http://www.foodproductiondaily.com/news/news-NG.asp?id=51212
Zinc appears to improve ADHD treatment
- 08/04/2004 - Zinc supplements could increase the effectiveness of stimulants
used to treat children with attention deficit hyperactivity disorder (ADHD),
the most common childhood behavioural disorder that affects around one in every
25 school-aged children, according to new research.
The effects of ADHD on individual children differ, but symptoms include
inattention, hyperactivity and impulsiveness. Stimulants are the most common
treatment prescribed, but some patients respond poorly to stimulants or are
unable to tolerate them. Also recent findings that vitamin and mineral
deficiencies correlate with ADHD suggest that dietary supplements could also
play a role in disease management. Researchers from Iran carried out a
controlled trial to assess the benefits of prescribing supplementary zinc
alongside the more conventional methylphenidate treatment. They found that
children taking additional zinc sulphate on a daily basis improved faster than
those taking a placebo.
“The efficacy of zinc sulphate to increase the rate of improvement in
children, seems to support the role of zinc deficiency in the pathogenesis of
ADHD,†say the authors of the study, published in this week’s issue of BMC
Psychiatry (4:8).
Research published earlier this year by a team at Karadeniz Technical
University in Trabzon, Turkey found that zinc sulphate significantly reduced
symptoms of hyperactivity, impulsivity and impaired socialization in patients
with ADHD, particularly older children and those with low zinc and fatty acid
levels. But the new study is thought to be the first controlled clinical trial
looking at the effects of zinc alongside conventional medication. The study
comprised 44 children who were diagnosed as suffering from ADHD at Roozbeh
Psychiatric Hospital, Tehran. Prior to the trial none of these patients had
taken any medication for their condition. For the six weeks of the trial, half
the children took zinc sulphate (55mg/day) in addition to the conventional
treatment; the other half took a placebo. A child psychiatrist assessed the
children’s condition fortnightly. The behaviour of both groups of children
improved over the course of the trial, but the children taking the zinc
supplements showed a more marked improvement in their condition after six
weeks, compared with those taking the placebo. Although the children taking
zinc sulphate were three times more likely to report that they were suffering
from nausea, the frequency of other side effects did not differ between the two
study groups. However, almost all of the children taking supplementary zinc
complained about the metallic taste of the tablets. Zinc supplements may exert
their positive effects by helping to regulate the function of the
neurotransmitter dopamine, suggested the researchers. Dopamine signalling,
which has been implicated in causing symptoms of ADHD, is believed to play an
important role in the feelings of pleasure and reward. The hormone melatonin,
made in the body but requiring zinc for its production, regulates dopamine and
has been shown to help regulate the sleep cycle of children with ADHD. Further
research on a larger group of subjects and with different dosages is needed to
confirm the positive effects of the supplements on children with ADHD, noted
the researchers.