Right when I decide it's about damn time for a vacation, my body deals me a swift punch in the face. Literally. Of course I get the most obnoxious head cold right in the middle of our trip. Maybe drinking wine every night and eating what I affectionately refer to as "the beige diet" which consists of eating nothing with any color whatsoever, did not help.
Now why is it whenever you get sick everyone has the cure? Have some tea! Have some Airborne! Have a nap! Have some soup! Drink some OJ! Take some zinc! Guess what? Once you are sick, you're sick. That's it. End of story. Remember back when that supplement Airborne was all the rage? It fizzed for God's sakes it must work!! It's effervescent! Well, it was scam. I said so the whole time. What do I love more than being right? Well, nothing actually. But the makers had to pay a whopping $23.3 million dollars in false advertising. Why? Because loading up on things like vitamin C and whatever the hell else is in Airborne isn't going to form a force field of health around you. What will protect you is a healthy immune system which is best achieved by a well-balanced diet and exercise and not some glorified form of Alka-Seltzer.
Imagine my sheer annoyance this morning when my chiropractor noticed my sniffles and told me to "eat some tangerines for the vitamin C and load up on zinc". Whoaaaaaa doc. Why don't you stick to cracking my neck and not dole out nutrition advice, whad'ya say?
What vitamin C (ascorbic acid) is: an antioxidant, necessary for collagen synthesis, necessary for carnitine synthesis, necessary for neurotransmitter synthesis (norepinepherine, serotonin and others), necessary for some hormones, a PRO-oxidant. That's right, at super high concentrations, vitamin C has been shown in lab tests to promote cell and lipid damage.
What is is not: a direct quote from my Advanced Nutrition and Human Metabolism book states "the possible pharmacological effects of vitamin C on the incidence, severity and duration of the common cold have been almost totally refuted by some investigators. High doses of acorbate (vitamin C) appear to be only weakly prophylactic, if at all, and to be of little or no use for treating colds".
The RDA for men and women is 90 mg and 75 mg, respectively. Now deficiencies are associated with weak immune systems, scurvy, cardiovascular disease and high levels have been shown in some research to help with cataracts and macular degeneration but super high levels are NOT good. Any anti-oxidant can turn into a pro-oxidant if taken in too high a dose. Since vitamin C is a water soluble vitamin, you will usually just pee out any extra and doses of 2 grams have been taken with no reported adverse effects, However, high doses of up to 10 grams a day have been shown to possibly cause kidney stones. Diabetics are at risk of vitamin C deficiency because it looks remarkably like a glucose molecule, so they may excrete it accidentally.
The bottom line on vitamin C, a deficiency definitely puts you at risk, but "loading up" on vitamin C isn't going to do your immune system, or your pocket book, any good. Stick with a well-balanced diet and you're good to go.
Zinc: what it is: an important micro mineral in the body, necessary for tissue and cell growth, cell replication, bone formation, skin integrity, host defense and cell-mediated immunity. Indeed, a very, very important micro mineral for immunity. Deficiencies affect cell-mediated and humoral immunity.
What it is not: a cure for the common cold. Another direct quote from my book "a meta-analysis of zinc salt lozenges and colds found no statistically significant benefit associated with the use of zinc lozenges for the treatment of colds."
The bottom line: a zinc deficiency is certainly going to put you at risk for getting sick, if you are meeting the current RDA for zinc, which is 40 mg, you will have plenty to keep your immune system functioning.
The bottom, bottom line: what you really need when you are getting sick: fluids and rest. Your body requires extra energy and fluid to battle the little war in your body so take care of it when you're ill. Sometimes we just get sick, and have to be sick and suffer and sniffle and be gross, but hey, that's life and that's just the way it goes. Just stay home and don't get everyone else around you sick;)
http://www.ncbi.nlm.nih.gov/pubmed/16373990
ReplyDeleteIt wouldn't hurt to do a little actual research next time.
Taken from the study you cite: " Therefore, both nutrients play important roles in immune function and the modulation of host resistance to infectious agents, reducing the risk, severity, and duration of infectious diseases. This is of special importance in populations in which insufficient intake of these nutrients is prevalent. In the developing world, this is the case in low- and middle-income countries, but also in subpopulations in industrialized countries, e.g. in the elderly. A large number of randomized controlled intervention trials with intakes of up to 1 g of vitamin C and up to 30 mg of zinc are available. These trials document that adequate intakes of vitamin C and zinc ameliorate symptoms and shorten the duration of respiratory tract infections including the common cold". I believe I specified that deficiencies will put you at risk but intakes of mega-doses don't lessen symptoms, which is exactly what this study states (notice the use of the word adequate when it addresses intakes).
ReplyDeleteAdditionally, this research was funded by Bayer Healthcare, a maker of drugs and supplements. It helps to know who is funding research when you look at the anticipated (and possibly biased) outcomes.