Chromium is used primarily to assist in the control of
blood sugar in cases of impaired glucose tolerance and
diabetes.(1,2)
Chromium may be useful to reduce obesity, enhance lean body mass, and to
lower triglycerides and total cholesterol, since chromium mediated insulin
function is related to these concerns.(1,2)
Chromium may be useful in treating and managing reactive
hypoglycemia.(3)
In 1957 Walter Mertz and Kenneth Schwartz isolated a
substance from pork kidney that was able to overcome impaired glucose
tolerance in rats, hypothesizing the existence of a glucose tolerance
factor. In 1959 chromium was found to be the active constituent in the
glucose tolerance factor. The hypothesized structure of the glucose
tolerance factor envisions chromium bound to nicotinic acid, and the amino
acids glycine, cysteine, and glutamic acid. It has not been possible to
purify the glucose tolerance factor to date, but low molecular weight
chromium compounds isolated from biological fluids do show an ultraviolet
absorption peak corresponding to nicotinic acid.(2)
Following the identification of chromium as a key player in the
performance of the glucose tolerance factor substance, other researchers
and clinicians found that giving simple chromium chloride in the order of
250 mcg per day markedly improved glycemic control and reduced exogenous
insulin requirements in diabetic patients.(2) These observations were
particularly important to patients on long-term total parenteral nutrition
who had drifted into diabetes and dyslipidemia because chromium was not
supplied.(2) Chromium has now become thoroughly established as an
important nutrient in the management of blood sugar and lipids. Clinical
studies have shown that chromium can decrease fasting blood sugar, improve
glucose tolerance, lower insulin levels, decrease total cholesterol and
triglycerides, and raise HDL cholesterol.(1,2) Even in non-diabetics,
chromium may have something to offer, however, its effects are not
remarkable in those who are not chromium deficient.(1,2) Other factors
contribute to insulin resistance and the many spin-off effects associated
with it. Chromium has also been used for weight loss, and is often used in
conjunction with hydroxycitric acid (Citrimax).
Chromium has a theoretical basis for being able to assist in weight loss,
since inappropriate weight gain is one of the features associated with
insulin resistance. However, chromium is not expected to do well if it is
not depleted from body stores. It should be encouraged for weight loss
because its usefulness can only be determined empirically. However, used
with Citrimax, the effect of chromium may not be evident. Chromium then
becomes more important after the Citrimax is discontinued. The older a
person is, the greater is the risk of being chromium depleted, and so
chromium supplementation in an older person may provide more noticeable
help in weight loss over time.
People who eat whole grains and whole grain flours and plant foods well,
may actually have sufficient chromium in their bodies. Too many calories,
too much carbohydrate high up on the glycemic index, and too much
saturated fat with too little omega-3 fat, are three common conditions
that will drive in the direction of insulin resistance, which will in turn
drive body fat mass up.
Chromium works at the insulin receptor site, but it is not the principal
agent in controlling how many receptors will be maintained and how
efficiently they work. The number and functionality of insulin receptors
is significantly influenced by cell membrane fluidity, which is related to
the degree that long chain omega-3 fatty acids comprise the phospholipid
tails, and by the degree that saturated fatty acid concentrations are
optimal. So even with good chromium stores, insulin receptors may under
perform due to membrane fluidity issues.(7,8)
Protracted high stress conditions contributes to
chromium excretion and may be a factor in the emergence of high blood
sugar and dyslipidemia.(2)
Initiation of chromium supplementation in diabetic patients on
sulfonylurea medication or insulin may potentiate sugar clearance quickly
enough to effect some degree of hypoglycemia.
Increasing gastric pH as in chronic use of antacids,
H2-blockers, or proton pump inhibitors may reduce the absorption of
chromium.(2,5)
ASA and NSAID medications may increase chromium absorption and retention
by blocking a prostaglandin inhibition to absorption, and
16,16-dimethyl-protaglandin E2 decreased chromium absorption.(2,5)
Corticosteroids can increase blood sugar by increasing urinary excretion
of chromium, and may precipitate diabetes or make diabetic control more
difficult.(6)
Chromium HVP is well tolerated at 200 mcg or less. There
have been many supplementation trials in humans with chromium chloride and
chelated chromium compounds without reports of toxicity.(2)
Reported adverse side effects are associated with amounts in excess of 200
mcg. Chronic use of high amounts of chromium picolinate, an American form
of chromium not legally sold in Canada, has been associated with
significant adverse effects. Amounts as high as 1200 to 2400 mcg per day
have been related to inappropriate weight loss, anemia, thrombocytopenia,
hemolysis, liver dysfunction, and renal failure.(4) Such use might be
possible in those who are irrationally concerned about losing weight or
achieving an athletic muscular body.
A concern that chromium may accumulate to toxic levels when excessive
amounts are used over a long time, have been expressed. Trivalent chromium
has been shown in animal models to cause DNA damage at high enough
concentrations.(9) What constitutes an amount that will lead to human
toxicity is not known, but there is no reason for consumers to use more
than 200 mcg per day, which is the amount that is most commonly found in
stores, and which is expected.
The traditionally recommended amount for adults is 50 to
200 mcg per day.(1) Research done in the mid to late 80s to establish an
adequate daily intake of chromium demonstrated that 25 mcg per day from
dietary sources was able to keep tested subjects in chromium equilibrium.
This observation most likely precludes any need to encourage use of more
than the commonly accepted 200 mcg per day, unless called for by a
clinician.
Among other factors, absorption of chromium is a function of dose, and the
status of chromium depletion. Higher does lead to reduced absorption by an
intrinsic homeostatic mechanism, and depleted subjects and animals absorb
incrementally more up to equilibrium and over time.(2) In one carefully
conducted study, supplemented chromium was excreted in the feces, and not
via a bile route, with a mean of 981 percent recoverable in the
feces.(2)
However, adequate intake in diabetic patients may be
better stated as 200 mcg per day.(2) Higher amounts may be useful in
diabetes. Chromium deficiency is common in type 2 diabetics.(1)
1. Murray, Michael T., Encyclopedia of Nutritional
Supplements, Prima Publishing, Rocklin, CA, 1996
2. Stoecker, Barbara J., Chromium, in Maurice E Shils, James A. Olson,
Moshe Shike, A Catharine Ross, editors, Modern Nutrition In Health and
Disease, ninth edition, Lippincott Williams & Wilkins New York, 1999
3. Anderson, R.A., et al, Effects of supplemental chromium on patients
with symptoms of reactive hypoglycemia, Metabolism, 36(4): 351-355,
1987 4. Cerulli, J., et al, Chromium picolinate toxicity, Ann
Pharmacotherapy, 32: 428-431, 1998
5. www.nap.edu/books/0309072794/html/
6. Ravina, A., et al, Reversal of corticosteroid-induced diabetes mellitus
with supplemental chromium, Diabet Med, 16(2): 164- 167, 1999
7. Simopoulos, Artemis P., Jo Robinson, The Omega Plan, HarperCollins, New
York, 1998
8. Slater, Simon J., et al, Polyunsaturation in cell membranes and lipid
bilayers and its effects on membrane proteins, Lipids, Vol 31, Supplement,
S189-S192, 1996
9. Sterns, D.M., et al, A prediction of chromium (III) accumulation in
humans from chromium dietary supplements, FASEB J, 9(15): 1650-1657,
1995
These statements have not been evaluated by the Food and Drug Administration (FDA). Products are intended to support general well being and are not intended to treat, diagnose, mitigate, prevent, or cure any condition or disease. If conditions persist, please seek advice from your medical doctor.
