Tim Sharpe

10/16/2008 2:13:10 PM #

The 2/16 ratio is certainly an encouraging topic in modern cancer prevention.  The problem I've found in using it is that there are no studies (that I'm aware of) that link lowering the ratio with decreased cancer risk.  It raises the age old question, are we killing the risk factor, or killing the messenger.  That question remains unanswered in my book, though I'm eager to be educated if more information is out there.

I see this as a similar issue to measuring homocysteine for cardiovascular risk.  We know high levels have higher risk than lower levels, but the only intervention studies to date don't indicate that lowering homocysteine reduces risk.  Certainly it seems like it should, and methylation is crucial for health, but it's also crucial to differentiate knowing what we know, and knowing what we think we know.

Both of these markers are I feel examples of lab testing being more advanced than the medicine that can use them.  It's tremendous information no doubt, but knowing what they tell us is more difficult than it seems.

-Tim Sharpe MAcOM LAc

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Richard Lord

10/16/2008 5:34:13 PM #

You make excellent points about limitations in the use of laboratory results. A well-worn analogy is the cholesterol-heart disease relationship. Although that one has received confirmation regarding benefit from lowering serum levels that are well above normal limits, the early conclusions that dietary cholesterol was a principal factor in etiology of heart disease is now thoroughly disproven, and the matter of how low is optimal for serum cholesterol is still unanswered. Other analogous situations abound.

Since there is abundant evidence that an elevated 2/16 ratio places a woman in high breast cancer risk categories, if interventions result in ratios moving to lower quintile ranges, then risk is automatically predicted to be lower. Similarly for homocysteine, greatly elevated levels confer high risk of heart disease, so actions that normalize serum concentrations, by definition, confer lower risk predictions. In neither case, however, should we go further than that to think that very low values are optimal. There are good reasons to avoid very low 2/16 ratios and very low serum homocysteine concentrations. Current evidence suggests that such states can lead to problems with osteogenesis and glutathione demand responses, respectively.

So the lab data are valuable guides, but they must be used by informed practitioners who know the limitations of benefit from each intervention.

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