| MadSci Network: NeuroScience |
You have asked a doozy of a question Phyllis. The short answer to both parts of your question is "it's not clear." Of course, I find that entirely unsatisfying, so let me try to explain by providing a bit of the background. First, this is not a question about a simple rubber band, but a commercially available elastic band that has a special button on the inside (As should be clear by the end, my inclusion of this link does not, in any way, constitute an endorsement for the advertised product. S.T.) This band is an acupressure device. Acupressure is a non-invasive form of acupuncture. So to understand this question and my answer, one must understand a small amount about acupuncture.
This means my reply is a bit long. In particular, my answer is preluded with a discussion of acupuncture. As it turns out, my answer is also a bit long winded, so if you wish you can skip directly to my punch line.
From my perspective, there are two general types of problems with the claims in favor of acupuncture. First are the a priori problems, meaning those things that just don't make sense to me. For example, why can't anyone give me a simple physical explanation of ch'i or meridians? And what is a "Triple Heater?"
The second set of problems are the empirical problems. From the scientific literature, it's relatively clear that acupuncture has certain capabilities: it can alleviate pain; in some cases it can replace anesthetics; it can aid in drug withdrawal; and relevant to your question, it can alleviate nausea. However, it appears to me that the important thing about acupuncture is not the point in which the needle is placed, but rather the type of tissue into which it's placed. When the acupuncturist places a needle, "correct" placement is always determined by having the patient report sensations of "heaviness" or "buzzing" in and around the needle placement site. This tells me that there is something special about the placement of the needle. In studies which take this into account, it seems that inducing this effect is sufficient to produce the desirable effects of acupuncture.
The elastic band indicated above is specially designed to provide acupressure to a point on the pericardial meridian called Neiguan or Nei Kuan, (we Anglophones call it P6 -- Pericardium point # 6). As you might imagine, since I'm somewhat dubious as to the importance of meridia and points in the use of acupuncture, I'm especially dubious about the use of acupressure, since this relies wholly on the use of points and meridia. So I have looked with reasonable care at five papers specifically studying whether acupressure at P6 eased nausea.
Two of the papers (Bruce et al., 1990; O'Brien et al, 1996) reported no significant effect of acupressure in the treatment of nausea and/or vomiting related to motion or pregnancy. Another two of the papers (Barsoum et al, 1990; Hu et al 1995) reported a significant effect on subjective reports of nausea and/or physiological measures of gastric function, although Barsoum et al specifically stated that the treatment had no significant effect on either vomiting or requests for anti-emetic drugs.
The final paper that I looked at was Dundee et al, 1989. Here they found that acupressure at P6 significantly reduced self-reports of nausea and vomiting among pregnant women. However, they also found that sham acupressure (applying the same regimen of pressure, but not at P6) significantly alleviated the symptoms of morning sickness.
References
Barsoum G, Perry EP, Fraser IA (1990) J Royal Soc Med, 83: 86
Bruce DG, Golding JF, Hockenhull N, Pethybridge RJ (1990) Aviat, Space, Envir Med, 61: 361
Dundee JW, Sourial FBR, Ghaly RG, Bell PF (1988). J Royal Soc Med 81: 456
Hu S, Stritzel R, Chandler A, Stern RM (1995) Aviat, Space, Envir Med, 66: 631
O'Brien B, Relyea MJ, Taerum (1996) Am J Obstet & Gyn, 174: 708.