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Fish oils

fish & omega-3 oils

Omega-6 oils linked to lower diabetes risk

A Finnish study involving 2,189 healthy men aged 42-60 found that over 19 years, 417 men (19%) were diagnosed with type 2 diabetes. Those with high omega-6 polyunsaturated fatty acid concentrations in their blood were 46% less likely to develop diabetes. When analyzed, it turned out that this association depended on linoleic and arachidonic acid concentrations only; high serum gamma-linolenic and dihomo-γ-linolenic acid concentrations were linked to a higher risk.

The serum linoleic acid concentration is determined by the person's diet, and the main sources of linoleic acid are vegetable oils, nuts and seeds. Arachidonic acid is present in meat and eggs; however, the human body can also make arachidonic acid from linoleic acid.

Gamma-linolenic acid and dihomo-γ-linolenic acid are mainly formed in the human body from linoleic acid, but their concentrations in serum are very low.

Linoleic acid is the most common omega-6 fatty acid, and has been linked to a reduced risk of cardiovascular diseases as well as type 2 diabetes.

http://www.eurekalert.org/pub_releases/2016-03/uoef-hso032416.php

Teymoor Yary, Sari Voutilainen, Tomi-Pekka Tuomainen, Anu Ruusunen, Tarja Nurmi, Jyrki K Virtanen 2016. Serum n-6 polyunsaturated fatty acids, delta-5- and delta-6-desaturase activities and risk of incident type 2 diabetes in men: The Kuopio Ischaemic Heart Disease Risk Factor Study. American Journal of Clinical Nutrition, Published online March 24, 2016 http://ajcn.nutrition.org/content/early/2016/03/23/ajcn.115.128629.abstract

Best practices for omega-3 clinical trials with cardiovascular outcomes

A review of recent neutral studies questioning the benefits of omega-3s for heart health suggests that the findings may have been due to a number of design issues, rather than a lack of substantiated clinical benefits in cardiovascular disease. The issues include such things as:

  • aggressive cardiovascular drug treatment overshadowing the benefits of long-chain omega-3s
  • high background long-chain omega-3 intake at study initiation
  • too few subjects in the study
  • treatment duration too short
  • insufficient LC omega-3 dosage
  • increase in omega-6 fatty acid intake during the study
  • failure to assess the LC omega-3 status of the subjects prior to and during treatment
  • lack of clarity concerning which mechanisms were expected to produce benefits

The existing body of gold-standard research showing omega-3s may reduce cardiovascular death risk, maintain healthy blood pressure and improve triglyceride levels also makes it difficult to conclude that EPA and DHA consumption does not contribute to a healthy heart.

http://www.eurekalert.org/pub_releases/2016-02/g-phb012916.php

Rice, H. B., Bernasconi, A., Maki, K. C., Harris, W. S., von Schacky, C., & Calder, P. C. (2016). Conducting omega-3 clinical trials with cardiovascular outcomes: Proceedings of a workshop held at ISSFAL 2014. Prostaglandins, Leukotrienes and Essential Fatty Acids (PLEFA), 107, 30–42. http://doi.org/10.1016/j.plefa.2016.01.003

Inflammation and depression fuel each other

A review of 200 studies on depression and inflammation has concluded that depression and inflammation fuel one another, with inflammation playing a key role in the development of depression in some people, and depression priming greater physiological responses to stress.

Moreover, depression that is caused by chronic inflammation is resistant to traditional therapy methods. However, it is more responsive to activities such as yoga, meditation, omega-3 fatty acids, NSAIDS and exercise.

The review indicates that treatment for depression needs to consider its pathway. The researcher suggests that chronic inflammation is most common in individuals who have experienced stress in their lives, including lower socio-economic status or those who experienced abuse or neglect as children. Other contributing factors are a high-fat diet and high body mass index.

If inflammation is a significant factor, it needs to be treated in tandem with the depression.

http://www.eurekalert.org/pub_releases/2015-12/ru-icf121815.php

Kiecolt-Glaser, J. K., Derry, H. M., & Fagundes, C. P. (2015). Inflammation: Depression Fans the Flames and Feasts on the Heat. American Journal of Psychiatry, 172(11), 1075–1091. http://doi.org/10.1176/appi.ajp.2015.15020152

Canola oil might help people with type 2 diabetes

A Canadian study involving 141 people with Type 2 diabetes, who ate either a low glycemic index diet that included bread made with canola oil, or a whole wheat diet known to reduce the risk of cardiovascular disease, found that those on the canola bread diet experienced both a reduction in blood glucose levels and a significant reduction in LDL, or "bad," cholesterol. Moreover, the canola bread diet seemed to have the most significant impact on people who needed help the most — those whose HbA1c test measuring blood glucose over the previous two or three months was highest.

On the other hand, those on the whole wheat diet seemed to have better blood flow after 12 weeks than those on the canola bread diet.

http://www.eurekalert.org/pub_releases/2014-06/smh-rsb061314.php

Jenkins, D. J. A., Kendall, C. W. C., Vuksan, V., Faulkner, D., Augustin, L. S. A., Mitchell, S., … Leiter, L. A. (2014). Effect of Lowering the Glycemic Load With Canola Oil on Glycemic Control and Cardiovascular Risk Factors: A Randomized Controlled Trial. Diabetes Care, 37(7), 1806–1814. http://doi.org/10.2337/dc13-2990

Omega 3 levels affect whether B vitamins can slow brain's decline

A study involving 266 people with mild cognitive impairment (aged 70+) has found that B vitamins are more effective in slowing cognitive decline when people have higher omega 3 levels.

Participants were randomly selected to receive either a B-vitamin supplement (folic acid, vitamins B6 and B12) or a placebo pill for two years. The vitamins had little to no effect for those with low levels of omega-3 fatty acids, but were very effective for those with high baseline omega-3 levels.

Fish reduces Alzheimer's risk for those with APOE gene

I've spoken before about how the presence or absence of the “Alzheimer's gene” may affect which lifestyle changes are beneficial for you. A new study has added to that idea with a finding that seafood consumption was associated with fewer signs of Alzheimer's-related pathology, but only among those with the APOEe4 gene.

Seafood consumption was also associated with increased mercury levels in the brain, with levels rising the more seafood was consumed. However, higher levels of mercury were not correlated with any neuropathologies.

Mediterranean diet reduces brain shrinkage in old age

Another study adds to the growing evidence that a Mediterranean diet is good for the aging brain.

The New York study used data from 674 non-demented older adults (average age 80). It found that those who closely followed such a diet showed significantly less brain shrinkage. Specifically, total brain volume was an average 13.11 milliliters greater, with grey matter volume 5 millilitres greater, and white matter 6.4 millilitres greater.

No benefit in omega-3 supplements for cognitive decline

A large, five-year study challenges the idea that omega-3 fatty acids can slow age-related cognitive decline. The study, involving 4,000 older adults, was part of the Age-Related Eye Disease Study (AREDS), which established that daily high doses of certain antioxidants and minerals can help slow the progression of age-related macular degeneration. However, a follow-up study found the addition of omega-3 fatty acids to the AREDS formula made no difference.

Impaired recovery from inflammation linked to Alzheimer's

Submitted by Fiona McPherson on

Analyses of cerebrospinal fluid from 15 patients with Alzheimer's disease, 20 patients with mild cognitive impairment, and 21 control subjects, plus brain tissue from some of them, has found that those with Alzheimer’s had lower levels of a particular molecule involved in resolving inflammation. These ‘specialized pro-resolving mediators’ regulate the tidying up of the damage done by inflammation and the release of growth factors that stimulate tissue repair. Lower levels of these molecules also correlated with a lower degree of cognitive function.

Abdominal fat accumulation prevented by unsaturated fat

Submitted by Fiona McPherson on

A study involving 39 young adult men and women of normal weight, who ate 750 extra calories in the form of muffins every day for seven weeks, found that those whose muffins were made with palm oil built significantly more fat and less muscle than those whose muffins were made with sunflower oil. Moreover, the palm oil group developed the fat in more dangerous places  — in the liver and abdomen. The groups gained the same amount of weight.

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