Omega-3 fatty acids are found in a high concentration in fish, olive oil, garlic, and walnuts. Though these foods are common, people don’t eat them in the adequate quantities it would take to get beneficial levels and supplements are often recommended.
Omega-3 plays a crucial role in reducing inflammation, which, in turn, may reduce your risk of osteoporosis, some cancers, heart disease, asthma symptoms, and other conditions.
In addition to the prevention aspects, Omega-3 stimulates hair and skin growth, and because of how important it is during an infant’s development, pregnant women are encouraged to take it to prevent problems associated with vision.
When you consider the immense benefits that Omega-3’s unsaturated fats have on the body, it’s easy to see why they are recommended to nearly everybody for their preventative and medicinal qualities.
Some benefits are merely anecdotal and research based, such as their belief to protect against memory issues and conditions, such as Alzheimer’s and other dementia issues. Regardless, their proven benefits to decrease joint problems and heart disease make it worth adding to your supplement regimen.
Omega-3’s major health benefits come primarily from its long-chain fatty acids (EPA and DHA). In fact, DHA is the most prevalent fatty acid found in the brain and there’s a direct correlation between the volume of DHA in the brain and memory/intelligence.
We’ve all heard of fish being called “brain food” and DHA is the main reasoning behind that. DHA fatty acid is vital to the creation and maintenance of certain cellular parts of the brain and retina, making it essential for brain health.
As your body ages, your body makes less and less DHA, which is one of the reasons believed to be behind mental decline with age. It’s incredibly important that anyone looking to stay on top of their mental game incorporate Omega-3 into their health care regimen.
The question of how much omega-3 to eat depends in large part on how much omega-6 we eat.
Over the course of human evolution there has been a dramatic change in the ratio of omega-6 and omega-3 fats consumed in the diet. This change, perhaps more than any other dietary factor, has contributed to the epidemic of modern disease.
The historical ratio of omega-6 to omega-3
Throughout 4-5 million years of hominid evolution, diets were abundant in seafood and other sources of omega-3 long chain fatty acids (EPA & DHA), but relatively low in omega-6 seed oils.
Anthropological research suggests that our hunter-gatherer ancestors consumed omega-6 and omega-3 fats in a ratio of roughly 1:1. It also indicates that both ancient and modern hunter-gatherers were free of the modern inflammatory diseases, like heart disease, cancer, and diabetes, that are the primary causes of death and morbidity today.
At the onset of the industrial revolution (about 140 years ago), there was a marked shift in the ratio of n-6 to n-3 fatty acids in the diet. Consumption of n-6 fats increased at the expense of n-3 fats. This change was due to both the advent of the modern vegetable oil industry and the increased use of cereal grains as feed for domestic livestock (which in turn altered the fatty acid profile of meat that humans consumed).
Vegetable oil consumption rose dramatically between the beginning and end of the 20th century, and this had an entirely predictable effect on the ratio of omega-6 to omega-3 fats in the American diet. Between 1935 and 1939, the ratio of n-6 to n-3 fatty acids was reported to be 8.4:1. From 1935 to 1985, this ratio increased to 10.3:1 (a 23% increase). Other calculations put the ratio as high as 12.4:1 in 1985. Today, estimates of the ratio range from an average of 10:1 to 20:1, with a ratio as high as 25:1 in some individuals.
In fact, Americans now get almost 20% of their calories from a single food source – soybean oil – with almost 9% of all calories from the omega-6 fat linoleic acid (LA) alone! (PDF)
This reveals that our average intake of n-6 fatty acids is between 10 and 25 times higher than evolutionary norms. The consequences of this dramatic shift cannot be overestimated. Therefore n-6 and n-3 fatty acids compete for the same conversion enzymes. This means that the quantity of n-6 in the diet directly affects the conversion of n-3 ALA, found in plant foods, to long-chain n-3 EPA and DHA, which protect us from disease.
So what are the consequences to human health of an n-6:n-3 ratio that is up to 25 times higher than it should be?
The short answer is that elevated n-6 intakes are associated with an increase in all inflammatory diseases – which is to say virtually all diseases. The list includes (but isn’t limited to):
- cardiovascular disease
- type 2 diabetes
- metabolic syndrome
- irritable bowel syndrome & inflammatory bowel disease
- macular degeneration
- rheumatoid arthritis
- psychiatric disorders
- autoimmune diseases
The relationship between intake n-6 fats and cardiovascular mortality is particularly striking. *taken from chriskresser.com