Benefits attributed to eating oily fish are mounting. Eating fish is now credited with combating depression, reducing the symptoms of arthritis, reducing the risk of heart disease, protecting vision, and most recently with reducing stress and improving working memory. Of course, this is due to oily fish, like salmon and mackerel, being very rich in omega-3 poly-unsaturated fatty acids and protein. White fish have fatty acids too but not as much.
A study published in the American Journal of Physiology – Regulatory, Integrative, and Comparative Physiology shows that fatty fish oils can “counteract the detrimental effects of mental stress (read that: the fight or flight reaction) on your heart.” The study, led by Jason Carter of Michigan Technological University, revealed that people who took 9 grams of fish oil supplements a day for over a month experienced less mental stress in measurements of cardiovascular health, including heart rate and muscle sympathetic nerve activity (MSNA) compared to those who took 9 grams a day of olive oil instead.
Oily fish are species of fish that contain significant amounts of oil throughout their body tissues and in their belly cavity. In contrast, whitefish only contain oil in their liver – and much less of it than oily fish. Other examples of oily fish include trout, sardines, kipper, eel, and herring.
The American Heart Association recommends that people eat at least two servings of fish every week. The National Health Service of the United Kingdom also advises people to eat at least two portions of fish a week, including one of oily fish.
It has been known since the famous Avon, England study of all the pregnant women in that city during one year in the 90’s that women who do not eat fish during pregnancy are more likely to experience high levels of anxiety at that time. The University of Bristol longitudinal study suggested that eating fish during pregnancy could help reduce stress levels, which – in turn – has the effect of reducing behavioral and attention problems in the offspring of oily fish eating mums.
My favorite study involved London cabbies, a stressed group who can always use some working memory improvement. The BBC reported on a small group of 10 cabbies who agreed to eat 4 portions of oily fish a week for 12 weeks. They were tested before and after the 12 weeks to see what affect the increased intake of oily fish had on their stress levels and memory.
At the end of the 12 weeks it was found that cabbies were better able to deal with stressful situations and their visualization-based memory had also improved significantly, something Omega 3 is believed to help with. As a group, their stress hormone as a whole was down by 22% and their anti-stress hormone up by 12%.
Since the study included only ten participants and had no control group the results are only suggestive. However, the cabbies could be heard to exclaim: “So long and thanks for all the fish…”
by Susan Andrews, PhD
The Psychology Times, October 2014
Dr. Susan Andrews, Clinical Neuropsychologist, is currently Clinical Assistant Professor, LSU Health Sciences Center, Department of Medicine and Psychiatry, engaged in a Phase III study on HBOT and Persistent PostConcussion Syndrome. In addition to private clinical practice, Dr. Andrews is an award-winning author of Stress Solutions for Pregnant Moms (2013).