A different kettle of fish

The cardiovascular benefits of Omega 3 fatty acids like those found in fish oil are mainstream medical knowledge, but a range of studies are emerging, helped by technology developed at the University of Stirling, which link increased Omega 3 intake with low instances of other common western conditions such as immune disorders, cancer and diabetes

he potential health benefits of consuming n-3 long-chain polyunsaturated fatty acids (LC-PUFA) is now well respected and there is a significant body of literature describing the health benefits of increasing our intake of LC-n-3 PUFA, especially with respect to inflammatory pathologies, particularly for coronary vascular disease (CVD) immune function, and rheumatoid arthritis1-4.

The scientists who first suggested that LC-n-3 PUFA had important health properties found that Greenland Inuit populations, despite consuming high-levels of lipids, had low levels of CVD and other inflammation related disorders and that the protective benefits were related to high fish intake5. The Nordic scientists, Drs Dyerberg, Bang and Hjorne, who first established the benefits of Omega 3 for human health compared the disease status in both Greenland natives and Danish citizens, who shared similar genetic origins. They established that in Greenland natives the incidence of many common conditions affecting those consuming a western diet, including myocardial infarction, multiple sclerosis, Psoriasis, thyrotoxicosis, bronchial asthma, diabetes and cancer were rare while in Danish citizens they were prevalent. This suggests that the beneficial factors were related to the higher intake of the Omega 3 fatty acids, eicosapentaenoic and docosahexaenoic acids, (EPA and DHA) in the Greenland diets6 (Ruxton).

There are a number of advisory intake levels for Omega 3 intake levels produced by different global organisations. One of the most important in advising on Omega 3 supplementation is the UK-based International Society for the Study of Fatty acids and Lipids (http://www.issfal.org). The ISSFAL advisory recommendation suggests a minimum daily intake of EPA + DHA of 250-500mg per day or up to 3.5g per week for good cardiovascular health in adults.

Principally, Omega 3 is derived from marine invertebrates that are consumed by fish and other marine organisms and are passed on up the aquatic food chain to a range of fish species. While all fish species contain Omega 3 it is the oily fish that deposit the highest levels of Omega 3 in their tissues and can provide the highest levels of EPA & DHA to human consumers. The fish species having the highest levels of Omega 3 include Atlantic and Pacific salmon, mackerel, herring, trout as well as smaller species such as sardines, anchovies and sprats. Omega 3 supplementation can also be provided from processed oil capsules. The largest data set describing Omega 3 benefits is related to studies investigating EPA and DHA supplementation in patients with a cardiac pathology, including CVD, which is the most common health related problem in the developed world. In the period from 1978 to 2011 around 452 clinical trials were conducted investigating a range of cardiac events. A summary of these trials suggests that supplementation with marine Omega 3, provided as food or supplements for at least 6 months can reduce cardiac events by 10% and cardiac deaths by 9% whilst also reducing coronary events by 18% and showing a trend towards lower total mortality7.

However, there are also significant non-cardiac related health benefits arising from Omega 3 supplementation, especially with respect to positive benefits in immune function, that can result in improved health and reduce the incidence of autoimmune disease. Benefits of Omega 3 have also been seen in patients suffering from rheumatoid arthritis where reductions in stiffness and pain have been recorded. The reduction in pain was due to reduced levels of the inflammatory cytokine PGE2. Additional benefits of Omega 3 supplementation include a 75% reduction in non-steroidal anti-inflammatory drugs (NSAIDs) as well as evidence that Omega 3 can reduce cartilage breakdown in patients with ankylosing spondylitis. There is also recent evidence that Omega 3 supplementation can provide relief of multiple sclerosis symptoms8.

However, not all unsaturated fatty acids are equally beneficial when it comes to health. Western diets tend to be deficient in Omega-3 fatty acids yet have excessive amounts of Omega-6 fatty acids which have been linked to various pathologies. Studies have provided evidence that optimising the Omega 3/Omega 6 ratio can prevent cancer risk particularly with respect to colon and breast cancers9. High levels of Omega 6 are pro-inflammatory and Omega 3 is anti-inflammatory thus it is advisable to have a higher Omega 3 level compared to Omega 6 for human health benefits. This is particularly important with respect to inflammatory pathologies, particularly for coronary vascular disease (CVD) immune function, and rheumatoid arthritis. Additional studies have also shown benefits of Omega 3 in the attenuation of joint inflammation and subsequent improvements in mobility10. Similar investigations have also observed reductions in osteoporosis where reductions in bone damage were observed when a high Omega 3 diet was compared to a normal Western diet11. In addition to the above there has been growing evidence that the use of Omega 3 can have benefits for high-performance athletes allowing reductions in recovery time from injury. The Omega 3 action allows increased blood flow to the muscles as well as increasing oxygen to the heart and reducing the impact of trauma thereby improving recovery from injury12.

Recently there have also been developments regarding the impact of Omega 3 supplementation in infants, especially with respect to DHA that is vital for neural development, retinal function and nerve growth. Thus, consumption of oily fish and/or Omega 3 capsules during pregnancy can improve the early development of infants as well as older children13, 14.

Reduced concentrations of both DHA and EPA have been reported in children with developmental disorders, including autism and ADHD, but there is also evidence that supplementation with LC-n-3 PUFA might be beneficial for the children in general. Evidence from clinical trials suggests that supplementation with DHA & EPA can improve general child learning and behaviour15.

Leading Omega-3 research company Glasgow Health Solutions (GHS Ltd) has welcomed the results of a recent study which links fish consumption, death rates and cardiovascular disease.  The study by the Harvard School of Public Health (HSPH) and the University of Washington 16 found that older adults with higher blood levels of Omega-3 fatty acids from fish and seafood had a 25% less chance of dying prematurely than those with low Omega-3 levels. Those who ate oily fish twice per week could live up to two years longer, with higher levels of Omega-3 fatty acids also found to reduce the likelihood of dying from coronary heart disease by as much as 40% and heart arrhythmias by 45%.

Scientists at the University of Stirling’s Institute of Aquaculture have recently collaborated with Presearch UK and GHS Ltd to provide a rapid blood analysis report which is available to a wide range of people, including individual patients, high-performance athletes and also clinical studies conducted by pharmaceutical companies and related organisations.  This finger prick blood test measures the level of Omega-3 in your blood, and determines the individual requirement of this super nutrient you need to improve your health. The test measures the vital balance of Omega-3 and omega-6 fats in the body, taking the guess work out of Omega-3 supplementation.It  provides a non-invasive method of sampling blood that can be especially important when dealing with vulnerable groups such as the young, the elderly and patients with behavioural disorders. The testing schedule has been further developed to include breast milk sampling.

For more information: To find out more, visit http://www.omegabloodcount.com or Nutrition Analytical Service, University of Stirling http://www.aqua.stir.ac.uk/nas/blood-spot-test

References:

1. Dyerberg, J., Bang, H.O., & Hjorne, N., American Journal of Clinical Nutrition (1975), 28, 958-966.
2. Ruxton, C.H.S., Calder, P.C., Reed, S.C., et al. Nutrition Research Reviews (2005), 18, 113-129.
3. Delgado-Lista, J., Perez-Martinez, P., Lopez-Miranda, J., Perez-Jimenez, F., British Journal of Nutrition (2012), 107, S201-S213.
4. Nordvik I., Myhr K.M., Nyland, H., et al., Acta Neurology Scandinavia (2000), 102 (3), 143-149.
5. Roynette, C.E., Calder, P.C., Dupertuis, Y.M., et al., Clinical Nutrition (2004), 23 (2): 139-151.
6. Goldberg, R., and Katz, J. Pain (2007), 129 (1-2): 210-223.
7. Martinez-Ramirez, M.J., Palma, S., Martinez-Gonzalez, M.A., et al., European Journal of Clinical Nutrition (2007), 61 (9): 1114-1120.
8. Yates, A., Norwig, J., Maroon., J., et al., Sports Health (2009), 1:1: 21-30.
9. Forsyth, J.S., Willatts, P., Agnostoni, C., et al., British Medical Journal (2003), 326 (7396): 953.
10. Richardson, A.J., Montgomery, P., Pediatrics (2005), 115 (5); 1360-1366.
11. Richardson, A.J., Burton, J.R., Sewell, R.P., et al., PLOS ONE (2012), 7 (9): e43909, doi; 10.1371.
12. Dariush Mozaffarian, Rozenn N. Lemaitre, Irena B. King, Xiaoling Song, Hongyan Huang, Frank M. Sacks, Eric B. Rimm, Molin Wang, David S. Siscovick; Plasma Phospholipid Long-Chain ?-3 Fatty Acids and Total and Cause-Specific Mortality in Older AdultsA Cohort Study. Annals of Internal Medicine. 2013 Apr;158(7):515-525.
13. Calder, P.C., Clinical Nutrition (2010) 29, 5-12.
14. Bjokkaer, T., Brun, J.G., Valen, M., et al., Lipids in Health and Disease. (2006) 5, 6.
15. Micallef, M.A., Garg, M.L., Atherosclerosis. (2009) 204 (2), 466-482.
16. Lee, T.H., Arm, J.P., Horton, C.E., et al., Allergy Proceedings. (1991), 12 (5), 299-303.

PROFESSOR GORDON BELL:Head of the Nutrition at the University of Stirling with 30 years experience in fish nutrition and lipid and nutrition related analysis. He has published more than 120 peer-reviewed papers on fish nutrition, human nutrition fatty acids, lipid soluble nutrients and antioxidants. g.jbell@stir.ac.uk

JAMES DICK : Chief analyst with responsibility for Quality Control in the Nutrition Group with over 25 years experience in lipid methodology. He has responsibility for the development of chromatographic techniques and is trained in all aspects of complex lipid analysis including HPLC, GC, GC/MS & GC/MS/MS. j.r.dick@stir.ac.uk