Written By Dr. Mercola |
Humans evolved with a staple source of the essential omega-3 fat docosahexaenoic acid (DHA) in their diets, namely seafood.
Animal based omega-3 fats are considered essential because they cannot be synthesized in appropriate quantities by your body and must be supplied through your diet.
The introduction of high-quality, easily digested nutrients from seafood into the human diet coincided with the rapid expansion of grey matter in the cerebral cortex–a defining characteristic of the modern human brain.
The DHA molecule has unique structural properties that provide optimal conditions for a wide range of cell membrane functions, and grey matter is a particularly membrane-rich tissue.
There’s no doubt you need omega-3 fat for proper brain function. In fact, mounting evidence suggests that deficiency in this essential fat may lead to brain degeneration. According to a recent article published in the journal Nutrients, “An emerging body of research is exploring a unique role for DHA in neurodevelopment and the prevention of neuropsychiatric and neurodegenerative disorders.”
Plant-Based versus Animal-Based Omega-3 Fats
Before we go any further, it’s important to recognize that animal-based omega-3 fat is not interchangeable with plant-based sources of omega-3. And while you do need both in your diet, animal-based omega-3 fats are particularly important for your brain health.
Dietary fish and marine oil supplements such as krill oil are a direct source of EPA and DHA. Plants, on the other hand, contain the parent omega-3, alpha-linolenic acid (ALA), which can be converted into eicosapentanoic acid (EPA) and docosahexanoic acid (DHA). However, as stated in the featured article, this conversion is ineffective in general, and appears to get progressively more ineffective with age:
“Unlike the photosynthetic cells in algae and higher plants, mammalian cells lack the specific enzymes required for the de novo synthesis of alpha-linolenic acid (ALA), the precursor for all omega-3 fatty acid syntheses. Endogenous synthesis of DHA from ALA in humans is much lower and more limited than previously assumed.
… [A]fter much intense research, the 1989 NATO Advanced Research Workshop on dietary n-3 and n-6 fatty acids on biological effects and nutritional essentiality, agreed by consensus that n-3 fatty acids generally: (1) have anti-inflammatory properties; (2) lower serum triglycerides and cholesterol; and (3) decrease thrombosis and platelet aggregation. Therefore administration was recommended as beneficial in cardiovascular disease, hypertension and rheumatoid arthritis
Since then, however, there has been a wealth of evidence to support the notion that the omega-3 fatty acids are not bioequivalent and that the longer chain EPA and DHA are much more important than their precursor ALA.” [Emphasis mine]
The reason why EPA/DHA are more important is because although ALA (that you get from plant sources) is an essential nutrient, the conversion of ALA to EPA and DHA is typically severely impaired by inhibition of delta 6 desaturase; an enzyme necessary for the conversion. Elevated insulin levels impair this enzyme, and over 80 percent of the U.S. population has elevated insulin levels, so chances are high that you’ll be part of this significant majority…Therefore, you want to make sure you get the bulk of your omega-3 from animal sources, not plant sources, to make sure you won’t develop a deficiency.
DHA: One of the Most Important Nutrients for Brain Function
Sixty percent of your brain is fat. DHA alone makes up about 15 percent to 20 percent of your brain’s cerebral cortex, as well as 30 percent to 60 percent of your retina, making it an essential nutrient for both brain and eye health.
It’s found in high levels in your neurons; the cells of your central nervous system, where it provides structural support. When your omega-3 intake is inadequate, your nerve cells become stiff as the missing omega-3 fats are substituted with cholesterol and omega-6 instead. Once your nerve cells become rigid, proper neurotransmission from cell to cell and within cells become compromised.
The influence of omega-3 fat on physical and mental health has been the subject of intense research over the last four decades, and there’s compelling evidence that animal-based omega-3 fats can help reduce the symptoms of a variety of psychiatric illnesses and degenerative brain disorders.
For more info, go to www.mercola.com
*This article was reprinted with permission from www.mercola.com.
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