A post here on the use of E300, sometimes called vitamin C, as a preservative in Czech beer got a bit of attention and a few comments, also bringing up an interesting question or two. Specifically: would vitamin C continue to exist unaffected in the presence of alcohol? And is this E300 the selfsame ascorbic acid many of us take as a nutritional supplement? If not, does it have similar health benefits?
The answers, apparently, are: Yes, No, and Probably not.
To find out, I contacted Dr. Victoria Drake at the Linus Pauling Institute at Oregon State University. In an email interview, Dr. Drake emphasized repeatedly that we should not recommend that people drink beer for the vitamin C. (Everyone clear on that?) In addition, she offered a few clarifications on the use of ascorbic acid as a food preservative.
A 5-7% alcohol solution like an everyday beer wouldn’t have a negative affect on vitamin C. “However,” she wrote, “if the bottle is warmed or exposed to light (if it’s in a clear bottle), vitamin C would oxidized fairly quickly.”
That said, the ascorbic acid used as a food preservative is not the same substance taken for its health benefits. “What is used as a food preservative is actually erythorbic acid, a stereoisomer of ascorbic acid. Erythorbic acid, like ascorbic acid, functions as an antioxidant and is therefore used as a preservative. However, erythorbic acid does not have vitamin C functions, and we don’t know if it actually functions as an antioxidant in the body.”
I asked for a clarification about what “vitamin C functions” erythorbic acid does not have. The answer, she said, is what’s listed on the Institute’s web page for vitamin C Functions. To wit: the synthesis of collagen; the synthesis of the neurotransmitter norepinephrine, critical for brain function and known to affect mood; the synthesis of carnitine, a molecule essential to transport fat to mitochondria, and so forth.
“To my knowledge,” Dr. Drake continued, “erythorbic acid is poorly absorbed and retained by the body. It may have ‘vitamin C activity’ when delivered to tissues, but compared to ascorbic acid, I would think that the ‘vitamin C activity’ would be very low.”
So, once again: don’t drink beer for the vitamin C — drink it for other reasons. Instead, eat a variety of fruits and vegetables to get plenty of vitamin C as well as other nutrients.
Unless you’re some kind of rodent.
“Keep in mind that not all animals require vitamin C,” Dr. Drake wrote. “For example, rats can endogenously synthesize vitamin C; humans and guinea pigs cannot synthesize vitamin C.”