admissions, in their discussion, they also reviewed studies which showed that fundoplication (with g-tube) was not associated with a reduced risk of respiratory complications and in fact, had higher rehospitalizations.

This current study, and previous studies, are limited by their design.  Patients were not randomized and g-tube-fed patients may have had more comorbidities, biasing the results.  The authors note that there were 11 children who failed oral thickening trials and needed g-tube placement.  At the same time, there are substantial numbers of children whose swallow function improve.  Also, the authors note that thickening agents have not been shown to lead to dehydration risk.

My take: the widespread availability of swallow studies has likely led to some children undergoing g-tube placement who may have been fine with ongoing orally-thickened feeds.  Avoiding g-tube placement for children who can tolerate and thrive on thickened feeds is worthwhile.

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Walnut Street Bridge & Tennessee River

Walnut Street Bridge & Tennessee River

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