What Is Insulin?

Insulin is THE most anabolic hormone in the body and its actions on glucose metabolism work primarily in three tissues:

Muscle
Adipose
Liver
Insulin's anabolic properties make it rather important when thinking about packing on muscle. However, too much insulin could cause you to resemble Professor Klump from The Nutty Professor. Here's why:

Insulin secretion occurs via the -cells in the pancreas with the consumption and digestion of food; particularly in response to a carbohydrate-rich meal. Amino acids can also increase insulin levels, although glucose (carbohydrate) has the greatest stimulatory effect on insulin. Basically, when you consume food, blood glucose rises and insulin is released to control blood glucose levels (not allowing them to go too high).

The best way to maintain healthy insulin levels throughout the day is by eating a wide variety of whole grains, lean proteins, healthy fats, fruits and vegetables. In fact, the only time you should deliberately increase insulin levels is after a workout.

With that being said, there are a number of dietary supplements that MAY enhance blood sugar control and, subsequently, insulin levels. This is by no means a recommendation to try any and all of these; you don't want the opposite effect to occur (low blood sugar, or hypoglycemia), which could happen with higher doses of these ingredients.

Alpha-Lipoic-Acid

First on the list is alpha-lipoic acid (ALA). ALA occurs naturally in cells, is involved with carbohydrate metabolism, and important for the production of our body's energy source, ATP.

ALA is both water and fat soluble (unlike most other vitamins and minerals, which are either water or fat soluble). Because of this, it is a very potent antioxidant, able to regenerate other antioxidants such as vitamins C and E and glutathione, aiding in the prevention of oxidative damage.

The connection between oxidative stress and the onset of insulin resistance been primarily studied in cell cultures with convincing results. There have also been a few studies to demonstrate this same connection occurs in vivo (in the body) too.

One recent study made this connection in insulin-resistant obese rats. Another more recent study in humans with type II diabetes (those who produce insulin but are resistant to it) came to the same conclusion.

Don't think this lets you off if are not obese or without diabetes, since insulin resistance is most common in these populations. This just demonstrates that there may be a correlation between higher levels of oxidative stress and insulin not working efficiently. Therefore, antioxidant consumption via foods is best and supplementation may a good idea; ALA is a good start.

In addition, ALA has been shown to aid in glucose uptake in the muscle cell. ALA can positively affect insulin signaling and glucose transport via its direct stimulation on the GLUT-4 transporter, which is one of the 5 GLUT-transporters necessary for glucose uptake. Unlike the other transporters, GLUT-4 is regulated by insulin, which is most likely where ALA comes into play.

In plain English this basically says that ALA may allow our cells to more efficiently take up nutrients (both food nutrients and dietary supplements), which could enhance their effectiveness. Potentially, ALA would be beneficial in conjunction with your post-workout meal to enhance the speed at which the cells take up and store the nutrients you feed them allowing for increased recovery time, glycogen storage, and protein synthesis.

With the evidence outlined above, it seems probable that reducing oxidative damage with ALA, in addition to its potential to increase cellular uptake of nutrients, this product may be a good one to add to your arsenal.

Bitter Melon

Bitter melon (BM) is one of the more popular products used worldwide to lower serum insulin and normalize blood glucose levels. BM fruit and juice are regular components of the diet in other areas of the world; however, it's not too common in the US. There is not a great deal of published research on bitter melon in humans, but that which is out there is promising.

It appears that BM's effects on glucose metabolism stem primarily from the fact that BM contains an insulin-like polypeptide called polypeptide P, or plant-insulin.

Plant-insulin has been shown to have similar effects to bovine insulin, which, as we know, lowers blood glucose. However, some speculate that all the positive effects from BM supplementation are likely induced by more than one compound.

A recent study was published to ascertain if the use of BM is warranted. Researchers fed male and female rats either high or low-fat diets and various doses of freeze-dried bitter melon juice (7.5 or 15.0 g/kg) to determine BM's effects on glucose levels, insulin resistance, energy efficiency and adiposity.

The results of this study demonstrated that BM reduced weight gain and body fat without affecting energy intake or fat absorption. In addition, the impaired glucose tolerance from the high fat diet was normalized from BM. Similarly, the BM supplemented groups lowered their serum insulin levels in a dose-dependent manner (the higher BM groups had non-significantly lower insulin levels). Hmmm, seems like an interesting product.

Again, let's go back to the intended discussion point of this article; assuming BM does indeed lower glucose levels and can make an individual more insulin sensitive, it may allow for an increase cellular uptake of nutrients.

Do keep in mind that high levels of bitter melon may cause diarrhea; however, this is not the case in all individuals. Therefore, proceed at your own risk and don't come knockin' at my door if you try bitter melon and then re-enact the scene from Dumb and Dumber when Jeff Daniels, AKA Harry Dunn, is in the bathroom after being sabotaged with a full cup of Turbo Lax "for fast, effective relief."

Flaxseed & Flaxseed Oil

Regardless of Flax seeds or oils effects on insulin sensitivity, I would recommend supplementing with both, but that's an article for another time. For now, let's stick to the topic at hand.

Flax (meaning both seeds and oil) is a good source of -linolenic acids and is the precursor of the n-3 fatty acids, eicosapentaenoic acid docosahexaenoic acid, found in fish.

Researchers know that total fat content of the diet can affect insulin sensitivity. As we know, all fats aren't created equal so wondering about the total fat content of the diet merely scratches the surface. Therefore, researchers have recently began delving into whether specific types of fat also affect insulin sensitivity. This is where flax seed comes into play.

One study that was presented about a decade ago at the 55th Conference of the Flax Institute of the United States (yes, there actually is such a thing) demonstrated that the addition of flaxseed to a rat's diet actually re-sensitized "insulin resistant" receptor's in the animals cells.

Another study demonstrated that supplementing with flaxseed oil improved insulin sensitivity in overweight, postmenopausal women. But even if I am off with this data extrapolation, flaxseed oil is still a darn good investment.

Dose:

Ground flaxseed (1-2 TBS/day). (you must grind the flax seeds to obtain the benefits; otherwise, they will pass right through undigested)

Flax seed oil (dependent on other types of fat in the diet. Shoot for a 3 or 4:1 ratio between n-3's and other fats in the diet)

Fenugreek

The seed of this plant is commonly used in other countries and evidence has shown it may exert a hypoglycemic effect. Its mechanism appears to be due to a compound known as 4-hydroxyisoleucine (4-OH-Ile), which is a constituent that makes up about 80% of the total content of free amino acids extracted from the fenugreek seeds.

4-Oh-Ile is an amino acid present only in plants and recent research discovered that 4-OH-Ile actually stimulates glucose-induced insulin stimulation from the -cells in the pancreas. What's interesting (well, to me at least) is that this glucose-dependent insulin-stimulating effect occurs only in the presence of moderate-high glucose concentrations. This may translate to helping lower the normal meal-induced rise blood glucose.

Now, be forewarned, fenugreek may come with some side effects very similar to what I described earlier with bitter melon. Don't say I didn't tell you. Also, there is some concern that fenugreek might have additive effects to antiocoagulant or antiplatelet drugs so use caution and speak with your physician if you are taking any of those medications.

Chromium

While some believe that the popularity of chromium died in the early 90's, it's somehow been able to hold on to its over-hyped claims to enhance weight loss. Chromium is the second most popular mineral sold, second only to calcium! Nevertheless, there may be some benefit from chromium supplementation if you have impaired glucose tolerance.

Chromium is an essential nutrient involved in normal carbohydrate metabolism. Chromium levels may decrease with age and from exercise. Chromium requirements are increased with glucose intolerance and diabetes. Therefore, it is sometimes recommended as a conjunctive therapy for those with type II diabetes to enhance glucose disposal and insulin variables, but not all studies support that belief.

A 2002 meta-analysis (review which compares a number of studies with like-characteristics) reviewed the literature on glucose and insulin responses in healthy, non-diabetic subjects.

After scrutinizing 20 different randomized, clinical trials assessing the effect of chromium on glucose, insulin, and glycated hemoglobin (a measure of blood glucose over the past 3-months), the authors concluded that "data from randomized clinical trials show no effect of chromium on glucose or insulin concentrations in nondiabetic subjects."

They did note that the studies reviewed had too few subjects with glucose intolerance (but not diabetic); however, the one study that did measure this found no effect from chromium.

This isn't to say that meta-analyses are the gold-standard by any means, but at this point chromium doesn't have much efficacy for healthy subjects. I guess the over-hyped ads promoting its use will remain just that; over hyped junk.

Anyhow, if you're still supplementing with chromium and wondering why you haven't lost any body fat, let me introduce you to my friend Betty who has been in the same step aerobics class for 10 years; she's wondering the same thing.

Conclusion

There are actually 100's more supplements, herbs, and even spices that may in fact positively affect insulin sensitivity. Some, like cinnamon and clove, are a little too new to report on; others, like quei fu di huang wan (no joke) I left out because I wanted to save you from the embarrassment of asking for that at your local supplement store.

If you plan to give any of these a whirl, I would recommend introducing them one at a time and not combining them with any prescription medications, such as insulin or metformin which are prescribed with the same intention as these supplements.

Finally, speak with your physician to ensure there are no additive effects that could be harmful if you are on other medications.