Also indexed as: Animal-Source Insulin: Iletin, Human Analog Insulin: Humanlog, Human Insulin (Humulin, Novolin), NovoRapid, Oralin
Insulin is a natural protein made by the pancreas that helps the body use sugar. Insulin is injected by all people with type 1 (insulin-dependent) diabetes mellitus and by some people with type 2 (non-insulin-dependent) diabetes mellitus to help control blood sugar levels.
Any substance (dietary, supplemental, herbal, and others) that affects blood sugar levels will directly or indirectly affect the amount of insulin required by a person with diabetes. For example, consumption of a high-fiber diet and/or supplementation with nutrients such as chromium, biotin, vitamin E, or herbs such as Gymnema sylvestre will often improve blood sugar control in diabetics. In such cases, the amount of insulin may need to be reduced in order to avoid a hypoglycemic reaction. Anyone taking insulin should consult the prescribing physician before making dietary changes or taking nutrients or herbs that are designed to lower blood sugar levels.
Summary of
Interactions with Vitamins, Herbs, and Foods
In some cases, an herb or supplement may appear in more than one category, which may seem
contradictory. For clarification, read the full article for details about the summarized
interactions.
 May Be Beneficial: Depletion or
interference—The medication may deplete or interfere with the absorption or
function of the nutrient. Taking these nutrients may help replenish them. |
DHEA |
| May Be Beneficial: Supportive
interaction—Taking these supplements may support or otherwise help your medication
work better. |
Biotin Fenugreek Vitamin E |
Avoid: Adverse interaction—Avoid these supplements when taking this
medication because taking them together may cause undesirable or dangerous results. |
Tobacco |
Check: Other—Before taking any of these supplements or eating any of
these foods with your medication, read this article in full for details. |
Chromium Gymnema sylvestre* |
| Side effect reduction/prevention |
None known |
| Reduced drug absorption/bioavailability |
None known |
An asterisk (*) next to an item in the summary indicates that the interaction is supported only by weak, fragmentary, and/or contradictory scientific evidence.
Interactions with Dietary Supplements
Chromium
Chromium supplements have been shown to improve blood sugar control in people with
diabetes.1 Consequently, supplementing with chromium could reduce blood sugar
levels in people with taking insulin, potentially resulting in abnormally low blood sugar
levels (hypoglycemia). While chromium
supplementation may be beneficial for people with
diabetes, its use in combination with insulin or with any other blood sugar-lowering
medication should be supervised by a doctor.
Dehydroepiandrosterone (DHEA)
Insulin has been shown to decrease the levels of DHEA and DHEA-sulfate in the
blood.2 More research is needed to determine the significance of this finding.
Interactions with Herbs
Fenugreek (Trigonella foenum-graecum)
In a controlled study of patients with type 1 diabetes, fenugreek (100 grams per day for ten
days) was reported to reduce blood sugar, urinary sugar excretion, serum cholesterol, and
triglycerides, with no change in insulin levels.3 In a controlled study of people
with type 2 diabetes, fenugreek (25 grams per day for 24 weeks) was reported to significantly
reduce blood glucose levels.4 People using insulin should talk with their
prescribing doctor before incorporating large amounts of fenugreek into their diet.
Gymnema
sylvestre
Although no interactions have been reported, gymnema may decrease the required daily dose of
insulin.5 Therefore, people currently using insulin for the treatment of diabetes
should discuss the use of this herb with their healthcare professional.
Interactions with Foods and Other Compound
Food
Diet is an important factor in effective
diabetes prevention and treatment. People using insulin should monitor their blood sugar
carefully and talk with their doctor about the role of diet in diabetes control.
Alcohol
Alcohol may increase the action of insulin, leading to hypoglycemia (low blood sugar).6 People
using insulin should avoid alcohol.
Tobacco (Nicotiana species)
Smoking may decrease insulin activity,7 and it compounds the health problems
associated with diabetes. People using insulin are cautioned to avoid smoking.
1. Anderson RA, Cheng N, Bryden NA, Polansky MM, Cheng N, Chi J, et al. Elevated intakes of supplemental chromium improve glucose and insulin variables in individuals with type 2 diabetes. Diabetes 1997;46:1786–91.
2. Lavallee B, Provost PR, Kahwash Z, et al. Effect of insulin on serum levels of dehydroepiandrosterone metabolites in men. Clin Endocrinol 1997;46:93–100.
3. Sharma RD, Raghuram TC, Sudhakar Rao N. Effect of fenugreek seeds on blood glucose and serum lipids in type 1 diabetes. Eur J Clin Nutr 1990;44:301–6.
4. Sharma RD, Sakar A, Hazra DK, et al. Use of fenugreek seed powder in the management of non-insulin dependent diabetes mellitus. Nutr Res 1996;16:1131–9.
5. Shanmugasundaram ER, Rajeswari G, Baskaran K, et al. Use of Gymnema sylvestre leaf extract in the control of blood glucose in insulin-dependent diabetes mellitus. J Ethnopharmacol 1990;30:281–94.
6. Threlkeld DS, ed. Hormones, Antidiabetic Agents, Insulin. In Facts and Comparisons Drug Information. St. Louis, MO: Facts and Comparisons, Oct 1997, 129f–9j.
7. Threlkeld DS, ed. Hormones, Antidiabetic Agents, Insulin. In Facts and Comparisons Drug Information. St. Louis, MO: Facts and Comparisons, Oct 1997, 129f–9j.