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Corn starch

The ultimate slow-digesting/low-glycemic carbohydrate. In 1908, a small agricultural export from China landed on the shores of America. It was a unique corn kernel that, when cut in half, looked like it was filled with wax. This golden, unpolished jewel became known as Waxy Maize Starch (WMS). In 1942, the first crop of waxy corn starch was sown and processed for commercial use by two different starch companies in the state of Indiana. In the 1950s, WMS was used in laundry starch, glues, adhesive creams, cake fillings, salad dressings and as a stabilizer and thickener for canned foods (1).

Waxy Maize has a higher molecular weight and much lower osmolarity than dextrose or maltodextrin, but what does this mean for the user? Mainly that Waxy Maize passes through the stomach undamaged, is first absorbed in the intestine and is immediately absorbed there. This all happens at a much faster rate than with dextrose or maltodextrin - almost twice as fast to be precise.

Waxy Maize can increase the absorption rate of many of your favorite supplements such as creatine monohydrate, creatine ethyl ester, cell volumizing supplements, nitric oxide supplements, etc. Nutrients like these often remain in the aggressive stomach acid environment, which negatively impacts their absorption rate. Waxy Maize helps move these nutrients through the stomach faster and allows the body to absorb these nutrients much quicker.

Waxy Maize has the ability to replenish the body's glycogen stores much faster than is possible with a mixture of dextrose and maltodextrin. Once again, this is made possible by Waxy Maize's ability to quickly pass through the stomach and enter the intestines for immediate absorption. The ability of Waxy Maize to pass all of these nutrients and starches quickly through the stomach gives the body an instant pump that you can physically feel in your muscles after a workout. You will see a much bigger, fuller and rounder muscle body.

The study

Unlike regular corn starch, WMS is made up of a very large percentage (up to 100 percent) of amylopectin. Amylopectin is a long chain of glucose molecules with branching side chains that resemble branches of a highway. Common corn starch consists of amylopectin and a significant amount of amylose, which is a long, coiled glucose chain without branches.

Fast forward 50 years to one of the top sports nutrition laboratories at Ball State University in Indiana. For nearly two decades, Dr. David Costillo's laboratory conducted numerous studies focusing on carbohydrates, performance and muscle glycogen utilization. In the early nineties of the 20th century, Costillo's laboratory conducted two different comparative tests:

  1. How does WMS perform in terms of glycemic (blood sugar) and insulinemic (insulin blood levels) response as a pre-exercise energy source, and how does WMS affect fat and carbohydrate burning?
  2. How does WMS affect muscle glycogen resynthesis after an exhaustive training session?

In the first study, 10 male elite cyclists (yes, I know, what the hell does a study on cyclists have to do with muscle development? But please read on anyway...) were given one of four different supplements at four different times:

  1. Dextrose (glucose)
  2. WMS (100 percent amylopectin)
  3. Resistant Starch (resistant to digestion and slow/poorly absorbable, consisting of 70 percent amylose and 30 percent amylopectin)
  4. An artificially sweetened placebo drink with no calories

All four supplements were sweetened and flavored and administered in the form of a drink (18.7 percent carbohydrate solution) at a dosage of 1 gram of carbohydrates per kilogram of body weight 30 minutes before a 2-hour training session on an ergometer (2).

The glucose and insulin response was 2 to 2.5 times higher after the administration of glucose than after the administration of WMS. This may be the first human study to show that WMS is a low-glycemic/low-insulin carbohydrate. After 15 minutes of exercise, all groups showed a drop in insulin levels and blood glucose levels to below baseline levels before supplementation. During the last 30 minutes of training, the subjects were encouraged to give everything they could. Dextrose and WMS enabled a work performance that was significantly higher than when the placebo was administered and was approximately in the same range for WMS and dextrose. There were no differences between dextrose and WMS in terms of carbohydrate and fat burning.

During the second study, 8 elite male cyclists (read on, there's a link here) were put on a moderate carbohydrate diet (55 percent carbohydrate/25 percent fat/20 percent protein) for two days before a training session to deplete carbohydrate stores (3). This was repeated four times, each time with a different one of the following carbohydrate supplements as the sole source of carbohydrate after depletion of carbohydrate stores:

  1. Dextrose (glucose)
  2. maltodextrin
  3. WMS (100 percent amylopectin)
  4. Resistant starch (100 percent amylose)

A quadriceps biopsy was performed immediately after training.

The carbohydrate supplements were consumed by the athletes in liquid form at a dosage of 6.5 grams of carbohydrates per kilogram of body weight during the following 12 hours before going to sleep. The next morning, another biopsy was taken (the ultimate pick-me-up!). Dextrose, maltodextrin and WMS intake showed no significant differences in muscle glycogen resynthesis, but the largest percentage increase (based on post-workout glycogen concentration) was observed after dextrose consumption. In 2002, the same university laboratory that developed the glycemic index compared a 75 gram dose of WMS with maltodextrin, sucrose (table sugar) and an amylose-rich cornstarch - all in the form of a beverage (4). Maltodextrin and sucrose showed a 1.6 to 2.9 times greater glycemic response during the first 15 to 45 minutes after consumption. Last July, a study confirmed that WMS is a first-class, slow-digesting, low-glycemic carbohydrate that causes a low insulin response. Scientists at Purdue University published a 4-hour glycemic index study comparing 50 grams of WMS to a mixture of 78 percent maltodextrin and 22 percent sucrose (MS) and white bread (5). WMS and the MS mixture were administered in the form of a sweetened gel. The glycemic response to WMS and white bread was almost identical and was approximately 2 to 3 times lower and slower than the glycemic response to the MS mixture during the first 60 minutes. After 3 and 4 hours, only white bread and WMS did not lead to a drop in blood glucose levels to levels below the baseline before carbohydrate administration. The maximum insulin response to WMS during the first 30 to 60 minutes was only about half as strong as the maximum insulin response to white bread and was only about a quarter of the maximum insulin response to the MS mix. The overall increase in insulin levels was almost a factor of 3 higher with MS Mix and almost a factor of 2 higher with white bread than with WMS.

What does this mean for bodybuilders and strength athletes?

These studies confirm that waxy maize starch is a slow-digesting, low-glycemic carbohydrate and suggest that WMS can be used for pre-workout energy by people who are susceptible to fluctuations in blood glucose levels or who exercise for longer than 2 hours. WMS can provide energy for exercise just as well as dextrose. The glycogen response of WMS is at least similar to that of glucose and maltodextrin, although exact values are only known for a 24-hour loading phase after depletion of glycogen stores, which is difficult to achieve with resistance training. The lower maximum insulin peak caused by WMS could possibly be enhanced by the addition of whey protein or branched-chain amino acids, although this has yet to be confirmed by further studies. What we do not yet know is how quickly WMS passes through the stomach (gastric emptying rate), as no studies have been conducted in this regard. Although the osmolality of WMS is much lower than dextrose or maltodextrin, studies examining the glycemic and insulinemic properties of WMS suggest that even if gastric passage were rapid, it could not overcome the rate-limiting steps of digestion and absorption.

References

  1. Anon. Agric Food Chem, 1955;3:105-7
  2. Goodpaster BH, et al. Int J Sports Med, 1996;17:366-72
  3. Jozsi AC, et al. Int J Sports Med, 1996;17:373-8
  4. Anderson GH, et al. Am J Clin Nutr, 2002;76:1023-30
  5. Sands AL, et al. Nutr Res, 2009;29:383-90