LEAD
Action News vol 10 no 2, June 2010, ISSN 1324-6011
Incorporating Lead Aware Times ( ISSN 1440-4966) and Lead Advisory Service
News (ISSN 1440-0561)
The Journal of The LEAD (Lead Education and Abatement Design) Group Inc.
Folate (Vitamin M)
and Folic Acid (Vitamin B9),
different forms of the same substance (folic acid is the supplementary
form), increase lead absorption in the gut but improve lead excretion and
may make it harder for lead to bind to blood elements. Recent studies
indicate it is associated with lower blood lead, and more importantly, may
protect to some degree from the intellectual impairment associated with
even moderate blood lead levels in children - though the mechanisms are
not yet understood. Folate deficiency can exacerbate lead-induced anemia
by adding megaloblastic anemia (depressed red blood cell production) to
hypochromic (caused by oxygen deficient red blood cells) and microcytic
(due to small short lived red blood cells) anaemia.
Folate is found in good
quantities in green leafy vegetables, fortified breakfast cereals,
legumes, some seeds or fruit, liver and baker’s yeast. Australia began
compulsory fortification of bread with B9 in mid September 2009, as have
other countries including the USA, but organic bread is not fortified.
Pasteurized cow’s milk contains reasonable levels, while some fermented
products (some yogurts and soft cheeses) have higher levels. Equally
importantly, cow’s milk may enhance the body’s ability to utilize
folate. Prolonged cooking can destroy most folate from vegetable sources
but has little impact on folate from animal sources. Alcohol, smoking, and
to a lesser extent coffee consumption can reduce serum (blood) folates,
while deficiencies in thiamine (B1), riboflavin (B2). niacin (B3) and
cobalamin (B12) can interfere with folate use within the body. It is
generally recommended that folate/folic acid intake not exceed 1mg a day,
as higher amounts may conceal vitamin B12 deficiency, which can lead to
neurological and nerve damage. High levels of serum folate have been
partially linked to mental decline in the elderly and tentatively, at
least in its supplemental form (folic acid), some cancers.
Folate or
folic acid (vitamin B9): Found predominantly in vegetables.
Significant quantities are obtained from breakfast cereal
[cornflakes, pictured] while the cow’s milk (rear row) consumed
with these products can enhance folate use inside the body. Yeast
abstract [vegemite, pictured] is extremely high in folate as is
liver (chicken, ox, calf, pig, goose) (centre, second row). Other
good sources include wheat germ, some cheeses (left centre row)
particularly soft cheeses and some yogurt (not pictured), beans (mung,
soy, white [pictured]), chickpeas (right, centre row), parsley
root, kale, chervil, spinach, and broccoli (front row). All
non-organic bread in Australia by law must be made with folic acid
enhanced flour (centre left).
Folic Acid Jane
Higdon The Linus Pauling Institute http://lpi.oregonstate.edu/infocenter/vitamins/fa/
[A good introduction but not as comprehensive of recent research as
the wikipedia entry. Has a good, brief easy to understand explanation
of interactions between B9, B6 and B12 to produce methionine
(mentioned later in this article) and cysteine (used to manufacture
glutathione).]
Folic Acid Wikipedia http://en.wikipedia.org/wiki/Folic_acid [Not as easy to read
as the Linus Pauling Institute article but is more comprehensive of
recent developments. It is recommended that you read this article
after the Linus Pauling article for a rounded general introduction to
the role of folate.]
Determinants of the
Blood Lead Level of US Women of Reproductive Age Lee, Mi-Gyung; Chun,
Ock Kyoung; Sung, Wan O. J Am College of Nutr, Vol. 24, No. 1, 1–9
(2005) www.jacn.org/cgi/reprint/24/1/1 [Finds that low folate levels
are associated with higher blood lead levels. Makes the point of the
different effects of folate on lead absorption and excretion.]
Associations between
Cognitive Function, Blood Lead Concentration, and Nutrition among
Children in the Central Philippines Solon, Orville; Ridell, TJ;
Qumbo,SA; Butrick,
E; Aylward, GP; Bacate,ML
& Peabody, JW The Journal of Pediatrics, Volume 152, Issue 2,
Pages 237-243. http://linkinghub.elsevier.com/retrieve/pii/S0022347607008530
[Finds that not only is folate associated with lower blood lead but
that it is linked with lower lead-induced IQ damage in children.
Further research would be needed to confirm this link.]
Effect of cow’s
milk on food folate bioavailability in young women Mary Frances
Picciano, Sheila G West, Amanda L Ruch, Penny M Kris-Etherton,
Guixiang Zhao, Kelley E Johnston Deborah H Maddox, Valerie K Fishell,
Douglas B Dirienzo, and Tsunenobu Tamura Am J Clin Nutr
2004;80:1565-9. Dec 2004 www.ajcn.org/cgi/reprint/80/6/1565
[Indicates that some folate indicators are improved by consuming
folate with dairy products, even when serum folate is unaffected]
Plasma Folate,
Vitamin B6, Vitamin B12, and Homocysteine and Pancreatic Cancer Risk
in Four Large Cohorts Eva Schernhammer, Brian Wolpin, Nader Rifai,
Barbara Cochrane, Jo Ann Manson, Jing Ma, Ed Giovannucci, Cynthia
Thomson, Meir J. Stampfer, and Charles Fuchs Cancer Res 2007; 67:
(11). June 1, 2007 http://cancerres.aacrjournals.org/cgi/reprint/67/11/5553
[Found that while folate in food slightly reduced the risk of
pancreatic cancer taking multi-vitamins (which use folic acid) may
increase the risk. This is one of a number of studies that indicates
that in its supplemental form, folic acid, it may increase cancer
risks, notably among smokers, though the evidence about folate or
folic acid in food is less clear.]
