Could a diet supplement supercharge your eyesight?


(Thinkstock)
(Thinkstock)
Researchers are claiming that taking supplements of a pigment found in food like spinach and eggs could sharpen vision. Douglas Heingartner looks at the evidence.
Eyesight is an easy thing to take for granted, but our ability to see is one of the human body’s most incredible senses. And there’s a lot more to it than simply discerning objects in the distance. Our eyes are capable of dealing with huge variations in contrast, for example.

One of the things that maintains healthy eyesight are pigments called macular carotenoids – like those that help make carrots orange or help create the colour in purple broccoli. These carotenoids, which can turn into a form of vitamin A, are thought to shield the retina from the damage caused by too much exposure to blue light, particularly the light emitted by the Sun.
In the past few years, researchers have found evidence that taking dietary supplements of these pigments could help to reduce glare and improve many other aspects of visual performance: sharper colours, enhanced contrast, faster recovery time, quicker visual processing speeds, and even the ability to see further.
This does not mean these supplements can replace eyeglasses in all people with refractive errors, such as near-sightedness. But could taking a daily pill really help improve our vision?
(Thinkstock)
(Thinkstock)
More than 600 carotenoids exist in nature, and they produce the many colours we see in fruits and vegetables. We cannot create them ourselves, so we metabolise them from our diet.
Carotenoid supplements have long been successfully used to treat a form of vision loss known as age-related macular degeneration (AMD) – it damages the macular region at the back of the retina and is currently the leading cause of blindness in the developed world.
Yet in the past few years, researchers have stepped up their investigations into whether these supplements might be able to improve vision in people who already have good eyesight.
Boosting vision
A 2013 study of 150 healthy people showed that higher levels of macular pigment in the eye lessened the effects of glare, and led to quicker recovery time after exposure to bright light. Another study involving 120 healthy drivers showed that supplementation with macular carotenoids improved contrast and glare sensitivity, and lutein supplements – a type of carotenoid found in the eye – have also been found to lead to better contrast sensitivity in healthy people who spend long hours in front of a computer.
(Waterford Institute of Technology)
Carotenoid supplements might dramatically improve night vision and reduce glare dazzle, as this simulation shows (Waterford Institute of Technology)
“We can get about 15-20% improved visual function in the healthy eye, which is remarkable really,” says John Nolan, a professor at the Waterford Institute of Technology in Ireland who is running an ongoing study exploring vision enhancement with these supplements. Improvements of about 30% can be achieved in patients with macular degeneration, he says. It takes about six to 12 months for the supplements to take their full effect.
Intriguing connections
Nolan refers to these carotenoids as “sunscreen for the eye” because they form a dense yellow filter in the centre of the retina, which shields it from blue light.
“It's not complicated,” says Nolan, who has published more than 60 papers on macular carotenoids. “We have a pigment in the eye. It's yellow, we get it from nutrients, and you can change it, you can increase it. And we know that by increasing it, you filter more of the blue light, and you get better visual performance.”
He argues carotenoid supplements could be particularly helpful as we get older. “We are all living longer, and we certainly do not consume enough of these particular nutrients. I believe that we're all walking around with sub-optimal visual performance,” he says.
(Thinkstock
Carotenoids are responsible for the rich colours of egg yolks (Thinkstock)
If this is the case, could you see effects by simply changing your diet? You can get carotenoids without supplements; vegetables, corn, oranges, and eggs also contain them. But about 20 mg of carotenoids daily are needed to achieve the visual benefits described above, claim the researchers, which can be difficult to pull off even in a health-conscious diet.
“As far as vision goes,” says Billy Hammond of the University of Georgia, “we’re all sort of in a deficient state. We have very low levels of these things within our eye that we once had very high levels of. It is actually pretty challenging these days to have a healthy diet, so supplements likely do have a role to play.”
Other researchers have been experimenting with carotenoid-enhanced eggs instead. The pigment is more “bioavailable” to humans in this form – that is, it’s easier for us to absorb – and also more palatable to consumers who don’t want to take more pills.
Brain improvements
There is also some evidence linking carotenoids with other processes in the body: in motor skills, hearing, immune responses, and cognition.
Nolan published a paper in July indicating that Alzheimer’s patients are highly deficient in their levels of macular pigment, in addition to having worse vision. And a 2013 study by Hammond found that higher macular pigment levels are associated with faster processing speed and better balance (measured by how long you can stand on one foot with both eyes closed).
While these associations do not necessarily mean that supplements can help, a few studies have suggested possible cognitive benefits from taking the pigment. A study Hammond co-authored in September found that macular carotenoid supplements lead to improvements in the brain’s visual processing speed in young people. And other recent research has shown that lutein supplementation leads to improved cognitive skills in older people.
Macular pigment “affects biology profoundly, not just in terms of preventing dementia and macular denegation, but also in how the brain functions overall,” claims Hammond. It’s worth pointing out, however, that most of the studies so far have identified only correlations between the pigments and brain function – the mechanism is not yet clear.
So, while it may be early to say that we should all embrace carotenoid supplements, the accumulating body of research about their benefits suggests that our diet may influence the health of eyes and brain more than we once thought.
bbc.

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Perhaps the most notable was King Hussein of Jordan. Continue reading the main story Find out more Matthew Teller presents Sandhurst and the Sheikhs, a Whistledown production for BBC Radio 4, on Wednesday 27 August 2014 at 11:00 BST It will be available on iPlayer shortly after broadcast Four reigning Arab monarchs are graduates of Sandhurst and its affiliated colleges - King Abdullah of Jordan, King Hamad of Bahrain, Sheikh Tamim, Emir of Qatar, and Sultan Qaboos of Oman. Past monarchs include Sheikh Saad, Emir of Kuwait, and Sheikh Hamad, Emir of Qatar. Sandhurst's links have continued from the time when Britain was the major colonial power in the Gulf. "One thing the British were excellent at was consolidating their rule through spectacle," says Habiba Hamid, former foreign policy strategist to the rulers of Dubai and Abu Dhabi. "Pomp, ceremony, displays of military might, shock and awe - they all originate from the British military relationship." Sheikh Hamad Bin Isa Al Khalifa, King Abdullah, Sultan Qaboos Sandhurst alumni: King Hamad of Bahrain, King Abdullah of Jordan and Sultan Qaboos of Oman It's a place where future leaders get to know each other, says Michael Stephens, deputy director of the Royal United Services Institute, Qatar. And Sandhurst gives the UK influence in the Gulf. "The [UK] gets the kind of attention from Gulf policy elites that countries of our size, like France and others, don't get. It gives us the ability to punch above our weight. "You have people who've spent time in Britain, they have… connections to their mates, their teachers. Familiarity in politics is very beneficial in the Gulf context." "For British people who are drifting around the world, as I did as a soldier," says Brigadier Peter Sincock, former defence attache to Saudi Arabia, "you find people who were at Sandhurst and you have an immediate rapport. I think that's very helpful, for example, in the field of military sales." The Emir of Dubai Mohammad bin Rashid Al Maktoum with his son after his Passing Out Parade at Sandhurst in 2006 Sheikh Mohammad bin Rashid Al Maktoum, Emir of Dubai, with his son in uniform at Sandhurst in 2006 Her Majesty The Queen's Representative His Highness Sheikh Hamad bin Khalifa Al-Thani, The Emir of Qatar inspects soldiers during the 144th Sovereign's Parade held at The Royal Military Academy Sandhurst on April 8, 2004 in Camberley, England. Some 470 Officer cadets took part of which 219 were commissioned into the British Army Hamad bin Khalifa Al-Thani, the Emir of Qatar until 2013, inspects soldiers at Sandhurst in 2004 Emotion doesn't always deliver. In 2013, despite the personal intervention of David Cameron, the UAE decided against buying the UK's Typhoon fighter jets. But elsewhere fellow feeling is paying dividends. "The Gulf monarchies have become important sources of capital," says Jane Kinninmont, deputy head of the Middle East/North Africa programme at the foreign affairs think tank Chatham House. "So you see the tallest building in London being financed by the Qataris, you see UK infrastructure and oilfield development being financed by the UAE. There's a desire - it can even seem like a desperation - to keep them onside for trade reasons." British policy in the Gulf is primarily "mercantile", says Dr Kristian Coates Ulrichsen, of the Baker Institute in Houston, Texas. Concerns over human rights and reform are secondary. The Shard at dusk The Shard was funded by Qatari investors In 2012 Sandhurst accepted a £15m donation from the UAE for a new accommodation block, named the Zayed Building after that country's founding ruler. In March 2013, Sandhurst's Mons Hall - a sports centre - was reopened as the King Hamad Hall, following a £3m donation from the monarch of Bahrain, who was educated at one of Sandhurst's affiliated colleges. The renaming proved controversial, partly because of the perceived slight towards the 1,600 British casualties at the Battle of Mons in August 1914 - and partly because of how Hamad and his government have dealt with political protest in Bahrain over the last three years. A critic might note that the third term of Sandhurst's Officer Commissioning Course covers counter-insurgency techniques and ways to manage public disorder. Since tension between Bahrain's majority Shia population and minority Sunni ruling elite boiled over in 2011, more than 80 civilians have died at the hands of the security forces, according to opposition estimates, though the government disputes the figures. Thirteen police officers have also lost their lives in the clashes. 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Over the years donations like this have saved the UK taxpayer a considerable amount of money." But what happens when Sandhurst's friends become enemies? In 2001, then-prime minister Tony Blair visited Damascus, marking a warming of relations between the UK and Syria. Shortly after, in 2003, Sandhurst was training officers from the Syrian armed forces. Now, of course, Syria is an international pariah. Journalist Michael Cockerell has written about Libyan dictator Colonel Gaddafi's time at the Army School of Education in Beaconsfield in 1966: "Three years [later], Gaddafi followed a tradition of foreign officers trained by the British Army. He made use of his newfound knowledge to seize political power in his own country." Ahmed Ali Sandhurst-trained Ahmed Ali was a key player in the Egyptian military's removal of Islamist President Mohammed Morsi That tradition persists. In the 1990s Egyptian colonel Ahmed Ali attended Sandhurst. In 2013 he was one of the key figures in the Egyptian military's removal of Islamist President Mohammed Morsi, now rewarded by a post in President Sisi's inner circle of advisers. In the late 1990s there were moves by the British government under Tony Blair to end Sandhurst's training of overseas cadets. Major-General Arthur Denaro, Middle East adviser to the defence secretary and commandant at Sandhurst in the late 1990s, describes the idea as part of the "ethical foreign policy" advocated by the late Robin Cook, then-foreign secretary. Tony Blair and Robin Cook Tony Blair and Robin Cook at one point planned to end Sandhurst's training of overseas cadets The funeral of King Hussein in 1999 appears to have scuppered the plan. "Coming to that funeral were the heads of state of almost every country in the world - and our prime minister was there, Tony Blair," says Major-General Denaro. "He happened to see me talking to heads of state - the Sultan of Brunei, the Sultan of Oman, the Bahrainis, the Saudis - and he said 'How do you know all these guys?' The answer was because they went to Sandhurst." Today, Sandhurst has reportedly trained more officer cadets from the UAE than from any other country bar the UK. The May 2014 intake included 72 overseas cadets, around 40% of whom were from the Middle East. "In the future," says Maryam al-Khawaja, acting president of the Bahrain Centre for Human Rights, "people will look back at how much Britain messed up in the [Middle East] because they wanted to sell more Typhoon jets to Bahrain, rather than stand behind the values of human rights and democracy." "It's one thing saying we're inculcating benign values, but that's not happening," says Habiba Hamid. Sandhurst is "a relic of the colonial past. They're not [teaching] the civic values we ought to find in democratically elected leaders." line Who else went to Sandhurst? Princes William and Harry, Winston Churchill, Ian Fleming, Katie Hopkins, Antony Beevor, James Blunt, Josh Lewsey, Devon Harris (From left to right) Princes William and Harry Sir Winston Churchill Ian Fleming, creator of James Bond (but did not complete training) Katie Hopkins, reality TV star Antony Beevor, historian James Blunt, singer-songwriter Josh Lewsey, World Cup-winning England rugby player Devon Harris, member of Jamaica's first bobsleigh team line Sandhurst says that "building international relations through military exchanges and education is a key pillar of the UK's international engagement strategy". Sandhurst may be marvellous for the UK, a country where the army is subservient to government, but it is also delivering militarily-trained officers to Middle Eastern monarchies where, often, armies seem to exist to defend not the nation but the ruling family.

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