There is a wealth of evidence supporting a role for omega-3's in reducing the risk of cardiovascular disease and boosting overall heart health, improving eye and brain development in our formative years, maintaining cognitive performance as we age. But can omega-3 have other benefits?
Fatty acids, once solely thought of as an energy source in our bodies, have been shown to be highly active molecules. They can act as transcription factors that regulate protein synthesis, play important roles in cell signalling, and act as membrane components that regulate the fluidity, permeability, and dynamics of cell membranes.
Omega-3 fatty acids, such as alpha-linolenic (ALA), eicosapentaenoic (EPA) and docosahexaenoic (DHA), have in-fact been associated in beneficial ways with a wide range of illnesses and diseases including cancer, heart disease, rheumatoid arthritis, asthma, lupus, alcoholism, visual acuity, kidney disease, respiratory disease, dermatitis, psoriasis, cystic fibrosis, schizophrenia, depression, neurologic and brain development, malaria, multiple sclerosis, and migraine headaches.
Indeed, it is difficult to find any human disorder where omega-3 fatty acids have not been tested.
A number of epidemiological and animal studies have reported potential role of omega-3 in the prevention and therapy of cancers.
For example, in the Japanese population, whose traditional diet includes much fish, the incidence of certain cancers such as breast cancer has increased along with a more ‘westernized’ food consumption and lifestyle.
Since this observation was made, several studies have found that omega-3 fatty acid consumption is associated with decreased cancer risk of the breast, prostate, colon, and kidneys. However, whether this effect is mediated by the actual omega-3 fatty acids EPA and DHA or by EPA- and DHA- derived eicosanoids and docosanoids is the subject of ongoing research.
Research has also suggested that DHA exerts anti-proliferative effects on cancer cells, and can work in synergy with chemotherapeutic drugs, whilst some studies have suggested that in certain settings, omega-3 supplementation could increase existing treatment efficacy by increasing tumour cell death (apoptosis) and prolonging the survival of patients.
DHA has also been suggested to reverse adverse side effects such as low blood counts and malnutrition – which could allow intensified or prolonged treatment if necessary.
A study published in Experimental Cell Research last year ( border=0>doi: 10.1016/j.yexcr.2010.02.039) noted that in addition to being toxic to cancer cells, DHA can protect healthy nervous tissue via the downstream products protectins, which may be of particular interest when treating cancers of the nervous system such as neuroblastoma and medulloblastoma – two childhood cancers with poor outcomes.
“In this case, DHA may work as both a sword and a shield, which would be highly useful since treatment of especially medulloblastoma often gives severe long-term cognitive impairment,” wrote the researchers.
Some recent studies have indicated that DHA could also provide protection against traumatic brain injury by reducing neural inflammation and increasing anti-apoptotic mediators.
Dr Rob Winwood, director of scientific affairs – Europe and Asia, for Martek Biosciences – a division of DSM Nutritional Products – told NutraIngredients that there is an increasing awareness of the risks of brain injury in professional head contact sports, which have been widely covered in recent U.S. news articles about NFL American footballers.
“It was recently estimated that 3.9 million sports- and recreational-related concussions are sustained annually in the U.S. and research in recent years has indicated that the effects of repeated sports-related concussions may be more far-reaching than previously believed,” said Winwood.
“For example, one study indicated that retired American football players reporting a history of three or more previous concussions were three fold more likely to be diagnosed with depression, while another study […] found that retired NFL football players are at higher risk for mild cognitive impairment, which can be a precursor to Alzheimer's disease,” he explained.
Recent work by Julian Bailes and James Mills of West Virginia School of Medicine, U.S.A, (doi: 10.1227/NEU.0b013e3181ff692b) has shown the protective effects of DHA to lab controlled induced brain lesions.
It was found that DHA supplementation reduced the production of the amyloid precursor protein (APP) following traumatic brain injury, and also reduced CD-68 and caspase 3 levels which are biomarkers of neural inflammations and cell death.
“When the supplementation level was 40mg/kg/day, then the levels of APP were similar to a sham injury. This preclinical data suggests that further clinical research should be undertaken to determine if the prophylactic supplementation of DHA could be used to protect against the effects of traumatic brain injury,” said Dr Winwood.
In addition to showing promise in brain trauma and cancer patients, omega-3’s have shown promise in many other areas in recent years, including boosting immune health and reducing degenerative muscle loss.
Research recently published in the journal Pediatrics (doi: 10.1542/peds.2010-1386), reported that mothers taking 400 milligrams of a supplement containing DHA had babies that overcame colds faster than babies with mothers not taking DHA.
In the study infants were examined at 1, 3 and 6 months old, and their mothers were asked whether, in the past two weeks, the infants had symptoms such as congestion, phlegm, vomiting and rashes and how long those lasted.
While both groups had similar numbers of illnesses, infants whose mothers had taken DHA saw many illness symptoms reduced.
“At one month, the DHA group experienced 26%, 15%, and 30% shorter duration of cough, phlegm, and wheezing, respectively, but 22% longer duration of rash,” said the researchers.
Daily supplements of omega-3 may boost also the production of muscle protein in older people, and thus reduce the risk of degenerative muscle loss.
A study published earlier this year (doi: 10.3945/ajcn.110.005611) reported that four grams per day of omega-3 fatty acids for eight weeks increased the rate of muscle protein synthesis, and was associated with increased supply of amino acids and insulin.