This Nutritive Golden Potato Is the Latest GMO Superfood
A genetically modified tuber with high amounts of vitamins A and E could potentially help to nourish the world — but will it ever make it to market?
Sufferers of malnutrition in the global south could soon find help from an unlikely source: a humble potato, genetically tweaked to provide substantial doses of vitamins A and E, both crucial nutrients for health.
Dubbed the “golden potato,” boosted levels of provitamin A carotenoids — which are found naturally in carrots and sweet potatoes — give the new tuber its yellow-orange flesh, and are converted into vitamin A by digestive enzymes when eaten.
The potato, created in a lab in Italy and studied at Ohio State University, is the most recent staple crop to be genetically transformed into a colorful superfood, joining such creations as antioxidant-rich purple rice and beta-carotene-enhanced golden rice.
But while foods with genetic tweaks to make them more commercially successful by increasing yield or longevity are relatively common — in the US, we have FDA-approved apples that don’t brown, bruise-free potatoes, and insect-resistant soy, among many other examples of genetically modified produce — these vitamin-enriched staples have yet to be grown commercially.
Potatoes are the fourth most popular crop worldwide, after rice, wheat, and corn, according to the US Department of Agriculture. It is a staple food in some Asian, African, and South American countries where vitamin A and vitamin E deficiencies are common.
Vitamin A deficiency (VAD) is the leading cause of preventable blindness in children, and is also key for growth, immunity, organ development, and reproductive health. Vitamin E protects against oxidative stress and inflammation, conditions that are associated with damage to nerves, muscles, vision, and the immune system.
A single serving of the golden potato could provide up to 42 percent of a child’s recommended daily intake of vitamin A and 34 percent of their recommended vitamin E intake, according to a recent study co-led by researchers at Ohio State, the Italian National Agency for New Technologies, Energy, and Sustainable Development (ENEA) in Rome, and the Italian Council for Agricultural Research and Economics.
Women of reproductive age could get 15 percent of their recommended vitamin A and 17 percent of their vitamin E intakes from the same 5.3 ounce serving, the researchers said.
Malnourishment is possible even when people appear to have ample food. This phenomenon is known as “hidden hunger,” as people can be surviving chiefly on crops that supply calories but lack essential nutrients for growth and health.
Mark Failla, a professor emeritus of human nutrition who lead the research at Ohio State, said that this is particularly prevalent in developing countries, where staple food crops have often been bred for high yield and pest resistance instead of nutritional quality.
“More than 800,000 people depend on the potato as their main source of energy and many of these individuals are not consuming adequate amounts of these vital nutrients,” said Failla in a statement.
The potato was genetically engineered in Italy using a technique called biofortification.
“Carotenoid biofortification has proven itself with ‘golden’ rice and maize,” said Giovanni Giuliano, coordinator of the studies from ENEA. “Potato was the third crop to join this group.”
Giuliano noted that the level of technology necessary for enrichment is dependent on the crop. Maize and cassava can be enriched with beta-carotene using traditional breeding techniques, where parents with the desired trait are crossed over several generations — a bit like breeding labradors to retrieve, or border collies to herd.
But with crops where beta-carotene is not naturally occurring, it has to be transgenically inserted. Traditional breeding can then pass the trait down the genetic line.
Once the potato had been genetically manipulated, researchers in Failla’s Ohio lab created a simulated digestive system — complete with virtual mouth, stomach, and small intestine — to determine how much provitamin A and vitamin E could potentially be absorbed by someone who eats a golden potato.
“We ground up boiled golden potato and mimicked the conditions of these digestive organs to determine how much of these fat-soluble nutrients became biologically available,” Failla explained.
The group began the work focused on provitamin A availability, so their discovery that the potato also supplied a 10-fold dose of vitamin E was an unanticipated and pleasant surprise.
“Universities and other research labs regularly put out press releases saying they have developed a GM crop that will help feed people.”
The potato will join a growing stable of other genetically modified staple crops. Just this July, biotechnologists at the Queensland University of Technology announced that they had created a vitamin A-enhanced “golden banana.”
But while researchers are keen to tout such crops as potentially transformational, the reality is that these foods are slow to have an impact. Golden rice was heralded with splashy headlines declaring its potential to save millions of lives when it was unveiled in 1999. But 18 years later, it still has yet to be marketed commercially.
One problem is that genetic engineers don’t always have control over where exactly the beta-carotene enhancing transgenes land in the target organism’s DNA, said Glenn Davis Stone, a professor of anthropology and environmental studies at Washington University and a longtime observer of golden rice.
It was only earlier this year that the International Rice Research Institution in the Philippines — the world’s top rice research institution and the center of the effort to commercialize golden rice — felt able to submit the enhanced grain for regulatory approval.
Before that, Stone noted, its yields were significantly lower than the same rice without the “golden” trait, “probably because the trait had been inserted into a gene that controlled root development.”
IRRI anticipates that the first high-yield varieties of golden rice will be available toward the end of the decade.
As for the chances of the golden potato and other new superfoods making it to market, Stone is skeptical.
“Universities and other research labs regularly put out press releases saying they have developed a GM crop that will help feed people,” he told Seeker. “Lycopene-enhanced tomatoes, sorghum with more digestible protein, iron-enhanced cassava, vitamin-E-enriched canola, and so on.”
“The biotech industry has shown no interest in commercializing these crops,” he added. “These potatoes will never be commercialized.”
Another challenge to crops like the golden potato is the fact that vitamin A is fat soluble, meaning we can only absorb it if it comes with enough dietary fat. As VAD often affects people with a generally poor diet, this is by no means assured.
In one heavily cited human trial of golden rice from 2012, the participating children were eating the rice as part of a balanced meal in which 20 percent of the calories were from fat. As Stone suggested in a 2015 blog post, this demonstrates only that golden rice successfully imparts vitamin A to children who don’t need it.
He pointed out that over the past decade or so, the Philippines has succeeded in slashing its VAD rate without using golden rice.
“For some reason, the GMO supporters who claim to be deeply concerned about VAD have not celebrated this,” Stone said.
WATCH: Solving Hunger Is Just a Matter of Logistics