- and help prevent dementia, depression, and impairment of your cognitive skills
People with elevated levels of omega-3 fatty acids in their blood have better circulation in those parts of the brain that handle learning, language, memory, and other cognitive functions, according to a recent report that is published in the Journal of Alzheimer’s Disease. The scientists also observed a link between blood levels of omega-3 and the rate of dementia and depression. They call their study an important discovery that supports earlier studies, which have shown how simple dietary adjustments such as increasing your intake of oily fish or fish oil supplements help preserve mental skills and a healthy mind.
The human brain is the superior organ of our nervous system. It receives around 20% of the blood that the heart pumps out in the body. A good cerebral blood flow is necessary for ensuring that all brain cells get the oxygen and nutrients they need to function properly.
Science expects a 300% increase in the rate of Alzheimer’s disease within the next few decades, which is why researchers are very keen on finding out if dietary changes have the potential to break the curve. There is also focus on other neurological diseases such as dementia and depression, where a similar rate increase has been noted.
New potential for preventing diseases with cognitive impairment
According to George Perry, a biology professor at the University of Texas, San Antonio, the study is a huge step forward because it shows with help from the latest technology how a few simple dietary adjustments can improve brain health.
Normally, the flow of blood increases in those parts of the brain that are stimulated by different types of challenges and tasks. The scientists therefore used a special technique called SPECT (single photon emission computed tomography) that enables them to measure the cerebral blood flow in the brain, while a person carries out different cognitive challenges.
The study included 166 participants that were referred from psychiatric clinics. The participants were divided into two groups, one with high concentrations of the omega-3 fatty acids, EPA and DHA, the other with low concentrations of the same fatty acids.
All participants were instructed to carry out various tests that measured their cognitive skills. At the same, the scientists conducted SPECT measurements in 128 parts of the participants’ brains.
The scientists found a statistically significant correlation between omega-3 levels in the blood and blood flow through the parts of the brain that were activated by the different cognitive challenges. There was also a positive correlation between the participants’ omega-3 status and their ability to perform the cognitive tests.
According to the researchers, these test results are extremely important and demonstrate a new potential for fish oil supplements as a way of improving cerebral blood flow and preventing the diseases that involve cognitive impairment. Earlier research has demonstrated that the omega-3 fatty acids, EPA and DHA, have many other functions that are important for cognitive skills and mood.
Omega-3 fatty acids counteract harmful brain proteins
One of the things that scientists have observed in Alzheimer’s disease over the past twenty years is an accumulation of large amyloid proteins. A study conducted by scientists at King’s College in London and the National Institute on Aging in the United States took a closer look at different parts of the brain with amyloid proteins. It turned out that in brains affected by Alzheimer’s disease, levels of omega-3 and omega-6 fatty acids were significantly lower. Scientists speculate that omega-3 in particular has the potential to counteract amyloid protein build-up.
The omega-3 fatty acid DHA makes cell membranes pliant and enhances enzyme activity
The human brain is basically a large lump of fat. All cell membranes consist of omega-3 and omega-6 fatty acids and cholesterol. Cell membranes either initiate or stop, by means of signals, those activities, which the cells need to carry out in the brain and in other parts of the body. Constituting 11% of the brain’s dry matter, the omega-3 fatty acid, DHA, helps maintain cell membrane pliancy, which is important for brain cells and their ability to perform and communicate.
DHA enhances a type of enzyme activity known as NOS (nitrogen oxide synthase) activity that is important for memory and learning. DHA also plays a role in the synthesis of neuroprotectin D1 (NPD1) that has a host of functions in the brain.
Several studies have shown that DHA levels in the brain are lower in people with Alzheimer’s disease than in people without the disease.
Did you know that around 60% of the brain’s dry matter is made up of lipids such as cholesterol and omega-3/omega-6 fatty acids?
EPA counteracts inflammation that occurs with Alzheimer’s disease and depression
The omega-3 fatty acids, EPA and DHA, work together in a biochemical interplay with the omega-6 fatty acid, arachidonic acid (AA). It is important to have the right balance between these different fatty acids. For instance, EPA and AA are in direct competition with each other to produce some hormone-like substances called prostaglandins, which help control inflammation. It is therefore vital to ingest omega-3 and omega-6 fatty acids in the right balance.
Most modern diets contain far too much omega-6 and too little omega-3. This sets the stage for inflammation in the body. Earlier studies have found that omega-3 fatty acids have an anti-inflammatory effect in the brain, which is useful for counteracting the type of inflammation that is seen with Alzheimer’s disease and depression.
Large quantities of EPA work best with depression
Although depression can have many causes, it is often brain inflammation that affects the brain’s production of different signaling substances. Harvard University researchers have conducted a study of 155 people with severe depression. For a period of eight weeks, the participants got a placebo, a supplement with EPA (1,016 mg) or a supplement with DHA (900 mg). The results of the study showed that EPA provided the best anti-inflammatory effect and therefore also had the best effect on depression.
When you buy a fish oil supplement, study the label to make sure that you get around 1,000 mg of EPA daily – the same as 3-4 standard fish oil capsules or a salmon steak.
Omega-3 fatty acids from fish or from supplements
Most people consume less than the recommended amount of fish (which is preferably 350 per week with 200 grams from oily fish that are particularly rich in EPA and DHA). For those who dislike the taste of fish, supplements are a convenient option. Fish oils based on free fatty acids are absorbed more easily in the digestive system. Make sure to choose a supplement that complies with government regulations with regard to peroxide count and content of environmental toxins.
How much omega-3 do we need?
International experts recommend the following:
- 500 mg – to prevent a deficiency
- 1 grams – for proactive supports (e.g. of the brain and cardiovascular system)
- 2-4 grams – for intensive support (e.g. inflammation and aching joints)
Fish oil and its importance for the brain
Nutrition insight. Neuroimaging Highlights Role of Omega-3 in preventing Cognitive decline. 2017
King´s College London. Alzheimer´s disease linked to the metabolism of unsaturated fats. ScienceDaily March 22, 2017
Stuart G Snowden et al. Association between fatty acid metabolism in the brain and Alzheimer’s disease neuropathology and cognitive performance: A non-targeted metabolomic study. PLOS Medicine 2017
Robert M. Carney et al: Baseline Blood Levels of Omega-3 and Depression Remission: A Secondary Analysis of Data From a Placebo-Controlled Trial of Omega-3 Supplements. Journal of Clinical Psychiatry. 2016
Rapaport MH et al. Inflammation as a predictive biomarker for response to omega-3 fatty acids in major depressive disorder: a proof-of-concept study. Molecular Psychiatry 2015
Search for more information...