DHA supplementation improves memory in healthy adults with age-related cognitive decline

New research indicates that regular supplementation with DHA may improve memory and learning in older adults with mild age-related memory loss.

Recent research published online in Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association illustrates a benefit for docosahexaenoic acid (DHA) supplementation in a clinical trial of individuals with age-related cognitive decline (ARC). DHA is a long-chain omega-3 fatty acids found most prominently in algae, fatty fish and fish oil supplements.

Participants included 485 individuals aged 55 and older with complaints of mild memory loss. The subjects were given a daily dosage of 900 milligrams of DHA or a placebo for 6 months. Memory and learning tests were given at the beginning of the study and at 12 and 24 weeks.

At the end of the study period, the group receiving the DHA supplement had improved test scores that correlated with an increase in plasma DHA levels. At 12 weeks there were no significant differences in the test scores of the two groups. However, at 24 weeks the group taking the DHA had a 2-fold reduction in the number of learning and memory errors tested compared to the placebo group.

The results of this study are the first to clinically confirm that DHA meaningfully improves memory and learning functions in healthy adults with age-related cognitive decline. Since it is estimated that up to one-third of the aging population in the U.S. will experience a decline in cognitive function with age, the benefits of a daily DHA supplement can have a significant impact on public health.

Source: Beneficial effects of docosahexaenoic acid on cognition in age-related cognitive decline, Yurko-Mauro K et al, Alzheimers & Dementia 29 April 2010

Source: USANA Health Sciences

Review of omega-3 fatty acids & heart disease risk

Evidence from three large trials suggests that intake of omega-3 fatty acids, whether from dietary sources or fish oil supplements, should be increased, especially in those with or at risk for coronary artery disease.

The June 2008 issue of Mayo Clinic Proceedings summarizes the latest findings on omega-3 fatty acids and cardiovascular health and advocates supplementation for the groups most likely to benefit.

Large trials of over 32,000 participants using fish oil supplements have shown reductions in cardiovascular events (heart attacks, stroke) of 19% to 45%. Researchers recommend consumption of EPA and DHA at 1 gram/day for those with known coronary artery disease, and at least 500 mg/day for those without disease. The recommendation is increased to 3 to 4 grams/day for those with high triglycerides, a dosage shown to lower triglycerides by as much as 20% to 50%.

Since two meals of oily fish per week generally provide only 400 to 500 mg/day of DHA and EPA, people with high triglycerides and heart disease are strongly encouraged to use fish oil supplements to reach beneficial levels. Researchers also state that the combination of omega-3 supplements and statin drugs provide significantly enhanced benefit over statin use alone in improving blood lipid levels.

Source: Omega-3 Fatty Acids for Cardioprotection, Lee et al, Mayo Clin Proc. 2008;83(3):324-332

Source: USANA Health Sciences

Omega–3 fatty acid intake & the incidence of age-related macular degeneration

Results recently published from a long-term study indicate that people at risk for age-related macular degeneration (AMD) may significantly reduce the risk of this disease by increasing their dietary intake of omega-3 fatty acids from oily fish, nuts and seeds, and fish oil supplements.

Omega-3 fatty acids are important for the vascular and neural health of the retina and may influence the risk of developing age-related macular degeneration (AMD). There are two forms of AMD: dry and wet. In the dry form, normal tissue in the macula slowly disappears, leaving a pale area referred to as central geographic atrophy (CGA). In the wet form, or neovascular (NV) AMD, abnormal blood vessels grow underneath the macula. These vessels leak serum or blood and eventually cause the normal macular tissue to be replaced by scar tissue.

Researchers recently investigated whether omega-3 fatty acid intake was associated with a reduced risk of developing both wet and dry forms of AMD. The study involved 1837 people from the Age-Related Eye Diseases Study (AREDS) who were at moderate to high risk of developing AMD. Clinical measurements were obtained in this group over a period of 12 years (from 1992 to 2005).

Participants who reported the highest omega–3 fatty acid intake were 35% less likely than their peers to develop dry (CGA) AMD, and 32% less likely to develop the more common, wet form (NV) AMD.

Over the 12 years of this study, the incidence of CGA and NV AMD was lowest for those reporting the highest consumption of omega-3 fatty acids, which are found primarily in oily fish, nuts and seeds, and fish oil supplements. If these results are applied to the general population, dietary intervention may have a significant preventive effect on the development and progression of AMD.

Source: Long-chain polyunsaturated fatty acid intake and 12-y incidence of neovascular age-related macular degeneration and central geographic atrophy: AREDS report 30, a prospective cohort study from the Age-Related Eye Disease Study, Sangiovanni et al, Am J Clin Nutr. 2009 Dec;90(6):1601-7

Source: USANA Health Sciences

Health benefits of Omega-3 fatty acids‏

These Swiss investigators reviewed 97 randomized, controlled clinical trials, which involved over 275,000 subjects. They looked at comparing the reduction in cardiovascular deaths between individuals who were taking the lipid lowering drugs called statins, those who consumed higher doses of omega-3 fatty acids, and a controlled group or placebo group. The statin group reduced cardiovascular deaths by 22%, while the omega-3 fatty acid group decreased cardiovascular disease by 32%. Statin drugs reduced overall mortality by 13%; however, the omega-3 fatty acid group reduced overall mortality by 23%. These were significant findings and brought up the fact that supplementing your diet with high-quality omega-3 fatty acids from pharmaceutical-grade filtered fish oil was more effective than the expensive statin drugs when it came to cardiovascular death and overall mortality.

Now statin drugs have been shown to decrease inflammation and part of their clinical effectiveness is due to this aspect of these drugs. So researchers are not sure if it is the lowering of cholesterol or the anti-inflammatory aspect of these drugs that provide their health benefits. However, omega-3 fats are the building blocks of the body’s natural anti-inflammatories. In fact, supplemental intake of the omega-3 fatty acids DHA and EPA found in filtered fish oil has been shown to significantly decrease inflammation throughout the body, including our arteries. They also do not have the adverse side effects that the statin drugs have.

Source: “Effect of different antilipidemic agents and diet on mortality: a systematic review", Studer M, Briel M, et al., Archives of Internal Medicine, 2005 April 11;165(7):725-30

Oily fish intake and dietary omega-3s may improve eye health

According to new research, eating one portion per week of fish rich in omega-3 fatty acids may reduce the risk of age-related macular degeneration (AMD) by over 50 percent.

Fish intake, the major source of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), may reduce the risk of age-related macular degeneration (AMD). There are two types of AMD: wet and dry. Of these two types, wet AMD is the primary cause of vision loss.

In a study recently published in the American Journal of Clinical Nutrition, researchers recruited 105 people (age 65 and over) with wet AMD and 2170 healthy people to act as controls, then compared their dietary habits using questionnaires. The scientists then investigated the association of oily fish and dietary DHA and EPA with wet AMD.

Compared to people who consumed less than one portion of fish per week, participants who consumed at least one serving of oily fish per week had a 50 percent reduction in risk of developing wet AMD. In addition, people who got at least 300 mg per day of DHA and EPA were 68 and 71 percent less likely to have wet AMD than those with lower consumptions.

The results of this study support previous research indicating a protective benefit of omega-3s against the onset of AMD. The benefit may be due in part to their important role in the layer of nerve cells in the retina.

Source: Oily fish consumption, dietary docosahexaenoic acid and eicosapentaenoic acid intakes, and associations with neovascular age-related macular degeneration; Augood et al; American Journal of Clinical Nutrition, Vol. 88, No. 2, 398-406, August 2008

Fish oil lowers heart rate‏

There is significant evidence that omega-3 fatty acids have a beneficial effect on heart arrhythmias (irregular heart beat), which can lead to a decreased risk of death from cardiovascular disease. New analyses indicate that regular fish oil intake could correspond to as much as a 5% reduction in population-wide sudden deaths.

A meta-analysis published in the journal Circulation further confirms the association between omega-3 fatty acids and heart health. Researchers from the Harvard School of Public Health compiled statistical data from thirty studies published from 1996 to 2005. These studies involved nearly 1,700 individuals treated with fish oil or placebo for up to one year. The average combined dose of EPA and DHA was 3.5 grams/day for an average of 8 weeks.

The overall estimated change in heart rate of those treated with fish oil was 1.6 beats per minute. The reduction in heart rate was even greater in trials where the participants had higher baseline heart rates. In those studies, treatment with fish oil resulted in a decreased heart rate of 2.5 beats per minutes. There was no evidence of a dose-response effect, and heart rate was not significantly different between higher and lower doses compared with placebo.

Although the overall effect of fish oil on heart rate appears small, researchers estimate that on a population-wide basis this could correspond to as much as a 5% reduction in sudden death.

Source: Effect of fish oil on heart rate in humans. A meta-analysis of randomized controlled trials. Mozaffarian D, Geelen A, Brouwer IA, Geleijnse JM, Zock PL, Katan MB. Circulation 2005;112:1945-1952.

Fish oil intake during pregnancy may be associated with lower asthma incidence during childhood

New research has shown a significant correlation between fish oil intake during pregnancy and asthma incidence during childhood. Children whose mothers supplemented with fish oil during pregnancy were significantly less likely to be diagnosed with childhood asthma than children from non-supplementing mothers.

Current evidence suggests that asthma development may be associated with maternal intake of marine omega-3 fatty acids during pregnancy. A recent study was conducted to examine whether an increase in omega-3 fatty acid intake during pregnancy could affect risk of asthma in their offspring.

A population-based sample of 533 women with normal pregnancies were randomly assigned 2:1:1 to receive either four one-gram fish oil capsules/day providing 2.7 grams of omega-3 fatty acids, four similar looking one-gram capsules/day with just olive oil, or no capsules at all.

During the 16 years that passed since childbirth, the rate of asthma incidence was reduced by 63% and the rate of allergic asthma was reduced by 87% in the fish oil group as compared to the olive oil group.

Assuming that the intake of olive oil had no significant influence one way or another, these results support the theory that increased fish oil omega-3 fatty acid supplementation in late pregnancy may provide important preventive potential in relation to childhood asthma development. Additional studies on this subject are currently in progress, which should shed more light on the mechanism behind this promising discovery.

Source: Fish oil intake compared with olive oil intake in late pregnancy and asthma in the offspring: 16 y of registry-based follow-up from a randomized controlled trial, Olsen et al, American Journal of Clinical Nutrition, Vol. 88, No. 1, 167-175, July 2008

Omega-3 fatty acids in pregnant women and early visual acuity in infants

Docosahexaenoic acid (DHA), an omega-3 fatty acid found most commonly in fish oil, is important to neural development. It is speculated that DHA intakes are low enough in some pregnant women to impair infant development.

A new study published in the American Journal of Clinical Nutrition compared eye development scores among infants of women who supplemented DHA versus infants of women with typical diets. Supplemental DHA at 400 mg/day or a placebo was consumed by the women from 16 weeks of gestation until delivery. Researchers determined maternal red blood cell fatty acids, dietary intakes at 16 and 36 weeks gestation, and infant visual acuity at 60 days of age.

Infant visual acuity was related to sex and maternal DHA levels. More infant girls in the placebo than in the DHA group had a visual acuity below average and maternal red blood cell fatty acids were inversely related to visual acuity in both boys and girls.

These results suggest that some pregnant women in the study population were DHA-deficient.

Source: Essential n–3 fatty acids in pregnant women and early visual acuity maturation in term infants, Innis and Friesen, American Journal of Clinical Nutrition, Vol. 87, No. 3, 548-557, March 2008

Regular exercise and fish oil may keep arteries clear and reduce body fat

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A combination of prolonged exercise and fish oil can dramatically reduce levels of a fat that can cause hardening of the arteries, a leading cause of heart disease. Fat in the bloodstream is a primary contributor to atherosclerosis, or partial blockage of the arteries.

A recent study found that people who do prolonged aerobic exercise have muscle cells that are able to quickly break down and reduce levels of a fat called triglycerides. Taking a fish oil supplement can reduce triglyceride levels even more.

The researchers studied triglyceride levels in recreationally active men after they'd eaten high-fat meals. One group ate a fatty meal after they exercised. A second group ate a high-fat meal after taking a four-gram fish oil supplement. A third group ate a high-fat meal after exercising and taking the fish oil supplement. A control group ate a high-fat meal only.

The study found a 38 percent decline in peak triglyceride levels in the men who took a fish oil supplement before they ate a high-fat meal. Peak triglyceride levels dropped 50 percent in the men who exercised and took a fish oil supplement before they ate a high-fat meal.

Regular exercise and fish oil supplements may be beneficial for people who are concerned about maintaining a healthy triglyceride level.

Source: Exercise plus n-3 fatty acids: additive effect on postprandial lipemia, Smith BK et al, Metabolism, 2004 Oct;53(10):1365-71.

In a similar, more recent study, combining fish-oil supplements with regular exercise improved both body composition and heart disease risk factors. Overweight participants with various heart disease risk factors were assigned to one of three groups: fish oil (approximately 1.9 grams/day of omega-3 fats), fish oil and exercise, or placebo (sunflower oil).

The exercise group walked 3 days/week for 45 minutes. Heart disease risk factors and body composition were measured at 0, 6, and 12 weeks. The group taking fish oil had a significant reduction in triglycerides, increased HDL cholesterol, and improved arterial vasodilation (blood flow). Both fish oil and exercise independently reduced body fat.

This study showed that increasing intake of omega-3 fatty acids could be a useful addition to exercise programs aimed at improving body composition and decreasing cardiovascular disease risk.

Source: Combining fish-oil supplements with regular aerobic exercise improves body composition and cardiovascular disease risk factors, Alison M Hill, Jonathan D Buckley, Karen J Murphy and Peter RC Howe, Am J Clin Nutr. 2007 May;85(5):1267-74.

Omega-3 fatty acid intake associated with lower heart disease risk

Increased consumption of omega-3 fatty acids in the diet is associated with lower levels of inflammation and endothelial activation, according to results from a study at Harvard. Dysfunction of the endothelium, which is the inner lining of the blood vessel wall, is an early event in the development of atherosclerosis and subsequent heart disease. Food frequency questionnaires completed in1986 and 1990 by 727 participants in the Nurses' Health study were evaluated for levels of the omega-3 fatty acids alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA). Alpha-linolenic acid consumption was found to be inversely associated with several plasma markers of inflammation, while EPA and DHA intake was inversely related to platelet aggregration. Results of this study indicate that in addition to reducing triglycerides, platelet aggregation and heart arrhythmias, omega-3 fatty acids may also reduce the body's production of hydrogen peroxide, which is involved in the inflammatory process.

Source: Consumption of (n-3) fatty acids is related to plasma biomarkers of inflammation and endothelial activation in women, Lopez-Garcia E, J Nutr 2004 Jul;134(7):1806-11

Omega 3 fatty acids reduce colorectal cancer risk

Although diets high in fat have been associated with an increase in cancer risk, a recent study published in the American Journal of Epidemiology concluded that a greater intake of omega-3 polyunsaturated fatty acids may be protective against colorectal cancer.

Researchers paired 1,455 men and women diagnosed with colorectal cancer with an equal number of healthy control subjects matched for age, gender and region of residence. Total fatty acid, as well as saturated fatty acid, monounsaturated fatty acid, omega-6 polyunsaturated fatty acid, omega-3 polyunsaturated fatty acid, trans-fatty acid, and trans-monounsaturated fatty acid intake were determined. Intake levels of individual fatty acids, such as eicosapentanoic acid (EPA) and docosahexanoic acid (DHA), were also calculated. Greater intake of omega-3 fatty acids, EPA, and DHA were dose-dependently associated with reduced colorectal cancer risk. Compared to those with the lowest intake, participants whose omega-3 intake was in the highest group experienced a 37 percent lower risk of colorectal cancer. Subjects with intakes of EPA and DHA in the top fourth had a reduced risk of 41 and 37 percent, respectively. The authors concluded that the observed effects of different types of fatty acids illustrates the importance of the type of fat in the origins and prevention of colorectal cancer.

Source: Dietary Fatty Acids and Colorectal Cancer: A Case-Control Study, Evropi Theodoratou, Geraldine McNeill, Roseanne Cetnarskyj, Susan M. Farrington, Albert Tenesa, Rebecca Barnetson, Mary Porteous, Malcolm Dunlop, and Harry Campbell, American Journal of Epidemiology 2007 166(2):181-195

Fish oil lowers heart rate

Fish oil is known to decrease the risk of heart arrhythmias, which are a potential cause of heart disease, stroke and sudden cardiac death. According to a new study, regular intake of fish oil can reduce heart rate and decrease the risk of sudden death by as much as 5% in the overall population.

There is significant evidence that omega-3 fatty acids can reduce arrhythmias, disorders of the regular rhythmic beating of the heart. Arrhythmias can occur in a healthy heart and be of minimal consequence, but they also may indicate a serious problem and lead to heart disease, stroke or sudden cardiac death. A recent meta-analysis published in the journal Circulation further confirms this association. Researchers from the Harvard School of Public Health combined statistical analysis of thirty studies published from 1996 to 2005. These studies involved nearly 1,700 individuals treated with fish oil or placebo for up to one year. The median combined dose of EPA and DHA was 3.5 grams/day for an average of 8 weeks. The overall estimated change in heart rate of those treated with fish oil was 1.6 beats per minute. The reduction in heart rate was even greater among trials whose participants had higher baseline heart rates. In those studies, treatment with fish oil resulted in a decreased heart rate of 2.5 beats per min. There was no evidence of a dose-response effect, and heart rate was not significantly different between higher and lower doses compared with placebo. Although the overall effect of fish oil on heart rate appears small, researchers estimate that on a population basis this could correspond to as much as a 5% reduction in sudden death.

Source: Effect of fish oil on heart rate in humans. A meta-analysis of randomized controlled trials, Mozaffarian D, Geelen A, Brouwer IA, Geleijnse JM, Zock PL, Katan MB, Circulation 2005;112:1945-1952.

Supplements reduce healthcare costs

With health care costs skyrocketing and the age of the population increasing, helping seniors live independently for longer is becoming increasingly important. A recent comprehensive review of existing scientific research literature found positive health effects associated with both omega-3 fatty acids and the carotenoids, lutein and zeaxanthin. Based on health insurance costs for the age group over 65, the five-year estimated savings resulting from daily intake of omega-3 fatty acids and lutein with zeaxanthin is approximately 5.6 billion dollars.

A recent comprehensive review of existing scientific research literature found positive health effects associated with both omega-3 fatty acids and the carotenoids, lutein and zeaxanthin. Researchers critically reviewed the scientific evidence of the two supplements' ability to reduce the risk of disease and developed estimates of potential health care savings. With health care costs skyrocketing and the age of the population increasing, helping seniors live independently for longer is becoming increasingly important. The group reviewed several hundred studies dating back over thirty years to arrive at an estimated cost savings of 3.1 billion dollars over the next five years with the daily use of omega-3 fatty acids. They estimated that the reduction in coronary heart disease in the elderly population would result in 384,303 fewer hospitalizations and physician fees. Loss of central vision caused by age-related macular degeneration results in numerous elderly becoming dependent on the community or a nursing facility. The researchers used over 15 years of research on lutein and zeaxanthin to estimate a potential net savings of 2.5 billion dollars over the next five years. Approximately 98,219 individuals could avoid the transition to dependence during this time through daily intake of 6-10 mg of lutein and zeaxanthin. Based on health insurance costs for the age group over 65, the five-year estimated savings resulting from daily intake of omega-3 fatty acids and lutein with zeaxanthin is approximately 5.6 billion dollars.

http://www.supplementinfo.org/anm/articlefiles/265- FINAL_DSEA_%20FACT_SHEET.pdf

Fish oil supplements may reduce heart disease risk more effectively than statin drugs

A large research review showed that the omega-3 fatty acids found in fish oil were more effective than statin drugs in reducing the risk of death from heart disease.

A large research review published in the April 11, 2005 issue of Archives of Internal Medicine analyzed the effects of various dietary and drug regimens on overall mortality and mortality from coronary heart disease. Researchers reviewed 97 clinical trials that, in total, included 275,000 men and women. This analysis evaluated the risk of death as a function of diet, the use of lipid lowering drugs, intakes of omega-3 fatty acids (commonly found in fish and fish oil supplements), and intakes of the B vitamin niacin. Statins (a class of lipid lowering drugs) and omega-3 fatty acids significantly lowered both overall mortality and death due to heart disease during the trial periods. When compared to controls, overall mortality risk was reduced 13% by statin drugs and 23% by omega-3 fatty acids. When the risk of death from heart disease alone was examined, statin drugs and omega-3 fatty acids lowered mortality by 22% and 32%, respectively. Omega-3 fatty acids did not reduce cholesterol levels significantly. As such, researchers suggested that their benefits may have been due to protection against heart arrhythmias and systemic inflammation.

Source: Effect of Different Antilipidemic Agents and Diets on Mortality, Marco Studer, Matthias Briel, Bernd Leimenstoll, Tracy R. Glass, Heiner C. Bucher, Arch Intern Med. 2005; 165:725-730.