Could mutant bananas save a child’s sight?

A genetically modified banana could hold the key to preventing up to half a million African children going blind each year.

A genetically modified version of the world’s most popular fruit could hold the key to preventing up to half a million children going blind each year. Courtesy Food and Drink / REX

It looks like a banana. It tastes like a banana. It even peels like a banana. But a genetically modified version of the world’s most popular fruit could hold the key to preventing up to half a million children going blind each year.

Australian scientists revealed last week that they have successfully modified the genetic make-up of the East African highland banana, boosting its levels of beta-carotene, which the body converts to vitamin A.

For the next six weeks, human guinea pigs in the United States will be eating the bananas to see whether they could help to eradicate one of East Africa’s biggest micronutrient deficiencies.

Professor James Dale, of Queensland University of Technology (QUT), said the human trials were a “significant milestone” that could lead to Ugandan farmers growing the bananas by 2020.

“We know our science will work,” he said.

The project was set up in 2005 with the help of a US$10 million (Dh37m) grant from the Bill and Melinda Gates Foundation, which says one of its goals is to “ensure that all children have the nutrition they need for a healthy start in life”.

The bananas were grown and harvested from the QUT field trial in Innisfail, north Queensland, and have been transported to the US for the human trial.

“We are aiming to increase the level of pro-vitamin A to a minimum level of 20 micrograms per gram dry weight to significantly improve the health status of African banana consumers,” said Prof Dale.

The East African highland banana is a staple food crop in Uganda, Tanzania and most other East African countries, but in its natural form it has relatively low levels of vitamin A and iron. It is known as a cooking banana, usually steamed and mashed and served as a main meal.

According to a 2007 International Food Policy Research Institute paper, per capita consumption of bananas per day in Uganda is 0.7kg. The fruit occupies the greatest portion of “utilised agricultural land” compared with any other important crop.

In neighbouring Tanzania, bananas are the staple food for between 20 and 30 per cent of the population, and in certain regions the proportion of households growing them is as high as 95 per cent, making them of huge economic importance.

The Australian research team hopes to introduce the genetically modified version into the crops within six years.

If successful, Prof Dale said, the technology could be used even farther afield.

“In West Africa farmers grow plantain bananas and the same technology could easily be transferred to that variety as well,” he said. “This project has the potential to have a huge positive impact on staple-food products across much of Africa, and in so doing lift the health and well-being of countless millions of people over generations.”

According to the World Health Organisation (WHO), vitamin-A deficiency is the “leading cause of preventable blindness in children”. It also increases the risk of severe illness and death from a range of common childhood infections, including diarrhoea disease and measles.

It is a particular problem for pregnant women, causing night blindness and increasing the risk of maternal mortality. In high-risk areas, WHO says, vitamin-A deficiency affects pregnant women in their final trimester when “demand by both the unborn child and the mother is highest”.

“WHO’s goal is the worldwide elimination of vitamin-A deficiency and its tragic consequences, including blindness, disease and premature death,” it says.

The East African highland banana – known as Matoke – is a huge part of the diets of adults and children alike, and therefore an obvious choice of foodstuff to boost the population’s vitamin-A levels.

Regular East African highland bananas have a cream-coloured pulp and are curved with blunt tips. The QUT version has a more orange pulp because of the extra carotene, which is converted to vitamin A by the body.

“The flesh of a pro-vitamin-A-enriched banana is orange rather than the cream colour we are used to, and in fact the greater the pro-vitamin-A content the more orange the banana flesh becomes,” said Prof Dale.

The University said that over the next three years an “elite line” of banana plants would be selected and used in multi-location trials in Uganda.

“We made all the constructs, the genes that went into bananas, and put them into bananas here at QUT,” he said. “Hundreds of different permutations went into field trials up north and we tested everything to make sure our science worked here in Queensland. Now the really high-performing genes have been taken to Uganda and have been put into field trials there.”

But as things stand, trading GM crops in the country is not legal. A bill to allow the crops to be commercialised is in the committee stage in the Ugandan parliament.

“With Ugandan government support, legislation and regulations to enable the commercialisation of genetically modified crops should be in place by 2020,” the university said.

Regulations to allow the field trials of the GM crops are already in place and many are hopeful that with a solution to vitamin A deficiency in sight, the remaining necessary legislation will go through before 2020.

Genetically modified foods have been the subject of government debate, public-health talk and research projects for decades.

Different countries and regions have their own rules on GM foods. Hawaii, for example, grows GM papayas that are resistant to the papaya ringspot virus, and they are approved for consumption in the US and Canada but not in Europe.

GM-modified tomatoes, engineered in the 1990s to have a longer shelf-life, were on sale throughout the US and Europe but have disappeared because they did not meet expectations.

In April, scientists in the UK announced the start of a trial to produce a crop of genetically modified plants that would yield omega-3 fatty acids, normally found in fish.

The camelina plants, which naturally produce oils, have been engineered in a laboratory but are starting tests at Rothamsted Research Centre in the south-east of England to see how they grow outdoors. The main aims of the project are to help the fish-farming industry and take the pressure off wild-fish populations.

Fish farms use omega-3 fatty acids as a food supplement for their stocks. Fish in the wild naturally produce these oils by eating algae but since fish farms cannot use algae as a feed they substitute it with fish oil, which in turn comes from fish caught in the wild.

If the GM camelina plants thrive out of the laboratory, the oil they produce means that fewer wild fish would need to be caught simply to be used as fish food, making fish farms more ecologically sustainable.

In addition, omega-3 fatty acids have been identified as an important part of the human diet, since they offer protection against coronary heart disease.

Genetically modified camelina plants were sowed last month but they will not be harvested until August or September when they flower and produce seeds.

UK-government controls mean that while some of the seeds will be used for further tests, the rest of the harvest must be destroyed until the authorities are sure it is safe.

Like the East African highland banana, it might be years before these new GM foods and plants are safe and available to everyone.