Q: Whilst reductionism has served our improvement in health outcomes as a society up until now, to what degree do you think it is becoming redundant in a world where our predominant health issues are a reflection of multiple causative factors, all acting at once, with various degrees of synergy?

A: I think the liabilities of reductionism have become a huge issue, as it were. In fact, that's just the problem: Due to reductionistic tendencies, the adverse consequences of reductionism wind up being too big to see!

I raise this issue all the time with regard to the primary area of my work, epidemic obesity and related chronic disease. There is, certainly, much insight to be gained by studying molecules through a microscope. But you won't see culture there -- it doesn't fit in the field of scrutiny. And obesity is cultural. You won't see suburban sprawl, or shopping malls, or... the big picture in general.

This is of considerable importance to my work. We have knowledge in hand -- indeed, have had it for decades -- to eliminate fully 80 percent of all chronic disease: heart disease, cancer, stroke, diabetes, dementia, etc. Fully 80 percent! Were this knowledge to become the power of routine action, it would rival -- and likely surpass -- the greatest public health advances of history.

But thus far, despite having the knowledge, it isn't power. Because we keep looking for silver bullets and active ingredients.

My own view is that the obesigenic elements of modern society are like a flood, and the solution is like a levee. There are no short cuts -- and no single sandbag will do what only the whole levee can do.

I think the plot is thicker still. I think medical expertise and medical error are, in some ways, the two faces of a common currency. With evermore sub-sub-sub specialization, the ability to see the whole patient is being squeezed out by an erudition for the parts. John Godfrey Saxe famously told us what ensues when we see only parts of the elephant in the room. Nothing better happens when we only see parts of our patients.

There may be an upside to seeing the world's leading authority on the upper, outer quadrant of your right kidney. Unless, of course, the actual problem resides in your liver, or left kidney, or anywhere else. In which case, god help you!

We cannot deny, and should not denigrate, the great advances to the human condition engendered by the painstaking toil of reductionist science. We are all beneficiaries of such effort and insight.

But that acknowledgment does not preclude the active ingredient in broccoli being... broccoli. It does not preclude the need to see the big picture, or the whole patient, and devise commensurate solutions to the problems, threats, and perils we encounter there.

We have gained too much from the reductionistic probings of science to abandon them. But we are losing much -- including lives every day -- for failing to see past them as the circumstances warrant.