Essential Fats/DHA by Lapis Blog entry

Blog: In The Raw
by Lapis

Essential Fats/DHA

Here is a good article from Dr. Dina concerning Essential Fatty Acids and how we can convert DHA without the need for animal protein.

Date: 3/8/2006 5:31:32 AM ( 18 y ) ... viewed 6655 times

Essential Fats and the Organic Athlete, Part 1
Contributed by Dr. Rick Dina
Monday, 27 September 2004
Whereas fats have traditionally been considered primarily as a source of calories and for their insulating properties, more recent research has uncovered a myriad of important functions in which fatty acids play a critical role. These includes such functions as hormone regulation, cell division, creating smooth and soft skin, creating stable heart rhythms, reducing platelet stickiness, regulating inflammatory processes, and becoming major parts of our cell membranes, which surround and affect the functioning of every cell in our body. Of particular importance to the athlete is the role of essential fats in the production of hemoglobin, oxygen transfer, energy production, and recovery from fatigue. Besides inhibiting athletic performance, fatty acid imbalances can create or contribute to such situations as lack of proper development of the nervous systems of infants and children, depression, cancer, diabetes, high blood pressure and cardiovascular disease.

Of primary concern is how we can assure ourselves we are obtaining adequate amounts of essential fatty acids to perform all of their critical functions, while avoiding an excess of unhealthful fats that damage our health and rob us of optimal performance. In order for this to make sense, this article will explain how fatty acids work in our bodies, and Part II will then build upon our foundation and give the specifics on which foods to both eat and avoid to keep us in optimal essential fatty acid balance.

A fatty acid is composed of a chain of carbon atoms, attached to hydrogen atoms on the top and bottom of the carbon chain. To start with the carbons, each carbon in the chain shares one electron with its neighbor to the right, and one electron with its neighbor to the left. This sharing of electrons creates a chemical bond that holds the fatty acid molecules together. Each carbon also shares one electron with a hydrogen above it, and one electron with a hydrogen below it. Each carbon has 4 electrons that it can share with other atoms, and that is why the typical mid-chain carbon has 2 carbon neighbors and 2 hydrogen neighbors. The carbons at each extreme end of the chain have slightly different attachments.

Certain enzymes, depending upon the specific situation, can either add or take away carbons, making the fatty acid chains either longer or shorter. Other enzymes can take away hydrogens, and then use the electron left over to create a double bond between two carbons, where two neighboring carbons share two electrons instead of one. Even other enzymes can break double bonds and add hydrogens. Each time one of these changes occurs, a different fatty acid is formed with a different structure than the one from which it was changed. Each different fatty acid structure performs a different function, just like a phillips head vs. a regular screwdriver or a spoon vs. a fork.

When a carbon chain has no double bonds, which means it simultaneously is completely surrounded by hydrogens, it is called a saturated fat, because it is “saturated” with hydrogen atoms. Saturated fats are stiff and rigid, tend to be non-reactive, and are usually solid at room temperature. Unsaturated fats contain double bonds, and are therefore missing one or more hydrogen atoms. This structure causes them to be more fluid and flexible, react more easily with other molecules, and be liquid at room temperature. The more unsaturated a fat, the more double bonds it has, therefore the more reactive it is and the colder it can get before it becomes solid.

Of the many types of fatty acids our bodies use for various functions, there are two fatty acids that our bodies do not have the enzyme systems to manufacture. They are known collectively as the two essential fatty acids (EFA’s) because it is “essential” that we consume them in our diets. The first, known as Linoleic Acid (LA), belongs to the Omega 6 family of fatty acids, and the other, Alpha-Linolenic Acid (ALA) or (LNA), is part of the Omega 3 family of fats. Each family has 6 different fatty acid members. From LA, the Omega 6 essential fatty acid, our body can make the other 5 Omega 6 fats, and from ALA, the Omega 3 essential fatty acid, our body can make the other 5 Omega 3 fats. The transformation of essential fatty acids into the other members of the same family must go in a linear and sequential manner. Fats other than those of the Omega 6 and Omega 3 family are created from other sources, such as the breakdown products of carbohydrates or protein, or from other fats we consume.

Beginning with each essential fatty acid, the first enzyme, known as a desaturase, takes away a hydrogen and creates a double bond. The next enzyme, known as an elongase, adds two carbons to make the chain longer. Then we have another desaturase, another elongase, and then a third desaturase to make the 6th fatty acid of each family. Each time a successive fatty acid is formed from the previous one, some of it is used for functions it is specifically designed for, and some of it is used to become the next fatty acid in the family.

LA, the omega 6 EFA, has 18 carbons in its chain, and two double bonds. Its shorthand name is 18:2w6. The first desaturase enzyme changes it into Gamma-Linolenic Acid, also known as GLA, the second member of the Omega 6 family, abbreviated 18:3w6, signifying it has 18 carbons, 3 double bonds, and is part of the Omega (w) 6 family. The elongase enzyme changes GLA into DGLA (20:3w6), and then the next desaturase changes DGLA into arachidonic acid, or AA (20:4w6). The 5th and 6th Omega 6 fatty acids have little nutritional significance.

In the Omega 3 family, we begin with ALA, or 18:3w3. It gets converted to 18:4w3, then 20:4w3, and then into 20:5w3, also known as EPA. That gets changed into 22:5w3, which in turn becomes 22:6w3, also known as DHA. ALA, EPA, and DHA are the key players in the omega 3 family.

Essential Facts about Essential Fats, Part 2
Contributed by Dr. Rick Dina
Monday, 05 December 2005
Depending upon which authority you are listening to, we need somewhere from 3 to 10 grams of Linoleic Acid per day, and about 2 to 5 grams of Alpha-Linolenic Acid per day. Omega 6 fats are widely found in a large variety of foods, so getting enough Omega 6 fats is rarely ever a problem. Omega 3 fatty acids, on the other hand, are much more elusive. In fact, it is estimated that 90-95% of Americans are deficient in Omega 3 fats.
So where do we get our Omega 3 fats from? First of all, they are in virtually all fruits and vegetables. Although it has been quite difficult to get an exact figure, it is fair to say that 1000 calories of “regular” fruits and vegetables contain approximately 1 gram of Alpha-Linolenic Acid, the Omega 3 Essential Fatty Acid (EFA). So if you consume 2000 calories and all of those calories come from fruits and vegetables, you have met your Omega 3 EFA requirements. Many athletes, of course, may consume considerably more calories than 2000 per day. There are very few people that consume such large quantities of fresh fruits and vegetables, and that is why they are not usually considered a major source of EFAs. Fruits and vegetables also contain Omega 6 fats, in the form of Linoleic Acid (LA) in about a 1:1 ratio with the omega 3 fats.

Next we consider leafy green vegetables. On average, they have about 10% of their calories from fat. Of this fat, 60-70% of it is Alpha-Linolenic Acid. The plant uses it in the process of converting sunlight into carbohydrates, fats, and proteins. 150 calories of leafy greens (broccoli is included in this as well) contains approximately 1 gram of ALA. In other words, you can potentially meet half of your Omega 3 requirements from eating only 150 calories of leafy greens per day. The organic athlete knows the importance of fresh fruits and vegetables and (hopefully) makes them the basis of their nutritional programs. Green leafy vegetables also contain LA, but in lesser amounts than ALA.

If this is not enough, then it is time to bring out the “heavy hitters” in the omega 3 plant world. The undisputed champ of this category is the flax seed. Flax contains approximately 58% of its fat in the form of ALA. One heaping TBSP of flax seeds contains 2 grams of ALA, or your entire daily requirement. Flax seeds contain about 4 times more Omega 3 fatty acids than Omega 6 fatty acids. Hemp seeds are another good source of Omega 3 fats, with about 20% of its fat coming from ALA, and 60% coming from LA, the Omega 6 EFA, creating a 3:1 ratio of Omega 6’s to Omega 3’s. Walnuts and soybeans also contain ALA, but they have about 10 times and 7 times more LA, respectively. Canola oil has about 4 times more w6 than w3.

Knowing the ratio of w6 to w3 is very important. In Part I we talked about each of the EFA’s getting longer and less saturated as they are acted upon by enzymes. As it turns out, it is the exact same enzymes that act upon both the Omega 3 and the Omega 6 family. If we consume too many Omega 6 fats, for example, then the enzymes are so busy working on the Omega 6 fats that they are less available to work on the Omega 3 family. This is known biochemically as competitive inhibition. It is similar to the difficulty of getting enough training time in if you work 90 hours per week.

The optimal ratio of w6 to w3 is somewhere from 4:1 to 1:1. Some experts even suggest a ratio of 1:2, or twice as much omega 3 as omega 6. The average American eats about 20 or more times more Omega 6 fats than Omega 3 fats. This is way out of balance, and in my opinion one of the major contributors to the poor health of people in modern society.

Why is the altered ratio such a problem? First of all, as mentioned above, this issue of competitive inhibition means that even if we have enough Omega 3 fatty acids in the form of ALA on an absolute scale, the excess of Omega 6 fats makes the enzymes that convert ALA into the important longer chain w3 fatty acids, EPA and DHA, less available to do that task. EPA and DHA deficiency can result. Secondly, the omega 6 fat LA gets converted into another omega 6 fat known as arachidonic acid, or AA. AA is the precursor for substances (series 2 prostaglandins (PGE2)) that initiate inflammation. The omega 3 fat EPA is the precursor for substances that control inflammation. When we have a balance of these two fatty acids, inflammation stays in check. When we have an excess of AA (omega 6) over EPA (omega 3), we tend toward an excess of inflammation, which not only contributes to obvious inflammatory conditions such as arthritis, but is also a major contributor to degenerative diseases such as heart disease, stroke, cancer, alzheimers, the complications of diabetes, etc.

AA is found in abundance in land animals and dairy products. LA is found in abundance in processed food, often including processed vegan foods, and quickly gets converted into AA once consumed. The oils that contain the most LA include corn, cottonseed, soybean, sesame, sunflower, safflower, and peanut. Because the average American lives mostly on animal products and processed foods, and eats small amounts of fruits and vegetables (especially the green leafy ones), flax, or cold water fish, we see then how we get such an overabundance of omega 6 fats over omega 3 fats. When we eat large amounts of fruits and vegetables, especially green leafy vegetables, and minimize or ideally completely avoid animal foods and processed plant foods, we tend to automatically get an optimum ratio of omega 6 to omega 3 fats, as well as an enormity of other nutritional benefits.

DHA is the longest chain omega 3 fatty acid, and is critically important for hormone regulation, optimal brain function, and for women who are pregnant or breast-feeding. Deficiency of this can contribute to diabetes, cancer, high blood pressure, depression and learning impairment, as well as many common complications of pregnancy such as pre-eclampia, gestational diabetes, and post-partum depression.

Cold water, fatty fish, such as wild salmon, sardines, mackerel, trout, herring, and eel, contain pre-formed EPA and DHA. When someone who eats a SAD (Standard American Diet) begins to include these cold water fish into their diets, there are often times notable health improvements. They are now consuming the much needed Omega 3 fats they were deficient in before. This helps in areas such as lowering blood sugar, blood pressure, total and LDL cholesterol, reducing inflammation, and may even improve mood and brain function. Part of this is directly due to the Omega 3 fats, and part is probably also from the fact that they are eating fish instead of their usual land animals. Generally speaking, fish is lower in saturated fat and is less calorically dense than land animals. Unfortunately, fish also comes with some inherent problems. It contains cholesterol and its own arachidonic acid (AA), has no fiber, vitamin C or phytonutrients, and has varying degrees of environmental contamination, most notably from mercury, dioxin, and PCBs. Even fish on the “safer” end of the spectrum are only supposed to be eaten a couple of times per week or month according to various authorities, such as the EPA (Environmental Protection Agency) and the FDA. This is especially troubling for pregnant and lactating women, who are cautioned to eat even less fish than the general population, and none of certain species. DHA is one of the most important raw materials to create the brain, spinal cord, and peripheral nerves of the developing nervous system of fetuses and infants, yet mercury is known to be very damaging to these structures, possibly even leading to birth defects.

So what does one do to ensure a safe and reliable source of DHA? Can we rely on our bodies to make enough DHA from ALA? Should we eat small amounts of fish or take purified fish oil supplements? Is there a plant source of DHA or EPA? We will cover these important topics in Part III.

Essential Facts about Essential Fats, Part 3
Contributed by Dr. Rick Dina
Monday, 05 December 2005
We left off Part II with the question of how to secure a reliable source of DHA without poisoning ourselves with mercury and other environmental contaminants found in cold water fish. As we discussed in part I, our bodies have the enzyme systems to convert the shorter chain fatty acids, such as ALA, the omega 3 essential fatty acid, found in fruits, vegetables, flax, hemp, etc. into the longer chain fats, such as EPA and DHA, which are also found pre-formed in cold water fish. EPA’s major role is in controlling inflammation, and DHA’s major roles are in brain function and hormone regulation.
There have been many studies that have questioned the body’s ability to covert ALA into DHA efficiently or effectively. Upon examining many of these studies very carefully, I have to say that many of the conclusions could be more scientifically valid in my opinion. We discussed in Part II how an excess of omega 6 fats inhibits the conversion of ALA into the longer chain omega 3 fats EPA and DHA, as the enzymes are too busy with the omega 6’s to work on the omega 3’s efficiently. It is also well known that trans fats (from hydrogenated oils found in margarine and other processed foods) and saturated fats interfere with the enzymes that convert the EFAs (LA and ALA) into their longer chain family members.

In one study of pregnant women commonly quoted in opposition to the idea that the body can effectively convert ALA into DHA, researchers gave the participants in the experimental group ALA in the form of margarine, with a 3.2 to 1 ratio of omega 6 to omega 3. The study did not discuss any other aspects of the women’s diets, so we do not know the overall dietary ratio of omega 6 to omega 3 fats. This particular study was done in the Netherlands, so it is fair to say that these Dutch women had diets probably not dramatically different from that of Americans, meaning much more omega 6 fats than omega 3’s. Giving participants omega 6 fats in the trans form doubly stacks the cards in opposition to optimal conversion of ALA into DHA, therefore does not seem like the most accurate way to test how well our bodies perform this conversion. The control group received margarine with only omega 6 fats in it, and no omega 3.

Among other measurements, this study looked at blood levels of ALA, DHA, and AA, as well as another fatty acid known as osbond acid. Osbond acid is an omega 6 fat that is nearly identical to DHA, except that DHA has one extra double bond in the omega 3 position. Levels of osbond acid increase if there is not enough DHA, as osbond acid is functionally the fatty acid most similar to DHA. In this way, it is seen by researchers as a functional indicator of DHA status. In other words, the higher the osbond acid level, the poorer the DHA status, and the lower the osbond acid level, the better the DHA status. This study noted an increase in osbond acid in the blood of the women who consumed the omega 6 only margarine, while those who consumed the ALA (omega 3) fortified margarine did not see this increase. In other words, the women who consumed ALA showed better functional DHA status than those who did not, despite the excess omega 6 trans fats.

Another flaw in this study was measuring only blood levels of DHA. The blood is only the transport pathway. DHA performs its critical roles when incorporated into the cell membranes. It is probable that the women who consumed ALA actually had higher cell membrane levels of DHA. That would explain the lower levels of osbond acid. They did not have to make the next best thing (osbond acid) because they had the real thing (DHA). It is also quite conceivable that any DHA that was converted from ALA would have gone directly to the cell membranes and thus would not have been reflected in the bloodstream levels.

The title of this study was “Alpha linolenic acid supplementation in pregnancy has no effect on maternal cognition or DHA in maternal and infant plasma.” Most health professionals only read the headline and possibly the abstract of an article. They therefore often times miss out on important information in the text of the article, such as the improvement in functional DHA status of women consuming ALA, despite having the odds stacked against them with omega 6 trans fats being consumed simultaneously.

Additionally, in terms of the cognitive function aspect, previous studies have shown a decrease in cognitive function in pregnant women as the pregnancy progresses, presumably from DHA depletion. This study, however, never established that any of the participants had any signs of impaired cognitive function before the experiment began. So to say there was no improvement in maternal cognition when no congnitive dysfunction was established is like saying that adding oil to an already well oiled machine will not make it run more efficiently. That does not mean that oil added to a machine that needs oil would not improve its function. But the typical reader would not know this from reading the title or abstract, and would only find this out by carefully reading the full text of the article. I cite this particular article as it is fairly indicative of many studies that question the body’s ability to covert ALA into DHA. Other studies have shown that we do effectively convert ALA into DHA, and that approximately 7% of ALA consumed ends up converted to DHA. That would mean that 3 grams of ALA, found for example in 2 Tablespoons of flax seeds, would provide about 200mg of DHA, which is a common amount found in omega 3 supplements, and adequate daily intake based on the recommendations of most authorities.

There is another very important point to consider in this question of ALA to DHA conversion. Many studies, including the two mentioned above, have implied that the body has a regulation mechanism so that it will not make more DHA than is necessary or needed.

Why not? To my knowledge, there has not been specific research to address this question. Let us, however, take a look at other nutrients that have regulation mechanisms to see if we can fit some pieces of the puzzle together. As we are capable of making DHA from ALA, we can also make Vitamin A from beta-carotene. There is no pre-formed Vitamin A found in any plant foods. Whole natural plant foods do, however, have an abundance of carotenoids, including beta carotene. When there is a need for Vitamin A, such as when there is no outside source of it, an enzyme cleaves beta carotene to produce two vitamin A molecules. It is well known that excess Vitamin A is toxic to the body, resulting in conditions such as dry, itchy skin, hair loss, headaches, bone and muscle pain, fatigue, nausea, irritability, and even birth defects in those who consume large quantities of Vitamin A over long periods of time. Therefore, the body only makes as much as is needed, even if you have a large amount of beta-carotene available. If you give someone with already adequate levels of Vitamin A extra beta carotene, you will find that there is no increase in the amount of vitamin A in their bloodstream. The regulation mechanism(s) would not make excess that could cause toxicity when there are already adequate amounts of Vitamin A present. One might conclude from this observation alone that beta carotene does not effectively get converted to vitamin A by human beings. But if you give someone low in Vitamin A status extra beta carotene, you will then find an increase in Vitamin A, as the beta carotene was converted to Vitamin A as the body had a need for it, and the levels produced were below the amount that would cause any toxic effects.

Another example of a nutrient regulation mechanism has to do with the absorption of iron. Both plant and animal foods contain iron. The iron is in different forms though. In animal foods, the iron is called heme iron, and in plant foods it is called non heme iron. Excess iron acts as a pro-oxidant. When it combines with hydrogen peroxide, it forms the hydroxyl radical, one of the most destructive free radicals known, which can even destroy DNA. Heme iron gets absorbed whether we need more iron or not. In other words there is no regulation mechanism with this form of iron. We end up with excess iron and free radical damage as a result. With non-heme iron, there is selective absorption. In other words, we absorb more when we need more, and absorb less when we need less. This helps regulate the amount of iron in the body so we don’t end up with an excess that contributes to free radical damage which undermines our health.

So what do these examples have to do with fat and the conversion of ALA to DHA? Research studies have shown that even with adequate levels of ALA, the body will not make extra DHA when there is already enough, such as when there is consumption from an outside source. The same studies show that more DHA is made from ALA when there is not an outside source of DHA, and therefore a greater need for DHA production. This again indicates a regulation mechanism for the production of DHA from ALA. In continuing to consider why this regulation mechanism exists, I feel it is important to consider the following. The less saturated a fat is, the more susceptible it is to oxidation, or free radical damage. As described in part I, less saturation means more double bonds. Many of us have heard, for example, that one should never use flax oil for cooking. That is because the ALA in flax contains three double bonds, and can break down and become rancid very easily. DHA contains 6 double bonds, and is therefore extremely susceptible to oxidation, even at body temperature. Oxidized fats (fats damaged by free radicals) contribute to blood vessel damage that can lead to heart attacks, angina, strokes, TIA’s, kidney disease, high blood pressure, impotence, claudication, etc. So it would not make sense for the body use its resources to produce something that #1) is not needed, and #2) could be damaging in excess amounts. I also suspect that the higher the levels of fat soluble antioxidants in one’s system (vitamin E, beta carotene, lycopene, etc.) the better the conversion of ALA to DHA, as those antioxidants would help protect DHA from free radical damage. In all fairness to the conversion studies, it must be noted that we have a population at large (much too large!) that consumes an average of 20 or so times more omega 6 fats than omega 3 fats, along with unhealthy levels of trans and saturated fats. It is probably fair to say that the average person who fits this dietary profile indeed does not do a very good job at converting ALA to DHA. I would love to see studies performed on healthy vegans and raw food vegans that looked at the actual cell membrane levels of the various fatty acids in question. As discussed earlier, knowing the cell membrane status is what really counts, and is a far better indicator of fatty acid status than measuring blood levels.

Fortunately, there are ways of testing the fatty acid status of our cell membranes. Thus far in my office, I have had one healthy long term (15 year) vegan patient who has utilized this test. She came to me for nutritional guidance as she and her husband are planning on starting their family within the next couple of years. This patient is a nearly all raw, fairly low fat, 100% vegan female in her mid thirties. She claims to have consumed flax seeds on occasion, but not with any regularity. She does not consume any vegan junk food or isolated oil. She has never taken any type of fatty acid or DHA supplement. Her diet consists of fruit and lots of green vegetables, and some nuts and seeds. All of her cell membrane omega 3 fats, including DHA, were well within the normal reference range. So we can be quite sure that this patient does indeed convert ALA into DHA effectively. One case history does not prove everything, but if this woman can convert ALA into DHA effectively, it is not too far of a stretch to speculate that others could do so as well. She has expressed an interest in follow up tests as she goes through pregnancy and breast feeding, so hopefully I’ll have some updates for everyone in the coming years. Studies have shown that women produce DHA more efficiently than men, and are even more efficient when pregnant and breastfeeding. This makes sense from a survival point of view, considering how important DHA is for the developing nervous systems of fetuses and infants. In fact, DHA is the most abundant fatty acid in the cell membranes of the central nervous system, in other words the brain and spinal cord. There is a major drain on DHA reserves of pregnant and breastfeeding women as they are creating a completely new nervous system for their fetuses, as well as supplying DHA for their infants via breastmilk. DHA depletion is strongly linked to many of the complications of pregnancy, such as eclampsia and pre-eclampsia, gestational diabetes, and post partum depression.

In the event that one does not have adequate cell membrane DHA levels, despite their best efforts, the good news is that there are vegan sources of DHA derived from algae. Algae is the original source of DHA for the fish who consume it (and the fish who consume them and on up the food chain) and thus contains DHA. As far as EPA is concerned, even the studies that question the conversion of ALA to DHA have always shown that plenty of EPA is made from ALA. Additionally, DHA can be converted to EPA. If one consumes adequate amounts of both ALA and DHA, then it is extremely unlikely that EPA needs would not be met. The bottom line for vegans and meat eaters alike is to eliminate the excess Omega 6 fats from their diets and eat a diet based on fresh fruits and vegetables, including large quantities of leafy green vegetables. Meat eaters would be wise to minimize their intake of animal products, as they contain the pro-inflammatory fatty acid AA. Flax, hemp or chia seeds can be consumed if there is concern about or need for additional ALA. These recommendations supply optimal levels of ALA, and allow the conditions for it to be converted into both EPA and DHA as needed. If necessary, an algae based DHA supplement can be consumed, ensuring a reliable source of pre-formed DHA without the health risks, ethical issues and environmental concerns associated with the consumption of fish.

Dr. Rick Dina has been a primarily raw food vegan since 1988. He is in private practice at Vitality Health Center of Marin, and can be reached for consultations regarding fatty acid balance and other issues of optimal nutrition and performance consulting at 415-472-7070. http://www.drdina.com