Since Watson and Crick first revealed the double helix of our genetic code in 1953, scientists have gained the ability to give just about every living thing a genetic makeover. Unsurprisingly, given their humanitarian and economic importance, many of these alterations have been to crop plants.
Many are being re-engineered to resist disease, drought and pests. Scientists are hoping to improve food security through greater yields and less waste, particularly in the face of climate change, but other researchers plan to tackle food security at its less obvious root: malnutrition.
When it comes to meeting global food security demands, it turns out that one way to use resources better is by producing more nutritious crops.
"We've relied on supplements for a long time to fight malnutrition," said James Dale, director of the Centre for Tropical Crops and Biocommodities at Queensland University of Technology in Australia. "But history shows that there is always a resistant part of [the] population that supplements can't get to."
Dr. Erick Boy, nutrition head of HarvestPlus, a challenge program run by the Consultative Group on International Agricultural Research, said that often, supplements are added to processed foods or sold as capsules, which isn't realistic for targeted populations.
One solution to this problem, he said, may lie in the genetic alteration of many staple crops by way of bio-fortification, a process that physically changes the nutritional content of plants.
"Nature can do this; so can conventional methods like selective breeding," Boy said. "But when nature doesn't give, we can manipulate crops with things like fertilizers or use transgenic techniques, adding an isolated gene from one organism to another, as Dale did."
In 2005, with the backing of the Bill & Melinda Gates Foundation, Dale began experimenting with ways to add beta-carotene, a nutrient the human body uses to produce vitamin A, to the East African Highland cooking banana, a staple in the Ugandan diet.
"This may finally give us access to this subset of the population," Dale said. "So I figured it was worth a shot."
In June, Dale's bananas made it to an important milestone, gaining approval to begin human trials in the United States, and in the process picked up a catchy new title: super-bananas. While the fate of the super-bananas has yet to be determined, what is known is just how these bananas became super.
"First off, a crop chosen must be eaten by a wide enough segment of people in high enough quantities to make a difference nutritionally," Dale said.
In this sense, choosing which plant to apply this technology to was really a no-brainer, Dale said.
Bananas: the potato of Uganda
Ugandans love bananas. In fact, many receive 30 percent of their daily caloric intake from them, eating three to 11 bananas daily, or roughly 500 to 800 pounds annually. The consumption numbers apply roughly to Ugandan's neighbors, as well, though to a lesser extent.
Hundreds of different varieties of bananas exist in the country, and they are harvested and eaten in a variety of ways, including stewed, roasted and ground into flour for storage or use as a starch base. While brewing forms of the banana are refined into alcohol, cooking bananas account for the bulk of the fruit consumed daily.
"Bananas are to Ugandans what potatoes are to Americans or rice is to East Asian countries," Dale said. "Every culture has a staple starch crop, and in Uganda, that crop is bananas."
Matthew Schnurr, an associate professor of international development studies at Canada's Dalhousie University who has been researching the social aspects of genetically modified crops, said bananas are more than just a food staple in Uganda; they are part of the cultural fabric.
"The Ugandan word for food is actually the same as the word for a traditional meal made of the stewed banana: matooke," he said. Because of this, Schnurr said, physical attributes of the fruit itself are particularly important to Ugandans, so altering the fruit could have social consequences.
"For example, when matooke is prepared properly, it obtains a certain yellow color. If you are a woman who prepares matooke of the incorrect color or texture for your husband, you can be beaten," Schnurr said.
The intricate role bananas play in Ugandan life is also partially to blame for the country's high rates of malnutrition.
An imperfect food
Relying too heavily on any one food will almost inevitably lead to vitamin and mineral deficiencies, meaning the Ugandan reliance on bananas is problematic in terms of nutrition.
"This is certainly not something unique to Uganda, or even developing countries," Boy said. "There's a disconnect with how we view agriculture and how we aim to meet food security and nutrition. In agriculture, we only focus on yields, without consideration for nutrition. This has made diets worldwide increasingly unbalanced."
Vitamin A deficiencies are particularly common in East African countries. "Roughly 15 to 30 percent of the Ugandan population under 5 and women of childbearing age suffer from a deficiency," Dale said. "These are fairly typical statistics for developing countries."
With as few as 600,000 and as many as 2.5 million child deaths worldwide, and another 300,000 cases of blindness, annually attributed to a lack of the vitamin, finding ways to insert the vitamin into staple foods has become popular.
But when it comes to vitamin A, this isn't an easy process. High levels actually become toxic to the body, and as there is no way to control how much people consume, there is really no safe way to add vitamin A directly to foodstuffs.
Instead, Dale decided to look for a gene carrying high levels of provitamin A, or beta-carotene, which the liver converts into the vitamin on a need-only basis.
While the fruit boasts high levels of potassium and a fair deal of protein, it is imperfect, like all foods, Dale said. Bananas, however, are particularly imperfect when it comes to genetics, because of human intervention.
Searching for a super gene
Unlike humans, who are diploid, meaning we have two sets of each of our chromosomes except for our sex chromosomes, bananas are triploid. Having three sets of each chromosome instead of two makes the plant sterile, but also edible.
In the wild, bananas are diploid like humans, but when fertile, they produce fruit chock-full of hard seeds with very little flesh. Over time, the wild types have been selected and bred to be triploid, but this dynamic also has halted the banana's genetic evolution.
Without proper seeds, the fruit must be cloned by grafting, meaning every new banana plant is a clone of its parent. Genes are neither introduced nor removed from the banana population, greatly decreasing the diversity of the plant and making it highly vulnerable to disease.
"We really haven't played around with bananas genes for a very long time," Dale said. "We thought it was high time to."
Looking at the still-remaining wild types, Dale searched for a gene from another banana variety to weave into the East African Highland cooking banana. What he found was that some bananas are actually pretty super in the wild all on their own.
Bananas have naturally occurring levels of beta-carotene, as do many other fruits and vegetables, like carrots. And they aren't hard to pick out in a crowd, as the provitamin bestows a distinctive bright orange color.
Dale ultimately found his gene in Papua New Guinea, where the fruits are "so full of beta-carotene they are literally bright orange, but also unpleasant to eat."
He's quick to point out that though the gene is added to his super-bananas, it's no new gene to the banana family. "This gene we isolated and put in our super-bananas is a banana gene, and it always has been," Dale said. "We simply toned down its influence."
Dale's bananas will have roughly 10 times the vitamin A potential of traditional bananas thanks to beta-carotene additions, but for these new bananas to truly become worthy of their title, they'll first have to be adopted by their target audience. This is where science begins to take the back seat in the story.
Genetically modified foods remain banned for commercial sale
Many issues, ranging from disease to politics, threaten the success of Dale's super-bananas. Persistent strains of wilt that entered the country nearly 15 years ago from Ethiopia continue to devastate the country's banana crops, and despite numerous attempts to produce a resistant version of the banana, efforts have gained little traction so far.
Climate change also hovers over agriculture on the African continent, putting pressure on nutritional needs broadly. According to the Intergovernmental Panel on Climate Change, increasing temperatures and changes in precipitation are very likely to reduce cereal crop productivity in many areas of the continent, and to reduce banana and plantain production potentially in lowland areas of East Africa, for instance.
In Africa, "food availability could be threatened through direct climate impacts on crops and livestock from increased flooding, drought, shifts in the timing and amount of rainfall, and high temperatures, or indirectly through increased soil erosion from more frequent heavy storms or through increased pest and disease pressure on crops and livestock caused by warmer temperatures and other changes in climatic conditions," the IPCC said in a report this year.
In Uganda, there are other pressures. Genetically modified crops have yet to be approved for commercial sale in the country, something Dale and Schnurr describe as a tricky situation.
"Every election, there's a new government, and the bill goes back to the start. We feel we're caught in a loop," Dale pauses, before chuckling. "We need the biosafety and commercial sale bill to release the bananas, but we might need the bananas to be ready for release before the bill is passed."
While testing crops are legal, it's unlikely farmers will be persuaded to convert to the new bananas without a way to physically sell the fruit. "The last I heard about the bill was in November of last year," Schnurr said.
And then there is public acceptance. Schnurr recently conducted hundreds of interviews with smallholder farmers in the country, asking them to rate what kind of improvements they would like to see in staple crops like the East African Highland cooking banana.
"When we asked what trait farmers would like to see most improved about their crops, they consistently selected nearly every other trait before nutrition," he said.
This, Schnurr said, makes him wonder if projects like Dale's are really meeting the target of increasing food security.
But this preference of farmers is a byproduct of the unbalanced relationship between agriculture and nutritional studies, Boy said.
"We can work against this by adding the nutritional benefits to crops bred for higher yield. This way, when a farmer sees their neighbor with fast-growing crops, they'll say, 'Hey, I want some of that.'"
But this logic doesn't always follow, Schnurr said. To see evidence of this is to look no further than the early 2000s, when the fia variety of banana was introduced. It has a massive yield, so researchers were quick to transplant species into East African countries, but the project never took off.
"People just hated it," Schnurr said. "The color, the texture, people rejected it. Now, virtually no one grows or eats fia bananas in the region."
Dale said many, if not all, of these factors have been taken into consideration. Just as they considered how much of the vitamin would be absorbed in the body, Dale's team looked at the cultural impacts of the super trait being added to the bananas.
"Our studies show the color change should be almost negligible and no real texture change," Dale said. "When mashed, or seen in the fields, it should be unrecognizable."
While no one can precisely predict whether Ugandans will welcome the new banana or not, super-banana backers are optimistic.
Dale is currently working with many other projects -- inside and out of the country -- to ultimately weave together a drought-, pest- and disease-resistant, higher-yielding and beta-carotene-rich banana, a super-banana 2.0, so to speak. If this banana combined farmer's yield interests with nutritional needs, it could be worthy of the title, helping save resources and reducing waste.
There is also less contention over the environmental implications of the super-banana, he said. Super-bananas won't be able to mix or spread their genes with wild varieties.
"This really wipes out the worry of genetic pollution many worry about with genetically modified crops," Schnurr said.
Success of the super-banana could open doors to many other genetically modified crops in not only Uganda, but other African countries that follow suit, Dale said.
This could have even larger implications for the genetically modified debate globally, Schnurr said. "It would mean the European Union was the only true region of the world still holding out against these kind of crops," he said.
Improving the health and food security of Ugandans and their neighbors also could reduce the aid needed for food or nutritional supplementation, freeing up national and international funds for other projects, analysts said.
But perhaps the success of super-bananas may not be measured with immediate or individual results.
As Africa is slotted to take on the bulk of the future world population's food demands, Dale's project is certainly not unique in the region, but its fate could influence other initiatives.
"We're also offering this technology for free; anyone is encouraged to take it and use it or build off of it," Dale said. This means the super-banana, unlike seed-bound crops, will never be bound or controlled by middlemen such as seed dealers.
"If we manage to pull this off, as with most technology, the next projects will be easier and cheaper, making bio-fortification an option for many more people and many more crops," said Dale, reflecting.
"This has to have some positive effect on food security and nutrition, not just in Uganda but worldwide," Dale said. "It just has to."
Reporter Christa Marshall contributed.
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