Research into the health benefits of fish oils has been contradictory.

Axar.az reports that over the last 10 years, there have been dozens of studies on fish oils and omega-3 oils. Some have backed up health claims, while others have not.

1. Multiple sclerosis (MS)
Fish oils are said to help people with MS. However, a study carried out by researchers from University Hospital in Bergen, Norway, found that omega-3 fatty acids do not help people with MS.

2. Prostate cancer
One study found that fish oils may reduce the risk of developing prostate cancer if a low-fat diet is also followed; however, another linked omega-3 levels to a higher risk of aggressive prostate cancer.

A study published in the Journal of the National Cancer Institute found that high fish oil intake raises the risk of high-grade prostate cancer by 71 percent and all prostate cancers by 43 percent.

3. Post-natal (post-partum) depression
Fish oils consumed during pregnancy may help protect mothers from post-partum depression. According to Dr. Michelle Price Judge of the University of Connecticut School of Nursing: "DHA consumption during pregnancy at levels that are reasonably attained from foods has the potential to decrease symptoms of postpartum depression."

4. Mental health benefits
A pilot study carried out in 2007 suggested that fish oils may help young people with behavioral problems, especially those with attention deficit hyperactivity disorder (ADHD).

The 8-week study demonstrated that children who consumed 8-16 grams of EPA and DHA per day, showed significant improvements in their behavior (rated by both their parents and the psychiatrist working with them).

5. Memory benefits
Omega-3 fatty acid intake can help improve working memory in healthy young adults, researchers reported in the journal PLOS One.

However, the benefits of fish oils for cognitive function in older populations may be less impressive. A study by researchers at the University of Iowa suggested that high levels of omega-3 are of no benefit to cognitive decline in older women.

6. Heart benefits
Omega-3 fatty acids found in fish oils may protect the heart from mental stress.

A study study published in the American Journal of Physiology revealed that people who took fish oil supplements for longer than 1 month had improved cardiovascular function during mentally stressful tests.

7. Protection from Alzheimer's disease
Claims were made for many years that regular fish oil consumption would help prevent people from developing Alzheimer's disease. However, a major study in 2010 found that fish oils were no better than placebo at preventing Alzheimer's.

In contrast, a study published in Neurology in 2007 reported that a diet high in fish, omega-3 oils, fruit, and vegetables reduced dementia and Alzheimer's risk.

8. Protection from vision loss
Adequate dietary consumption of DHA protects people from age-related vision loss, Canadian researchers reported in the journal Investigative Ophthalmology & Visual Science.

9. Epilepsy
A 2014 study published in the Journal of Neurology, Neurosurgery & Psychiatry claims epilepsy patients could reduce seizure frequency by consuming low doses of omega-3 fish oil every day.

The research team at the University of California-Los Angeles (UCLA) School of Medicine, says their findings may be particularly useful to epilepsy patients who no longer respond to medication.

10. Schizophrenia and psychotic disorders
In what was believed to be the first study of its kind, researchers revealed the omega-3 fatty acids found in fish oil may be effective for reducing the risk of psychosis.

The study, published in Nature Communications, details how a 12-week intervention with omega-3 supplements substantially reduced the long-term risk of developing psychotic disorders.

11) Benefits for the fetus
Omega-3 consumption may help boost fetal cognitive and motor development.

In a study published in 2008, scientists found that omega-3 consumption by the mother during the last 3 months of pregnancy improved the baby's sensory, cognitive, and motor development.