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@ Stress-Reducing Fatty Acids Also May Defuse Health Risks |
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Stress and Lipids A. High insulin (fed
state) , epinephrine, glucocorticoids 1. increased
glycolysis, increased glycerol-3-P, increased TG
synthesis, increased FA synthesis, decreased
beta-oxidation;
increased phosphatidate phosphohydrolase and packaging of
phospholipids and TG into VLDL 2. increased
lipoprotein lipase; increased FA uptake by adipose;
increased adipose glycolysis; increased storage of TG Insulin dominates
stress hormones B. Low Insulin,
epinephrine, glucocorticoids 1. increased cAMP
and protein kinase due to increased glucagon, epinephrine; in
adipose, increased cAMP leads to increased
hormone sensitive lipase, increased lipolysis, and
increased FA release to liver; 2. in liver FACoA
increased and increased cAMP decreases ACoA
carboxylase; decreased malonyl CoA leads to decreased CPT,
increased beta-oxidation; phosphatidate phosphohydrolase
decreased by cAMP; decreased TG and PL synthesis; C. Severe Stress 1. large increases
in epinephrine, glucocorticoids, glucagon 2. large increase in
lipolysis 3. large influx FFA
and glycerol to liver 4. large increased
in FFA to liver offsets PP inhibition by cAMP;
increased TG and PL synthesis can lead to fatty liver if
VLDL secretion not
increased; 5. under stress VLDL
go to muscle where LPL is increased by stress hormones; decreased
insulin ensures low adipose LPL and
low adipose uptake More than half of all patients who visit general physicians suffer from symptoms triggered or made worse by stress--headaches, ulcers, fatigue or even emotional distress. Two research studies demonstrated that essential fatty acid nutritional supplements can increase resistance to stress--and its debilitating and costly side effects. The first study, published in the Journal of Clinical Investigation in 1996, tested the anti- stress power of docosahexaenoic acid (DHA), an omega-3 fatty acid most commonly derived from fish oil but also found in algae. Eicosapentaenoic acid (EPA), a close cousin of DHA, may be effective in reducing heart disease risk and treating rheumatoid arthritis and intestinal inflammations like Crohn's disease. DHA has different beneficial properties and appears to be particularly important in brain biochemistry. For instance, it is involved in the maturation of brain cells during gestation and infancy. The DHA study involved 41 healthy fourth-year medical students. They took either fish-oil capsules containing 1.5 g to 1.8 g of DHA daily or a placebo made mainly of soybean oil. They underwent psychological testing, first during summer vacation, and again three months later during final exams. Not surprisingly, the control group showed increased feelings of aggression during the exams compared to their scores during summer vacation. However, the students taking DHA showed a modest decrease in this negative emotion. The authors speculate that reducing the tendency toward anger and hostility might be another way that a diet high in fish and omega-3 fats could protect against heart attacks. The second study, published in the Journal of Human Hypertension in 1989, found similar beneficial results from a different fat, gamma linolenic acid (GLA). GLA is a component of borage oil, primrose oil and black currant seed oil. Thirty healthy Canadian university students volunteered to take either nine borage oil capsules (containing 1.3 g per day of GLA) or an olive oil placebo. Each student received a standard psychological stress test known as the Stroop color-word conflict test, both before and after 28 days of supplements. The Stroop test consists of 200 words such as "red" or "green," each printed in a color different from the one it actually signifies. Thus, the word "red" might be printed in green ink and the word "green" in red ink. Subjects proceed through the list as rapidly as possible for two minutes, calling out the color of the ink. The test's deliberately mixed message typically stresses people and induces physical changes including rapid heart rate, increased blood pressure and cold fingers due to blood vessel spasms. Students taking the placebo showed little change in their vulnerability to stress. However, those taking high-GLA borage oil showed reduced stress vulnerability after 28 days of supplementation. The Bottom Line Both studies demonstrate that stress vulnerability is not "just" psychological. How we eat affects our ability to resist stress. If this is true for young, healthy students, how much more so might it be for older or sick people? It's unfortunate that neither study looked at subjects' red blood cell fatty acid levels--a relatively inexpensive test offered by several suppliers. Measuring people's fatty acid profiles might make it possible to recommend fatty acid supplements that better meet their needs. These reports are scientifically important, but they also illustrate changing attitudes toward nutrition. The borage oil study appeared in the Journal of Human Hypertension, a respected but little-read journal. No one since has bothered to repeat the study to either confirm or refute it. And I never see the article footnoted in the journals I read. The DHA study was published in the Journal of Clinical Investigation--JCI to those in academic medicine. While not well- known to the public, no journal ranks higher in prestige within the halls of academia. Will the JCI's pedigree save the DHA article from obscurity? Perhaps not. Few practicing physicians read the journal. But the fact that the journal editors accepted a paper on DHA and stress--and earmarked it for quick publication--shows how much respect nutrition research has gained. We still have much guesswork in our nutritional prescriptions, but the scientific basis for our field is getting stronger every month. In academic medicine, at least, the leaders are noticing. Richard Podell, M.D., is clinical professor of family medicine at the UMDNJ-Robert Wood Johnson Medical School in New Brunswick, N.J. He is the author of Patient Power: How to Protect Yourself Against Medical Error (Fireside, 1996). @
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LIPIDS |
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@ Fatty acids are
straight-chain carbon acids usually with an even number of carbon
atoms that may contain isolated cis-double bonds. Fatty acids
without double bonds are called saturated fatty acids. Those with
one double bond are called monounsaturated fatty acids (MUFAs) and
those with more than one double bond are known as polyunsaturated
fatty acids (PUFAs).
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Fatty acids are components of fats and oils. They are different in the number of carbon atoms and the placement and nature of their molecular bonds. Fats provide energy, are important for the absorption of vital nutrients, the manufacturing of hormone-like substances (eicosanoids), and the building of cell membrane structures. Consumption of a moderate amount of fat is essential to one's physical and mental well-being. Latest research shows that eating a fat free diet, embraced by many weight loss programs, can prompt the body into making fat from other food sources to protect from a potential fat famine. Consuming the right type of fat is as essential for optimum health as taking vitamins and minerals. There are two kind of fats, saturated fats, found mainly in animal meat, dairy products, and unsaturated fats found mainly in vegetables.
Trans fatty acids are manufactured from unsaturated, liquid fats by applying heat and/or pressure to turn them into solid fats. Trans fatty acids are un-natural type of fats and will likely increase LDL (bad cholesterol) and decrease HDL (good) cholesterol levels.
Unsaturated fats are essential because the body cannot make them and therefore they have to be supplied by the diet. There are two groups of unsaturated fats: mono- and poly-unsaturated fats. The two most important poly-unsaturated fatty acids for the human body are the omega-3 and omega-6 fatty acids. It was found that these oils should be consumed in the 1:1 ratio. The typical North American diet however provides an unhealthy 20:1 ratio of omega-6 to omega-3.
OMEGA-6 ESSENTIAL FATTY ACIDS
Omega-6 oils are converted into a type of eicosanoid thromboxane, which is a potent constrictor of arteries contributing to increase in blood pressure. Omega-3 acids on the other hand increase the production of "nitric oxide", which relaxes arteries. Individuals given fish oil supplements had a 43% increase in nitric oxide production.
Fats high in omega-6 essential fatty acids are suspected to promote cancer development. Cancers infused with omega-6 fatty acids (even in trace amounts) grow at an accelerated rate which is dose dependent (Leonard A. Sauer and Robert T. Dauchy Cancer Research laboratory at the Mary Imogen Bassett Hospital)
Researchers have discovered a strong association between the function of macrophages and depression. Macrophages are white blood cells that engulf microorganisms and manufacture a variety of substances that exert powerful physiological effects on the body. Healthy functioning macrophages produce optimal quantities of growth hormone, mood elevating endorphins and interferon. An imbalance of omega-6 to omega-3 fatty acid ratio negatively influences the immune/inflammatory system and macrophages may produce excessive amount of cytokines and other inflammatory substances. Excessive quantities of interferon and some interleukins are known to cause bouts of major depression. The mood regulating cytokines are interleukin-beta (IL-1), IL-6 and tumor necrosis factor. These cytokines stimulate the hypothalamus, which stimulates the adrenals and pituitary glands to produce stress hormones. Excess of corticosteroids can trigger either mania or depression. Omega-3 fatty acids especially EPA suppress abnormal inflammatory responses and abnormal cytokine production.
OMEGA-3 ESSENTIAL FATTY ACIDS
Healing properties of the omega-3 oils have been proven and recorded by hundreds of research studies and scientific journals.
There are long and short chain omega-3 fatty acids. Long chain omega-3 fatty acids are produced by marine and fresh water algae. The best source of long chain omega-3 fatty acids are a variety of deep salt water fish such as salmon, tuna, mackerel etc. that accumulate omega-3 fatty acids by feeding on the above mentioned algae. Long chain omega-3 fatty acids are absolutely necessary for health function of the brain. Fish oil contain two kinds of long chain fatty acids, EPA and DHA. DHA is found incorporated into cell membranes throughout the body, highest concentration found in the retina, brain and sperm. DHA is absolutely crucial for proper brain development and healthy cognitive and visual functioning of the fetus. EPA is the active anti-inflammatory omega-3 fatty acid that compensates for the pro-inflammatory effects caused by omega-6 fatty acids. Recent findings provide some evidence that it is EPA that has the most mood influencing activity. The turnover rate of EPA is high so it must be replenished by the diet daily.
The omega-3 oils found in flax seed consists of a shorter chain and are therefore slightly different from the fatty acid found in fish.
Consuming high omega-3 content diet the body uses more energy to burn the same number of calories, that results in weight loss in specific regions of the body.
Essential fatty acid imbalance often accompanies autoimmune diseases. Researchers at the Candiff University, Wales made a major discovery showing that omega-3 essential fatty acids can inhibit cox-2, a pro-inflammatory enzyme, blocked by a new anti-inflammatory drugs such as Celebrex. These fatty acids appear to protect the cartilage from damaging enzymes. Other studies found that essential fatty acids brought about significant improvement or even remission of lupus another autoimmune disease.
"Omega-3 oils are one of the most abundant constituents of brain cell membranes and are converted to crucial brain chemicals, that are needed for normal nervous system function. As a result of this omega-3 oils seem to be involved in mood regulation, attention and memory, and psychosis."
Lack of omega-3 fatty acids controls hostility and violence under stressful conditions in animal and human subjects alike, researchers found. Rats fed the combination of DHA and EPA had 40% more dopamine in their frontal lobes compared to control animals. The animals with the higher dopamine levels were calmer more relaxed than their counterpart.
LDL (bad) cholesterol is transported through the arteries inside of macrophagies (a type of white blood cells). LDL cholesterol is harmful only if it is oxidized before it is engulfed by these white blood cells. Omega-3 oils have found to slow the oxidation of LDL cholesterol.
Omega-3 oils protect from blood clot formation by decreasing the stickiness of platelets making them less gluey, and decrease the production of fibrinogen, the long strands of protein that become tangled with the platelets and result in blood clot formation.
Animal studies demonstrated the effectiveness of omega-3 essential fatty acids in the prevention of malignant arrhythmia. Malignant arrhythmia following a heart attack is often lethal. By administering fish oil only sixty minutes prior to inducing heart attack in seven out of the eight animals arrhythmia never developed. In the previous experiment eight out of eight in the untreated animals had suffered from arrhythmia.
Omega-3 fatty acids augment traditional chemo- and radiation therapy by enhancing the effectiveness of these therapies. In addition omega-3 fatty acids have been found to prevent or even reverse rapid weigh loss in cancer patients.
An Australian researcher, Leonard Storlien, found that people whose muscle cells contain low levels of omega-3 and high levels of omega-6 fatty acids are more likely to be insulin resistant. Diet high in omega-3 fatty acids lowers insulin resistance, fasting glucose levels, hypertension, and blood triglycerides.
Feeding omega-3 essential fatty acid enriched infant formula to babies results in higher intelligence score later in life. Mother's milk naturally contain DHA. If this metabolite of the fish oil is not replenished by the mother, multiple pregnancies end in decreasing DHA content of breast milk, therefore this essential nutrient will not be available for the next baby. Babies fed on omega-3 fatty acid deficient diet developed a syndrome characterized by decreased skin pigmentation, loss of muscle tone, insufficient kidney, liver, lung function, and increased susceptibility to infections. Omega-3 acid supplementation is recommended even before conception to ensure sufficient levels of this essential fatty acid for normal brain development of the fetus. Low levels of omega-3 fatty acid can result in premature birth and lower birth weight.
Postpartum depression is more common in mothers who breastfeed if their diet is lacking omega-3 fatty acids.
Researchers found that children diagnosed with Attention Deficit Syndrome have much lower levels of DHA and EPA. The lower the level of these essential fatty acid metabolites the more intense is their abnormal behavior.
People taking high amounts of fish oil have lower risk of arthritis, emphysema, bronchitis, asthma, MS, Crohn's disease and psoriasis. Omega-3 fatty acids block the production of inflammatory substances called prostaglandins E2 or PGE2 and thus help to relieve menstrual pain.
People who regularly consume fish oil are less likely to suffer from depression. The lowest depression rate is found in fishing villages and in northern hemisphere communities where fish is a staple diet. Animal experiments demonstrated that increasing omega-3 fatty acid content of the diet increases the neurotransmitter dopamine levels in the brain. Increased dopamine levels increase drive, and motivation in the depressed person.
Alcohol depletes the brain of its DHA content.
From
the point of view of human nutrition, there are two groups of omega-3
polyunsaturates, those with a short chain length (18 carbon atoms or less) and
those with a long chain length (20 carbon atoms or more). The difference is
quite critical, since the body requires the long chain omega-3s, but doesnft
seem to have any particular direct use for the short chain versions. The latter
are in theory capable of being converted to the long chain form, but doubts
persist as to the extent to which this conversion process is capable, under
modern lifestyle and dietary conditions of contributing significantly to the
required amounts of long chain omega-3fs.