Tuesday, July 10, 2012

Is R.I.C.E. Paleo?

OK, pretty facetious title there, but a serious topic. R.I.C.E. stands for Rest, Ice, Compression, Elevation (sometimes Protection is prepended to the acronym, as you'll see).

If you've ever gotten a sprained ankle or similar soft-tissue injury, you've no doubt been advised to do RICE on the affected part. It's nearly a religious ritual for athletes. What I've learned about medicine in the last few years of my barefoot-style running and Paleo/Primal diet experiment is that practices will persist in medicine for decades, if not longer, which not only have no basis based on the medical and scientific literature but which have often been contradicted by that literature, again, often for decades.

So whenever you hear "everyone" telling you that you should do something, you should be skeptical.

In this case, there's good reason to be skeptical, as RICE has been tested extensively, and found lacking:
"The Use of Ice in the Treatment of Acute Soft-Tissue Injury: A Systematic Review of Randomized Controlled Trials

"Results: Twenty-two trials met the inclusion criteria. There was a mean PEDro score of 3.4 out of of 10. There was marginal evidence that ice plus exercise is most effective, after ankle sprain and postsurgery. There was little evidence to suggest that the addition of ice to compression had any significant effect, but this was restricted to treatment of hospital inpatients. Few studies assessed the effectiveness of ice on closed soft-tissue injury, and there was no evidence of an optimal mode or duration of treatment.

"Conclusion: Many more high-quality trials are needed to provide evidence-based guidelines in the treatment of acute soft-tissue injuries."
So the evidence that we have offers little to no validation of RICE. Recognizing this, this study was proposed:
The PRICE study (Protection Rest Ice Compression Elevation): design of a randomised controlled trial comparing standard versus cryokinetic ice applications in the management of acute ankle sprain.

"...Given these findings, it seems a logical progression to examine if the analgesic effects of intermittent ice application can facilitate earlier therapeutic exercise, and subsequently improve clinical outcome following acute ankle sprain. The safety and effectiveness of incorporating therapeutic exercise with periods of intermittent ice application has not previously been examined in patients with acute soft tissue injury...."
(Unfortunately, I can't find the completed study: I have no idea if it was or was not completed.)

Now, you might find this hard to believe, but devising a treatment and then never bothering to test it in a scientific fashion is par for the course in the medical profession, as is continuing to use the treatment after it's been shown to have no suporting science behind it and to be of questionable efficacy. People would rather "do something", than do nothing, even if doing nothing is the correct course of action. The PRICE study notes this, as well as noting some of the potential issues with the treatment:
"...Recent evidence has suggested that the addition of exercise to ice application is more effective than ice application alone after various soft tissue injuries, including acute ankle sprain [19]. However, by reducing the conduction velocity of other, non-nociceptive fibres, cold application may also have a number of deleterious effects, including reduced muscle torque [20]. This is of particular relevance if ice is to be applied in combination with therapeutic exercise in the early stages after an acute soft tissue injury. Such effects could lead to the development of altered neuromuscular control patterns and potentially, to an increased risk of re-injury...."
The "logic" behind this treatment is the same as that of the use of anti-inflammatory medications: inflammation is associated with pain, and despite the fact that "correlation does not equal causation", the inflammation is treated as if it is the cause of the pain (link to PDF):
"Treating soft tissue injuries with protection, rest, ice, compression and elevation has been the mantra of physiotherapists for many years. Commonly shortened by the acronym ‘PRICE’, this approach is also widely accepted by layman as an essential component of first aid practice....

"...For many clinicians, their rationale for using modalities such as ice and compression after an injury is simply that it controls the clinical signs of inflammation. Applying a cold compress on an injury that is hot, red and swollen is commonsensical; but it clearly overlooks other potentially important physiological, cellular and molecular events. We use the term inflammation constantly in the clinic when referring to acute injuries however few can define what they mean by it. There is continued confusion as to whether inflammation is a ‘bad’ process, or, whether it is in fact fundamental for optimal repair.3 With major advances in our understanding of the inflammatory response in recent years, we can now begin to put these questions into context and consider the clinical implications and pathophysiological rationale for common interventions such as ice...."

"...It is clear that physiotherapists cannot recommend an optimal protocol for ice application beyond conjecture. Similarly, deciding on the most effective compression bandage or quantifying how much rest to advice, is also challenging. O’Sullivan and Keane’s1 study provides further evidence that developing clearer evidence based guidelines for PRICE is an important aim for the future. However, given the complexity of contemporary models of inflammation, we must also consider if is still realistic to produce one set of definitive guidelines to suit every type of soft tissue injury? Furthermore, we must consider that by recommending PRICE, we are recommending a combination of different treatment modalities each with their own unique molecular, cellular, physiological and clinical effects."
The evidence with NSAIDS, a common class of anti-inflammatory medicines, is that by blocking inflammation, they can permanently impair the body's healing process. Inflammation is, of course, the initial response of the body to some injury, and if inflammation is prevented the body does not have a plan B to heal.

From an evolutionary perspective, this "logic" for RICE is nonsense, of course: the body has a healing protocol that, ignoring animal precedents, was honed over millions of years of evolution in Africa, where ice is a rarity. The notion that ice is therefore necessary, or anything more than a distraction, therefore deserves great skepticism. Most likely, by impairing the body's proper function (inflammation), the healing process is impaired, as suggested by higher rates of re-injury.

Your body has evolved a protocol for healing which involves inflammation and pain (to reduce use of the injured part). I think the wisest course is to let the body's protocol operate: it has far more development time behind it than RICE does. (Even the Rest part of the protocol is of dubious value: for many injuries the medical profession now recognizes that immediate activity is essential for proper healing. If this is true for an injury as severe as a colon resection, broken hip, or a hip replacement, why shouldn't it be true for a simple sprained ankle?

My own view of RICE is that its value is in the fact that it simply distracts the injured from thinking about the injury. The discomfort of the ice against the skin gives you something else to think about. There are other means of distracting the injured party: when I had my wisdom teeth pulled, the dentist used music instead of general anaesthesia to keep my mind off what was happening. This was surprisingly effective, without any of the downsides of general anaesthesia.

And without any concern about impacting the healing process.
"Surprise: Scientists discover that inflammation helps to heal wounds

"...Zhou and colleagues found that the presence of inflammatory cells (macrophages) in acute muscle injury produce a high level of a growth factor called insulin-like growth factor-1 (IGF-1) which significantly increases the rate of muscle regeneration. The research report shows that muscle inflammatory cells produce the highest levels of IGF-1, which improves muscle injury repair. To reach this conclusion, the researchers studied two groups of mice. The first group of mice was genetically altered so they could not mount inflammatory responses to acute injury. The second group of mice was normal. Each group experienced muscle injury induced by barium chloride. The muscle injury in the first group of mice did not heal, but in the second group, their bodies repaired the injury. Further analysis showed that macrophages within injured muscles in the second group of mice produced a high level of IGF-1, leading to significantly improved muscle repair...."
P.S. Mark Sisson covers this as well.

P.P.S. Follow-up. The doctor who coined the acryonym R.I.C.E has come around.