Ironjustic
Sun, Aug-12-07, 17:17
http://www.townsendletter.com/May2007/shorts0507.htm
Iron Intake, Meat, and Type 2 Diabetes Consumption of heme
iron found in animal products, particularly red meat, is
associated with increased insulin resistance and diabetes risk
in men and women. Unlike iron found in dried fruit, kelp, some
whole grains, and brewer's yeast, heme iron from red meat,
fish, and poultry is highly bioavailable and readily stored in
the body. Epidemiological studies, cited by Swapnil Rajpathak
and colleagues at Harvard Medical School, have associated high
iron stores with an increased risk of cardiovascular disease,
metabolic syndrome, gestational diabetes, and type 2 diabetes.
Different hypotheses have been proposed for this relationship.
Increased oxidative stress due to iron's action as a catalyst
in the formation of hydroxyl radicals is one possible factor.
Also, high iron levels may slow the liver's extraction of
insulin from the bloodstream. A third explanation is that iron
deposits in pancreatic b-cells may hamper insulin secretion.
A prospective cohort study, conducted within the Nurses'
Health Study, reported "no association between total, dietary,
supplemental, or non- heme iron intake and the risk of
diabetes" among women. Heme iron, however, showed a
statistically significant association with diabetes risk.
Rajpathak and colleagues reported that relative risk increased
as consumption increased, after controlling for age, body mass
index (BMI), and other risk factors. The group of women who
consumed the most meat increased their risk of diabetes by
28%. When not controlling for other diabetic risk factors, the
group of women who ate 2.25 mg or more of meat a day had a 52%
greater risk of developing diabetes than the group who ate
less than .75 mg of meat per day. Another study by Harvard
researchers found that women who eat bacon, hot dogs, and
sausage frequently have a greater risk of developing diabetes
than meat-eaters who stick to beef, lamb, and/or pork.
A third Harvard study looked at the relationship of iron
intake and diabetes among men. As in the women's study, total
iron intake was not associated with type 2 diabetes. This
study, however, found that only heme iron from red meat was
associated with an increased risk: "...the association may
have been confounded by other components of red meat intake
because heme-iron intake from sources other than red meat
(e.g., fish, chicken, and egg) was not associated with the
risk of type 2 diabetes."
A 2001 study involving 30 lacto-ovo vegetarians and 30
meat-eaters reported a correlation between insulin resistance
and body iron stores, as measured by serum ferritin
concentrations. The vegetarians had eaten eggs but no meat
within the previous five years. Meat-eaters had eaten animal
muscle at least once a day for five years before the study.
All sixty participants were lean, glucose-tolerant, and had
normal blood pressure. Nancy W. Hua and co-authors reported,
"Lacto- ovo vegetarians were more insulin-sensitive than
meat-eaters, with a steady-state plasma glucose (mmol/l) of
4.1 (95% CI 3.5, 5.0) v. 6.9 (95% CI 5.2, 7.5) for meat-eaters
(P=0.0028)." Six of the male meat- eaters also underwent
phlebotomy to lower their blood iron concentration range to
that of the vegetarian group. Steady-state plasma glucose
concentrations were 41% lower after phlebotomy (P=0.0008),
"indicating enhancement of insulin-stimulated glucose disposal
following Fe depletion."
Hua NW, Stoohs RA, Facchini FS. Low iron status and enhanced
insulin sensitivity in lacto-ovo vegetarians. British Journal
of Nutrition. 2001;86:515-519.
Jiang R, Ma J, Ascherio A, et al. Dietary iron intake and
blood donations in relation to risk of type 2 diabetes in men:
A prospective cohort study. American Journal of Clinical
Nutrition. 2004;79:70-75. Available at:
www.ajcn.org/cgi/reprint/79/1/70. Accessed February 8, 2007.
Rajpathak S, Ma J, Manson J, et al. Iron intake and the risk
of type 2 diabetes in women. Diabetes Care. June
2006;29(6):1370-1376. Available at:
www.hu.usp.br/plotufo/testo%20MCM%205882%2012%2009%.2006.pdf.
Accessed February 8, 2007. (April 2007: Try this link:
http://care.diabetesjournals.org/cgi/reprint/29/6/1370.pdf
88KB .pdf)
Schulze MB, Manson JE, Willett WC, Hu FB. Processed meat
intake and incidence of type 2 diabetes in younger and
middle-aged women. (Abstract) Diabetologia. November 2003.
Available at: www.springerlink.com/content/5m0a47bn3y3tmvd7/.
Accessed February 8, 2007.
Who loves ya. Tom
Jesus Was A Vegetarian! http://jesuswasavegetarian.7h.com
Man Is A Herbivore! http://tinyurl.com/a3cc3
DEAD PEOPLE WALKING http://tinyurl.com/zk9fk
Iron Intake, Meat, and Type 2 Diabetes Consumption of heme
iron found in animal products, particularly red meat, is
associated with increased insulin resistance and diabetes risk
in men and women. Unlike iron found in dried fruit, kelp, some
whole grains, and brewer's yeast, heme iron from red meat,
fish, and poultry is highly bioavailable and readily stored in
the body. Epidemiological studies, cited by Swapnil Rajpathak
and colleagues at Harvard Medical School, have associated high
iron stores with an increased risk of cardiovascular disease,
metabolic syndrome, gestational diabetes, and type 2 diabetes.
Different hypotheses have been proposed for this relationship.
Increased oxidative stress due to iron's action as a catalyst
in the formation of hydroxyl radicals is one possible factor.
Also, high iron levels may slow the liver's extraction of
insulin from the bloodstream. A third explanation is that iron
deposits in pancreatic b-cells may hamper insulin secretion.
A prospective cohort study, conducted within the Nurses'
Health Study, reported "no association between total, dietary,
supplemental, or non- heme iron intake and the risk of
diabetes" among women. Heme iron, however, showed a
statistically significant association with diabetes risk.
Rajpathak and colleagues reported that relative risk increased
as consumption increased, after controlling for age, body mass
index (BMI), and other risk factors. The group of women who
consumed the most meat increased their risk of diabetes by
28%. When not controlling for other diabetic risk factors, the
group of women who ate 2.25 mg or more of meat a day had a 52%
greater risk of developing diabetes than the group who ate
less than .75 mg of meat per day. Another study by Harvard
researchers found that women who eat bacon, hot dogs, and
sausage frequently have a greater risk of developing diabetes
than meat-eaters who stick to beef, lamb, and/or pork.
A third Harvard study looked at the relationship of iron
intake and diabetes among men. As in the women's study, total
iron intake was not associated with type 2 diabetes. This
study, however, found that only heme iron from red meat was
associated with an increased risk: "...the association may
have been confounded by other components of red meat intake
because heme-iron intake from sources other than red meat
(e.g., fish, chicken, and egg) was not associated with the
risk of type 2 diabetes."
A 2001 study involving 30 lacto-ovo vegetarians and 30
meat-eaters reported a correlation between insulin resistance
and body iron stores, as measured by serum ferritin
concentrations. The vegetarians had eaten eggs but no meat
within the previous five years. Meat-eaters had eaten animal
muscle at least once a day for five years before the study.
All sixty participants were lean, glucose-tolerant, and had
normal blood pressure. Nancy W. Hua and co-authors reported,
"Lacto- ovo vegetarians were more insulin-sensitive than
meat-eaters, with a steady-state plasma glucose (mmol/l) of
4.1 (95% CI 3.5, 5.0) v. 6.9 (95% CI 5.2, 7.5) for meat-eaters
(P=0.0028)." Six of the male meat- eaters also underwent
phlebotomy to lower their blood iron concentration range to
that of the vegetarian group. Steady-state plasma glucose
concentrations were 41% lower after phlebotomy (P=0.0008),
"indicating enhancement of insulin-stimulated glucose disposal
following Fe depletion."
Hua NW, Stoohs RA, Facchini FS. Low iron status and enhanced
insulin sensitivity in lacto-ovo vegetarians. British Journal
of Nutrition. 2001;86:515-519.
Jiang R, Ma J, Ascherio A, et al. Dietary iron intake and
blood donations in relation to risk of type 2 diabetes in men:
A prospective cohort study. American Journal of Clinical
Nutrition. 2004;79:70-75. Available at:
www.ajcn.org/cgi/reprint/79/1/70. Accessed February 8, 2007.
Rajpathak S, Ma J, Manson J, et al. Iron intake and the risk
of type 2 diabetes in women. Diabetes Care. June
2006;29(6):1370-1376. Available at:
www.hu.usp.br/plotufo/testo%20MCM%205882%2012%2009%.2006.pdf.
Accessed February 8, 2007. (April 2007: Try this link:
http://care.diabetesjournals.org/cgi/reprint/29/6/1370.pdf
88KB .pdf)
Schulze MB, Manson JE, Willett WC, Hu FB. Processed meat
intake and incidence of type 2 diabetes in younger and
middle-aged women. (Abstract) Diabetologia. November 2003.
Available at: www.springerlink.com/content/5m0a47bn3y3tmvd7/.
Accessed February 8, 2007.
Who loves ya. Tom
Jesus Was A Vegetarian! http://jesuswasavegetarian.7h.com
Man Is A Herbivore! http://tinyurl.com/a3cc3
DEAD PEOPLE WALKING http://tinyurl.com/zk9fk