Alzheimer’s, rightly feared for its ability to destroy the mental gifts of the elderly, may have a worthy adversary born of nature: Docosahexaenoic acid (DHA).
What is Alzheimer’s affect on the brain?
Alzheimer’s is a degenerative disease of the brain that causes the cerebral cortex to atrophy. This means that the cerebral cortex shrinks, and this shrinkage is dramatically different from the cerebral cortex of a normal brain. The cerebral cortex is the outer surface of the brain. It is responsible for all intellectual functioning.
There are two major changes that can be observed in the brain at autopsy:
- The amount of brain substance in the folds of the brain (the gyri) is decreased.
- The spaces in the folds of the brain (the sulci) are grossly enlarged.
The two major findings in the Alzheimer’s brain are amyloid plaques and neurofibrillary tangles. Amyloid plaques are found outside the neurons, neurofibrillary plaques are found inside the neurons. Neurons are the nerve cells within the brain. Plaques and tangles can also be found in the brains of people without Alzheimer’s. It is the gross amounts of them that are significant in Alzheimer’s disease.
Most people with Alzheimer’s disease show evidence of both plaques and tangles, but a small number of people with Alzheimer’s only have plaques and some only have neurofibrillary tangles.
- People with “plaque only” Alzheimer’s show a slower rate of deterioration during their lives.
- People with neurofibrillary tangles are more likely to be diagnosed with frontotemporal dementia.
How can Alzheimer’s be reversed?
To reverse Alzheimer’s, a treatment would have to be capable of removing plaques and protecting neurons.
What is DHA and how does it affect the brain?
DHA is an omega-3 fatty acid found in fish oils and micro-algae. It is the most abundant omega-3 fatty acid found in the brain and retina. It comprises 40% of the polyunsaturated fatty acids found in the brain and 60% f those found in the retina. 50% of the neuron’s plasma membrane is composed of DHA. This is no doubt why DHA deficiency is associated with cognitive decline, increased neural cell death and severe depression.
Pregnant and lactating women are being encouraged to take DHA, because studies have shown that their infants will have better visual acuity and longer attention spans than those whose mothers did not take the supplement.
Why do these abilities make reversal of Alzheimer’s possible?
Any substance that positively affects neurons will increase cognitive ability, but fully one half of a neuron’s plasma membrane is composed of DHA. This fact alone would make DHA indispensable to the treatment and reversal of Alzheimer’s.
Currently, the NIH (US National Institute for Health) is running an intervention trial to evaluate DHA in Alzheimer’s disease. This is the first large scale Human trial of DHA and Alzheimer’s disease.
Animal studies in the TG3 transgenic mouse model of Alzheimer’s disease linked decreases in amyloid plaques and tau to dietary DHA. Animal studies also show that when combined with arachidonic acid (also present in fish oil), the effectiveness of DHA for preventing plaques was less than without it. This would suggest that vegetarian DHA, manufactured using micro-algae, is more effective than fish oil based DHA for the treatment of Alzheimer’s.
Alzheimer’s is one of the most dreaded diseases out there, because of its ability to rob its victims of what we all hold most dear — our memories, our identity, our ability to reason and learn. But now there is hope.
All trials and studies aside, even if there were only a 1% chance that DHA — a natural substance that has been shown to reduce the risk of heart disease by reducing the level of blood triglycerides in Humans — were effective in treating Alzheimer’s, it would still be well worth trying.
- Rare genetic mutation found that protects against Alzheimer’s (fox6now.com)
- Alzheimer’s infects from neuron to neuron (eurekalert.org)
- Alzheimer’s study finds signs years before symptoms – Irish Times (irishtimes.com)
- Scientists find Alzheimer’s mutation (bigpondnews.com)
- Alzheimer’s Plaques in Brain Scans Predict Future Cognitive Decline (sciencedaily.com)