Dietary Supplement Trends, 1999-2012

SOURCE: Kantor ED, Rehm CD, Du M, et al. Trends in dietary supplement use among US adults from 1999-2012. JAMA 2016;316:1464-1474.

According to results from in-home interviews with 37,859 U.S. adults, 52% reported use of a supplement within the 30 days prior to the interview. Included under the canopy of “supplements” were multivitamins, fish oil, and individual supplements (such as vitamin D). Of concern (depending on your personal philosophical-scientific position on the issue), the use of supplements has remained essentially stable during the 1999-2012 interval.

Although some major players have declined over the past decade (multivitamin/multimineral use decreased from 37% to 31%), others have increased substantially: fish oil use increased from 1.3% in 1999 to 12% in 2012, and vitamin D increased from 5.3% to 19%. The authors reported that approximately 25% of supplement use had been recommended by a healthcare provider.

With the exception of folate supplementation for women, support for the benefits of supplements, in the absence of predefined deficiency, is scant.

The item that provided me that greatest reason for pause was not in the article itself but an editorial about this article in the same issue of JAMA, which I believe deserves to be quoted in full (reader discretion is advised): “... even after high-quality studies that show no meaningful clinical differences between supplements and placebos are published, the law provides [supplement] manufacturers latitude to continue advertising their products based on earlier, low-quality data. For example, Ginkgo biloba continues to be sold ‘to support mental sharpness’ despite a large, high-quality, NIH-funded study that found evidence to the contrary.”

I am already reasonably supple. In the absence of strong evidence, I will continue to eschew supplements.

New Tools for Glucose Monitoring

SOURCE: Bolinder J, Antuna R, Geelhoed-Duijvestijn P, et al. Novel glucose-sensing technology and hypoglycaemia in type 1 diabetes: A multicentre, non-masked, randomised, controlled trial. Lancet 2016;388:2254-2263.

The inconvenience of frequent finger-stick testing to assess control of diabetes is particularly problematic for type 1 diabetics. The FreeStyle Libre (trade name) is a sensor the size of a human hair that is inserted in the skin of the upper arm and attached to a patch that records glucose readings over eight hours. The reading device can be downloaded and has the capacity to store up to 90 days of readings. Does the FreeStyle Libre outperform traditional fingerstick methodologies?

To test this hypothesis, Bolinder et al randomized participants with already well-controlled type 1 diabetes (n = 328) to use the “flash glucose monitoring system” or typical finger-stick monitoring. The primary outcome of the trial was amount of time in hypoglycemia during six months of follow-up. Time in hypoglycemia was reduced by 38% with the Freestyle Libre device, compared to “traditional” methods. A small number of participants (n = 10) experienced local reactions at the site of insertion of the sensor.

The device recently received FDA approval. A FreeStyle Libre “starter kit” currently is advertised at $359.

Placebo for Osteoarthritis Pain

SOURCE: Dieppe P, Goldingay S, Greville-Harris M. The power and value of placebo and nocebo in painful osteoarthritis. Osteoarthritis Cartilage 2016;24:1850-1857.

Terminology about placebo, according to Dieppe et al, might be more useful if divided into placebo response (“a change seen in response to a sham intervention”) and placebo effect (“the difference between doing nothing ... and giving a sham treatment”). The authors chose to focus on the symptomatic improvements that can occur for patients simply as a result of an encounter with a health professional.

By comparing pain reduction achieved in placebo groups of randomized, controlled osteoarthritis trials with treatment arms that received no treatment (not even placebo), the authors determined that an effect size of about 0.5 is seen with placebo, comparable to that seen with many “active” interventions. Context also may be important. For instance, injection placebos were particularly powerful.

The physiologic underpinnings of placebo response for pain indicate it is not “imaginary.” For instance, the pain reduction of placebo can be blocked by pre-administration of naloxone, suggesting that such responses may be reflective of activation of endogenous endorphins.

The authors concluded that positive placebo response from patients occurs most fruitfully when patients feel safe, calm, and validated by their clinician.