Fish oils come from fatty fish, also called "oily fish". They are found in the tissue of these fatty fish, such as trout, tuna, mackerel, herring, salmon, and sardines.
Experts have long been seeking to understand how fish oils protect the heart. However, in this study published in the American Journal of Physiology - Regulatory, Integrative, and Comparative Physiology, titled "Fish Oil and Neurovascular Reactivity to Mental Stress in Humans" researchers have finally found that fish oil is able to "counteract the detrimental effects of mental stress on the heart."
The study was led by Jason R. Carter of Michigan Technological University; it revealed that people who took fish oil supplements 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 olive oil instead.
These results may indicate the mechanism behind how fish oils are beneficial to the heart which could help professionals prevent heart disease in certain populations.
A total of 67 adults participated in the study. They each underwent a series of tests to evaluate their: blood pressure, MSNA, cardiovascular function and blood flow through the calf and forearm.
They conducted the tests while the participants were at rest and again when they were performing a stressful mental arithmetic test under pressure.
The participants were then either given 9 grams of fish oil per day or 9 grams of olive oil - a placebo that hasn't been proved to have the same cardiovascular benefits of fish oil. None of them were aware which supplement they were given.
8 weeks later the participants took the same tests.
The rest results between the two groups didn't differ too much when they were at rest. However, when they were made to take the tests under stress, those who took the fish oil performed better. Those in the olive oil group had blunted heart rate activity compared to those who took fish oil.
The findings show the protective effect fish oil can have on cardiovascular function during mental stress, finally revealing why fish oils keep the heart healthy.
Further studies are necessary to evaluate what kind of effect taking fish oil for a prolonged period might have.
The authors concluded:
"Overall, the data support and extend the growing evidence that fish oil may have positive health benefits regarding neural cardiovascular control in humans and suggest important physiological interactions between fish oil and psychological stress that may contribute to disease etiology."
Health benefits of taking fish oilsOver the past few decades, there have been numerous studies on fish oils and omega-3 oils to see whether any of the health claims associated with their consumption are true.
Researchers have revealed that there are actually several benefits when they are included in a human diet:
- Prostate Cancer - Fish oils have been shown to reduce a man's risk of developing prostate cancer if they also follow a low-fat diet.
- Post-Natal Depression - Dr. Michelle Price Judge, of the University of Connecticut School of Nursing, said after carrying out a study in 2011, "DHA consumption during pregnancy at levels that are reasonably attained from foods has the potential to decrease symptoms of postpartum depression."
- Mental Health - Fish oils have been shown to help young people with behavioral problems, particularly those with ADHD.
- Protection from Vision Loss - adequate dietary consumption of DHA (from fish oil) protects people from age-related vision loss, according to research published in the Journal Investigative Ophthalmology & Visual Science.
- Healthy Fetus - omega-3 consumption boosts fetal cognitive and motor development.