The Right Chemistry: Linus Pauling and vitamin C – Montreal Gazette
There are some memories that become indelibly etched in one’s mind. It was a June day in 1980 at the Chemical Institute of Canada’s annual conference that I found myself waiting to hear from Linus Pauling, one of the most famous scientists in the world. Pauling had already won a Nobel Prize in Chemistry in 1954 and one for Peace in 1962, the only person to have been awarded two unshared Nobels.
As I was forging my own career in chemistry, I had become fascinated with Pauling’s breadth of contributions. His seminal ideas about chemical bonding, based on the arrangement of electrons in “orbitals” around atoms, are featured in every introductory chemistry textbook, and no biology text is complete without a reference to Pauling’s demonstration of sickle cell anemia being caused by an abnormal protein. Indeed, sickle cell anemia was the first disease to be understood at the molecular level. Pauling also introduced the concept of electronegativity, a measure of an atom’s affinity for electrons, making possible the prediction of the strength of bonds formed between different atoms. He made huge contributions to protein chemistry, and almost solved the structure of DNA before Crick and Watson.
I was also intrigued by the story of how Pauling had become interested in chemistry. It happened at the age of 13 when a schoolmate, Lloyd Jeffress, who would go on to become a noted psychologist, invited him over to see some experiments he had carried out with his chemistry set. Pauling was smitten and soon began his own experiments, in one instance concocting mixtures that would explode when a street car passed over them. That recalled my own tinkering with ammonia and iodine to make nitrogen triiodide, a chemical that explodes with a snap on slightest contact, even a touch with a feather.
There was another reason I was keen to hear Pauling speak. Although he was much admired in the scientific community for his contributions to chemistry, and for establishing the field of molecular biology, he had received a fair degree of criticism for his 1970 book, Vitamin C and the Common Cold. In this little volume, he outlined his belief that high doses of vitamin C cured colds. The problem was that the famous scientist, who had published more than 800 peer-reviewed research papers, based his pet theory on his personal experience. Nevertheless, spurred by Pauling’s claim, a number of trials had been carried out by 1980, all failing to show a curative effect.
Pauling’s enthusiasm for vitamin C did not stop with the common cold. He claimed that large doses of vitamin C were beneficial in the treatment of cancer, a notion that was put to test in various trials with most studies concluding that the vitamin worked no better than a placebo. Pauling countered that the trials failed because oral instead of intravenous doses were used. This notion still holds sway with some researchers and with some non-mainstream clinics that offer vitamin C therapy for cancer. Pauling also promoted vitamins for the treatment of mental disease, and coined the term “orthomolecular medicine” for the treatment of disease with substances normally present in the body, a concept criticized by conventional practitioners. So by 1980, Pauling was both revered and scorned. I was anxious to hear his address.
The great man began by describing vitamin C’s role in the formation of collagen, the structural protein in connective tissue. Collagen is composed of protein strands linked together into a three-dimensional network through their lysine residues by the action of lysyl hydroxylase, an enzyme that requires vitamin C to function. A lack of vitamin C disrupts the links between collagen’s protein strands, resulting in scurvy. At this point, Pauling declared that such damage to collagen is also the cause of heart disease. He explained that collagen strands in an artery break down in the absence of enough vitamin C and the liberated lysine residues then bind to the lipoproteins that transport cholesterol around the bloodstream. This leads to the buildup of plaque in arteries that can eventually rupture and trigger the formation of a blood clot that can cause a heart attack.
Then came a stunning moment. Pauling showed a graph demonstrating the decline of deaths from heart disease starting in 1970. He then overlaid a curve showing the increase in vitamin C supplement sales, probably thanks to his book published that same year, and astonishingly offered this as evidence that vitamin C was instrumental in reducing the risk of heart disease. Actually, the decline started some 10 years earlier, but there was a bigger issue. Although I was not as tuned in to the difference between associations and cause and effect relationships as now, I remember thinking, “woaaa!” Just because heart disease deaths had declined and vitamin C sales had increased did not mean that there was a causative connection.
Curiously, I had just been talking in one of my classes about the nutritional value of frozen foods and the concern raised by the increasing sales of “TV dinners” due to the large doses of salt added to make up for the taste lost to freezing. As I was listening to Pauling, it occurred to me that one could just as well have made the argument that TV dinners reduced the risk of heart disease. As I pondered this, Pauling had already gone on to suggest that heart disease can be treated with large doses of vitamin C and lysine. And so it was that day back in 1980, my scientific hero lost some of his lustre.
In 1992 I heard him speak again. After revealing he had prostate cancer, a brave soul actually had the temerity to ask why his daily dose of 18 grams of vitamin C had not offered protection. Without blinking, the nonagenarian Pauling retorted that if had he not take the vitamin, he would have been afflicted decades earlier.
Joe Schwarcz is director of McGill University’s Office for Science & Society (mcgill.ca/oss). He hosts The Dr. Joe Show on CJAD Radio 800 AM every Sunday from 3 to 4 p.m.