Bjorksten 1942, “The Chemistry of Duplication”
Bjorksten 1951, “Cross Linkages in Protein Chemistry”
Bjorksten 1958, “A Common Molecular Basis For The Aging Syndrome”
Andrews et al 1965a, “The reaction of an autoxidized lipid with proteins”
Andrews et al 1965b, “Chemical Composition Of Enzyme-Fractionated Aged Heart Tissue”
Bjorksten 1968, “The crosslinkage theory of aging”
Bjorksten & Ashman 1970, “Nitrogenous compounds immobilized in an aged rat”
Bjorksten et al 1971, “Gerogenic fractions in the tritiated rat”
Bjorksten et al 1972, “Enzymatic lysis in vitro of hyalin deposits in human kidney”
Bjorksten 1976, “The crosslinkage theory of aging: clinical implications”
Bjorksten 1978, “A unifying concept for degenerative diseases”
Bjorksten 1981, “Selenium in nutrition”
Bjorksten 1982a, “Dietary aluminum and Alzheimer’s disease”
Bjorksten 1982b, “Aluminum as a cause of senile dementia”
Bjorksten 1989, “The role of aluminum and age-dependent decline”
Bjorksten & Tenhu 1990, “The crosslinking theory of aging—added evidence”
see also Dean 2014
…My Science Fair project was entitled “Suspended Animation in Plants and Animals,” and the following year, an article with this picture of this man appeared in my local newspaper’s weekly Sunday Supplement magazine section in an article entitled “Will We Live Forever?”
I’m betting you have no idea who this gentlemen was? At the time, he was one of the foremost and most credible research gerontologists in the world. His name was Johan Bjorksten, and he had a clever idea about what might be the root cause of aging. He had noticed that as organisms age, they tend to accumulate insoluble, often pigmented matter inside their non-dividing cells. Lipofuscin, which accumulates most prominently in brain and cardiac cells, is one such “age pigment”. Bjorksten was a chemist, in fact he was an early polymer chemist, and had invented a number of refinements to the first practical document duplicating device the hectograph, which had been invented by the Russian Mikhail Alisov, in 1869. Bjorksten determined that this insoluble material, which could occupy as much as as 30% to 40% of the volume of non-dividing cells in aged animals, consisted largely of cross linked molecules of lipids and proteins. So molecularly cross linked, compact and tough was this material that it was completely resistant to digestion by trypsin and other commonly available “digestive” biological enzymes.
This posed a puzzle for Bjorksten, because if no living systems could decompose this material, it was so stable that it would necessarily remain as indigestible debris after each organism died. Thus, the earth should be covered in such debris by now! Clearly, this is not case, and so this implied to Bjorksten that there must, in fact, be living organisms with specialized enzymes capable of breaking down this material. The source of these cross links? Free radicals were a good candidate for generating such dense, insoluble macromolecules.
As it turns out, Bjorksten wasn’t far off the mark. Today, we know that lipofuscin and related species are the indigestible and highly cross linked debris of old mitochondria that have been reprocessed through the lysosomes of cells. Bjorksten thought these cross linked molecules interfered with normal cell metabolism and possibly acted as toxic species which caused cells to senesce. He set out to find enzymes in nature which could reverse these cross links and thus, he thought, reverse aging.
Whether or not Bjorksten did indeed find the “microproteases” and “microlipases” he was looking for remains unknown, but he did find a strain of microorganism that could digest the age pigment from geriatric humans and animals in the form of the beta hemolytic bacterium Bacillus cereus—a ubiquitous bug present in soil which is also the cause of Fried Rice Syndrome—a variety of “24-hour food poisoning” that is characterized by nausea, vomiting diarrhea and abdominal cramping. By the early 1970s, Bjorksten was optimistic he had the tools in hand to if not defeat aging, then to dramatically prolong lifespan. Of course, Bjorksten has been dead for many years, but his cross linkage theory of aging lives on. He clearly identified a notable factor in the pathophysiology of aging—though whether it is a cause or effect is still a subject of debate.
However, the most important points in this story are: Johan Bjorksten is dead and you have to do a careful search of the literature to find out who he was and what his contributions were to experimental gerontology. He doesn’t even have a Wikipedia page! [A bibliography of Bjorksten’s work is appended at the end.] Bjorksten, and many of his contemporaries in both experimental and interventive gerontology were truly optimistic that aging would be conquered in their lifetimes. And who was I, a 15 year old boy, to disagree?