Fish oil protects older people against vision loss –Study

A chemical found in fish oil boosts the daily survival of cells critical to vision protecting against age-related vision loss. According to findings of a new study published in ‘Cellular and Molecular Neurobiology,’ a component of fish oil prevents retinal cells from dying.

The omega-3 fatty acid DHA, abundant in oily fish, and its derivatives ‘precondition’ photoreceptors that are sensitive to light and the RPEs (retinal pigment epithelials) – a layer of support cells under the retina – which process it.

Damage to these result to the degeneration of the macula – the central area of the retina. Fish oil contains two types of polyunsaturated fatty acids (PUFAs) – omega-3 DHA (docosahexaenoic acid) and omega-6 AA (arachidonic acid), said the researchers from the Louisiana State University. They said the oily fish chemical ‘preconditions’ the cells to counteract future stressors – such as when blood supply is cut off for a short period.

The protective response would carry over to a subsequent blood supply shortage – much like the immunity a vaccine confers against future exposures to disease. The most widely available dietary source of EPA and DHA is cold-water oily fish, such as salmon, herring, mackerel, anchovies, and sardines. Oils from these fish have a profile of around seven times as much omega-3 oils as omega-6 oils. Before this new study, scientists had predicted that cases of blindness would rise from the current 36 million to 115 million by 2050, if treatment is not improved by better funding. Part of the reasons behind this trend is the growing ageing population, occasioned by healthy living and the impact of modern medicine.

The World Health Organisation (WHO) estimates that some of the highest rates of blindness and vision impairment are in South Asia and sub-Saharan Africa. Analysis of data from 188 countries suggests there are more than 200 million people with moderate to severe vision impairment.

That figure is expected to rise to more than 550 million by 2050, according to the estimate. Globally, chronic eye diseases are the main cause of vision loss. Uncorrected refractive errors and then un-operated cataract are the top two causes of vision impairment.

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