Sugar, Vitamin C and Competitive Inhibition

Carboloading of a different variety.

Saturday in Tucson before the 1982 version of the Tucson Marathon we were sitting on the Gentle Ben's patio with some of our running friends from Albuquerque having some carbohydrates of the liquid variety. Bob would consume 18 Dos Equis and run a blazing 2:31 marathon the next day. Sitting at another table was one of Tucson's running greats, Dr. Tom. Tom at one time had run a 2:21 marathon which was near world class at that time. Tom was loading yet a different variety -a cheeseburger. He would not run as fast as Bob the next day and would not run up to his amazing capability.

The battle over vitamin C.

At the 1978 version of the Fiesta Bowl marathon in Phoenix I was lucky enough to hear Dr. Thomas Bassler speak. When it came to running injuries he recommended vitamin C. I had been running 100 mile weeks in preparation and was aching all over. That day I got a bottle of vitamin C and ran the next day with no pain at all. I have been using vitamin C ever since with good results. The battle, however, would rage on. Dr. R never took vitamin C since he believed that it did not do any good since most of it he said "would be excreted in the urine." Dr. Bassler, on the other hand, stated emphatically that you should not run if you don't supplement vitamin C. My own experience has verified the latter, on an ongoing basis for all of my 25 year and two month running streak.

Does the human body need supplemental vitamin C?

Before we go any further, let's try to establish first whether or not the body needs vitamin C from outside sources, ie foods, drinks or supplements. To do this, we will take a brief look at the biochemistry of vitamin C from Stryer's Biochemistry Fourth Edition. Collagen is the major protein of connective tissue such as the Achille's tendon or the ligaments and tendons of the knee. Without going into a lot of biochemical detail, ( vitamin C "ascorbate" is necessary for the formation of hydroxyproline and it is hydroxyproline that stabilizes collagen) vitamin C is crucial for the proper synthesis of collagen. Primates (you and me) are unable to synthesize vitamin C. We have to get it from outside sources.

The first observation of scurvy.

Scurvy was first noticed in 1536 by Jacques Cartier when it afflicted his men who were exploring the Saint Lawrence River.

"Some did lose all their strength, and could not stand on their feet ...Others also had all their skins spotted with spots of blood of a purple colour: then did it ascend up to their ankles, knees, thighs, shoulders, arms, and necks. Their mouths became stinking,their gums so rotten, that all the flesh did fall off, even to the roots of the teeth, which did also almost all fall out."

This is one of the earliest descriptions of the disease scurvy. The preventative for this was later discovered by a Scottish physician, Dr. James Lind, in 1753. He recommended greens or fresh vegetables and ripe fruits. He urged the inclusion of lemon juice in the sailors' diets. This was ingored for forty years but finally the admiralty took his advice and lemon juice was included in the sailors' diets. Lime juice was later substituted. Hence the British sailors became known as "limeys."

There is no question -the human body does need vitamin C.

There is no doubt today that the human cannot synthesize vitamin C and does have to obtain it from outside sources. Now that we have established the need for vitamin C, let's look at how much vitamin C we need. According to Dr. Tom we didn't need any additional supplementation outside of what we got in our normal food sources. According to Dr. Bassler you had to supplement vitamin C, especially if you were running since running is a stress both on the connective tissues of the body, but also a stress on the whole body. Emotional stress is another time for supplementation of vitamin C, since any stress at all releases vitamin C into the bloodstream from the tissues and soon it is excreted in the urine. The more stress you have to deal with the more vitamin C you will need to supplement. Yes, extracellular vitamin C will be excreted in the urine if it is not driven back into the cells very quickly.

Vitamin C and the immune system.

One of the earlier proponents of vitamin C was Dr. Linus Pauling, whose work demonstrated that the body's white blood cells needed high levels of vitamin C "inside the cell" to fight infection. Thus, he recommended high doses of supplemental vitamin C to fight the common cold. And, both he and Dr. Bassler clearly emphasized that there was no magical dose -you just took vitamin C until you got better. Dr. Bassler recommended 2 grams every two hours for running injuries until they quit hurting. I have done that and it works.

The phagocytic index, sugar, insulin and competitive inhibition.

Having utilized vitamin C for well over 25 years I have often been asked how much should I take and often wondered myself about the dosage levels. This really became apparent when, after discovering my own adult onset diabetes in July 1997, I quit sugar. My vitamin C dosage level to maintain my body for 50-100 mile running weeks plummeted. I was startled to discover that the amount I needed after I quit sugar was about one quarter of what it had been while I was still ingesting sugar. Now in this interesting discussion is the answer.

The more sugar you ingest -the more vitamin C you will need.

The molecules of vitamin C, glucose and fructose very closly resemble each other. If you are skeptical of this, it is a very interesting exercise to check out their molecular structures (in Stryer's Fourth Edition of Biochemistry, vitamin C is on page 455 and sucrose, glucose and fructose are on page 471). When you get a cold or other infection, white blood cells and macrophages go to work to rid the body of the invading bacteria or virus. Insulin transports the vitamin C into these cells so that they can scurry around and rid the body of the infectious agent. The real problem arises when one ingests any sugar at all.

If there is more glucose(sugar) around than there is vitamin C, insulin will preferentially allow the sugar to enter the cell. A blood sugar level of only 120 mg/ml (normal fasting blood sugar should be 100 mg/ml or less) will reduce the phagocytic index (an index of the cell's ability to rid the body of the bacteria or virus) by a whopping 75%. Loosely translated, your immune system slows to a crawl. This is known as "competitive inhibition" ie one molecule competes for the same spot to get into the cell with another similar appearing but biochemically different molecule. The molecule that is preferred(in this case glucose) inhibits the entry of the other molecule (in this case vitamin C).

The more sugar you ingest -the more vitamin C you will need to fight infection or keep your connective tissues (tendons and ligaments etc) intact. One should also be aware of the two signs of too much vitamin C, headache and diarrhea. I can't really count the number of times that I would get a headache about the same time, or just after, the running injury I was treating in myself would quit hurting.

Why orange juice is not a good source of vitamin C.

Over all these years and battles (discussions) about the need for supplemental vitamin C I have heard many times "Oh, I just drink lots of orange juice." The problem with orange juice is that in addition to the vitamin C it also contains large amounts of sugar. The more you drink the more sugar you ingest. You may also be getting some vitamin C but that vitamin C will probably never find its way into the white blood cells and macrophages because its entry into the cell will be competitively inhibited by all the sugar. Lemon juice and lime juice would be better sources since they do not contain as much sugar. Optimally you would not consume the juice but the whole fruit as mother natured intended. It would also help to eat a diet high in organic vitamin C rich foods (such as the MericleDiet) and supplement vitamin C as needed. You would also want to take into consideration how much sugar you ingest and adjust your supplemental dose accordingly.

Conclusions:

The human body has to have vitamin C from outside sources.

The dose is different for different individuals but the concept that supplementing vitamin C is a waste of money because "it all goes out in the urine" is completely flawed and has no basis in human biochemistry.

Linus Pauling was correct in stating that you should take vitamin C as a supplement until the cold or flu abates. This concept was then and still is -biochemically correct.

Once competitive inhibition of vitamin C's entry into the cell by glucose was established then the explanation for the large variance in "doses that work" is explained.

There is no "magical" dose of vitamin C.

The more sugar you ingest the more vitamin C you will need to supplement.

Supplemental vitamin C is a well founded concept and has a solid basis in human biochemistry.

Post Script.

I haven't heard much lately from Bob other than he was either winning or coming in second at the Pike's Peak Ascent. The last time I saw Dr. Tom, he was in a full length leg cast for an anterior cruciate tear in his knee. I am in the 25th year of my running streak (minimun 4 miles or 30 minutes every day) and just completed a six mile run this morning. My vitamin C dose is down to about 1 gram a day and I am running pain free. As an added bonus I have been about 25 years without either a cold or flu or even worse, viral gastroenteritis.

Recommended reading:

Stryer Biochemistry Fourth Edition

Natural sources of vitamin C:

chili peppers, broccoli, bell peppers, kale, cauliflower, strawberries, lemons, mustard and turnip greens, brussels sprouts, papaya, chard, cabbage, spinach, kiwifruit, snow peas, cantaloupe, oranges, grapefruit, limes, tomatoes, zucchini, raspberries, asparagus, celery, pineapple, lettuce, watermelon, fennel, peppermint, parsley and collard greens.

I don't disagree with those who feel that we should try to get our vitamin C from natural sources. I also agree that natural sources are the best, however, during periods of intense stress or if you are running a lot, it may not be possible to ingest enough vitamin C from natural sources to ward off a cold, keep your Achille's tendons happy or just keep your head on "straight."

To visit the 100% Sugar-Free, Vegan and 100% Organic MericleDietplease visit: http://www.DrMericle.com.

Copyright John Mericle M.D. 2005 All Rights Reserved

http://www.DrMericle.com is devoted to achieving optimal health and peak performance through diet and lifestyle change. Dr. Mericle brings together a unique blend of formal medical education, 29 marathons, 3 Hawaii Ironman competitions and a lot of practical real life experience.