A Disquieting Possibility

Could climate change be making us fat? Politico has published an article from a series on the future of health that suggests the answer may be yes.

The article began by describing a 1998 experiment in which scientists made algae grow faster in order to provide more food for zooplankton. They increased the algae by shining more light onto them, and gave the  zooplankton more to eat. But rather than flourishing, as expected, they began struggling just to survive.

The increased light was making the algae grow faster, but they ended up containing fewer of the nutrients the zooplankton needed to thrive. By speeding up their growth, the researchers had essentially turned the algae into junk food. The zooplankton had plenty to eat, but their food was less nutritious, and so they were starving.

A mathematician and biologist named Loladze was intrigued–and spent the next 17 years exploring the obvious question:

Could the same problem affect grass and cows? What about rice and people? “It was kind of a watershed moment for me when I started thinking about human nutrition,” he said.

In the outside world, the problem isn’t that plants are suddenly getting more light: It’s that for years, they’ve been getting more carbon dioxide. Plants rely on both light and carbon dioxide to grow. If shining more light results in faster-growing, less nutritious algae—junk-food algae whose ratio of sugar to nutrients was out of whack—then it seemed logical to assume that ramping up carbon dioxide might do the same. And it could also be playing out in plants all over the planet. What might that mean for the plants that people eat?

What Loladze found is that scientists simply didn’t know. It was already well documented that CO2levels were rising in the atmosphere, but he was astonished at how little research had been done on how it affected the quality of the plants we eat. For the next 17 years, as he pursued his math career, Loladze scoured the scientific literature for any studies and data he could find. The results, as he collected them, all seemed to point in the same direction: The junk-food effect he had learned about in that Arizona lab also appeared to be occurring in fields and forests around the world. “Every leaf and every grass blade on earth makes more and more sugars as CO2 levels keep rising,” Loladze said. “We are witnessing the greatest injection of carbohydrates into the biosphere in human history―[an] injection that dilutes other nutrients in our food supply.”

Evidently, agricultural researchers have known for some time that many foods have been getting less nutritious. The mineral, vitamin and protein content of fruits and vegetables has dropped steadily over the past 50 years. Researchers had attributed the drop to the fact that farmers have been breeding crops for higher yields, rather than nutrition–that the “significant” decline in everything from protein to calcium, iron and vitamin C could mostly be explained by the varieties farmers were choosing to grow.

More recent research suggests otherwise.

Across nearly 130 varieties of plants and more than 15,000 samples collected from experiments over the past three decades, the overall concentration of minerals like calcium, magnesium, potassium, zinc and iron had dropped by 8 percent on average. The ratio of carbohydrates to minerals was going up. The plants, like the algae, were becoming junk food.

Even climate change deniers concede that CO2 levels have risen. Plants require CO2, so the assumption has been that these higher levels were actually good for agriculture. The emerging research suggest that at certain levels, CO2 depletes the nutritional value of the crops–which contributes to the obesity epidemic, among other things.

The Politico article is lengthy, but it’s well worth reading. And pondering.

Comments

The Carrot and the Stick

In yesterday’s blog, I suggested that–despite efforts to wage class warfare over the demise of the Twinkie–market forces were the real culprit. That prompted my cousin the cardiologist, whom I’ve quoted here before, to consider the proper role of government in promoting healthy eating. As he noted,

Studies showing that the ready availability of foods high in sugar, fat, sodium, and calories increase average body weight. Adults living closer to fast food restaurants consume such food more frequently than those who don’t and, consequently, are heavier. This is especially important for children; schools that serve more unhealthy foods or provide vending machines with unhealthy foods tend to be heavier than children whose schools do not permit such practices. Similarly adolescents who attend schools near fast food restaurants are more likely to be obese.

    Compounding these problems are other economic forces surrounding foods: The cost per calorie of healthy foods exceeds those of poor nutrient foods. In the past 30 ears, this cost disparity has increased; between 1985 and 2000, the prices of healthy foods, like fruits and vegetables, fish, and dairy products increased at more than twice the rate of prices of sugar and sweets, fats and oils, and carbonated beverages.

    Finally, we must consider portion sizes as another contributor to obesity. For children alone, between 1977 and 2006 the average portions of soft drinks, pizza, and Mexican foods increased by 34, 140, and 139 calories, respectively,. Sodas, sold originally in 6.5 oz. bottles, are now typically sold in 20 ounce containers. Studies have shown in general that increased portion sizes lead to rises in calorie intake: as a result, US adults now consume over 500 calories per day in 2006 compared to that in 1977. This trend has been further exacerbated by our increased eating away from home, for in 2008, Americans spent 49% of their food budget on food away from home compared with 33% in 1970. On average, each meal eaten outside the home increases that day’s consumption by about 134 calories, while, at the same time shifts the content toward less nutritious ingredients such as saturated fat and added sugar.

In New York, as we all know, Mayor Bloomberg led the fight to ban the sale of large sodas. I agree with my cousin that no matter how well-intentioned, efforts to have government “decree” healthy portion sizes are not the answer. Nor is the answer some “nanny state” that requires us to eat our vegetables or limit meals eaten out.

Does government even have a role in our personal eating habits? It’s hard not to sympathize with a libertarian response–“What business does the state have telling me what to eat, after all? Next thing you know, the local constable will come knocking on my door to see whether I’ve eaten my broccoli!”

Even those of us with a libertarian bent must concede that–at the very least–consumers need information upon which to make our choices. We need to know what’s in the “food” we are eating (note quotes around food); much of it has been so processed and adulterated, there’s no way to know what it contains. We depend upon government-required labels to tell us just how nutritious (or not) it is.

Can government go farther? Here’s where the battle lines get drawn. Public health officials justify added interventions by pointing to the economic consequences of the obesity epidemic, and the medical consequences of poor eating habits. Bans on large soft drinks or other sugary treats will be a hard sell, though, in a country where individual choice is prized.

From my perspective, raising tax rates on such drinks makes more sense. Since 2009, 19 states and eight cities have proposed such taxes on these drinks, according to the Rudd Center for Food Policy and Obesity. The advantage of raising such taxes can be taken from that of tobacco products. Cigarettes are clearly the cause of numerous diseases, costly in both human suffering as well as expenses to society at large. Thus heavy taxes provide the dual advantage of discouraging their consumption as well as raising taxes that can aid in the care of these afflicted individuals. In the case of sugary drinks (and other similar products), taxing these products, plus providing healthier alternatives such as fruit juices in public places would move us in the right direction. A penny-per-ounce excise tax on sugary drinks would effectively raise the shelf price of these drinks by about 20%. According to a number of studies, this would result in a 14 to 20% reduction in the consumption of the taxed beverages.

Makes sense to me.

Comments

Couldn’t Have Said It As Well

I have been meaning to post on this very issue, but Doug Masson has said precisely what I intended to say, and better, so I’m just going to say “amen.”

I will only add that a similar argument is made when the subject is poverty, and policies to address the structural elements in the economy that make it difficult for families to move into the middle class. There are strong echoes of Calvinism in the dismissive belief that, if someone is poor, it must be due to laziness, lack of drive, or other moral defect. As Calvin taught, if God loved you–if you were among the “saved”–then you wouldn’t be poor.