Global Dietary Patterns--Generally Getting Worse Not Better

Historical data suggest that improving diets--especially more calories--helped raise life expectancy in Europe up to about 40 years at the beginning of the 19th century. Public health improvements such as clean water, sewerage, validation of the germ theory, and vaccinations, helped push life expectancy up into the 60s. It takes medical advances to get much beyond the 60s and we are headed that way globally, except for the fact that diets are now holding us back. This idea was first put forward by Barry Popkin at UNC Chapel Hill and his colleagues as the natural consequence of the nutrition transition. Finding data to track trends has not been easy, however, which is why the paper just published in The Lancet Global Health is so informative (this is open access so it is available to everyone). A group of researchers associated with the Global Burden of Diseases Nutrition and Chronic Diseases Expert Group tracked down every national level survey they could find that included dietary intake data collected at the individual levels. This way they could evaluate differences not only by country, but also by age and sex. The results suggested that age and sex were less important than overall national differences, based especially on overall levels of income.

Nations with higher incomes had larger improvements in diet patterns based on healthy items than did nations with lower incomes; for example, by 2·5 points (95% UI 0·5–4·6) comparing high-income to low-income countries. By contrast, middle-income nations showed the largest worsening in diet patterns based on unhealthy items: compared with high-income nations, greater worsening by 2·5 points (95% UI 0·5–4·5) and by and 2·8 points (95% UI 0·9–4·8) was noted in upper-middle nations and lower-middle income nations, respectively. Although most world regions showed modest improvements in dietary patterns between 1990 and 2010 on the basis of more healthy items, such improvements were generally not noted in the poorest regions, including in sub-Saharan Africa and the Andean states of Latin America. Conversely, most regions of the world showed substantial declines in diet quality based on increased consumption of unhealthy items. The exceptions included many of the wealthiest regions including the USA and Canada, western Europe, Australia, and New Zealand, where consumption of these unhealthy items modestly decreased. Of note, for these world regions and nations, this improvement was superimposed on a poor starting score in 1990 (appendix pp 47–49 figure S24). Thus, despite some improvement by 2010, dietary scores for unhealthy items in wealthy countries remained among the worst in the world.

The map below shows the global pattern when good and bad dietary elements are balanced against one another. The best diets at the moment are actually in the poorer countries that have not yet moved into the income categories where they can afford the less healthy, but obviously desirable, diets. We have to hope that we can alter that trajectory and keep them on better diets even as incomes improve.

Drought and the Syrian Crisis

If you've read the 12th edition of my text, or read my blog post from nearly two years ago, you'll be familiar with the argument that one of the likely causes of the current crisis in Syria was a major drought that sent a lot of farmers to cities looking for work. They were rebuffed and the rest, as they say, is history. A paper recently published in the Proceedings of the National Academy of Sciences goes even further, to suggest that the drought was likely caused by human-induced climate change. The New York Times covered the story.

The drought was the worst in the country in modern times, and in a study published Monday in Proceedings of the National Academy of Sciences, the scientists laid the blame for it on a century-long trend toward warmer and drier conditions in the Eastern Mediterranean, rather than on natural climate variability.

The researchers said this trend matched computer simulations of how the region responds to increases in greenhouse-gas emissions, and appeared to be due to two factors: a weakening of winds that bring moisture-laden air from the Mediterranean and hotter temperatures that cause more evaporation.

Colin P. Kelley, the lead author of the study, said he and his colleagues found that while Syria and the rest of the region known as the Fertile Crescent were normally subject to periodic dry periods, “a drought this severe was two to three times more likely” because of the increasing aridity in the region.

Some social scientists, policy makers and others have previously suggested that the drought played a role in the Syrian unrest, and the researchers addressed this as well, saying the drought “had a catalytic effect.” They cited studies that showed that the extreme dryness, combined with other factors, including misguided agricultural and water-use policies of the Syrian government, caused crop failures that led to the migration of as many as 1.5 million people from rural to urban areas. This in turn added to social stresses that eventually resulted in the uprising against President Bashar al-Assad in March 2011.

To be sure, the refugees from drought would not have had to elicit the kind of response that they did from President Assad of Syria. So, drought is not the immediate cause of the conflict. But demographic change--in this case an unwelcome influx of rural people into urban areas--is something that societies must always deal with. As it turned out, the Syrian government did not deal well with it, and the result has been a vastly larger disaster than the drought itself.

The Hidden Threat of Dengue Fever in West Africa

Ebola is obviously the headline-catching disease in West Africa and we must continue to take it seriously, in order to avoid new flareups. At the same time, malaria is still a bigger killer in the region, so we cannot take our eyes of prevention efforts for malaria. But, wait! It turns out that a significant fraction of children in Ghana who are diagnosed with malaria also have dengue fever. This tells us that dengue fever (transmitted by mosquitos, albeit a different species than carries the malaria parasite) is also prevalent in West Africa, despite the fact that few physicians are looking for it when they treat sick patients. These were the surprising findings of a paper just published by Justin Stoler of the University of Miami and associates of his in Ghana in the American Journal of Tropical Medicine and Hygiene. The article is behind a subscription, but Justin was interviewed today on Voice of America, where his findings were summarized.

“The best data we have is from Accra, Ghana’s capital. And we see there roughly 40 to 45 percent of all outpatient visits – anyone presenting at a hospital, a healthcare facility – for any reason – are walking out of there with a presumptive malaria diagnosis, which is a staggering number in and of itself. Now, what we’re just starting to learn in the last few years is that when you actually do confirmatory blood tests -- and you look at who really has malaria -- typically it’s less than 10 percent of that group, who’s presumed to have malaria,” he said.

So, if those figures are correct, what diseases could the rest actually have?

“Well, we started with dengue because it’s widespread across the tropics. It’s recognized. It’s something many people have heard of. But in reality it’s probably just a small piece of the pie. There are bacterial infections, other viral fevers, viral infections – things like influenza – fungal diseases, other parasitic infections…really a whole menu of things that people are dealing with on a regular basis,” said Stoler.

Stoler said the findings have the potential to cause donors to re-think their anti-malaria strategies. The Roll Back Malaria Global Action Plan estimates nearly $6 billion a year is spent to fight malaria.

“At least in parts of rapidly urbanizing Africa, maybe malaria is not their biggest problem. I don’t mean to undermine the importance of fighting malaria in sub-Saharan Africa and around the world, in general. But malaria has traditionally been a rural disease and that’s probably still where most of the burden exists. But really all the action is in urban places and there a lot of other things that people are dealing with there,” he said.

We Need More Saving, Not More Spending

One of the major concerns in richer, aging societies is how will the older population be supported in its dotage. The assumption is made that people will live an ever longer number of years in retirement and that they will not have saved enough money for that retirement, so the younger generation will have to begrudgingly support them. The solution to this problem is really very straightforward, as I have pointed out before: (1) keep people in the labor force longer (so that the number of retirement years is consistent with increasing life expectancy at the older years); and (2) make sure everyone is saving for their retirement (so that they are not totally reliant on intergenerational transfers from younger people).

These ideas seem so simple, but the problem is that in the short term economists want people to spend money, while in the long term economists want people to save for their old age. It's very hard to have it both ways, and I was thinking about this as I read in today's New York Times that the drop in oil prices over the past few months has not produced the kind of boom in consumer spending that some economists were expecting.

While few outside of Texas and North Dakota are complaining about this huge savings that consumers have enjoyed since energy prices began falling last summer, economists have been stumped recently trying to figure out exactly what consumers are doing with the windfall. 

They have not gone on a shopping spree at the mall or online. Results at many retail chains have been mixed, and some stores that are middle-class fixtures, like Sears and J.C. Penney, continue to struggle. 

One hint at what consumers might be thinking came Monday, when new government data on the economy showed a healthy gain for wages and salaries in January, even as spending by consumers inched lower for the second month in a row. As a result, the savings rate ticked upward to 5.5 percent, the highest level in just over two years.

If this is really true, we can only say "thank goodness"! The future may look brighter than we thought. Let's see if we can keep this up. 

Don't Drink the Water--Chinese Style

We humans need water to survive. And clean water at that, because polluted water is bad for your health. Indeed, as Justin Stoler has detailed in his research, "pure" water sold in sachets throughout West Africa may well prevent children from getting diarrhea which can lead to an early death. Now, I admit that whenever I travel outside the U.S. I routinely buy bottled water because I'm never sure where the local water might be coming from, but I was still amazed to read in this week's Economist that there is a huge demand for bottled water in China due to concerns about water quality.

Hygiene and health concerns among China’s rising middle class have stoked demand as more migrate to cities, where water is more polluted and the bottled sort more common (typically, 19-litre barrels installed in homes). In 2009 the World Bank said water problems cost the country over 2% of GDP every year—mostly due to damage to health. In 2013 thousands of rotting pigs’ carcasses were found in the Huangpu river, which supplies four-fifths of tap water to Shanghai, China’s most populous city. Last April, in the industrial city of Lanzhou in the north-west, a leak from an oil company’s pipeline poisoned tap water for 2.4m locals with carcinogenic benzene. And even if water meets drinking standards at source, it can be harmful by the time it reaches the tap after coursing through decaying pipelines.

Yikes! That really is disgusting. Of course, if the Chinese went back to more vegetables and fewer pigs, things might start to improve. Still, the article points out that China has 20% of the worlds' population, but only 7% of the global freshwater supply. That doesn't sound sustainable to me. The article suggests that one of the penalties of higher urban incomes in China is going to be the cost of daily consuming imported bottled water. Now, if they could just import cleaner urban air...