Age-related macular degeneration (AMD) is a leading cause of blindness for which treatment options are limited, the macula is responsible for detailed, fine central vision and is located at the center of the retina. Researchers at the Harvard medical school, have just released a major study that points to a close association between the development of AMD and the consumption of certain fats. The major contributors to the increased risk were high intake of linolenic acid and trans fatty acids with a 35 percent increased risk of AMD. In contrast, a high intake of docsahexaenoic acid (DHA), a main component of marine oils was found to lower the risk of AMD by about 30 percent.
During menopause, your ovarian function starts to decline, reducing your bodies production of estrogen by about two-thirds (your adrenal glands and fat cells make the remaining amount). During this time of rapid hormonal changes, your body's eicosanoids balance gets thrown off, giving rise to hot flashes and other discomforts. New evidence suggests that hot flashes may stem rapidly changing levels of eicosanoids and may be due in part to overproduction of the 'bad' eicosanoids PGE 2 series. One reason may be that the plunge in estrogen levels during menopause also leads to a corresponding increase in the production of insulin. The increase in insulin leads to increased production of Arachidonic acid, the building block of 'bad' eicosanoids such as the PGE 2 series. High doses of marine oil (omega 3 fatty acids) will reduce the production of eicosanoids by lowering the level of Arachidonic acid.
Moreover, Japanese and Chinese woman who consume large amounts of seafood and soy rarely suffer from hot flashes. Researchers have found that eating 20 grams of soy protein (which is rich in a chemical called phytoestrogens) per day provides a modest decrease in the variety of menopausal symptoms. However, phytoestrogens are not the cure all that they were hoped to be, because without adequate levels of long chain Omega 3 fatty acids, there would not be the full inhibition of excess PGE 2 Series production.
Researchers at the National Institute of Alcohol Abuse and Alcoholism believe that the increasing rates of depression seen in North America over the last 100 years are due to a significant shift in the ratio of n-6 (arachidonic acid, linoleic acid) to n-3 (docosahexaenoic acid, linolenic acid) fatty acids in the diet. The human race evolved on a diet having a ratio of about 1:1 of these acids; it is now estimated to be between 10:1 and 25:1. Docosahexaenoic acid (DHA) is a main component of the synaptic membranes and a lack of it has been linked to depression. Seal oils are a rich source of DHA and it can also be biosynthesized in the body from linolenic acid. The researchers speculate that the depressions which often accompany alcoholism, multiple sclerosis, and childbirth (postpartum depression) are all due to a lack of DHA and can be corrected by increasing the dietary intake of DHA or linolenic acid. They also point out that depression and coronary heart disease are strongly associated and that a low intake of n-3 fatty acids has been linked to both.
Multiple Sclerosis is a disease, which leaves the patient in an unresponsive body but with mental functions intact. With Multiple Sclerosis, the insulating membrane that coats the nerve cells unravels, making it difficult for the nerve cells to transmit their signals. Although the molecular cause of multiple sclerosis is unknown, scientists have learned that its primarily driven by inflammation.
Multiple Sclerosis is virtually unknown amongst the Eskimos of Greenland. Their high intake of long chain Omega 3 fatty acids provides a clue to the prevention and treatment of this condition. Like all inflammatory conditions, multiple sclerosis?s characterized by overproduction of 'bad' eicosanoids.
Long chain Omega 3 fatty acids are anti-inflammatory agents that can cross the blood-brain barrier. Patients with Multiple Sclerosis are known to have low levels of DHA in the brain. It is also known that long chain Omega 3 fatty acids inhibit the production of pro-inflammatory cytokines like gamma interferon, similar effects that are behind the theory of constant injections with beta-interferon. This may explain why populations that consume the most fish have the lowest rates of multiple sclerosis.
Omega 3 fatty acids which increase metabolic rates, can be used for weight loss. The right kind of fat can actually help you with losing weight. Omega 3 serves as building materials for series 3 prostaglandin, some of which help our kidneys get rid of excess water held in tissues. The excess weight of some overweight people is largely retained water (edema). Omega 3 helps to dump this water. Omega 3 increase metabolic rate, oxidation rate, and energy production. This effect begins to show up when 3 or more tablespoons of Omega 3 (5 capsules) per day are used. When metabolic rate goes up, more fat and glucose are burned. Less fat deposition takes place.
This increased production of energy is the opposite of what happens when we fast or diet, on calorie- restricted programs. The latter decrease our metabolic rate, and lead us to put on weight even on a small intake of food. There is evidence that obesity is the result of gross over eating in only 10% of cases. The other 90% are lacking exercise and choosing foods lacking important essential nutrients. Omega 3 helps us to lose weight and increase our energy levels, with the end result being more energetic. This is a special bonus, because activity makes us feel good, builds lean body (muscle) mass, makes us healthier, increases our metabolic rate and resets our fat thermostat to a lover level, helping make weight loss permanent.
According to Crawford (1995), the first pregnancy-related need for PUFAs (both omega-6 and omega-3) occurs during the three months prior to conception. This critical period for cell commitment and division requires ARA and DHA to facilitate growth and development. It has been suggested that supplementation with fish oil, or increased fish intake, during pregnancy prevents the pregnancy-induced hypertension, prolongs gestation, increases birth weight and reduces the incidence of premature birth
- Gerrard et al, 1991, Olsen et al, 1992
Recent data support the view that the intake of DHA during pregnancy should be in the amount of at least 0.1-0.4 g/day
- Crawford, 1995
Fetal stage DHA is important for optimal nervous system development. During the last trimester of pregnancy, when the fetal demand for neural and vascular growth are greatest, there is an elevated accretion of DHA in the liver and brain of the fetus. A maternal diet high in DHA will greatly enrich the DHA concentration in the blood of the newborn infant. Even levels as low as 0.7g EPA+DHA/day during the period from 25th to 35th week of pregnancy seem to be beneficial
- Connor et al, 1995
DHA levels in maternal plasma are lower in multigravidae compared to primigravidae and the smaller the baby, the lower DHA-level
- Al et al, 1995
Consequently, it is therefore especially important for multigravidae to increase the intake of DHA.
Pre-eclampsia During pregnancy, blood lipids, triglycerides and cholesterol may rise several folds. There may also be an increase in blood pressure. The risk of developing pre-eclampsia and subsequent premature birth is increased if these, otherwise normal changes are increased above certain levels. Severe forms of pregnancy-induced hypertension have been reported to be beneficially modulated by omega-3 fatty acids
- Secher et al, 1991
In light of their very strong hypotriglyceridemic and hypotensive effects, omega-3 fatty acids along with other nutritional factors, may be significant for the prevention of pre-eclampsia. The maternal blood pressure responses depend on the ARA/EPA ratio in the vessel wall. Multicenter studies are currently in progress and the first results are expected to be available before 1997. In the meantime, it would generally seem prudent to recommend an increased intake of omega-3 fatty acids during pregnancy. EPA will benefit the mother's heart and circulation, and DHA will definitely be good for the development of fetal brain and nervous system.
Recent studies have demonstrated that DHA supplementation during pregnancy and lactation is necessary, to prevent deficiency of the mother's DHA status during these periods, to meet the high fetal requirement for DHA. It has been shown that premature babies have lower levels of DHA in their tissues as compared to full-term babies. Thus, supplementation of infant formula with DHA/marine oils may be necessary in order to provide them with as much DHA as that available to their breast-fed counterparts. Feeding of infants with formula devoid of omega-3 fatty acids resulted in lack of deposition of DHA in their visual and neural tissues with adverse effects on vision and nervous systems.
According to Dr. Connor, "The signs of omega-3 deficiency in infancy are subtle, for example, omega-3 fatty acid deficiency in infants can translate into:
- impaired vision
- abnormalities on the electroretinogram (measures retinal nerve function)
- behavioral changes such as polydypsia (excessive thirst), hyperactivity and perhaps less cognitive ability.
Some of these changes have been described only in subhuman primates. So it's clearly essential for pregnant and breast feeding women to ensure their dietary intake of omega-3 PUFA is adequate."
Several studies have shown an inverse relationship between blood levels of fish oils (eicosapentaenoic acid [EPA] and docosahexaenoic acid [DHA]) and the risk of prostate cancer. A study just completed by medical researchers at the Karolinska Institute confirms this association.
The Swedish study involved 3136 pairs of male twins born between 1886 and 1925. The participants completed food frequency questionnaires in 1961 and 1967 and were then followed up for 30 years. By December 31, 1997 the researchers had recorded 466 diagnoses of prostate cancer (340 fatal ones). The average age of diagnosis was 76.7 years. After adjusting for other known risk factors the researchers conclude that men who never eat fish have a two-to-threefold higher risk of prostate cancer than do men who eat moderate to high amounts. The researchers emphasize that only fatty fish such as salmon, herring and mackerel, which contain high amounts of omega-3 fatty acids (EPA and DHA), would be expected to be beneficial.
Psoriasis is a fairly common skin disease characterized by thick, silvery white scales surrounded by a red, inflamed border. Psoriasis is accompanied by high concentrations of arachidonic acid in the plaques and profound changes in the metabolism of eicosanoids leading to an increase in proinflammatory agents. It is known that eicosapentaenoic acid (EPA) counteracts the formation of these proinflammatory agents and some studies have shown that oral supplementation with fish oils benefits psoriasis patients.
A team of researchers from Austria, the Czech Republic, the Slovak Republic, Germany, and Poland now report that intravenous infusions of a fish oil emulsion is quite effective in ameliorating the symptoms of chronic plaque-type psoriasis. Their double-blind, randomized, placebo-controlled, multicenter trial involved 54 men and 29 women between the ages of 18 and 80 years who had been hospitalized with severe psoriasis. The patients were randomized into two groups. Group 1 (43 patients) received twice daily infusions of a fish oil emulsion (100 ml of a 10% emulsion infused over a period of 90 minutes) while group 2 (40 patients) received twice daily infusions of a placebo emulsion based on linoleic acid. Physicians assessed the severity of the psoriasis on days 0, 4, 7, 11 and 15 of the two-week trial.
Sixteen of the 43 patients (37%) receiving fish oil showed at least a 50% improvement in their condition at the end of the trial as compared to 9 out of 40 patients (23%) in the placebo group.