fish & omega-3 oils
A Finnish study has found that people who increased their intake of fatty fish to a minimum of 3–4 weekly meals had more large HDL cholesterol in their blood than people who were less frequent eaters of fish. Large HDL particles are believed to protect against cardiovascular diseases.
http://www.eurekalert.org/pub_releases/2014-03/uoef-iio030314.php
Middle-aged Japanese men living in Japan had lower incidence of coronary artery calcification, a predictor of heart disease, than middle-aged white men living in the United States, after accounting for risk factors such as smoking, cholesterol, alcohol consumption, diabetes and high blood pressure.
A study involving 362 children with reading problems has found that 16 weeks of daily 600 mg supplements of omega-3 DHA from algal sources improved their sleep. According to a sleep questionnaire filled out by parents, 40% of these children had significant sleep problems. Monitoring of 43 of the poor sleepers found that children taking daily supplements of omega-3 had nearly one hour (58 minutes) more sleep and seven fewer waking episodes per night compared with children taking a placebo.
A meta-analysis of 72 studies with over 600,000 participants from 18 nations has concluded that total saturated fatty acid, whether measured in the diet or in the bloodstream as a biomarker, was not associated with coronary disease risk. Nor was there any significant association between consumption of total monounsaturated fatty acids, long-chain omega-3 and omega-6 polyunsaturated fatty acids, and cardiovascular risk.
Data from AREDS2, involving 4,203 older adults with age-related macular degeneration, has found that daily dietary supplements of either omega-3 polyunsaturated fatty acids (also found in fish) or lutein and zeaxanthin (nutrients found in green leafy vegetables) were not associated with reduced risk for cardiovascular disease (CVD).
http://www.eurekalert.org/pub_releases/2014-03/tjnj-sna031414.php
The question of whether supplements of omega-3 fatty acids can help memory and cognition has been a contentious one, with some studies showing a positive effect and others failing to find an effect. My own take on this issue is that, like so many other things, it all depends on what you’re working with. It seems unsurprising if only those who have a deficient diet, or greater demands on their system (e.g., because of stress or age), or greater needs (e.g., because of a lack of cognitive reserve) might benefit from supplementation.
A review of three high quality trials comparing the putative benefits of omega-3 fatty acids for preventing age-related cognitive decline, has concluded that there is no evidence that taking fish oil supplements helps fight cognitive decline. The trials involved a total of 3,536 healthy older adults (60+). In two studies, participants were randomly assigned to receive gel capsules containing omega-3 PUFA or olive or sunflower oil for six or 24 months.
A new study, involving 1,219 dementia-free older adults (65+), has found that the more omega-3 fatty acids the person consumed, the lower the level of beta-amyloid in the blood (a proxy for brain levels). Consuming a gram of omega-3 more than the average per day was associated with 20-30% lower beta-amyloid levels. A gram of omega-3 equates to around half a fillet of salmon per week.
A rat study has shown how a diet high in fructose (from corn syrup, not the natural levels that occur in fruit) impairs brain connections and hurts memory and learning — and how omega-3 fatty acids can reduce the damage.
We know that these unnaturally high levels of fructose can hurt the brain indirectly through their role in diabetes and obesity, but this new study demonstrates that it also damages the brain directly.
A study involving 1,575 older adults (aged 58-76) has found that those with DHA levels in the bottom 25% had smaller brain volume (equivalent to about 2 years of aging) and greater amounts of white matter lesions. Those with levels of all omega-3 fatty acids in the bottom quarter also scored lower on tests of visual memory, executive function, and abstract thinking.
The finding adds to the evidence that higher levels of omega-3 fatty acids reduce dementia risk.