What if the best medicine isn't a pill or vaccine — but it's cold cash?
There's a growing body of research that suggests economic programs that give money to very poor people can have major health benefits. Now, a new study — out on Friday in Nature Medicine — proves this approach can work when it comes to the world's deadliest infectious disease: tuberculosis, which killed more than 1.25 million people in 2023.
The study is impressive in its scale. Researchers combined two Brazilian datasets — one from the Ministry of Health and one that tracks social programs for the poorest half of the population — enabling them to zero in on 54 million people in Brazil living in poverty. In this group, 44% of them received cash each month from a government program while 56% did not. The families that received the cash were significantly less likely to contract TB. Among the extremely poor in this category, TB cases and deaths dropped by more than 50% and in the Indigenous population the drop was even more dramatic: more than 60%.
"There are very large benefits — large and underappreciated — of these [types of] programs," says Dr. Aaron Richterman, an assistant professor of infectious diseases and health policy at the University of Pennsylvania who was not involved in the study.
The findings could have far-reaching implications for global efforts to end the TB epidemic. "If we think about what can take us to the next level, it's not the next drug," he says. "It's probably not the vaccine that we're all waiting for. It may be something like this, which I think we have good reason to believe would help potentially end something like a TB epidemic."
Here's a look at how the conditional cash transfer program works, why it's having unintentional – but welcome – health impacts and what the implications are.
Free money with some strings attached
Twenty years ago, Brazil started what was then a revolutionary program. The government would give poor people a regular cash handout with a few strings attached. Today, the program, which is called Bolsa Familia (Portuguese for Family Allowance), helps 21 million families in Brazil or about a quarter of the population.
To be eligible, a family must live below the poverty line. The government gives these households a monthly cash benefit that's the equivalent of at least $120; the amount can increased, based on their neediness and the number of children. For some families, that sum doubles their income.
Recipients can spend the money as they please. But they must meet certain requirements: sending their kids to school and regular check-ups for pregnant women and kids, including prenatal visits and childhood vaccinations.
The program is focused on "the long game," says Seema Jayachandran, a professor of economics and public affairs at Princeton University, who was also not involved in the study.
"The philosophy of conditional cash transfers was to break the cycle of poverty by investing in the younger generation," she says. "And it's through two prongs: One is making sure they get educated, they grow up healthy with access to health care. And then the second is giving the family money so that they can have better food or school uniforms."
There's lots of data to show that programs like Bolsa Familia reduce economic and social inequalities. But lately, she says, studies have been showing an added bonus: "There are some extra benefits that are actually quicker wins."
How money is helping people avoid and fight TB
Tuberculosis is famously a disease of poverty.
People are exposed to the bacteria that causes TB in overcrowded, under ventilated spaces.
This type of scene is, unfortunately, familiar to many in Brazil, says Priscila Scaff, an author of the study and a postdoctoral researcher at the Federal University of Bahia's Institute of Collective Health. In low-income families, she's seen 10 people living in one room. In poor urban areas, she adds, there are sometimes houses "where they don't have access to the sunlight" or fresh air. These are perfect conditions for TB to flourish — the tuberculosis bacteria spreads through the air, traveling on a cough, sneeze, spittle, or even a laugh. The monthly payouts might enable a family to move to larger, better ventilated quarters.
The cash transfer can also lead to a healthier diet — and that can help avoid TB even if someone's exposed to the bacteria. "People who have poor nutrition – it increases the risk very, very substantially for progression to tuberculosis," says Richterman. Again, Scaff says, poor people in Brazil often don't have access to enough food — or nutritious food.
But things get better when a household enrolls in Bolsa Familia. It's one of the program's primary goals: On its website, the government claims to have reduced hunger for millions of families. A series of studies have found that families spend more on food than those who didn't get the payments and that they buy healthier foods.
And, finally, the treatment for TB is intensive — and can lead to a loss of income. "You have to treat it for at least six months. There's a lot of side effects and toxicities related to the medicines," says Richterman. "Even if you have free medicines, you have to take medicines every day, you have to get to the clinic, you have to get transported there. You're sick and you can't work," he says.
He explains that many day laborers — or others living hand-to-mouth — can't afford to take time off work. Unless, of course, they have that extra cushion provided by Bolsa Familia.
"So you can see how cash support — or poverty alleviation, more generally — can work at every single step of the way, from exposure to TB outcomes," Richterman says.
And there may be something else going on too, says Davide Rasella, a study author and head of the health impact assessment and evaluation group at the Barcelona Institute for Global Health or ISGlobal. It's possible, he says, that because the program insists on regular checkups for kids, parents become more connected to the health system.
"Sometimes the [health] outpost is not even so distant, but somehow it is not accessed," he says. "[But with the requirements of the Bolsa Program] the families are in more contact with the health post. They trust more health professionals and they get diagnosed earlier."
But wait! It's not just TB
The magnitude of the drop in TB cases and deaths surprised even the study authors. "We were expecting an effect but not so big," says Rasella.
"What we are discovering – the more we study – is the effects are really strong. It's not just tuberculosis. We have seen it in HIV/AIDS, child mortality, etc.," he says. "We have a study showing an enormous effect on reduction of hospitalization, or millions of hospitalizations that have been avoided in the last two decades because of the [Bolsa Familia] program."
The study results are echoed in other parts of the world. In a study published last year, Richterman and colleagues looked at cash transfers in 37 low- and middle-income countries and found huge benefits for reducing mortality, including a 20% reduction in risk of adult women dying.
He says they found that a program spends about $11,000 for each life that is saved. He calls that "an extraordinarily cost effective intervention just for that" — an stunning result from a program that was never intended to save lives. And protection from fatal illness is not the only payoff from payouts: "These programs do a lot of things. They improve education. They improve women's empowerment. They reduce poverty. They improve food security. They improve child nutrition," he says.
There are now conditional and unconditional cash transfer programs all over the world — including in the U.S. "It's an example of something that has spread from lower-middle income countries to rich countries," says Jayachandran. And these efforts got a big boost during the pandemic when many countries were looking for ways to help households who'd lost income because of lockdowns and the like, especially without requiring in-person meetings.
But these programs are not cheap. Bolsa Familia costs about 14 billion Brazilian reais — or about $2 billion — a month; the money comes from the state as well as groups like the World Bank and the Inter-American Development Bank.
As policymakers debate whether they can afford to start or expand such programs, Rasella says, the message from Brazil is clear: It's not just an economic program. It's also an "impressive" health program.
Copyright 2025 NPR
