The regular consumption of fish oil supplements reduces cognitive decline and brain atrophy in older adults, a new study finds.

There's no denying that fish oil supplements are good for health. Though researches claim that these supplements do little to protect against heart diseases, they still have a very positive effect on the brain and a recent study supports this hypothesis.

For the study, researchers used neuropsychological tests and brain magnetic resonance imaging (MRI) to assess 229 older adults with normal cognitive abilities, every six months. All participants were part of the Alzheimer's Disease Neuroimaging Initiative (ADNI) study. During the study, 397 were diagnosed with mild cognitive impairment and 193 with Alzheimer's disease (AD).

Researchers found that the participants who consumed fish oil supplements regularly during the study period experienced significantly lower rates of cognitive decline as measured by the Alzheimer's Disease Assessment Scale (ADAS-cog), and the Mini Mental State Exam (MMSE). Unfortunately, the benefits were observed only in participants without dementia at the start of the study.

"Additionally, serial brain imaging conducted during this study showed that the participants with normal cognition who reported taking fish oil supplements demonstrated less brain shrinkage in key neurological areas, compared to those who did not use the supplements," principal investigator Lori Daiello said in a press statement. "Also, the positive findings on cognitive testing and brain MRI were only observed in persons who did not carry the best-studied genetic risk factor for AD, APOE-4. More research is needed, but these findings are promising and highlight the need for future studies to expand the current knowledge of the effects of FOS use on cognitive aging and AD."

Fish oil has always been considered the biggest source of these fatty acids. However, the smell is repelling to some people, who are forced to look for other alternatives.  An Organic Valley funded study conducted last December revealed that organic milk contains greater amount of Omega 3 fatty acids helpful in preventing cardio-vascular diseases.

Alzheimer's disease incidents have gone up in recent years, according to official estimates. More than five million Americans are living with the condition as of 2014. The most common form of dementia, Alzheimer's disease is characterized by neurodegeneration - a harrowing process whereby nerve connections in the brain are gradually broken down. This typically results in a range of debilitating cognitive impairments, including confusion, disorientation, loss of motor skills and memory loss. These symptoms generally bring with them a number of lifestyle changes as well as an increased risk of injuries.

Scientific authorities have predicted age-related dementia will more than triple by 2050. This means that the current 44 million dementia patients will go up to 135 million in less than four decades.

"It's a global epidemic and it is only getting worse," Marc Wortmann of Alzheimer's Disease International (ADI) said, speaking to BBC News. "If we look into the future the numbers of elderly people will rise dramatically. We must tackle dementia now, for those currently living with the condition across the world and for those millions who will develop dementia in the future. The G8 is our once-in-a-generation chance to conquer this condition and we must see meaningful action after the talking is over."

Previous studies have linked alcohol consumption, even in moderate levels, to an increased risk of developing dementia. In a study conducted by Loyola University Chicago Stritch School of Medicine, researchers found that this risk can be warded off by consuming omega 3 fish oil. The study found that brain cells of rats that had been exposed to high contents of alcohol could be protected against inflammation and cell death when given fish oil.

Like there are two sides to every study, the label given to fish oil as "brain food" was questioned by University of Iowa researchers. According to them, omega-3 fatty acids may not necessarily benefit thinking skills.

"There has been a lot of interest in omega-3s as a way to prevent or delay cognitive decline, but unfortunately our study did not find a protective effect in older women. In addition, most randomized trials of omega-3 supplements have not found an effect," said author Eric Ammann, a doctoral student in the UI College of Public Health Department of Epidemiology, in a statement. "However, we do not recommend that people change their diet based on these results. Researchers continue to study the relationship between omega-3s and the health of the heart, blood vessels, and brain. We know that fish and nuts can be healthy alternatives to red meat and full-fat dairy products, which are high in saturated fats."

The current study was published online in the journal Alzheimer's & Dementia. The project was funded by the Agency for HealthCare Research and Quality, National Institute on Alcohol Abuse and Alcoholism, National Cancer Institute, National Institute of Nursing Research, National Heart, Lung and Blood Institute, National Center for Complementary and Alternative Medicine, National Institute on Drug Abuse, National Institute of Diabetes and Digestive Kidney Disorders and National Institutes of Health.