I know what you are all thinking, “Part 1? This guy is going to try and drag something out for multiple parts when he’s already dealing with people holding on to the last bit of attention they have?!” Yes. In fact I am doing a multipart series precisely for that reason. My hope is that by cordoning off this humongous project into multiple parts I can better absorb it, and you can too. I will give a biiiiiiig caveat though, I can almost guarantee the result of all this research is going to come out with one enormous disappointment of an answer: it depends. HOLD ON FOR JUST ONE SECOND THOUGH. I am giving guidelines here, not answers. I can’t answer for everyone, but I can consolidate the information into an informative and entertaining (at least I think so) format. At the end of the series I will try to compile a table of all the results to help you when cross-referencing your choices, and for those of you who are truly distracted I will highlight major points within my review to help isolate important information. Without further adieu, my research into diet.
Let’s get right into this with one statement I think most Americans, if not everyone, can agree. The public school system, and likely the private too, teaches you absolutely garbage information in regards to day to day life. Want to file taxes? Good luck. Need to know how to get a job? See yah. Want to know how to eat properly to maintain good health? The door is right over there. It’s somewhat reminiscent of the South Park cable providers rubbing their nipples knowing that they aren’t going to do jack about your issues. Now I will extend an olive branch, the complexity of dietary issues is extensive and to provide a catchall solution is impossible. Regardless it’s nice to know how foods affect you before you go smashing glazed donuts down your gullet. So first let’s explore how foods affect our brain, as that seems to be the biggest issue for those of us with deficits in our cortical abilities.
Let’s take a look at what the science is saying, because it’s saying a whole lot after decades of research. As a cautionary though, the data provided will likely change as test methods improve and our understanding of brain mechanisms become more nuanced, everyday is a better day in terms of scientific knowledge. And of course as with any scientific investigation we start with… boobs (I’m 12, I know, sorry). Breastfeeding to be more specific. You may have heard rumors of the benefits of breastfeeding over formula and numerous observational studies, randomized control trials, and meta analysis have been written on the topic of breastfeeding, but right now let us turn to a meta analysis written by Joyce C. McCann and Bruce N. Ames titled Is Docosahexaenoic Acid, an n−3 Long-Chain Polyunsaturated Fatty Acid, Required for Development of Normal Brain Function? An Overview of Evidence from Cognitive and Behavioral Tests in Humans and Animals (McCann and Ames, 2005). Though an overview of more than breastfeeding, I think it provides some chronological order to the effects we see of one important aspect of diet: Omega 3 fatty acids. So what does this have to do with breast feeding? Beside the fact that it is included in McCann and Ames’ meta analysis, an article in the same journal reviewed docosahex… you know what lets just skip the $100 dollar word and call it DHA like everyone else – DHA levels in the breast milk of women around the world finding a levels averaging 0.32% ± 0.22% (Brenna et al., 2007). Now, typically when a journal based on clinical nutrition is publishing a study of the levels of a certain molecule anywhere in the body, it is pertinent to the function or malfunction of the body. In the case of McCann and Ames’ paper, they seem to have focused on the effect of DHA on the brain, though there are implications that we will investigate further later. Lets look into what DHA does to the brain from birth.
McCann and Ames’ detailed 33 studies of breastfeeding and long chain polyunsaturated fatty acid (LCPUFA) supplementation and their effect on the developing brain. The majority of the studies found positive correlation between the effect of one of these two feeding methods and the cognitive functions of the children being breastfed/supplemented. There were a few studies indicating a negative correlation or no connection at all, though this is expected when there are a number of studies. Just like you and me, scientists don’t think of everything and unfortunately they have the burden of isolating as many confounding factors and variables as possible when determining the efficacy of a claim, and even then there are many left on the table in these studies such as control of maternal IQ (McCann and Ames, 2005). The difficulty associated with this task is the reason test methods are repeated, changed, and scrutinized. This diversity of studies can give a better idea of the general consensus on the correlations made. Luckily these studies were proving correlations in bodily biochemistry that were quantified without explanation of function previously in studies such as Quantification and Fatty Acid and Fatty Aldehyde Composition of Ethanolamine, Choline, and Serine Glycerophosphatides in Human Cerebral Grey and White Matter where it was found that grey matter comprised close to, and possibly more than, 50% of the phospholipid membrane, the membrane that contains all the cellular contents (0’Brien et al., 1964). So, the gist? DHA is highly abundant in the membrane of the grey matter brain cells and babies who are breastfed or supplemented DHA benefit from increased cognition likely due to multiple factors, not least the fact that it is a crucial building block during a time of massive synaptic growth in the brain. Are you bored yet? Too bad. After this your breath will smell so pungent with fish oil that your family will disown you. Luckily for you, you’ll be sharp as a tack to deal with that familial disappointment.
Alright moving on to animal studies. Now before I start you may be thinking “But Connor, can you really associate how some stupid ferret relates to the cognition of a person?” and I would say… well, no not exactly, but also yes, kinda. There are draw backs to animal studies as they do not mimic the biochemical pathways of humans one for one, but they do give a good idea and they also provide one fantastically concrete advantage: we can control for almost all external factors when designing tests. There are also benefits in the way we can quantify results. The legal and ethical obstacles of obtaining near instant blood serum samples and postmortem sampling in children would be daunting, yah know, considering they would have be killed and all. But, with the shorter life span and regulatory loopholes out of the way with animals such as rats and rhesus monkeys (Ummm aaaaakkkkkkshually is a rhesus macaque!), there are significant benefits to be had in advancing the knowledge we have of how mechanisms work in the body. I digress, lets just jump into the summary so you can get back to doing absolutely nothing during quarantine.
So since we can do things like restrict the diets of rats to dangerous level, lets do that. The studies presented in McCann and Ames’ paper generally use a strategy of depleting the DHA levels as much as possible in order to eliminate N-3 fatty acids from lipid membranes as much as possible. Why do it this way rather than just feeding extra like the human studies? Well that’s a great question. In order to provide good evidence to a claim you generally collect data first, then you establish a correlation. From this correlation you start to formulate theories as to why the correlation might exist. You then take the theories and design studies to eliminate variables and isolate one theory’s variable to establish causality. In the rat studies this is the attempt they are going for. The data has been established that there is a correlation between omega-3 intake and an increase in cognitive function/development. The mechanism has been established hence the study of presence in the structure of nerve cells, now the only thing left is to do is establish causality and to reproduce results. Science is all about models of predictive capability and we need to understand why those models are predictable in order to find other models related to them. So you are all wondering, what happened? Were the brave scientists able to provide sufficient evidence that a restricted diet of DHA impaired cognitive function? Yes. And they also showed that DHA addition can cause reversal (McCann and Ames, 2005). Some of the papers even suggested the pathways that cause this to happen, but thats a rabbit hole we do not have time for. All of this is good news for us! Omega-3 supplementation can help cognition and help reverse cognitive impairment. For those of us who struggle with our cognitive faculties in the first place, this is a miracle. Now maybe there are other things we can do to help…
Before I let you get on with your day I want to explain something about this whole article and future articles. One of my main goals is to summarize the summaries of multiple studies to concisely and quickly display the results as they show. Another is to teach you how and why certain methods are used in studies in order to help you research for yourself and scrutinize data and methods to figure out for yourself what you should believe. These posts are not meant to be a deep dive, which may disappoint some of you die-hard nerds, but lets face it, many people aren’t particularly interested in weeding through research and quite honestly I don’t have the time either. That is why I use meta-analysis in order to expedite my knowledge on the topic. its much more practical and the authors are consolidating data for a reason; it’s too time consuming for everyone to research every article on a topic like omega-3, let alone all aspects of diet. Regardless I make mistakes, my meta-meta-analysis may be flawed and I hope you all can let me know if I screwed up or missed something. My goal is to be as intellectually honest as possible. Thank you for taking the time to read and I hope the utility of these articles builds on your life!
Need some citations? Here they are!: