In 2010, a strange meme spread across Facebook. People’s feeds were suddenly filled with one-word statuses saying the name of a color, nothing more. And most of these posts were from women.

The women had received messages from their Facebook friends that were some variation on this, according to The Washington Post: "Some fun is going on ... just write the color of your bra in your status. Just the color, nothing else. It will be neat to see if this will spread the wings of breast cancer awareness. It will be fun to see how long it takes before people wonder why all the girls have a color in their status. Haha."

Oh, okay. It was for breast cancer awareness. Except, no, wait—how? The Susan G. Komen Foundation had nothing to do with it, though it did get them some Facebook fans, according to the Post story. It wasn’t clear at all who started it. There was no fundraising component to the campaign. And the posts weren’t informative at all. In fact, their whole point was to be mysterious. Maybe people asked their friends what they meant by just posting “beige” or “green lace” and then they had a meaningful conversation about breast-cancer screenings and risk factors, but I’d guess that happened rarely, if at all.

This incident is just one example of the nebulous phenomenon of “raising awareness” for diseases. Days, weeks, months are dedicated to the awareness of different health conditions, often without a clear definition of what “awareness” means, or what, exactly, is supposed to come of it.

According to a commentary published this month in the American Journal of Public Health, the United States has almost 200 official “health awareness days.” (The U.S. Department of Health and Human Services lists all national health observances on its website.) And that’s not counting all the unofficial ones, sponsored by organizations.

The paper was an attempt to begin to investigate whether awareness days actually improve people’s health. Jonathan Purtle, an assistant professor at Drexel University’s School of Public Health, teamed up with Leah Roman, a public-health consultant, to see whether awareness could even be quantified.

“We both kind of anecdotally observed that there seem to be more [awareness days] than ever,” Purtle says. “In public health, and in medicine, we’re putting more and more emphasis on evidence-based practices. Everything should be informed by science in some way. We asked ourselves, has anybody ever evaluated these things, do we know if they’re effective at all?”

The answer: Not many people have, and we really don’t.

Awareness days do seem to be on the rise, by at least a couple measures—the researchers found that more than 145 bills including the words “awareness day” have been introduced in U.S. Congress since 2005, a huge leap compared with previous years. Articles that reference "awareness day"  in the PubMed database have followed a similar, but less extreme, upward trajectory.

Trends in Attention to Awareness Days in U.S. Congress and Health Science Literature

American Journal of Public Health

But most of the articles Purtle and Roman found in their search (which was just preliminary, not a systematic metareview) were editorials or commentaries announcing or discussing awareness days. Only five studies empirically evaluated the effects of an awareness day, “but the designs weren’t that rigorous,” Purtle says. The best one, according to Purtle, found that on “No Smoking Day” in the U.K., five times more people called a quit smoking hotline than the daily average. “But that was about it,” Purtle says.

So evidence really is lacking on what good these awareness days do.

Liz Feld, president of the nonprofit advocacy organization Autism Speaks, says she has seen results from World Autism Awareness Day, which was April 2, and Autism Awareness Month, which goes on for all of April. The organization has raised more than $10 million so far in April, more than 50,000 people registered on Autism Speaks’ website, and more than 18,000 buildings around the world illuminated with blue lights on April 2 as part of the “Light it Up Blue” campaign. A spokesperson also told me that “Light it Up Blue” was a trending topic on Facebook and Twitter on April 2.

The money is something concrete that came out of the awareness month, but what about the rest?

“One-third of people who live with autism are nonverbal,” Feld says. “The power of a global blue-light movement is very strong. On that day, that is the collective voice of the autism community. That’s a show of power. The blue lights are really a voice.”

Here, "awareness" seems to mean sending a message, getting attention, and getting people to talk about the issue, at the very least on social media. During the week of the most recent World AIDS Day, December 1, 2014, got the most engagement and new followers of the entire year, Miguel Gomez, the director of, told me in an email. Perhaps not coincidentally, the organization’s HIV Testing and Care Service Locator got nearly triple its average traffic on December 1.

Social-media activism gets a lot of criticism, some of it deserved, some of it less so. (There's even a somewhat pejorative term for it: slacktivism.) On one hand, it’s an easy way to reach a lot of people, and it often amplifies the voices of the marginalized. On the other hand, changing your profile picture for an awareness day (something Autism Speaks asked people to do for Light It Up Blue) might just be the smallest possible unit of support for a cause. If not backed up by money or deed, it’s little more than lip service. But lip service is not nothing—if enough people do it, it could help shift cultural norms, as Melanie Tannenbaum wrote in Scientific American, about people supporting marriage equality by making equals signs their profile pictures.

“Based on everything that we know about our brains and their bafflingly strong desires to fit in with the crowd, the best way to convince people that they should care about an issue and get involved in its advocacy isn’t to tell people what they should do—it’s to tell them what other people actually do,” Tannenbaum writes. “And you know what will accomplish that? That’s right. Everyone on Facebook making their opinions on the issue immediately, graphically, demonstrably obvious.”

With a controversial issue like marriage equality, enough equals signs on Facebook pages could send the message that this is a common cause to support, and just maybe, gather more support, in a snowball-rolling-down-a-hill sort of way. The thing is, though, that with diseases, everybody’s pretty much already on the same side. There aren’t pro-cancer people who need convincing to come around.

“The question I would ask Autism Speaks or someone who's doing some sort of initiative like ‘Make your picture blue,’ is how they think that will trickle down into some sort of positive outcome for people with autism,” Purtle says.

So I asked.

“First of all, anyone who takes the time to change their picture, they feel invested, like they’re part of something,” Feld says. “That’s the culture we live in now. It’s a way for them to participate. It creates a sense of a community, it really goes back to that. People like to be part of something, look at the ALS ice-bucket challenge. They wanted to be part of something that was bigger than themselves. It’s free, it makes you happy, it makes you feel like you're doing something.”

But Feld recognizes that this isn’t enough.

“You’ve got to follow it up with something else,” she says. “What comes with raising awareness is a responsibility to do something about what you’re aware of. I always say to people, ‘April 2nd is great but what happens April 3rd?’”

The statue of Christ the Redeemer is lit up in blue for the "Light It Up Blue" campaign to mark the World Autism Awareness Day in Rio de Janeiro April 1, 2015. (Pilar Olivares/Reuters)

When so much is vying for people’s attention, especially online, including the couple hundred other awareness days, even if you get people to listen, how do you get them to do more than just post a status?

There is a sociological theory called narcotizing dysfunction, which proposes that the more people learn about an issue from the media, the less likely they are to do something about it. Purtle and Roman posit that this might be an unintended effect of awareness days, that people might “conflate being knowledgeable about a health issue with taking action to address it.” It’s not enough to just say “this is a problem, and we need to do something about it.” There are a lot of problems in the world that need doing something about.

So in addition to awareness-raising, to try to get people to do something, Autism Speaks fundraises and asks people to sign petitions. “[When we try] to get corporate sponsors, I always tell people here, you can’t just go pitch this as a moral imperative,” Feld says. “There are a lot of moral imperatives. An effective awareness day has got to give people a window into what a real person who's living with autism is going through. My goal is for people to see the face of someone with autism on Autism Awareness Day, so that they carry that with them on April 3rd, April 4th, April 5th.”

Awareness days wouldn’t be so popular if there weren’t an appetite to address health problems. “People want to do something, which is good,” Purtle says. What he worries is that awareness campaigns’ focus on the individual—what you need to know, what you can do—could reinforce existing troublesome ideas about the origins of health, especially with conditions like obesity and heart disease, where lifestyle is a big risk factor.

A lot of people believe, he says, that “it’s really people’s choices that determine their health outcomes and if they’re unhealthy it's either: 1. They made bad choices, or 2. They’re just unlucky and have some genetic thing. These awareness [days] seem to be reinforcing that if you’re aware of the health issue, it’s a good step, and it might be even sufficient to address the health issue. That really flies in the face of the complexity of the various forces that influence a person’s health and a population’s health.”

Those forces include environmental, societal, and economic factors—things that can’t be fixed with knowledge alone. “I think if more people understood that, perhaps we’d see awareness days looking a little bit different,” Purtle says. A better awareness day, he thinks, would spread information about the prevalence of a condition and its risk factors, as well as policy changes that could lessen disparities or help people living with the condition.

“Neither Leah nor I think awareness days are necessarily a bad thing, nor is awareness a bad thing,” Purtle says. “Awareness can be a first step toward changing behavior, but in my opinion, more importantly it would be a first step to positively address the policies that impact a population's health.”