Protecting Your Brain
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In this newsletter, we will take a look at just how quickly bad dietary choices can affect our brains. As is often done, the study we are to examine (published in the journal Brain, Behavior, and Immunity), was done with rats, providing them with a diet that mimicked human “fast foods”, including foods packaged for long shelf life. While foods such as potato chips and other snack foods were part of the rat’s diet, other foods that we might all consume semi-regularly were also included, foods like frozen pizza and pasta dishes, and deli-style meats containing nitrate preservatives.
In these days of Skip-the-Dishes, and their ilk, many of us are consuming more restaurant foods than we did before. And frankly, the vast majority of restaurant food falls into the above category. They reheat prepared frozen foods, use cheap vegetable oils for cooking, and contain many chemically-preserved and heavily processed ingredients.
Such diets, containing highly processed food, are already linked with obesity and type 2 diabetes, but given that this study was only four weeks long, it seems that these foods quickly cause some damage that is less obvious.
Let’s have a look at what those rats ate, during the four weeks this study ran. Some of the rat subjects were given their normal food (32%calories from protein; 54% from wheat-based complex carbohydrates; 14% from fat), while other randomly chosen rats were given the highly processed diet (19.6% calories from protein; 63.3% from refined carbohydrates such as cornstarch, maltodextrin, and sugar; 17.1% from fat). Finally, a third group was given the appalling diet along with supplemental DHA (an omega-3 fatty acid).
The result of the study provided good news for young rats, and bad news for older rats. In the older rats given the processed diet, without DHA added, pro-inflammatory proteins, and other markers of inflammation, were significantly elevated in the amygdala and hippocampus (areas of the brain). This was not observed in the younger rats nor, interestingly, in the older rats who received supplemental DHA along with their processed foods diet. As well, the older rats also showed evidence of memory loss (shown through behavioral experiments), again, something not demonstrated in the younger rats, nor the older rats supplemented with DHA.
Now, one other aspect of this study was the resulting effects of inflammation in the amygdala.Those rats showing inflammation in the amygdala, did not display the correct fear behavior when provided with a “danger cue”. According to one of the authors of the study (Ruth Barrientos), “The amygdala in humans has been implicated in memories associated with emotional – fear and anxiety producing – events. If this region of the brain is dysfunctional, cues that predict danger may be missed and could lead to bad decisions”.
The most worrisome aspect of the study, for the researchers, was how little time (4 weeks) it took for those effects to manifest. Barrientos went on to conclude that, “These findings indicate that consumption of a processed diet can produce significant and abrupt memory deficits — and in the aging population, rapid memory decline has a greater likelihood of progressing into neurodegenerative diseases such as Alzheimer’s disease. By being aware of this, maybe we can limit processed foods in our diets and increase consumption of foods that are rich in the omega- fatty acid DHA to either prevent or slow that progression”.
This research adds to a body of work, already existing, which links a short-term, high-fat diet to memory loss and brain inflammation in older animals, and to data which had found that DHA levels are lower in the the amygdala and hippocampus regions of the brain, in aged rats. (Study)
Should We Supplement with DHA?
The two primary omega-3 fatty acids are DHA (docosahexaenoic acid) and EPA (eicosapentaenoic acid), which are found mostly in fish and other seafood, though flax oil and walnuts are also a good source. Put simply, DHA is usually associated with cognition and learning, and vision, while EPA is often used to treat inflammation in the body, and to improve the mood. Each, of course, has many more functions than just those, and one of the functions of DHA in the brain is to prevent inflammatory responses. However, this is the first study to demonstrate that DHA can protect the brain from inflammation due to a diet of processed foods.
Now, while supplementing the processed diet with DHA prevented memory problems from occurring, and almost totally reduced the inflammatory markers, in the older rats, one should not rush to take a DHA supplement. As usual, the reductionist Western medical model has led to the marketing of isolated DHA, and EPA, products, for people wishing to target certain health concerns. For example, pregnant women will take DHA products to ensure healthy prenatal brain development, and those with arthritis might take an EPA product for its anti-inflammatory properties. (EPA seems to be a better anti-inflammatory for the body, while, as this study illustrates, DHA seems to serve a better anti-inflammatory function in the brain.)
However, what is often overlooked with this reductionist approach, is that DHA and EPA are essentially cofactors, and like with the B-vitamins, if you take too much of one you deplete the body of another. So, one is better advised to take a mix of both omega-3 fatty acids, in order to avoid depleting their body of the other primary fatty acid. Squid oil, for example, is naturally high in DHA (probably because octopus are highly intelligent, and both belong to the same genus), but also contains a reasonable amount of EPA. And there are high EPA products that also contain appreciable amounts of DHA. These mixed products are almost always a better choice than taking pure isolated DHA or EPA supplements.
It is now well known that while eating fish has consistently proven to prevent stroke and heart disease one cannot say the same for supplementing with most fish oils. That is because, again due to reductionist thinking, fish oil has been processed to remove almost all other omega fatty acids (5, 6, 7, 8, and 9), and so, while it might provide certain health benefits, it no longer has all the beneficial attributes that eating the whole fish provides. (One good example of how those other fatty acids, still present when you eat fish, is to look at omega-7. Omega-7 fatty acids can prevent, and reverse, the build-up of arterial plaque, a cause of heart disease and stroke. Source)
This is why, for maximum benefit, I usually advise taking an unprocessed fish oil, such as salmon or krill. These oils contain all the fatty acids found in the whole creature, and so can provide a wider range of protection than most processed fish oils. Of course, you want a trusted manufacturer, since if salmon is not tested for contaminants it may not be as clean as a processed fish oil. Part of the processing of fish oils is to concentrate the DHA and EPA, but the other aspect is to clean out mercury and other contaminants from the fish body oil.
Krill doesn’t have that problem since it is a small, short-lived crustacean, and does not accumulate such toxins (nonetheless, our NutriKrill product is tested for all contaminants by the Norwegian producers). As well, though krill oil appears to be much lower in DHA and EPA than conventional fish oils, it has the advantage of being in a phospholipid form, which essentially means that it is absorbed at least five times more efficiently than other fish oils (which are in a triglyceride form). This increased absorption is due to the fact that our cells are also phospholipid in nature, and thus (much like with liposomal products), the fatty acids from krill can enter directly into the cells.
Here’s a quick look at a germane study, designed to investigate “the influence of ingestion of krill oil on cognitive function in elderly subjects”. “Forty-five healthy elderly males ages 61-72 years were assigned to receive 12 weeks of treatment with: medium-chain triglycerides as placebo; krill oil, which is rich in n-3 PUFAs (i.e. omega-3 fatty acids) incorporated in phosphatidylcholine; or sardine oil, which is abundant in n-3 PUFAs incorporated in triglycerides.”
“This study provides evidence that n-3 PUFAs activate cognitive function in the elderly. This is especially the case with krill oil, in which the majority of n-3 PUFAs are incorporated into phosphatidylcholine, causing it to be more effective than sardine oil, in which n-3 PUFAx are present as triglycerides.” (Study)
So, if you are a young adult rat, you don’t have too many worries, yet, since these rats showed no signs of cognitive problems or brain inflammation, while consuming the processed diet. However, us older rats are advised by these scientists not to think that we can simply eat all the processed foods we want, as long as we just take a DHA-containing supplement. For one thing, both age groups gained a lot of weight on the processed diet, the older rats gaining significantly more than the younger ones. And, they point out that, in this study, those older rats receiving DHA, were not spared from the weight gain resulting from consuming highly processed foods. And of course, there are many other health issues associated with regularly consuming large amounts of refined carbs, sugars, bad fats, and preservatives. Therefore, the takeaway is: eat less processed and restaurant foods, ensure your diet is high in omega-3 fatty acids, and if you are an older rat, also supplement with krill, or some other unprocessed fish oil.