Could a video game help eradicate a cancer-causing poison? A newly launched project is giving ordinary gamers the chance to solve a biological puzzle, potentially leading to new ways of making our food supply safer.
Aflatoxins, the carcinogenic products of molds that grow on agricultural crops like corn and peanuts, are a scourge in the developing world. Eating aflatoxin-contaminated crops can cause acute poisoning and death. But low-level exposure over a long period of time can cause immune system problems, stunt children’s growth, and be a major risk factor for liver cancer. While high-income countries like the United States screen crops for the presence of aflatoxins, some 4.5 billion people, largely in lower income countries, are still at risk.
Though the problem has been recognized for more than 50 years, researchers have yet to find a comprehensive solution. Now, a project, sponsored by the Mars, Incorporated candy company in conjunction with several nonprofits and universities, aims to move research forward by finding an enzyme that can degrade aflatoxins. They hope to do this by tapping humans’ natural love of games and problem-solving.
The team has uploaded a series of aflatoxin puzzles on Foldit, a gaming platform that has users experiment with folding different protein structures. Folding proteins into proper three-dimensional structures with potential real-life uses requires spatial reasoning and pattern matching skills, which makes the process ripe for gamification—Foldit’s cofounder once described it as “like Tetris on steroids.”
Foldit users have been given a potentially aflatoxin-degrading enzyme to begin with, and are tasked with improving the enzyme to best neutralize the toxin. The best five or ten solutions will go on to be synthesized and then tested at the University of California, Davis. All information will remain in the public domain. The team hopes that tapping the potential of non-experts will help them gather unexpected solutions, thinking outside the box in the way computers still can't.
"In essence, the video game is looking to capture human imagination of 'what could be' for the protein structure," says Justin Siegel, a chemist at UC Davis involved in the project. "It provides real-time feedback on the likelihood that the structure as envisioned by the player would be physically possible."
Foldit, developed by computer scientists at the University of Washington and Northeastern University, has been used successfully in health research before. In 2011, it took Foldit users three weeks to discover the structure of an enzyme that helps the AIDS virus reproduce, paving the way for potential new treatments. It was a problem that had been perplexing scientists for a decade.
Aflatoxin has been with humans for thousands of years, but it wasn’t identified until 1960, when thousands of turkeys on English poultry farms began to sicken and die without obvious cause. Scientists called the problem “Turkey X disease,” and eventually linked it to peanut meal imported from Brazil. The feed was found to be contaminated with a type of mold called Aspergillus flavus, whose poisonous metabolites came to be known as aflatoxins.
Research eventually discovered that two molds, Aspergillus flavus and Aspergillus parasiticus, were mainly responsible for aflatoxin production. These molds flourish in warm and humid conditions, and can contaminate crops in the field, during harvest, and in storage. They grow on a number of staple crops, including corn, peanuts, millet, wheat, cottonseed and tree nuts. They can also contaminate milk and other dairy products if animals eat moldy feed.
Many countries, including the U.S. and the nations of the EU, have strict standards for the maximum amount of aflatoxins allowed in food and animal feed. But many developing world countries have lesser standards or none at all, or have a difficult time regulating the standards they do have. Residents eating locally grown contaminated foods suffer both immediate effects—a 2004 outbreak of aflatoxicosis (acute aflatoxin poisoning) killed 125 people in rural Kenya—and long-term consequences—people exposed to aflatoxins who also have Hepatitis B (which is very common in the developing world) have a risk of liver cancer some 30 times higher than normal.
“When you think about it, the word ‘plague’ comes to mind,” says Howard Shapiro, the Chief Agricultural Officer of Mars, Incorporated.
Aflatoxin is also an economic burden. Since developed countries won’t accept contaminated food, farmers lose millions of dollars in income from rejected shipments and lowered crop values. Peanut export, once thriving in many African countries, has dropped sharply since the 1970s over aflatoxin fears.
The problem can be partially managed with proper harvest and storing techniques, though these are sometimes out of reach of small farmers. Current research on aflatoxin control looks at breeding resistant plants, using non-toxic varieties of mold to compete with the toxic ones, and aflatoxin-killing chemical treatments. But nothing has yet provided anything like a full solution.
Mars, Incorporated, which goes through tons of peanuts, corn and other staples every year in candies such as M&Ms and Snickers, has long been concerned with aflatoxin issues. At one point, Shapiro says, some 70 percent of shipments from a particular supply chain were being rejected because of contamination. Shapiro and his team have been working on breeding aflatoxin-resistant crops, a project he hopes will see results in five to eight years. He hopes the FoldIt project will bear fruit sooner. The enzymes discovered by Foldit users could help lead to new compounds to control aflatoxin at various points in the growing and storage process, potentially working in synergy with resistant plants further down the road.
“I feel like this could be a big breakthrough,” Shapiro says. “If we get lucky, this is not just for Mars. This is a global effort.”