Topical vitamin A prevents wrinkles
Thirty-six elderly subjects (mean age, 87 years) were randomly assigned
to apply, in double-blind fashion, topical 0.4% vitamin A (retinol)
lotion to one arm and placebo (vehicle) to the other arm three times
per week for 24 weeks. The mean improvement in the score for fine
wrinkling (as determined from biopsy samples) was significantly
greater in the active-treatment group than in the placebo group
(-1.64 vs. -0.08 on a 9-point scale, with 0 being no wrinkles and
9 being severe wrinkles; p < 0.01 for the difference in the change
between groups). Application of vitamin A significantly increased
the production of glycosaminoglycans, which are known to retain
water, and of collagen, which may increase skin integrity.
(Retin-A), a vitamin A analogue, has been known for many years to
be effective for the prevention and treatment of age-related skin
wrinkling. The results of the present study indicate that vitamin
A itself is also effective for this indication. Topical vitamin
A may be better tolerated than tretinoin, which can cause skin irritation,
redness, peeling, blistering, photosensitivity, allergic reactions,
and other adverse effects.
Kafi R, et al. Improvement of naturally aged skin with vitamin A
(retinol). Arch Dermatol.
Zinc effective for hidradenitis
Twenty-two patients with hidradenitis suppurativa, mainly of grade
I or II in Hurley's classification (with I being the least
severe and III being the most severe) who had failed to respond
to conventional medical or surgical treatment were treated with
90 mg per day of zinc (as zinc gluconate). The mean follow-up period
was two years. All patients improved, and eight patients (36.4%)
had a complete resolution of the skin condition. The duration of
treatment before improvement occurred was not specified. When the
maximum improvement was maintained for four months, the dosage of
zinc was decreased by 15 mg per day every two months, depending
on the clinical response. The zinc dosage needed to maintain the
initial improvement was usually 30-60 mg per day. Patients with
more severe disease required higher doses of zinc to maintain their
improvement than did those with less severe disease. Three patients
experienced gastrointestinal side effects from zinc.
Comment: Hidradenitis suppurativa is
a chronic, frequently painful, suppurative dermatosis involving
apocrine glands. It affects 0.3-0.4% of people in industrialized
societies. Results of conventional therapy, which may include antibiotics,
local antiseptics, isotretinoin, or surgery, are frequently disappointing.
Although controlled trials are needed, the results of the present
study suggest that zinc is an effective treatment for mild-to-moderate
Brocard A, et al. Hidradenitis suppurativa and zinc: A new therapeutic
approach. A pilot study. Dermatology.
prevent eczema in infants
Two hundred fifty-nine bottle-fed infants who were at risk of developing
atopy were randomly assigned to receive, in double-blind fashion,
a hydrolyzed protein formula supplemented with a prebiotic mixture
consisting of 90% short chain galacto-oligosaccharides and 10% long
chain fructo-oligosaccharides (0.8 g per 100 ml) or the same formula
supplemented with placebo (maltodextrin). The incidence of atopic
dermatitis in the first six months of life was 9.8% in the prebiotic
group and 23.1% in the placebo group (58% reduction with active
treatment; p = 0.014). Active treatment was associated with a significantly
higher number of fecal bifidobacteria compared with placebo.
Comment: Oligosaccharides are a component
of human milk. They promote the development of an intestinal flora
dominated by bifidobacteria and lactobacilli. The prebiotic mixture
used in the present study was designed to mimic the oligosaccharide
content of human milk. In a previous study, supplementation with
this oligosaccharide preparation was found to produce intestinal
flora similar to that of breast-fed infants. While breast-feeding
is preferable to formula-feeding for many reasons, infants at risk
for atopy who cannot be breast-fed may benefit from a formula that
Moro G, et al. A mixture of prebiotic oligosaccharides reduces the
incidence of atopic dermatitis during the first six months of age.
Arch Dis Child. 2006;91:814-819.
obsessive-compulsive "grooming disorders"
Of five patients with various combinations of trichotillomania (pathological
hair-pulling), pathological nail biting, and pathological skin picking,
three experienced a resolution of these disorders after treatment
with N-acetylcysteine (NAC). The initial dose was 600 mg per day,
which was increased to 1,200 mg per day. Improvements were noted
in each case after the dose was increased to 1,200 mg per day. Further
improvement occurred when the dose was increased again. At a final
dose of 1,800 mg per day (n = 2) or 2,400 mg per day (n = 1), the
patients remained free of these compulsive behaviors during follow-up
periods of three-to-five months.
Comment: Hyperactivity of glutamatergic
neurotransmission has been implicated in the pathogenesis of obsessive-compulsive
disorder (OCD). NAC is believed to reduce synaptic glutamatergic
activity. In a previous case report, administration of NAC resulted
in improvement of chronic OCD in a middle-aged woman. The results
of the present study suggest that NAC may also be useful in the
treatment of compulsive grooming disorders that share certain characteristics
Odlaug BL, Grant JE. N-acetyl cysteine in the treatment of grooming
disorders. J Clin Psychopharmacol.
Trans-forming a big
Male monkeys were assigned to diets containing approximately eight
percent of energy either as cis-monounsaturated fatty acids (control)
or as the trans-isomers for six years. The diets provided maintenance
energy requirements and were intended not to promote weight gain.
Mean change in body weight (7.2% vs. 1.78%; p < 0.05), mean ratio
of intra-abdominal fat volume to subcutaneous fat volume (1.67 vs.
1.36; p < 0.02), and mean postprandial serum insulin concentration
(18 µIU/ml vs. 4.5 µIU/ml; p < 0.05) were significantly
greater in animals fed trans-fatty acids than in controls.
Comment: The results of this study
indicate that long-term consumption of trans-fatty acids by monkeys
increases body weight and intra-abdominal fat deposition and promotes
the development of insulin resistance, even in the absence of excessive
caloric intake. These findings raise the possibility that trans-fatty
acid consumption is one of the factors contributing to the epidemic
of obesity in Western societies. The mechanism by which eating these
industrially produced fatty acids might cause weight gain is not
clear, although trans-fatty acids probably interfere with multiple
aspects of intermediary metabolism and cell membrane function. This
study adds to the growing list of adverse effects of partially hydrogenated
Kavanagh K, et al. Trans fat diet induces abdominal obesity and
changes in insulin sensitivity in monkeys. Obesity.
Does vitamin D prevent
Of 69 patients with type 2 diabetes, 34 (49%) had a serum 25-hydroxyvitamin
D level less than 50 nmol/L (mean, 38.3 nmol/L). Those 34 patients
were randomly assigned to receive, in double-blind fashion, a single
dose of 100,000 IU of vitamin D2 or placebo during the winter. Compared
with placebo, vitamin D significantly improved flow-mediated vasodilatation
(FMD) of the brachial artery (a measure of arterial health). The
improvement in FMD remained significant after adjusting for changes
in blood pressure. The mean systolic blood pressure (BP) decreased
by 7.3 mm Hg in the vitamin D group and increased by 6.6 mm Hg in
the placebo group (difference between groups, 13.9 mm Hg; p = 0.001).
The mean diastolic BP decreased by 2.2 mm Hg in the vitamin D group
and increased by 2.3 mm Hg in the placebo group (difference between
groups, 4.5 mm Hg; p = 0.08).
Comment: For many years, doctors were
concerned about the possibility that excessive vitamin D intake
could cause cardiovascular disease. Those concerns were based on
animal studies, in which feeding large doses of vitamin D3 or vitamin
D2 caused arterial calcifications and other changes that resembled
human atherosclerosis. While very large amounts of vitamin D were
administered in most of these studies, feeding as little as 2,000
IU of vitamin D3 per kg of diet to swine was sufficient to cause
intimal lesions and calcification of coronary arteries in one study.
Because of these concerns, many multivitamin products limited their
vitamin D content to 100-200 IU per day.
In contrast, a recent observational study found that the prevalence
of cardiovascular disease decreased with increasing serum 25-hydroxyvitamin
D levels. Those findings, when combined with the results of the
new study, should alleviate concerns that taking moderate doses
of vitamin D (up to 2,000 IU per day) might increase the risk of
developing heart disease. Whether vitamin D supplementation actually
prevents heart disease remains to be determined.
Sugden JA, et al. Vitamin D improves endothelial function in patients
with type 2 diabetes mellitus and low vitamin D levels. Diabet
Melatonin enhances preoperative
Thirty-three patients (mean age, 44 years) undergoing abdominal
hysterectomy were randomly assigned to receive, in double-blind
fashion, 5 mg of oral melatonin or placebo the night before and
one hour before surgery. The severity of postoperative pain and
the amount of postoperative morphine use were significantly less
in the melatonin group than in the placebo group. Of the patients
who had moderate or intense pain during the first 24 hours after
surgery, the incidence of high anxiety was 30% in the melatonin
group and 77% in the placebo group. Of the patients who had no pain
or mild pain, the incidence of high anxiety was 20% in the melatonin
group and 33% in the placebo group. The number of patients that
needed to be treated to prevent one additional patient reporting
high postoperative anxiety and moderate-to-intense pain in the first
24 hours after surgery was 2.53 (95% CI, 1.41-12.22) and 2.20 (95%
CI, 1.26-8.58), respectively.
Comment: Melatonin has sedative and
analgesic effects. The results of the present study indicate that
preoperative administration of melatonin can produce clinically
relevant anti-anxiety and analgesic effects in the first 24 hours
Caumo W, et al. The clinical impact of preoperative melatonin on
postoperative outcomes in patients undergoing abdominal hysterectomy.
Anesth Analg. 2007;105:1263-1271.
Is the RDA for vitamin B6 too low?
Plasma concentrations of pyridoxal 5'-phosphate (PLP; the biologically
active form of vitamin B6) were measured in 6,000 people participating
in the National Health and Nutrition Examination Survey (2003-2004).
The proportion of subjects whose dietary vitamin B6 intake was less
than the Recommended Dietary Allowance (RDA) of 2 mg per day ranged
from 35% in men aged 13-54 years to 65% in menstruating women. The
proportion of subjects who had a low plasma PLP level while consuming
2.0-2.9 mg/day of vitamin B6 was 19% for boys and girls younger
than 13 years, 10% for males aged 13-54, 20% for menstruating females,
14% for men and women aged 65 or older, 12% for white males aged
13 or older, and 9% for male nonsmokers aged 13 or older. The prevalence
of low plasma PLP level while consuming 3.0-4.9 mg per day of vitamin
B6 was 3-7% in the different groups. The prevalence of low plasma
PLP level while consuming more than 5.0 mg per day of vitamin B6
was 1-6% in the different groups, with three of the five groups
studied having a prevalence of 4-6%.
study demonstrates that laboratory evidence of vitamin B6 deficiency
is relatively common, even among people whose diets exceed the RDA
for this vitamin. In 1984, I wrote a book called The
Doctor's Guide to Vitamin B6,
in which I pointed out that a number of different environmental
pollutants may be interfering with the way our body utilizes this
important vitamin. Certain diseases that respond to high doses of
vitamin B6 have increased in prevalence over the past several decades
(such as asthma and ADHD) or were unknown 50 years ago (such as
carpal tunnel syndrome). The results of the new study support that
possibility that many people need more vitamin B6 than was previously
thought. A copy of my book can be obtained by sending $23 to Nutrition
Seminars, 12 Spaulding Street, Concord, New Hampshire 03301 (free
shipping in the US, add $10 for shipping to Canada).
Morris MS, et al. Plasma pyridoxal 5'-phosphate in the US population:
The National Health and Nutrition Examination Survey, 2003-2004.
Am J Clin Nutr.
Alan R. Gaby, MD