There Is No Nutrition News
No Nutrition News
Given the almost dizzying frequency of diet-related headlines, the one true revelation about nutrition is superficially the least likely: there is no real news about nutrition.
There is still a lot we don’t know about this fatty acid or that, this vitamin-like compound, that resistant starch, or those soluble fibers. But those advances inform understanding pertinent to the supplementation of the overall diet, not substitutions that reconstitute the basic character of it. Eating, of the variety that prevails, is about foods in combinations, not nutrients in isolation, and there- despite all the news- there really is no news.
Consider, for instance, the latest high-profile paper about butter, predictably precipitating the latest spate of headlines insinuating either whatever editors think will capture eyeballs (so-called “click bait”), or the preconceived preference of the writer. The study basically showed a modest, positive association between butter intake as an isolated variable and all-cause mortality; and a modest, negative association with diabetes. In other words, to the extent these associations overcome difficult methodologic limitations bedeviling any effort to attribute health effects to any one food or nutrient, they mean: a bit more butter leads to a bit more risk of early death, and a bit less diabetes.
I think my colleague, and senior study author, Dr. Dariush Mozaffarian, pretty much nailed the interpretation by saying: “Overall, our results suggest that butter should neither be demonized nor considered ‘back’ as a route to good health. More research is needed to better understand the observed potential lower risk of diabetes, which has also been suggested in some other studies of dairy fat. This could be real, or due to other factors linked to eating butter — our study does not prove cause-and-effect.” In response to this, I can pretty much only append: amen.
The larger context here extends beyond butter to the on-going debate about saturated fat in general, and associated health outcomes. The matter has, in my view, been badly misrepresented. Arguments “for” saturated fat routinely quote two meta-analyses, one from 2010, the other from 2014, which showed comparably high rates of heart disease at the low and high ends of the population scale for saturated fat intake. For whatever it’s worth, that scale was quite narrow; saturated fat intake did not really vary all that much.
But across the range of variation that was observed, heart disease rates did not vary. This in no way indicates that saturated fat or its usual dietary sources are “good” for us now, since high rates of heart disease did not decline as saturated fat intake went up. They stayed the same. All this really means is that whatever people are eating instead of saturated fat appears to be almost exactly as bad; there appears to be more than one way to eat badly.
Just that has since been shown. Neither the 2010 nor the 2014 meta-analysis looked at what people were eating instead of saturated fat, or vice versa. But a study in 2015 did so in roughly 85,000 people. When saturated fat was replaced by trans fat, things got worse. When it was replaced by sugar and refined starch, as it often has been, things were comparably bad both times (i.e., the adverse health effects of added sugar and of saturated fat from meats and dairy look to be almost stunningly commensurate). However, when saturated fat calories were replaced with whole grain calories, and/or unsaturated fat calories from nuts, seeds, avocado, olive oil, fish or seafood, rates of cardiovascular disease declined significantly.
And then, hot off the presses is an epidemiologic study in roughly 125,000 people followed for approximately 30 years. The study found increases in all-cause mortality with increases in both saturated fat and trans fat intake; and decreases in mortality with increases in both polyunsaturated fat intake, and monounsaturated fat intake. So, butter is clearly a better choice than stick margarine made with trans fat, something we have known for literal decades. It is not nearly as good a choice as olive oil.
Which means the entire debate took us around a circle to deposit us more or less back where we thought we were at the beginning: eating mostly vegetables, fruits, whole grains, beans, lentils, nuts, seeds, and water when thirsty is apt to promote our health. Olive oil is clearly good for us. Eating more butter isn’t- but it’s not the one thing wrong with our diets, either. The plant-predominant dietary pattern best for human health also happens to be best for the planet.
Today’s news is that there really isn’t any news about the fundamentals of good nutrition. Accepting that is the first step toward putting what we have long known to far better use.
-fin Dr. David L. Katz;www.davidkatzmd.com; author, Disease Proof; founder, True Health Initiative
