Can omega-3 help prevent Alzheimer's disease? Brain SPECT imaging shows possible link

An example of the Omega-3 Index, the method utilized in this study for measuring omega-3 fatty acid levels in red blood cell membranes in the study. Credit: William S. Harris, PHD

The incidence of Alzheimer's disease (AD) is expected to triple in the coming decades and no cure has been found. Recently, interest in dietary approaches for prevention of cognitive decline has increased. In particular, the omega-3 fatty acids have shown anti-amyloid, anti-tau and anti-inflammatory actions in the brains of animals. In a new article published in the Journal of Alzheimer's Disease, researchers have found that for patients with high omega-3 levels, blood flow in specific areas of the brain is increased.

20 may 2017--"This study is a major advance in demonstrating the value of nutritional intervention for brain health by using the latest brain imaging," commented George Perry, PhD, Dean and Professor of Biology, The University of Texas at San Antonio, and Editor-in-Chief of the Journal of Alzheimer's Disease.
Single photon emission computed tomography, or SPECT, can measure blood perfusion in the brain. Images acquired from subjects performing various cognitive tasks will show higher blood flow in specific brain regions. When these images were compared to the Omega-3 Index, a measure of the blood concentration of two omega-3 fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), investigators found a statistically significant correlation between higher blood flow and higher Omega-3 Index. In addition, they evaluated the neuropsychological functions of the subjects and found that omega-3 levels also correlated with various psychological feelings using a standardized test battery (WebNeuro).
This study drew from a random sample of 166 participants from a psychiatric referral clinic for which Omega-3 Index results were available. The participants were categorized into two groups of higher EPA+DHA concentrations (>50th percentile) and lower concentrations (<50th 128="" and="" brain="" brains="" completed="" computerized="" conducted="" each="" neurocognitive="" of="" on="" p="" participant="" percentile="" quantitative="" regions="" spect="" status.="" testing="" their="" was="">Results indicated statistically significant relationships between the Omega-3 index, regional perfusion on brain SPECT in areas involved with memory, and neurocognitive testing.
Overall, the study showed positive relationships between omega-3 EPA+DHA status, brain perfusion, and cognition. Lead author Daniel G. Amen, MD, of the Amen Clinics Inc., Costa Mesa, CA, adds, "This is very important research because it shows a correlation between lower omega-3 fatty acid levels and reduced brain blood flow to regions important for learning, memory, depression and dementia."
Co-author William S. Harris, PhD, University of South Dakota School of Medicine. Vermillion, SD, lends this perspective, "Although we have considerable evidence that omega-3 levels are associated with better cardiovascular health, the role of the 'fish oil' fatty acids in mental health and brain physiology is just beginning to be explored. This study opens the door to the possibility that relatively simple dietary changes could favorably impact cognitive function."

More information: Journal of Alzheimer's Disease (2017). DOI: 10.3233/JAD-17028

Provided by IOS Press

Studies link healthy brain aging to omega-3 and omega-6 fatty acids in the blood

New studies link specific nutrients to the structure and function of brain regions that are particularly sensitive to aging and neurodegenerative disease. 

19 may 2017--Two new studies link patterns of polyunsaturated fatty acids in the blood to the integrity of brain structures and cognitive abilities that are known to decline early in aging.
The studies add to the evidence that dietary intake of omega-3 and omega-6 fatty acids can promote healthy aging, the researchers said. Further research is needed to test this hypothesis, they said.
The brain is a collection of interconnected parts, each of which ages at its own pace. Some brain structures, and the abilities they promote, start to deteriorate before others, said University of Illinois M.D./Ph.D student Marta Zamroziewicz, who led the new research with psychology professor Aron Barbey.
"We studied a primary network of the brain—the frontoparietal network - that plays an important role in fluid intelligence and also declines early, even in healthy aging," Zamroziewicz said. Fluid intelligence describes the ability to solve problems one has never encountered before.
"In a separate study, we examined the white matter structure of the fornix, a group of nerve fibers at the center of the brain that is important for memory," she said.
Previous research has shown that the fornix is one of the first brain regions to be compromised in Alzheimer's disease.
In both studies, the researchers looked for patterns of polyunsaturated fatty acids in the blood of adults ages 65 to 75. They analyzed the relationship between these nutrient patterns and subjects' brain structure and performance on cognitive tests. This research differs from other such studies, which tend to focus on only one or two polyunsaturated fatty acids, Zamroziewicz said.
"Most of the research that looks at these fats in health and healthy aging focuses on the omega-3 fatty acids DHA and EPA, but those come from fish and fish oil, and most people in the Western Hemisphere don't eat enough of those to really see the benefits," she said. Other fatty acids, like alpha-linolenic acid and stearidonic acid, are precursors of EPA and DHA in the body. Those fats can be derived from land-based foods such as nuts, seeds and oils.
"A central goal of research in nutritional cognitive neuroscience is to understand how these nutrients affect brain health," Zamroziewicz said. "Some of these nutrients are thought to be more beneficial than others."
In a study reported in the journal Nutritional Neuroscience, the researchers looked for relationships between several omega-3 fatty acids in the blood, the relative size of structures in the frontal and parietal cortices of the brain, and performance on tests of fluid intelligence in healthy elderly adults.
The team found correlations between blood levels of three omega-3 fatty acids—ALA, stearidonic acid and ecosatrienoic acid—and fluid intelligence in these adults. Further analyses revealed that the size of the left frontoparietal cortex played a mediating role in this relationship. People with higher blood levels of these three nutrients tended to have larger left frontoparietal cortices, and the size of the frontoparietal cortex predicted the subjects' performance on tests of fluid intelligence.
"A lot of research tells us that people need to be eating fish and fish oil to get neuroprotective effects from these particular fats, but this new finding suggests that even the fats that we get from nuts, seeds and oils can also make a difference in the brain," Zamroziewicz said.
In the second study, the team found that the size of the fornix was associated with a balance of omega-3 and omega-6 fatty acids in the blood, and that a more robust fornix coincided with memory preservation in older adults. Again, the researchers saw that brain structure played a mediating role between the abundance and balance of nutrients in the blood and cognition (in this case, memory). The findings are reported in the journal Aging & Disease.
"These findings have important implications for the Western diet, which tends to be misbalanced with high amounts of omega-6 fatty acids and low amounts of omega-3 fatty acids," Zamroziewicz said.
"These two studies highlight the importance of investigating the effects of groups of nutrients together, rather than focusing on one at a time," Barbey said. "They suggest that different patterns of polyunsaturated fats promote specific aspects of cognition by strengthening the underlying neural circuits that are vulnerable to disease and age-related decline."

More information: Marta K. Zamroziewicz et al, Determinants of fluid intelligence in healthy aging: Omega-3 polyunsaturated fatty acid status and frontoparietal cortex structure, Nutritional Neuroscience (2017). DOI: 10.1080/1028415X.2017.1324357


Provided by University of Illinois at Urbana-Champaign

Omega-3 margarines fail to help in heart study

STOCKHOLM, 30 aug 2010 - Giving patients with a history of heart attacks a margarine enriched with omega-3 oils in addition to standard drugs appears to make no difference to their chances of having a repeat attack.

A 40-month study of more than 4,800 patients showed taking low doses of omega-3 fatty acids in margarine did not significantly reduce rates of serious heart attacks and other cardiovascular events, Dutch researchers said on Sunday.

The finding raised questions about the benefits of omega-3, which has been shown in previous studies to make for healthier hearts. The margarines used in the study were developed for the researchers by food and consumer goods giant Unilever.

Doctors, however, are unlikely to rush to change clinical practice. Many already prescribe omega-3 fish oil capsules, including GlaxoSmithKline's Lovaza, to reduce triglycerides, a type of blood fat linked to clogged arteries.

"It will be viewed as a largely negative study and people who are enthusiasts for omega fatty acids will continue to be enthusiasts and people who are skeptics will continue to be skeptics," said Scott Wright of the Mayo Clinic in the United States, who was not involved in the research.

Daan Kromhout of Wageningen University, who led the study, told the European Society of Cardiology the lack of efficacy might reflect the good background drug treatment patients were receiving, with 85 percent on cholesterol-lowering statins, as well as blood pressure and blood-thinning tablets.

"We found the cardiovascular mortality rate in the study population was only half that expected, probably because of their excellent treatment," he said.

"This may also be why the rate of major cardiovascular events during follow-up was no lower in the fatty acid groups than in the placebo group."

All the men and women in the Dutch study were aged between 60 and 80 and had suffered a heart attack roughly four years previously.

They were randomly assigned use of one of four margarines on bread instead of their regular spread -- one containing no extra omega-3 fatty acids; one with 400 milligrams a day of extra eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA); one with 2 grams of alpha-linolenic acid (ALA); and one with a combination of EPA-DHA and ALA.

Fish like salmon, herring and sardine are a common source of EPA-DHA, while ALA is found in vegetables including soybeans, flax seeds and walnuts.

Despite the overall negative results, researchers did find there was a reduction in repeat heart attacks and other cardiovascular events in women who took ALA margarine, although this was not statistically significant. Diabetes patients also showed a possible benefit.

Unilever, whose margarine brands that contain omega-3 include Flora and I Can't Believe It's Not Butter, said the lack of benefit seen with EPA and DHA was surprising, considering the weight of evidence published to date.

"The results indicate that more investigation is required into the efficacy of vegetable omega 3, but do not question the current authoritative dietary recommendations and advices for omega 3 intakes on which our products are based," the company said in a statement.

The results of the study, which was supported by the Netherlands Heart Foundation, the National Institutes of Health, and Unilever, were also published in the New England Journal of Medicine.

Omega-3s Show Benefit in Cardiovascular Conditions

Review of decades of research illustrates that evidence is strong

07 aug 2009-- Current evidence from decades of studies has shown that omega-3 polyunsaturated fatty acids (PUFA), found primarily in fish oils, can help prevent cardiovascular conditions, according to a review in the Aug. 11 issue of the Journal of the American College of Cardiology.

Carl J. Lavie, M.D., from Ochsner Medical Center in New Orleans, and colleagues note that the strongest evidence of the benefits of omega-3 PUFA has come from four controlled trials of nearly 40,000 individuals who were randomly assigned to eicosapentaenoic acid (EPA) with or without docosahexaenoic acid (DHA) for primary prevention, after myocardial infarction, and in heart failure.

The researchers note that current evidence suggests recommended EPA+DHA dose should be at least 500 mg per day in people without known cardiovascular disease and 800 to 1,000 mg per day in people with known coronary heart disease and heart failure.

"Convincing evidence from extensive research over the past three decades points out the potential beneficial effects of omega-3 PUFA in primary prevention, coronary heart disease and post-myocardial infarction, sudden cardiac death, heart failure, atherosclerosis, and atrial fibrillation," Lavie and colleagues conclude. "Based on the growing evidence for the benefits of fish oils, we agree that this story represents a 'fish tale with growing credibility'."

Several authors reported financial or consulting relationships with several pharmaceutical companies.

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