Do you remember the 'protective effect'
from daily cod liver oil (over 1 year)
against childhood leukemia reported in 1988
and discussed in my 'Childhood Leukemia' topic?
Well, another protective effect has recently
been found studying multiple sclerosis:
Outdoor activities and diet in childhood and adolescence
relate to MS risk above the Arctic Circle.
Kampman MT, Wilsgaard T, Mellgren SI.
Dept. of Neurology, University Hospital of North Norway, P.O. Box 33, 9038, Tromsø, Norway.
BACKGROUND : A relationship between the latitude-related distribution of multiple sclerosis (MS) and exposure to sunlight has long been considered. Higher sun exposure during early life has been associated with decreased risk of MS.
OBJECTIVE : Since Norway is an exception to the latitude gradient of MS prevalence, we tested here whether sunlight exposure or vitamin D-related dietary factors in childhood and adolescence are associated with the risk of MS.
METHODS : Retrospective recall questionnaire data from 152 MS patients and 402 population controls born at and living at latitudes 66-71 degrees N were analysed by means of conditional logistic regression analysis accounting for the matching variables age, sex, and place of birth.
RESULTS : Increased outdoor activities during summer in early life were associated with a decreased risk of MS, most pronounced at ages 16-20 years (odds ratio (OR) 0.55, 95% CI 0.39-0.78, p = 0.001, adjusted for intake of fish and cod-liver oil).
A protective effect of supplementation with cod-liver oil was suggested in the subgroup that reported low summer outdoor activities (OR 0.57, 95% CI 0.31-1.05, p = 0.072).
Consumption of fish three or more times a week was also associated with reduced risk of MS (OR 0.55, 95% CI 0.33-0.93, p = 0.024).
CONCLUSION : Summer outdoor activities in childhood and adolescence are associated with a reduced risk of MS even north of the Arctic Circle. Supplemental cod-liver oil may be protective when sun exposure is less, suggesting that both climate and diet may interact to influence MS risk at a population level.
J Neurol. 2007 Apr;254(4):471-7. Epub 2007 Mar 21.
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...and now kids, drink your milk and go play outside!
(old-wives motto)
The "Vitamin D Tsunami" is definitely coming,
spinning out of the restricted scientific circuit.
Finally prof. Michael Holick is in the New England
Journal of Medicine...
and -as usual- lay press will follow pretty soon!
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"...rickets can be considered the tip of the vitamin D-deficiency iceberg. In fact, vitamin D deficiency remains common in children and adults."
Michael F. Holick "Vitamin D Deficiency" N Eng J Med 2007;357:266-81.
July 19, 2007 splendid review article in 'Medical Progress'
Unfortunately this one is not available in free full-text...you may go to last year paper published in J Clin Invest for similar refreshing good news:
http://www.jci.org/cgi/content/full/116/8/2062
As far as this topic is concerned, multiple sclerosis is obviously mentioned, and four references cited:
"...Among white men and women, the risk of multiple sclerosis decreased by 41% for every increase of 20 ng per milliliter in 25-hydroxyvitamin D above approximately 24 ng per milliliter (60 nmol per liter) (odds ratio, 0.59; 95%CI, o.36 to 0.97; P=0.04). Women who ingested more than 400 IU of vitamin D per day had a reduced risk of developing multiple sclerosis."
Ultraviolet radiation and autoimmune disease: insights from epidemiological research.
Ponsonby AL, McMichael A, van der Mei I.
National Centre for Epidemiology and Population Health, The Australian National University, Canberra ACT 0200, Australia. anne-louise.ponsonby@anu.edu.au
This review examines the epidemiological evidence that suggests ultraviolet radiation (UVR) may play a protective role in three autoimmune diseases: multiple sclerosis, insulin-dependent diabetes mellitus and rheumatoid arthritis. To date, most of the information has accumulated from population studies that have studied the relationship between geography or climate and autoimmune disease prevalence. An interesting gradient of increasing prevalence with increasing latitude has been observed for at least two of the three diseases. This is most evident for multiple sclerosis, but a similar gradient has been shown for insulin-dependent diabetes mellitus in Europe and North America. Seasonal influences on both disease incidence and clinical course and, more recently, analytical studies at the individual level have provided further support for a possible protective role for UVR in some of these diseases but the data are not conclusive. Organ-specific autoimmune diseases involve Th1 cell-mediated immune processes. Recent work in photoimmunology has shown ultraviolet B (UVB) can specifically attenuate these processes through several mechanisms which we discuss. In particular, the possible contribution of an UVR-induced increase in serum vitamin D (1,25(OH)2D3) levels in the beneficial immunomodulation of these diseases is discussed.
Toxicology. 2002 Dec 27;181-182:71-8.
Multiple sclerosis and vitamin D: an update.
VanAmerongen BM, Dijkstra CD, Lips P, Polman CH.
Department of Molecular Cell Biology and Immunology, VU Medical Center, Amsterdam, The Netherlands. b.m.van.amerongen@inter.nl.net
MS is a chronic, immune-mediated inflammatory and neurodegenerative disease of the central nervous system (CNS), with an etiology that is not yet fully understood.
The prevalence of MS is highest where environmental supplies of vitamin D are lowest.
It is well recognized that the active hormonal form of vitamin D, 1,25-dihydroxyvitamin D (1,25-(OH)(2)D), is a natural immunoregulator with anti-inflammatory action. The mechanism by which vitamin D nutrition is thought to influence MS involves paracrine or autocrine metabolism of 25OHD by cells expressing the enzyme 1 alpha-OHase in peripheral tissues involved in immune and neural function. Administration of the active metabolite 1,25-(OH)(2)D in mice and rats with experimental allergic encephalomyelitis (EAE, an animal model of MS) not only prevented, but also reduced disease activity. 1,25-(OH)(2)D alters dendritic cell and T-cell function and regulates macrophages in EAE. Interestingly, 1,25-(OH)(2)D is thought to be operating on CNS constituent cells as well. Vitamin D deficiency is caused by insufficient sunlight exposure or low dietary vitamin D(3) intake. Subtle defects in vitamin D metabolism, including genetic polymorphisms related to vitamin D, might possibly be involved as well. Optimal 25OHD serum concentrations, throughout the year, may be beneficial for patients with MS, both to obtain immune-mediated suppression of disease activity, and also to decrease disease-related complications, including increased bone resorption, fractures, and muscle weakness.
Eur J Clin Nutr. 2004 Aug;58(8):1095-109.
Serum 25-hydroxyvitamin D levels and risk of multiple sclerosis.
Munger KL, Levin LI, Hollis BW, Howard NS, Ascherio A.
Department of Nutrition, Harvard School of Public Health, and Channing Laboratory, Brigham and Women's Hospital and Harvard Medical School, Boston, Mass 02115, USA.
CONTEXT: Epidemiological and experimental evidence suggests that high levels of vitamin D, a potent immunomodulator, may decrease the risk of multiple sclerosis. There are no prospective studies addressing this hypothesis. OBJECTIVE: To examine whether levels of 25-hydroxyvitamin D are associated with risk of multiple sclerosis. DESIGN, SETTING, AND PARTICIPANTS: Prospective, nested case-control study among more than 7 million US military personnel who have serum samples stored in the Department of Defense Serum Repository. Multiple sclerosis cases were identified through Army and Navy physical disability databases for 1992 through 2004, and diagnoses were confirmed by medical record review. Each case (n = 257) was matched to 2 controls by age, sex, race/ethnicity, and dates of blood collection. Vitamin D status was estimated by averaging 25-hydroxyvitamin D levels of 2 or more serum samples collected before the date of initial multiple sclerosis symptoms. MAIN OUTCOME MEASURES: Odds ratios of multiple sclerosis associated with continuous or categorical levels (quantiles or a priori-defined categories) of serum 25-hydroxyvitamin D within each racial/ethnic group. RESULTS: Among whites (148 cases, 296 controls), the risk of multiple sclerosis significantly decreased with increasing levels of 25-hydroxyvitamin D (odds ratio [OR] for a 50-nmol/L increase in 25-hydroxyvitamin D, 0.59; 95% confidence interval, 0.36-0.97). In categorical analyses using the lowest quintile (<63.3 nmol/L) as the reference, the ORs for each subsequent quintile were 0.57, 0.57, 0.74, and 0.38 (P = .02 for trend across quintiles). Only the OR for the highest quintile, corresponding to 25-hydroxyvitamin D levels higher than 99.1 nmol/L, was significantly different from 1.00 (OR, 0.38; 95% confidence interval, 0.19-0.75; P = .006). The inverse relation with multiple sclerosis risk was particularly strong for 25-hydroxyvitamin D levels measured before age 20 years. Among blacks and Hispanics (109 cases, 218 controls), who had lower 25-hydroxyvitamin D levels than whites, no significant associations between vitamin D and multiple sclerosis risk were found.
CONCLUSION: The results of our study suggest that high circulating levels of vitamin D are associated with a lower risk of multiple sclerosis.
JAMA. 2006 Dec 20;296(23):2832-8.
Vitamin D intake and incidence of multiple sclerosis.
Munger KL, Zhang SM, O'Reilly E, Hernán MA, Olek MJ, Willett WC, Ascherio A.
Department of Nutrition, Harvard School of Public Health, 665 Huntington Ave., Boston, MA 02115, USA. kgorham@hsph.harvard.edu
BACKGROUND: A protective effect of vitamin D on risk of multiple sclerosis (MS) has been proposed, but no prospective studies have addressed this hypothesis.
METHODS: Dietary vitamin D intake was examined directly in relation to risk of MS in two large cohorts of women: the Nurses' Health Study (NHS; 92,253 women followed from 1980 to 2000) and Nurses' Health Study II (NHS II; 95,310 women followed from 1991 to 2001). Diet was assessed at baseline and updated every 4 years thereafter. During the follow-up, 173 cases of MS with onset of symptoms after baseline were confirmed.
RESULTS: The pooled age-adjusted relative risk (RR) comparing women in the highest quintile of total vitamin D intake at baseline with those in the lowest was 0.67 (95% CI = 0.40 to 1.12; p for trend = 0.03). Intake of vitamin D from supplements was also inversely associated with risk of MS; the RR comparing women with intake of >or=400 IU/day with women with no supplemental vitamin D intake was 0.59 (95% CI = 0.38 to 0.91; p for trend = 0.006). No association was found between vitamin D from food and MS incidence.
CONCLUSION: These results support a protective effect of vitamin D intake on risk of developing MS.
Neurology. 2004 Jan 13;62(1):60-5.
Environmental risk factors for multiple sclerosis. Part II: Noninfectious factors.
Ascherio A, Munger KL.
Department of Nutrition, Harvard School of Public Health, Boston, MA.
As discussed in Part I of this review, the geographic distribution of multiple sclerosis (MS) and the change in risk among migrants provide compelling evidence for the existence of strong environmental determinants of MS, where "environmental" is broadly defined to include differences in diet and other behaviors. As we did for infections, we focus here primarily on those factors that may contribute to explain the geographic variations in MS prevalence and the change in risk among migrants. Among these, sunlight exposure emerges as being the most likely candidate.
Because the effects of sun exposure may be mediated by vitamin D, we also examine the evidence linking vitamin D intake or status to MS risk. Furthermore, we review the evidence on cigarette smoking, which cannot explain the geographic variations in MS risk, but may contribute to the recently reported increases in the female/male ratio in MS incidence. Other proposed risk factors for MS are mentioned only briefly; although we recognize that some of these might be genuine, evidence is usually sparse and unpersuasive.
Ann Neurol. 2007 Jun;61(6):504-13.
Some hints from this recent scientific review in 'Neurological Progress' section:
"The effects in EAE (experimental autoimmune encephalomyelitis), an animal model of MS, appear particularly striking; in several experiments, injection of 1,25(OH)2D was found to completely prevent the clinical and pathological signs of disease.(41-42)
Furthermore, the onset of EAE was accelerated in vitamin D deficient mice (42) and was delayed and attenuated by providing vitamin D supplements (43)."
41) J Clin Invest 1991;87:1103-1107.
42) Proc Natl Acad Sci USA 1996;93:7861-7864.
43) J Immunol 2005;175:4119-4126.
Just look at the publication years of these articles...
Talking about how Science is going too FAST!!!
ikod [;D]
Facts do not cease to exist because they are ignored
Aldous Huxley
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Childhood sun exposure influences risk of multiple sclerosis in monozygotic twins.
Islam T, Gauderman WJ, Cozen W, Mack TM.Department of Preventive Medicine, University of Southern California, Los Angeles, CA, USA.
OBJECTIVE: To address the role of childhood sun exposure on the risk of multiple sclerosis (MS) after controlling for genetic susceptibility, we investigated the association between sun exposure and MS comparing disease-discordant monozygotic (MZ) twins.
METHOD: Twins with MS were sought by yearly newspaper advertisements throughout North America from 1980 to 1992. Diagnosis was verified by updated medical documentation through 2005. This analysis was restricted to 79 disease- and exposure-discordant monozygotic twin pairs who had ranked themselves before 1993 in relation to each of nine childhood sun exposure activities. A sun exposure index (SI) was defined as the sum of those exposures for which one twin ranked higher than his or her co-twin. The SI difference within each twin pair was calculated by subtracting the SI value of the affected twin from the SI value of the unaffected twin (range -9 to +9). The results were then analyzed using conditional logistic models.
Result: Each of the nine sun exposure-related activities during childhood seemed to convey a strong protection against MS within MZ twin pairs. Depending on the activity, the odds ratio (OR) ranged from 0.25 to 0.57. For example, the risk of subsequent MS was substantially lower (OR 0.40, 95% CI 0.19 to 0.83) for the twin who spent more time suntanning in comparison with the co-twin. For each unit increase in SI, the relative risk of MS decreased by 25%.
CONCLUSION: Early sun avoidance seems to precede the diagnosis of multiple sclerosis (MS). This protective effect is independent of genetic susceptibility to MS.
Neurology. 2007 Jul 24;69(4):381-8.