Four Big Issues

Is food a human right?

All citizens of the world have a right to food.

Under UN guidelines, the right to adequate food is everything from nutritional quality to sufficient calories, so food adequacy is this broad concept of good, healthy, safe and culturally appropriate food.

Globally about 2.5 billion people lack food security. Almost a billion are malnourished. Policy changes are needed to support small farmers in low-income countries with better seeds and fertilizer, better use of water, access to markets and protection from subsidized commodities from high-income countries.

When you look at the statistics in the U.S., 15 percent of the population lives in poverty. Even with SNAP (the Supplemental Nutrition Assistance Program), many people run out of benefits halfway through the month and turn to cheap, high-calorie, processed food because it's available in low-income neighborhoods.

That is a failure of the federal government to fulfill the right to nutritious, affordable food. And it's a factor in the 600,000 premature deaths in the U.S. that are the result of a poor diet.

If we could ensure food security tomorrow to the 18 million people in the U.S. who don't have access to enough food-or the right kinds of food-the number of premature deaths would plummet.

As public health people, through our training and research and knowledge, we have the duty to work more effectively for better food policies and for greater access to healthy foods.

Are GMOs a good idea?

People want to know: Are genetically modified organisms (GMOs) causing diseases? Are they bad for my health? The science isn't really settled on those questions. It's not clear if there are direct negative health effects from consuming GMOs.

But to really evaluate GMOs from a public health perspective, we need to look beyond food consumption. Food production affects the environment, populations in surrounding communities and people working throughout the food system.

The two most widely used GMO crops in the U.S. are corn and soy designed to withstand a specific herbicide. Monsanto sells both the GMO seeds and the herbicide, known as Roundup. Over the years, Roundup-treated weeds have become tolerant to the herbicide, leading to increasing doses and runoff, resulting in growing risks to public health and the environment.

The latest chapter of the GMO story is the development of GM salmon for human consumption. GM animals produced for direct human consumption is something we've never seen, and FDA officials evaluating its safety are relying on data from the company seeking approval.

Overall, the use of GMOs to date has been a negative for the food system and for public health because of increased use of chemicals and other issues. It's conceivable that genetically modified food could be used in a positive manner, but many factors need to be considered in addition to dietary intake risks.

Are we reaching the end of cheap food?

It's difficult to predict the future. But I really do think we cannot continue long-term with the availability of cheap food-and in saying this, I should note that for many, it already seems anything but cheap.

We're not paying the full cost of the food, which includes the overuse of natural resources, the contaminants we're putting out there and the fact that food system workers often don't earn a living wage. Someday those costs will show up in our food prices.

With a global population that's expected to hit 9 billion by 2050, the UN predicts we'd have to expand food production by 70 percent. But environmental threats are going to make it challenging even to maintain current levels. It's hard to imagine that technological fixes are going to solve these problems.

I don't say it's impossible, but I think it will require some big changes. We could feed a lot more people by reducing meat consumption because it's so inefficient to produce. And cutting into food waste is critical: Thirty to forty percent of all the food that's produced is wasted-in fields, during storage and transport, and by retail, restaurants and consumers.

We eventually will have to move into more sustainable types of food production and distribution systems. It's happening now, but not even close to the scale that's needed.

Why are there so many food allergies now?

It's likely that many things have changed in the environment, in our diets and in child-rearing practices that have led to an increase in food allergies in the past 20 years.

One of the most popular theories is the hygiene hypothesis. If the developing immune system is not exposed to enough levels and types of germs and bacteria, its focus may shift, leading to allergies or autoimmune diseases. Worldwide, there's a lot of evidence to support this, as food allergies are much more common in developed countries. But the hygiene theory does not seem to be the most important factor in developed countries. Higher rates of food allergies in inner-city populations contradict the hypothesis.

In terms of nutrient-related allergy causes, two theories have some evidence to support them: vitamin D deficiency and excess folate. Compared to two decades ago, there's a much higher rate of vitamin D deficiency-especially in northern climates. This may be diet-related, but it's also because most of us spend more time indoors.

And about 20 years ago, women who were pregnant began taking supplements with high levels of folic acid to prevent birth defects. So there's been a major change in developing infants' exposure to folic acid.

I think we're going to learn that there are quite a few more contributors to food allergies. Some are under investigation; some we haven't thought of yet.