Paul John Scott's June 22 commentary ("Chocolate milk in the schools and other products of expert opinion") about the follies and outright deceptions in yesteryear's low-fat diet "science" cannot be read without seeing parallels to today's climate-change debate.
Scott points out that the good intentions of a passionate scientist do not equate to good scientific reasoning or sound government policy. In the case of the saturated-fat-causes-heart-disease hypothesis, which for decades erroneously guided federal and local school policies, it turns out that researcher Ancel Keys reportedly hid evidence (including 600 questionnaires) that didn't comport with his opinion of the origin of coronary disease. Naysayers were put on the defensive against this fad science.
Scott also indicts the "eager and unquestioning health press," including the redoubtable Time magazine, which in 1961 put Keys on its cover, which reminds me of the equally redoubtable Newsweek that in 1975 proclaimed an inevitable coming ice age.
Oops. What lesson can we learn from these two stories?
As a nation, we are quick to adopt dietary fads, and also to accept the authority of media and government. Oops, indeed.
Now, after decades of scientific review, whole milk, butter and bacon are exonerated from causing coronary disease. (Obesity is a different subject altogether.) Sugar and food preservatives don't cause hyperactivity, contrary to the widely published inspirations of Dr. Benjamin Feingold in the 1970s-90s.
Should these lessons not give us pause about the so-called "settled science" about climate change? No side of the climate debate can claim the high ground, especially when the inconvenient measured fact is that earth's average temperature has not risen in the last 17 years, that doomsday projections are based on speculative models, not fact, and that higher CO2 levels may have as many positive effects as negative. We just don't know.
Though world temperatures are higher than they were in the 18th century, the science isn't settled on what all of the causes are, what the human contributions are or what to do about them.
True scientists are agnostic. Scientific theory remains just theory for a very long time — until practical measurements provide reproducible data that can't be denied. And even then, data raise ever more questions ad infinitum.
The media, and slavish policymakers, rush to judgment based presumably on good intentions but a poor understanding of basic science. Witness the daily "cancer cures" reported by the breathless media.
Good science takes time and patience and independent confirmation. Power brokers use selective opinions to support their agendas, their quest for money and especially their appetite for political influence. There are liberal scientists and conservative scientists, but the only ethical scientists are those who admit what they don't know and go about the laborious, unglamorous task of testing theories — free of political and ego-serving motives.
The only ethical media are those that, mindful of the same ethical precepts and of their role as public educators, refrain from promoting fads, premature conclusions and politically driven pseudoscience.
Richard Morris, of Wayzata, is a physician.