Citrus bioflavonoids were first identified by Albert Szent-Gyorgyi in 1936, winner of The Nobel Prize for the discovery of vitamin C. He reported that citrus bioflavonoids strengthened blood vessel walls and prevented capillary permeability in ways that vitamin C did not. Indeed, he called these bioflavonoids 'vitamin P' after the Permeability factor because they prevented the permeability of capillaries. It was in the course of isolating vitamin C that he came across the bioflavonoids. Certain vitamin C deficiency symptoms (i.e. easy bruising, bleeding gums) were found in early studies to be relieved by crude vitamin C extract but not by purified vitamin C. Szent-Gyorgyi had a friend with bleeding gums and thought this condition might have something to do with a vitamin C deficiency. He gave the man some raw, impure vitamin C, and sure enough the bleeding gums cleared up. Later on, confronted by a recurrence of bleeding gums, he decided to try again; this time with pure vitamin C. He expected to observe an even more dramatic result but it did not occur. The man's gums went right on bleeding. Szent-Gyorgyi re-examined his earlier preparation and decided that the effective impurity was bioflavonoids. He then tried these by themselves, and reported that they worked. He named these substances "vitamin P." Bioflavonoids thus first came into use as protectors of capillaries, the tiniest blood vessels in the body. Later studies disputed his findings because a deficiency state could not be identified and so these compounds (including hesperidin) never actually attained full vitamin status. This is because there are over 4,000 different flavonoids with different properties and biological activities. Later studies done by Dr. Jacques Masquelier of France found that certain bioflavonoids called oligomeric proanthocyanidins (concentrated in grape seeds, grape skins, red wine, pine bark and many tree leaves) are the most effective components of the 'vitamin P' mixture that Szent-Gyorgyi spoke of. Clinical studies now confirm that hesperidin also has significant 'vitamin P' activity.
|
