Omega-3 fatty acids

Hello friend,

As we, followed by the rest of the world, increasingly invite creature comforts into our sedentary lifestyles, there is a tendency to obesity. Associated with obesity is metabolic syndrome leading to increasing diabetes and cardiovascular disease, leading to death or at best a decreased quality of life.

Something I read quite some time ago … I think I first read of it in Deepak Chopra’s book Perfect Health …… improving health, slowing the aging process and increasing longevity by caloric restriction. There have been anecdotal reports of individuals practicing this through history. Recently, diets have been developed based on this principle, like the Okinawa diet and the CRON (calorie restriction with optimal nutrition) diet.

The following is a mechanism that is brought into play in caloric restriction. As less food is absorbed from the gastro-intestinal tract into the blood, there is less need for insulin. As a result, there is a decrease in insulin and insulin-like growth factor 1 (IGF-1). By a cascade of cellular mechanisms, this leads to an increase in the activity of a protein in the cell nucleus, called peroxisome proliferator-activated receptor (PPAR) gamma co-activator 1 (PGC-1). PGC-1 and other PPAR activators increase the activity of nuclear receptors that play a major role in the effects of caloric restriction (The Journals of Gerontology Series A: Biological Sciences and Medical Sciences 60:1494-1509 (2005) © 2005 The Gerontological Society of America). They activate lipid transport and lipolysis (fat burning mechanisms). The resulting beneficial effects include decrease in blood pressure, decrease in total and bad cholesterol (LDL), decrease in triglycerides, increase in good cholesterol (HDL), decrease in blood glucose, and through all these, increased longevity.

It has now been shown that omega-3 fatty acids in our diet activate the same factors above that are activated by caloric restriction. In addition, omega-3 fatty acids decrease the levels of  hepatic sterol regulatory element binding proteins (SREBP). These proteins are genetic  transcription factors that are master regulators of lipid homeostasis. Reduction in SREBP results in a decrease in the activity of enzymes responsible for fat biosynthesis and storage. Bottom line, omega-3 fatty acids decrease fat synthesis and storage. So, it may be said that instead of starving yourself, just pop some omega-3 (read the book The Omega Diet by Dr. Artemis Simopoulos). No, please don’t take this as license to be corpulent …. the ill effects of obesity are not cancelled by omega-3 fatty acids.

Alright! What are omega-3 fatty acids? Let’s get back to basics. The macronutrients we ingest in our diet are proteins, carbohydrates and fats. (Fats are a part of a larger group of compounds called lipids. Also, lipids include sterols like cholesterol, phospholipids and others). Fats are a very concentrated form of energy. A gram of fat gives the body more than double the energy of a gram of carbohydrate or a gram of protein. Chemically, all fats are a “three-pronged” glycerol molecule linked via those three “prongs” (ester bonds) to long chain fatty acids. Each long chain fatty acid is a long chain of carbon atoms with hydrogen atoms bonded to the chain of carbon atoms. Each carbon atom (except the one forming the end of the chain) can be bonded to a maximum of two hydrogen atoms. When all the carbon atoms constituting the chain is bonded to the maximum number of hydrogen atoms they can be bonded to, it is called a saturated fatty acid. The triglyceride (that is, the glycerol linked by ester bonds to three fatty acids) is then called a saturated fat molecule. Too much saturated fat, obtained in the diet from dairy products, lard, coconut oil and cottonseed oil, is bad for the cardiovascular system. High levels can also cause breast cancer and prostate cancer. Smoking and regular alcohol ingestion increases the levels of saturated fat in the blood.

In monounsaturated fats, two of the adjoining carbons in the long chain fatty acid are not saturated with hydrogen atoms. They are each attached to only one hydrogen atom and double-bonded to each other. So, two carbon atoms saturated with hydrogen atoms would be bonded as -CH2-CH2-, whereas unsaturated double-bonded carbon atoms would be bonded as -CH=CH-. In polyunsaturated fats, there are more than one double bond in the fatty acid chain. “Omega” is the last letter of the Greek alphabet. Omega means the end. In our discussion, the omega carbon atom is the last carbon atom in the fatty acid chain. Omega-3 fatty acids are those that have a double bond at the carbon atom which is third away from the end of the fatty acid chain. Aha!

Essential fatty acids (EFAs) are those that cannot be synthesized by the human body from other components of the diet or body biochemistry. So, EFAs are required to be part of our diet. There are two groups of EFAs, the omega-3 fatty acids that we discussed above. and the omega-6 fatty acids. The latter are of course those that have a double bond at the carbon atom sixth away from the end of the fatty acid chain.

The balance of omega-3 and omega-6 fatty acids is important in the body. The ideal ratio of omega-6 to omega-3 in the diet is said to be less than 4 is to 1. In the diet of industrialized nations, the typical ratio is 10 to 1 or more. This could be cause for cardiovascular events, arthritis, cancer, depression and other mood disorders, osteoporosis and inflammation. In fact, cumulative research suggests that a lot of modern health conditions have inflammation as the underlying cause. There are signaling molecules in the body called eicosanoids, derived from omega-3 and omega-6 fatty acids. Eicosanoids from omega-6 fatty acids are pro-inflammatory, whereas those derived from omega-3 fatty acids are anti-inflammatory. To maintain equilibrium in these body processes, both omega-3 and omega-6 fatty acids are required, in the right ratio.

The important omega-3 fatty acids in our diet are eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) and alpha-linolenic acid (ALA). Research supports the use of EPA and DHA to prevent cardiovascular disease. EPA and DHA are biosynthesized by sea-water microalgae. Fish consume these microalgae and retain large amounts of these omega-3 fatty acids in their bodies. So, consuming fish or omega-3 fatty acids extracted from fish is ….. good for health. Plant omega-3 fatty acids are not EPA or DHA, but ALA. The human body is able to convert ALA to EPA and DHA. Flaxseed is commonly used as a vegetarian alternative to fish oil.

Omega-3 fatty acids have been shown in various research studies to be beneficial against cancer as well as developmental disorders like ADHD and autism. There have also been benefits to the immune system. When given to pregnant women and lactating mothers, the babies were shown to have higher IQs. More and more scientific research gives us greater insights into the benefit of omega-3 fatty acids. We do have to be careful, though, of not slipping into one of our weaknesses in modern society. Excess! If something is good for us, well, more of it must be better. Not really.

Moderation is important. Very large doses of omega-3 can cause hemorrhagic stroke. Also, when someone has congestive cardiac failure, chronic recurrent angina or any condition where the heart is not getting enough blood flow, the normally beneficial stabilizing effect of omega-3 fatty acids is a negative because it slows down the few hyperexcited cells of the heart. This can lead to sudden cardiac death. Bleeding can be excessive in a patient who is already on aspirin and/or warfarin.

Bottom line – omega-3 fatty acids are a blessing. However, excess can be a curse. Balance, balance in everything. So ….. what should the dose be? The National Institutes of Health recommend between 650 and 900 mg daily of EPA and DHA combined, or 2.2 gm of ALA (for vegetarians). Two tablespoonsful of flaxseed contain about 3 gm of ALA.

Be well, my friend. Until next month, take care of yourself and your health.

Warm regards,

Dr. Ajit Damodaran

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