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NCCIH Clinical Digest

for health professionals

Use of Natural Products by Children: What the Science Says

July 2018

Clinical Guidelines, Scientific Literature, Info for Patients: 
Use of Natural Products by Children

kids school lunch

Fish Oil/Omega-3 Fatty Acids

Current data are inconclusive on whether omega-3 fatty acids could provide any benefit for the symptoms of ADHD in children and adolescents. Some randomized controlled trials have conferred modest benefits in treating ADHD; however, omega-3 fatty acids are less efficacious than traditional stimulant medications for ADHD symptoms.

Fish oil supplements, a specific source of omega-3 fatty acids, may be more beneficial than docosahexaenoic acid (DHA), according to some preliminary clinical research.

What Does the Research Show?
Several studies, including randomized controlled trials, reviews, and meta-analyses have examined the effects of fish oil/omega-3 fatty acid supplements in children with ADHD.

  • A 2014 review found some evidence suggesting that omega-3 fatty acid supplementation may be useful for the treatment of ADHD. However, evidence to support the use of omega-3 fatty acid supplements in children with other primary disorders, such as dyslexia, is less clear. The review concluded: “Cumulative evidence suggests that there is currently Center for Evidence-Based Medicine (CEBM) level-1 evidence demonstrating the efficacy of omega-3 fatty acids for the treatment of ADHD.”
    • This review included a 2011 meta-analysis of 10 trials involving 699 children with ADHD, which demonstrated a small but statistically significant benefit of omega-3 fatty acid supplementation compared with placebo. Other systematic reviews had similar results.
    • However, a 2012 Cochrane review concluded that there is little evidence of benefit from polyunsaturated fatty acid supplementation for the symptoms of ADHD in children and adolescents.
  • Another 2014 review of two meta-analyses examined blood levels of omega-3 fatty acids in relation to ADHD and a larger sample of randomized intervention trials in a total of 25 studies. The review found that omega-3 levels are reduced in children with ADHD, and that supplementation with omega-3 fatty acids may provide modest improvement in symptoms. However, it is not yet clear if supplementation should be confined to children with below normal blood levels.

Safety

  • Omega-3 fatty acid supplements usually do not have negative side effects. When side effects do occur, they typically consist of minor gastrointestinal symptoms.
  • It is uncertain whether people with fish or shellfish allergies can safely consume fish oil supplements.
  • Omega-3 supplements may extend bleeding time. People who take anticoagulants or NSAIDs should use caution.

Melatonin

There are limited data from rigorous clinical trials on melatonin for sleep disorders among young people. A 2011 review suggested a beneficial effect on sleep disorders (when administered for 4 weeks), with minimal side effects, in healthy children as well as youth with ADHD, autism, and several other populations. There is insufficient data to make conclusions about the safety and effectiveness of long-term melatonin use, although one 2009 study evaluated the efficacy and safety of long-term (mean time up to 3.7 years) treatment of melatonin for children with ADHD and insomnia, and no serious adverse events were reported.

What Does the Research Show?
Only a few studies have examined the effects of melatonin in children with sleep problems.

  • A 2014 review of two randomized, placebo-controlled trials of melatonin children with ADHD and sleep onset insomnia, along with meta-analyses of melatonin for children with sleep disorders (and without a comorbid diagnosis of ADHD) found evidence to suggest that melatonin may reduce sleep-onset latency in children with chronic sleep-onset insomnia. The review also found no evidence to suggest melatonin improves ADHD symptoms.
  • A 2007 randomized controlled trial involving a total of 105 medication-free children, 6 to 12 years of age, with ADHD and chronic sleep-onset insomnia found improved sleep onset and increase in total time asleep with melatonin compared with placebo. However, no significant effect was seen on behavior, cognition, and quality of life. Reviewers of this study concluded that, “taken together, these trials and meta-analyses suggest that melatonin has Center for Evidence-Based Medicine (CEBM) level-1 evidence for reducing sleep-onset latency in children with chronic sleep-onset insomnia (regardless of a comorbid diagnosis of ADHD) but there is no evidence to suggest melatonin improves ADHD symptoms.”
  • A 2006 randomized controlled trial of 27 stimulant-treated children, 6 to 14 years of age, with ADHD and initial insomnia concluded that melatonin was safe, well tolerated, and statistically and clinically superior to placebo in reducing initial insomnia. Findings suggest that a combination of sleep hygiene and melatonin is likely to improve initial insomnia.

Safety

  • Melatonin appears to be safe when used short-term, but there is lack of long-term studies.
  • Side effects of melatonin are uncommon but can include drowsiness, headache, dizziness, or nausea. There have been no reports of significant side effects of melatonin in children.

Probiotics

For Antibiotics-Associated Diarrhea
There is preliminary evidence that some probiotics are helpful in preventing diarrhea caused by infections and antibiotics and in improving symptoms of irritable bowel syndrome, but there are insufficient and conflicting data about the effectiveness of the varying species, preparations, or strains.

What Does the Research Show?
Many studies, including randomized controlled trials and reviews, have examined the effects of probiotics in children with antibiotics-associated diarrhea.

  • A 2015 Cochrane review of 23 studies involving a total of 3,938 children (2 weeks to 17 years of age) concluded that there is moderate quality evidence suggesting a protective effect of probiotics in preventing antibiotics-associated diarrhea. The authors noted that among the various probiotics evaluated, Lactobacillus rhamnosus or Saccharomyces boulardii at 5 to 40 billion colony forming units/day may be appropriate.

For Acute Respiratory Tract Infections
There is some evidence that probiotics reduce the duration of acute respiratory infections in otherwise healthy children. There is also some limited evidence that probiotics may be more beneficial than placebo for preventing upper respiratory tract infections; however, the quality of the research was low or very low. Currently, not enough research has been conducted to determine whether probiotics may prevent colds in children.

What Does the Research Show?
Several studies, including randomized controlled trials, reviews, and meta-analyses have examined the effects of probiotics in children with upper respiratory infections.

  • A 2015 Cochrane review of 13 randomized controlled trials involving 3,720 participants including children, adults, and older adults found that probiotics (any specified strain or dose) were better than placebo in reducing the number of participants experiencing episodes of acute upper respiratory tract infections (URTI), the mean duration of an episode of acute URTI, antibiotic use, and cold-related school absences. These findings suggest that probiotics may be more beneficial than placebo for preventing URTIs; however, the quality of the evidence was low or very low.
  • A 2014 systematic review and meta-analysis examined the effectiveness of probiotics on the duration of illness in healthy children and adults who develop common acute respiratory infections and found evidence from “good-quality” randomized controlled trials that probiotics reduce the duration of illness in otherwise healthy children and adults.

Safety

  • As pointed out in a 2011 Agency for Healthcare Research and Quality assessment of the safety of probiotics, little is known about the long-term effects of probiotics in children or adults.
  • A 2015 Cochrane review of 23 studies involving a total of 3,938 children (2 weeks to 17 years of age) concluded that until further research has been conducted, probiotic use should be avoided in pediatric populations at risk for adverse events.
  • It appears that most people can use probiotics without experiencing any side effects—or with only mild gastrointestinal side effects such as gas—but there have been some case reports of serious adverse effects, and the risk of serious side effects may be greater in people with underlying health conditions. Probiotics should not be used by people with serious underlying health problems except with close monitoring by a health care provider.

Echinacea

The effects of echinacea in children are uncertain; only a small amount of research has been done in children, and the results of that research are inconsistent. In adults, although there is the potential that some preparations of echinacea are more effective than placebo for treating colds, the overall evidence for clinically relevant treatment effects is weak.

What Does the Research Show?
Only a few studies have been conducted to examine the effects of echinacea preparations in children with the common cold.

  • A 2012 review of two randomized controlled trials of Echinacea purpurea for colds found no difference in severity of symptoms, peal of symptom severity, number of days of fever, or parental report of severity score compared with placebo. The reviewers concluded that echinacea products are ineffective for treating cold symptoms in children.

Safety

  • Few side effects have been reported in clinical trials of echinacea; however, some people may have allergic reactions.
  • In a 2003 randomized controlled trial conducted in children, use of Echinacea purpurea was associated with an increased risk of rash.

Cranberry

There is mixed evidence that cranberry can help prevent urinary tract infections (UTIs).

What Does the Research Show?
Cranberry supplements have been the focus of many randomized controlled trials, reviews, and meta-analyses, but only a few have involved children.

  • A 2012 systematic review and meta-analysis of 13 randomized controlled trials suggested that cranberry may help reduce the risk of UTIs in certain groups, including children; however, a 2016 study of 147 women found decreased bacteria levels in their urine but no decrease in frequency of UTIs over one year.

Safety

  • Drinking cranberry juice appears to be safe, although large amounts can cause stomach upset and may over time increase the risk of kidney stones.
  • Large doses of cranberry may alter levels of warfarin, an anticoagulant (blood-thinner).
  • People who think they have a UTI should see a health care provider for a diagnosis and treatment. Don’t use cranberry products in place of proven treatments for infections.

Garlic Supplements

A recent Cochrane review concluded that there is insufficient clinical trial evidence regarding the effects of garlic in preventing or treating the common cold.

Some studies indicate that certain groups of people who eat more garlic may be less likely to develop certain cancers, such as stomach and colon cancers. However, garlic in dietary supplement form has not been shown to help reduce the risk of these cancers. The National Cancer Institute recognizes garlic as one of several vegetables with potential anticancer properties but does not recommend using garlic dietary supplements for cancer prevention.

What Does the Research Show?
Only a few clinical trials have been conducted to examine the effects of garlic supplements on the common cold, and there is a lack of data in children.

  • A 2014 Cochrane review of a single randomized controlled trial, involving 146 participants (adults) who received either a garlic supplement or a placebo for 12 weeks, concluded that there is insufficient clinical trial evidence regarding the effects of garlic in preventing or treating the common cold. The single trial suggested that garlic may prevent occurrences of the common cold but more studies are needed to validate this finding.

Safety

  • Garlic is probably safe for most people in the amounts usually eaten in foods; however, excessive consumption can cause some side effects, such as strong breath and body odor, heartburn, and upset stomach. These side effects can be more noticeable with raw garlic. Some people have allergic reactions to garlic.
  • Garlic also acts as a natural blood thinner and should be avoided by pregnant women, people about to undergo surgery, and people taking blood thinners, such as warfarin.
  • Garlic has been found to interfere with the effectiveness of some drugs, including the HIV medication saquinavir.

Ginseng

There are some preliminary data that Korean red ginseng extract may provide beneficial effects for children with inattention and hyperactivity/impulsivity symptoms. There is currently no conclusive evidence supporting any health benefits of Asian ginseng.

What Does the Research Show?
Very little research has been conducted on the effects of ginseng on children with any condition.

Safety

  • Short-term use of Asian ginseng in recommended amounts appears to be safe for most people. However, questions have been raised about its long-term safety, and some experts recommend against its use by infants, children, and women who are pregnant or breastfeeding.
  • The most common side effects of ginseng are headaches, sleep problems, and digestive problems.
  • Some evidence suggests that Asian ginseng might affect blood sugar and blood pressure.
  • The risk of interactions between ginseng and medications is believed to be low, but there are uncertainties about whether ginseng might interact with certain medications, such as the anticoagulant warfarin (Coumadin).

References

  • Bloch MH, Mulqueen J. Nutritional supplements for the treatment of ADHD. Child Adolesc Psychiatr Clin N Am. 2014;23(4):883-897.
  • Bloch MH, Qawasami A. Omega-3 fatty acid supplementation for the treatment of children with attention-deficit/hyperactivity disorder symptomatology: systematic review and meta-analysis. J Am Acad Child Adolesc Psychiatry. 2011;50(10):991-1000.
  • Fashner J, Ericson K, Werner S. Treatment of the common cold in children and adults. Am Fam Physician. 2012;86(2):153-159.
  • Gillies D, Sinn JKH, Lad SS, Leach MJ, Ross MJ. Polyunsaturated fatty acids (PUFA) for attention deficit hyperactivity disorder (ADHD) in children and adolescents. Cochrane Database of Systematic Reviews. 2012;7:CD007986.
  • Goldenberg JZ, Lytvyn L, Steurich J, Parkin P, Mahant S, Johnston BC. Probiotics for the prevention of pediatric antibiotic-associated diarrhea. Cochrane Database of Systematic Reviews. 2015;12:CD004827.
  • Hao Q, Dong BR, Wu T. Probiotics for preventing acute upper respiratory tract infections. Cochrane Database Syst Rev. 2015;2:CD006895.
  • Hawkey E, Nigg JT. Omega-3 fatty acid and ADHD: blood level analysis and meta-analytic extension of supplementation trials. Clin Psychol Rev. 2014;34(6):496-505.
  • Juthani-Mehta M, Van Ness PH, Bianco L, et al. Effect of cranberry capsules on bacteriuria plus pyuria among older women in nursing homes: a randomized clinical trial. JAMA. 2016;316(18):1879-1887.
  • King S, Slanville J, Sanders ME, et al. Effectiveness of probiotics on the duration of illness in healthy children and adults who develop common acute respiratory infectious conditions: a systematic review and meta-analysis. Br J Nutr. 2014;112(1):41-54.
  • Ko HJ, Kim I, Kim JB, et al. Effects of Korean red ginseng extract on behavior in children with symptoms of inattention and hyperactivity/impulsivity: a double-blind randomized placebo-controlled trial. J Child Adolesc Psychopharmacol. 2014;24(9):501-508.
  • Lissiman E, Bhasale AL, Cohen M. Garlic for the common cold. Cochrane Database Syst Rev. 2014;11:CD006206.
  • Taylor JA, Weber W, Standish L, et al. Efficacy and safety of echinacea in treating upper respiratory tract infections in children: a randomized controlled trial. JAMA. 2003;290(21):2824-2830.
  • Van der Heijden KB, Smits MG, Van Someren EJ, et al. Effect of melatonin on sleep, behavior, and cognition in ADHD and chronic sleep-onset insomnia. J Am Acad Child Adolesc Psychiatry. 2007;46(2):233-241.
  • Wang CH, Fang CC, Chen NC, et al. Cranberry-containing products for prevention of urinary tract infections in susceptible populations: a systematic review and meta-analysis of randomized controlled trials. Arch Intern Med. 2012;172(13):988-996.
  • Weiss MD, Wasdell MB, Bomben MM, et al. Sleep hygiene and melatonin treatment for children and adolescents with ADHD and initial insomnia. J Am Acad Child Adolesc Psychiatry. 2006;45(5):512-519.

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