So here’s a title of an article bound to catch your attention, in Tufts Health & Nutrition Letter: “Calorie Restriction May Promote Cognitive Function.”
For those of us in our middle, or higher, years (Disclaimer: I’m now 66, and feel in my middle years though most studies would put in me in the elder category), news such as this is noteworthy. All of us over 50 have had increasing incidents of tip-of-the-tongue forgetfulness that, if there’s any family history of cognitive disease – as my dad died with Alzheimer’s – scare the dickens out of you. What can we do to minimize our risk for the pathologic decline of mental function?
Surely we’re all aware of exercise’s benefits in this regard. Besides better blood flow to the brain, a lower state of chronic inflammation, a learning challenge that often accompanies exercise habits, better blood sugar control, weight management, kidney and respiratory functions, etc, regular exercise at various intensities – the jury’s out but some recent studies are suggesting the harder the workouts, the better for the brain – seems to confer health benefits to both the heart and brain in parallel. See here, here and here for more on these benefits.
Likewise, diet – or rather, caloric balance that manages weight healthfully – also is correlated with better brain function in later years. Not only eating healthy foods like fruits, veggies, unsaturated fats, fish, dairy, but avoiding unhealthy ones like processed foods of all sorts, salty or sugary foods, etc. is correlated with overall generally better health including cognitively.
But does restricting calories, as the study in Germany suggests in this article, really make the difference in cognitive test scores…or is it weight loss? Or reduced intake of unhealthy, pro-inflammatory foods? Or, perhaps, is it simply paying attention to what, when and how you eat, i.e. self-discipline? There’s some data showing benefits for weight loss – here, here and here – but not much on cognition. The article doesn’t sift through the details of why its headline is written as it is.
And that’s the crux of this blog post.
As in a previous post, the essence of the media’s presentation of study results is to catch eyeballs. Maybe it’s also to effect behavior change, especially since most folks won’t read the entire article let alone do so critically. Despite the advent of political ‘fake news’, and the few but serious recorded violations of public trust within the medical research community, not to mention the shifting sands of medical advise and standards, sifting through the merits of any one article, regardless of its source, is not easy.
Thus, taking this article’s review by an otherwise highly-reputable source such as Tufts at face value, I am, for your sake, being the critic. As the title of my post suggests, there are a variety of simple alternative conclusions one can draw from the little information we can glean here. Is it actual restriction, or reduction, or weight, or fat loss? We simply don’t know. Furthermore, how large is the study? How was the restriction imposed – by educating subjects to change their normal intakes or by supplying foods for them to eat for X-number of weeks? And how long do you have to restrict to see benefits?
But here’s a kicker for you, one that the original study may have addressed but Tufts didn’t: is there a learning effect from having done the cognitive tests previously that enable you to do better next time? Granted, the control groups also learned if there is such an effect, and a 20% increase sounds really good, but is that statistically significant – I assume it is – or does it meet a standard more applicable to our concerns:
Is it clinically significant?
The difference is crucial. The data might be significant enough to demonstrate that, for the size of the study groups involved, the researchers can declare a successful intervention. But if you test better at the end of the study after having reduced calorie intake for several weeks, how long does this benefit last? Does on-going restriction yield even better, longer-lasting benefits? Do you start to backslide after a long period of calorie restriction? Or does further weight loss by any means yield equal results?
I don’t want to try to answer these questions directly. I’m simply trying to wake you up to the fact that it’s your eyeballs, and maybe your behaviors, that headlines try to change. But without more depth to both the article about the study or even the study itself, I’m afraid anything you read is, if not fake news, not enough news to hang your lifestyle on.
That is, other than eating less/better and exercising more. From that simple lifestyle change, many a health benefit has more than enough research to demonstrate its value and merit.
And maybe that’s why you should consider a professional exercise trainer. We may not be able to help your brain avoid cognitive decline per se, but we’ll sure help your body avoid physical decline. And that, my friendly reader, invariably has been shown to correlate highly with brain function as we age.