BUENOS AIRES -- Argentine President Cristina Fernández de Kirchner is the latest in a series of Latin American presidents and ex-presidents who've come down with cancer. News of her thyroid cancer diagnosis has set off an unprecedented flurry of speculation about what seems to be a disproportionately high number of regional leaders struck by the illness.

Some are asking: does power cause cancer?

Given the growing the growing list of cancer-stricken leaders, it's tempting to say there may indeed be a link. Besides the recently reelected "Cristina K," the list of presidents who've had run ins with the disease or are currently receiving cancer treatment includes Venezuela's Hugo Chávez; Brazilian President Dilma Rousseff; her predecessor, Luiz Inácio Lula da Silva; and Paraguayan President Fernando Lugo.

Most likely, however, what we're looking at here is more of a statistical illusion. Democracy, when it's well established, generates a high turnover of presidents. The exception to the rule is Chávez, who is keen to stay on indefinitely. Venezuela aside, Latin America welcomes or bids farewell to two or three presidents per year. The more presidents there are, the more likelihood that some current or former heads of state will suffer from cancer.

Another factor to consider is the welcome and powerful advance of diagnosis techniques. With increasing frequency, the sophisticated checkups that leaders, business people and other top-earning professionals receive regularly result in early discovery of the illness. Presidents had cancer in previous eras as well. But in many cases they didn't diagnosis it until it had reached a terminal stage. By then, the leaders were already out of office. In some cases, presidents weren't even aware it was cancer that killed them.

A third factor is that some types of cancer are simply more abundant these days – for different reasons. Think, for example, about all the different industrial food colorings that are finally taken off the market only when their carcinogenic effects had become absolutely irrefutable. Then there's the who-can-stand-it-the-most sport of suntanning, which has led to increased cases of skin cancer.

When micro tumors grow

Yet even with all that in mind, there may actually be something to the idea that the power position influences certain types of cancer, at least in terms of how quickly the disease spreads. This past September, Garth H. Rauscher, an associate professor of epidemiology at the University of Illinois's Chicago School of Public Health, presented research linking stress to tumor aggressiveness among breast cancer patients. More stress made for more aggressive tumors and vice-versa. His research, based on 2,000 cases, shows a clear correlation.

A connection can be drawn here to the work of Dr. William Li, president of the Angiogenesis Foundation. Through his research, Li has found that 40% of all 40 to 50-year-old women who die in car accidents had "micro tumors' – roughly the size of a ballpoint pen tips – in their bodies. He also found that half of 50 to 60-year-old men have such micro tumors in their prostates. And by age 70, almost all people – men and women – have micro tumors… in their thyroids, like Cristina Kirchner.

Why, then, doesn't everyone get sick? According to Li, it's because most of these dwarf tumors don't have enough oxygen and nutrients to grow more. Given this logic, it's possible to speculate that for some people who are under permanent stress, these tumors find a way to grow.

Robert M. Sapolsky, perhaps the world's top expert on the stress/cancer correlation, argued years ago that stress influences how cancer develops in humans. Sapolsky suggested that people who face stress agents such as a deep depression are at higher risk of contracting cancer years later. The logic is that during periods of stress, the body suppresses in many areas activity related to the immune system. In other words, it shuts off its defenses.

One unproven and certainly debatable hypothesis for why our bodies would do such a risky thing is that we mammals don't like to come off as vulnerable or sick in the eyes of our competitors or predators. The normal actions of our immune system – think of how the body reacts to an allergy – do just the opposite. They don't help us look "normal," which is an important thing to seem to be in order to survive in the forest or savanna.

The men and women who hold the highest positions of power in Latin America's presidential system are targets of endless demands and attacks, both by their allies and adversaries. Millions of people and dozens of rivals, some of them outright cruel, are there day in and day out watching and evaluating every sign of strength or weakness. For the region's presidents, in other words, permanent stress is the norm rather than the exception. It's logical, therefore, to assume the immune systems of our leaders would be compromised.

If that really is that case, it is bad news – and it could help explain our historic tendency to have either authoritarian presidents, weak escapist presidents, or leaders that end up sick. The first group, sociopaths incapable of empathizing with anyone, are less stressed than the average person. The second group of leaders, overly conscious of the gravity of affairs, become paralyzed or simply avoid making decisions. And the third, the conscious fighters, the true political acrobats, spar elegantly over and over again, keeping up appearances until they eventually fall ill.

This theory of presidential cancer could be an argument in favor of a parliamentary system: how many sick prime ministers do we tend to see in Europe? Not many. It may be because they know they can leave or return to power at any moment. Either that, or they secretly practice meditation to keep the stress down. The world may never know.

Read the original story in Spanish

Photo - dilmarousseff