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Blood Glucose

How much glucose, or blood sugar, is floating around in your blood. Fasting blood glucose is measured during a fasted state and Postprandial blood glucose after a meal. Both used as indicators of diabetes risk.

Research analysis led by Kamal Patel.
All content reviewed by the Examine.com Team. Published: Feb 6, 2013
Last Updated:

Things To Know & Note

Also Known As

blood sugar

Human Effect Matrix

The Human Effect Matrix looks at human studies (it excludes animal and in vitro studies) to tell you what supplements affect blood glucose
Grade Level of Evidence
Robust research conducted with repeated double-blind clinical trials
Multiple studies where at least two are double-blind and placebo controlled
Single double-blind study or multiple cohort studies
Uncontrolled or observational studies only
Level of Evidence
? The amount of high quality evidence. The more evidence, the more we can trust the results.
Outcome Magnitude of effect
? The direction and size of the supplement's impact on each outcome. Some supplements can have an increasing effect, others have a decreasing effect, and others have no effect.
Consistency of research results
? Scientific research does not always agree. HIGH or VERY HIGH means that most of the scientific research agrees.
Notes
grade-a Minor Very High See all 29 studies
In looking at the entirety of the data on type II diabetic persons, there does appear to be a mild reduction in fasting blood glucose despite no apparent changes in insulin sensitivity or HbA1c. No significant or reliable effect in non-diabetic persons.
grade-a Minor Moderate See all 10 studies
A decrease in fasting blood glucose has been noted over time with standard supplemental doses of panax ginseng in diabetics, with this dose being ineffective in altering the blood glucose of non-diabetics; high (20g) doses may acutely reduce blood glucose in healthy persons
grade-a - High See all 19 studies
No significant alterations in fasting glucose are seen over time with fish oil supplementation
grade-b Strong Very High See all 4 studies
The usage of berberine in reducing blood glucose, according to the most recent meta-analysis, is comparable to the oral hypoglycemic drugs Metformin or Glibenclamide; this suggests berberine is one of the more effective supplements for blood glucose reductions.
grade-b Notable Very High See all 3 studies
The decrease in blood glucose is acute due to blocking carbohydrate absorption (no studies on long-term glucose influence) and standard supplemental doses range between 20-25% inhibition of carbohydrate absorption, with is quite reliable and significant.
grade-b Minor High See all 3 studies
There may be an acute increase in blood glucose when caffeine is paired with a carbohydrate containing meal, but long term ingestion of caffeine does not appear to adversely influence glucose (only acutely)
grade-b Minor Low See all 4 studies
No apparent influence on fasting blood glucose, but an 11-22% reduction in the postprandial spike.
grade-b Minor - See all 24 studies
The reduction in glucose is likely small and inconsistent overall, and most likely to be meaningful for people with type 2 diabetics. It is unlikely that plain turmeric has notable effects, and high potency curcuminoids are more likely to have an effect.
grade-b Minor Moderate See all 9 studies
Blood glucose can be reduced in women with PCOS secondary to treating that condition.
grade-b Minor Very High See all 3 studies
A decrease in blood glucose has been noted with carnitine supplementation
grade-b Minor Moderate See all 8 studies
There appears to be some reduction in blood glucose in diabetics and persons with elevated glucose with magnesium supplementation, which may be secondary to better insulin functioning from the pancreas. The reduction in glucose is not overly impressive and is somewhat unreliable, and increases in glucose have been noted to occur during exercise when magnesium is supplemented in healthy persons
grade-b Minor Very High See all 4 studies
Reductions in blood glucose seen with psyllium seem to occur reliably in persons with high blood glucose, but are transient benefits and not of a remarkable magnitude.
grade-b Minor Low See all 3 studies
There may be a very small glucose reducing effect of stevia consumption, but it does not appear to apply to everybody and is unreliable. Requires more evidence.
grade-b Minor High See all 7 studies
There appears to be an increase in fasting glucose concentrations among users of pharmacological doses of niacin when compared to controls, thought to be related to insulin resistance.
grade-b Minor - See all 20 studies
Studies are very mixed, however, there appears to be a modest benefit to fasting glucose in type 2 diabetics. More research is needed before having great confidence in this effect. The vast majority of studies don't treat this outcome as their primary outcome and more glucose-specific research is needed.
grade-b Minor High See all 3 studies
A reduction in blood glucose has been observed alongside improvements in insulin sensitivity in obese persons who may have been zinc deficient.
grade-b - - See all 3 studies
grade-b - High See all 5 studies
Although the leaf extract has once been associated with a reduction in blood glucose, the fruits do not appear to inhibit carbohydrate absorption nor reduce fasting glucose concentrations.
grade-b - Very High See all 3 studies
There do not appear to be any significant influences of supplemental citrulline on blood glucose concentrations
grade-b - High See all 10 studies
It is possible that the improvement in insulin sensitivity could beneficially influence blood glucose, but most studies assessing diabetic or healthy subjects find no difference in fasting glucose concentrations. The increase in serum glucose in response to an oral glucose tolerance test may be attenuated somewhat.
grade-b - Very High See all 9 studies
Insufficient evidence to support reliable increases in blood glucose
grade-b - High See all 3 studies
Most evidence suggests no alterations to fasting blood glucose levels
grade-b - Very High See all 4 studies
No known alterations in fasting blood glucose concentrations or glucose concentrations during exercise seen with betaine supplementation.
grade-b - Very High See all 5 studies
Vitamin E does not appear to influence blood glucose in otherwise healthy persons nor in diabetics (type I or type II) relative to placebo.
grade-c Notable Very High See 2 studies
Decrease in blood glucose in diabetics given gynostemma tea or root appears to be greater than other supplements; currently no studies in otherwise healthy persons.
grade-c Minor Very High See all 5 studies
A small decrease in blood glucose has been noted with ashwagandha, but evidence for people with type 2 diabetes is lacking.
grade-c Minor - See study
Appears somewhat potent at acutely reducing blood glucose following a meal (possibly by inhibiting absorption) but no long term studies.
grade-c Minor - See study
A possible reduction in blood glucose may occur secondary to pancreatic stimulation with high doses of capsaicin
grade-c Minor - See study
Not overly remarkable reductions in blood glucose
grade-c Minor - See study
May decrease blood glucose in diabetics at low doses, but the evidence at this moment in time is limited (due to differences between groups at the start of the study)
grade-c Minor - See study
May reduce blood glucose levels, not overly potent in doing so
grade-c Minor - See study
A decrease in glucose consumption during exercise (without affecting metabolic rate and due to an increase in fat oxidation) has once caused an acute lowering of glucose. The magnitude is quite minor, and there is no evidence to assess the effects of eleuthero on fasting blood glucose or in diabetes management
grade-c Minor Very High See all 3 studies
Appears to result in a decrease of blood glucose following ingestion of fenugreek
grade-c Minor Very High See 2 studies
An increase in blood glucose may occur from direct conversion of glutamine into glucose following oral ingestion
grade-c Minor - See study
A decrease in fasting blood glucose is noted with green tea catechin ingestion
grade-c Minor - See study
May reduce fasting blood glucose following prolonged supplementation; confounded with both weight loss (seen in trials) and industry influence
grade-c Minor Moderate See 2 studies
There appears to be significant interactions with olive leaf and diabetes, and research is too preliminary to come to conclusions. Olive leaf may reduce blood glucose in diabetics only
grade-c Minor - See study
A decrease in blood glucose has been noted, practical significance unknown
grade-c
Minor
- See 2 studies
A decrease may occur in persons at risk of cardiovascular disease with daily ingestion of Rooibos tea, although at least one study noted an inexplicable acute increase in otherwise healthy persons (faded within an hour of ingestion).
grade-c Minor Very High See 2 studies
May slightly reduce blood glucose in otherwise healthy older persons, but not to a remarkable degree
grade-c Minor Moderate See all 3 studies
Has been implicated in reducing postprandial glucose while having no significant influence on fasting glucose levels.
grade-c Minor - See study
An increase in glucose has been noted with sea buckthorn, but it was from one study which had the control group (coconut oil) also raise blood glucose; this may just be due to added calories.
grade-c Minor Moderate See all 3 studies
Reductions in blood glucose seen are not overly remarkable or noteworthy
grade-c - - See study
Insufficient evidence to support changes in blood glucose
grade-c - - See study
No significant influence on blood glucose relative to control.
grade-c - See study
A small decrease in blood glucose is noted with oral supplementation of ALA, related to the glucose disposal properties
grade-c - - See study
grade-c - Very High See 2 studies
No significant influence on fasting blood glucose concentrations even in persons with impaired glucose tolerance
grade-c - Very High See 2 studies
There is still a possibility that artichoke extract is able to aid the blood glucose of diabetics, but currently the best evidence does not support this conclusion
grade-c - - See study
grade-c - - See study
No significant influence on blood glucose levels
grade-c - Moderate See 2 studies
There does not appear to be a likely alteration in blood glucose concentrations per se with BCAA supplementation, but the increased fat oxidation may attenuate the decline in glucose seen during prolonged exercise (which would appear to be a relative increase at later time points)
grade-c - Very High See 2 studies
Insufficient evidence to support changes in blood glucose with CoQ10 supplementation
grade-c - - See study
No significant alterations in blood glucose noted with ECA supplementation
grade-c - - See study
grade-c - - See study
Supplementation of garlic does not appear to significantly reduce fasting blood glucose in persons with metabolic syndrome.
grade-c - - See study
In diabetics, ginkgo does not appear to significantly reduce blood glucose
grade-c - - See study
No significant influence noted on fasting glucose levels (may reduce postprandial slightly)
grade-c - Very High See 2 studies
There are no known significant alterations in blood glucose seen with supplementation of hesperidin
grade-c - Very High See 2 studies
No significant alterations in blood glucose noted
grade-c - - See study
Blood glucose appears to be unaffected following ingestion of Japanese knotweed in otherwise healthy lean persons
grade-c - - See study
No significant influence on blood glucose levels
grade-c - - See study
grade-c - - See study
grade-c - - See study
No significant influence on blood glucose levels
grade-c - - See study
No significant influence on fasting glucose levels
grade-c - Very High See all 5 studies
Although the best evidence to date shows no change in blood glucose, these studies were not structured to assess the influence on diabetics; in diabetics, there appears to be a significant reduction in glucose.
grade-c - - See study
Supplementation of pterostilbene in hypercholesterolemic adults does not appear to influence blood glucose relative to control.
grade-c - - See 2 studies
grade-c - - See study
No significant alterations in blood glucose are detected with quercetin supplementation.
grade-c - Very High See 2 studies
No significant influence on fasting blood glucose concentrations are known with supplementation of red clover extract.
grade-c - Very High See 2 studies
Both fasting and postprandial glucose in persons given prolonged rose hip supplementation is not affected relative to placebo.
grade-c - Very High See 2 studies
No significant effect on blood glucose concentrations at rest or during exercise is seen with sodium bicarbonate supplementation
grade-c - - See study
No significant influence on fasting glucose levels
grade-c - - See study
Ursolic acid with meals in athletic subjects has failed to alter fasting glucose concentrations relative to placebo.
grade-c - - See study
No significant influence on fasting blood glucose levels
grade-c - - See study
Despite an improvement in insulin sensitivity, the lone study failed to note any significant changes in blood glucose concentrations in a fasted state
grade-c - Very High See all 5 studies
No significant influence on fasted blood glucose levels, may decrease postprandial glucose levels (relative to no protein ingestion) due to the release of insulin
grade-c - - See study
No significant influence on fasting blood glucose in nondiabetic obese women who consume Yacon relative to placebo, despite weight loss.
grade-d Notable - See study
The reduction in blood glucose appeared to range from 20-30%, which is more than usually seen with dietary supplements.
grade-d Notable - See study
Preliminary evidence suggested that 3g of the fruits (a fairly reasonable dosage) was as effective as 5mg glibenclamide twice daily
grade-d Minor - See study
Requires more studies before conclusions can be made, appears to simply be exerting anti-oxidant effects.
grade-d Minor - See study
Appears to reduce the spike and overall exposure to glucose following an oral glucose tolerance test in both healthy and diabetic adults
grade-d Minor - See study
Preliminary trial in type II diabetics noted a reduction in fasting glucose concentrations to 10-14% with four weeks of colostrum supplementation; no control was used for reference.
grade-d Minor - See study
A lone study that is underpowered suggest a decrease in blood glucose (measured by chance during a blood panel); not enough robust evidence supports a reduction in blood glucose but it cannot be ruled out
grade-d Minor - See study
May reduce blood glucose, with the potency demonstrated (fairly good) limited by the quality of the evidence currently
grade-d Minor Very High See 2 studies
There appears to be a decrease in postprandial blood glucose following a meal in type II diabetics (21%), and this hypoglycemia may apply to non-diabetics based on rodent research, and appears to increase with time.
grade-d Minor - See study
A reduction reaching 10.2% blood glucose has been noted with continual supplementation of ruscus aculeatus in type II diabetic persons in this non-placebo controlled study; requires replication.
grade-d Minor - See study
One randomized, controlled trial found a modest reduction in fasting and 2 hour postprandial glucose when taking 1 g/d of a Tribulus extract
grade-d Minor - See study
A decrease in blood glucose has been noted in type II diabetics which is thought to be secondary to reducing hepatic synthesis of glucose
grade-d Minor - See study
A slight decrease in blood glucose has been noted with Mate consumption in type II diabetics; no evidence in otherwise healthy persons
grade-d - - See study
No significant alterations in blood glucose seen with ginger ingestion
grade-d - - See study
grade-d - - See study
Insufficient evidence to support alterations in blood glucose.
grade-d - - See study
Short term ingestion of PQQ supplementation in otherwise healthy adults has failed to significantly influence serum glucose concentrations.
grade-d - - See study
No significant alterations in fasting blood glucose are noted with daily berry consumption in otherwise healthy persons.
grade-d - - See study
No significant influence on blood glucose in diabetics
grade-d - - See study
No significant influence on blood glucose in diabetics detected
grade-d - - See study