Monday, March 29, 2010

Salt policy

Some major food companies -- Kraft, ConAgra, Unilever -- have announced voluntary initiatives to reduce salt. In other countries, such as the United Kingdom, public policy plays a bigger role alongside voluntary measures. On WBUR's syndicated radio show Here and Now, host Robin Young today covers salt policy. She interviewed Cheryl Anderson at Johns Hopkins University and myself.
New York City is calling on the food industry to cut back on sodium. The plan is voluntary and its goal is to reduce the amount of sodium people eat by 25%. Recent research shows that a decrease in sodium would cut new cases of coronary artery disease by 60,000 a year. Our guest is Dr. Cheryl Anderson of Johns Hopkins University. We’re also joined by Parke Wilde of the Friedman School of Nutrition Science and Policy at Tufts University, who discusses the role of public policy in debates about diet.

Monday, March 22, 2010

New study on high-fructose corn syrup

A Princeton University research team is reporting that HFCS increases obesity in rats more than sucrose does. The research appeared in February in the Pharmacology, Biochemistry, and Behavior.

As always, no one study settles the argument on this type of debate. This study moves the needle five degrees toward showing that HFCS is metabolically different from equivalent amounts of table sugar.

The study appears in a refereed journal. It includes a strong research design, randomly assigning rats to a treatment (HFCS) group and two control groups.

[Update 3/23: part of the study includes two control groups, which received either plain sucrose or an ordinary rat food diet, so one can distinguish HFCS from sucrose; a comment says that another part of the study included only one control group, which received the rat food diet, so it is not possible to distinguish HFCS from sucrose].

On the other hand, studies in rats are just one element in an array of evidence. Other elements include human studies and describing a plausible biological mechanism. One mystery is how HFCS (55% fructose) could be much different from sucrose (50% fructuse). The conclusion section of the new article spends most of its time talking about the metabolism of fructose, mentioning but then somewhat breezing over the similarity in fructose content between HFCS and sucrose.
Given that sucrose is a disaccharide, which is metabolized to one fructose and one glucose molecule (Caspary, 1992), it has been argued that there is little difference between fructose and sucrose, since both provide about 50% fructose and 50% glucose in the blood stream; and until recently, there was no evidence that HFCS contributes to long-term weight gain beyond what sucrose contributes (Forshee et al., 2007). However, the present study suggests that HFCS and sucrose can have different effects on body weight and obesigenic measures.

HFCS is different than sucrose in many ways. First, HFCS-55 has proportionately slightly more fructose than sucrose (White, 2008). Second, fructose is absorbed further down the intestine than glucose, with much of the metabolism occurring in the liver, where it is converted to fructose-1-phsophate [sic], a precursor to the backbone of the triglyceride molecule (Havel, 2005). Third, fructose is metabolically broken down before it reaches the rate-limiting enzyme (phosphofructokinase), thereby supplying the body with an unregulated source of three-carbon molecules. These molecules are transformed into glycerol and fatty acids, which are eventually taken up by adipose tissue, leading to additional adiposity (Hallfrisch, 1990). And fourth, HFCS causes aberrant insulin functioning, in that it bypasses the insulin-driven satiety system (Curry, 1989). Whereas circulating glucose increases insulin release from the pancreas,... fructose does this less efficiently, because cells in the pancreas lack the fructose transporter.... Typically, insulin released by dietary sucrose inhibits eating and increases leptin release (Saad et al., 1998), which in turn further inhibits food intake. As previously discussed, meals of HFCS have been shown to reduce circulating insulin and leptin levels (Teff et al., 2004). Thus, fructose intake might not result in the degree of satiety that would normally ensue with a meal of glucose or sucrose, and this could contribute to increased body weight.
In each passage above where it seems the authors plan to talk about a mechanism that is specific to HFCS, the subsequent detail turns out to be all about fructose.

I enjoyed hearing a talk earlier this month by Barry Popkin (author of The World is Fat). Though he has also speculated about a possible distinct effect of HFCS, he now emphasizes just the sweetness and food energy content.

And this brings me to the final point that I wish news coverage of this topic emphasized more heavily. HFCS is a large part of our food supply, perhaps 40% or more of all caloric sweeteners. In these quantities, a special metabolic effect for HFCS is really beside the point for policy purposes. It could well be true that HFCS is making Americans obese in any case, just because we consume so much of it.

Friday, March 19, 2010

Child Nutrition Reauthorization

You have probably already been enjoying the Fed Up With Lunch blog, a photographic journal of a year of school meals. If you think school lunch should be better, a lot depends on Child Nutrition Reauthorization in Congress this Spring. Here is a sampling of blog and new media coverage.

Tom Philpott at Grist:
Obama's proposed increase would boost the current daily per-lunch outlay by less than 20 cents -- not enough to buy an extra apple a day for every kid.

Now Blanche Lincoln (D.-Ark), the agribiz-friendly chair of the Senate Ag committee, has come out with her draft of the School Lunch Reauthorization Act. She may be calling it the "Healthy, Hunger-Free Kids Act," but what she proposes doing is slashing Obama's proposed increase by more than half, to $4.5 billion over ten years.

If Obama can't spare an extra two dimes per day per kid to spend on ingredients, Lincoln won't even fork over a single extra dime. If Obama's proposal wouldn't even net an extra apple a day, Lincoln's would have trouble procuring a single stick of gum -- not that school kids need any more sugar.

And it gets worse. Because of Congress' "pay-as-you-go" rules, Lincoln has to balance her modest increase with cuts in other agricultural spending. Naturally, she has chosen to target conservation, hunger, and even other school-lunch programs -- leaving commodity payments, beloved of her state's large-scale cotton farmers, intact.
Nutritionist Julie Negrin, M.S., writes at the daily table:
It’s bewildering to me why the government is hemming and hawing over how much money they should invest in CNR. It could be as low as a half a billion (which sounds like a lot but divide that by five years and millions of schools) and as much as $4 billion (which would be a miracle). When they give so little for each child’s school lunch, how can the school staff be expected to produce healthy, balanced meals for growing children? Even the most talented chefs I know would have a hard time coming up with a well-rounded meal appropriate for children if they only had a couple of bucks to spend per person. And had little to no kitchen equipment. And were given low-quality ingredients.
In the new online magazine Agriculture from the Environmental Working Group (EWG), Craig Cox takes the Lincoln bill to task for pitting child nutrition against conservation programs.
In a critical miscalculation, she would cap the amount of money spent on the Environmental Quality Incentives Program (EQIP) to pay for the nutrition increase. EQIP, a program chronically underfunded and repeatedly targeted for cuts, helps ensure cleaner water, soil and air for the children in rural communities.

The senator would be much smarter to look to the bloated farm subsidy program.

Wednesday, March 17, 2010

Sam Fromartz on small-scale slaughterhouses

Sam Fromartz, keeper of the blog Chews Wise and author of the book Organic Inc., has a fascinating piece in today's Washington Post about small-scale slaughterhouses.

Meat processing is one of the most concentrated sectors of the entire food system. Fromartz describes the efforts of one Joe Cloud in Harrisonburg, VA, to break into the business.
Cloud is riding a wave of consumer demand for meat from local farms, which has burgeoned along with the rash of deadly E. coli food poisoning incidents, hamburger recalls and undercover videos about grossly inhumane practices at a few large plants. Prominent chefs, who work with farmers and processors like T&E to get high-quality meat, have also championed the products.

For farmers, the sales are alluring; they make more money per animal when they sell direct, even if these channels represent less than 2 percent of all meat sales. It's also a way to escape the conventional system of meat production, since Virginia cattle typically are raised in-state for a year before being shipped to feedlots in Nebraska, Kansas and Texas to be fattened up and slaughtered -- and then shipped back as meat.

"Every step of the journey, someone has their hand in your pocket," said Jeff Lawson, who raises cattle and sheep at Green Hill Farm in Churchville, Va., a few miles outside Staunton. "If I could sell every animal I raised through Joe Cloud to get to your dinner table, I would. Any farmer would."

Tuesday, March 16, 2010

GMA science forum 2010

This afternoon, I will participate with Jane Black and Sam Fromartz in a panel at the Grocery Manufacturers Assocation (GMA) annual science forum. The panel is about consumer interests in alternative food movements. The (perhaps slightly dismissive?) session title is "New Foodism."

I focus on three themes: nutrition, environment, and small farms and food businesses. Here is a section of what I will say:
The “New Foodists” favor fresh whole foods that frequently are not required to carry a Nutrition Facts panel. They generally believe that good health will follow automatically from choosing the right food pattern. From a nutrition science perspective, it frequently happens to me that I doubt a specific claim I hear from this movement, and yet I end up believing the broad thrust of its perspective on nutrition. For example, organic food advocates sometimes emphasize comparatively small differences in micronutrient content between organic and conventional food, whereas a more mainstream nutrition scientist would instead emphasize the comparatively low average sodium content of the typical organic food diet. As another example, “New Foodists” favor grass-fed beef and local pork and cheese, seldom expressing much concern about saturated fat, whereas a more mainstream nutrition scientist may think it is probably just as well that these products are priced comparatively high, so that the overall saturated fat content of the New Foodist diet remains reasonable.

But, these distinctions make little difference in evaluating the overall nutritional wisdom of the focus on healthy eating patterns. The big important contribution of the Good Food Movement is not its diagnosis of micronutrient content. Rather, the big contribution is that this movement makes eating healthy more tasty, fun, and inspiring.

You probably won’t believe me if I quote Michael Pollan on this topic, so let me instead quote my colleagues Alice Lichtenstein and Robert Russell, who are, respectively, a renowned nutrition scientist and the former director of the Jean Meyer Human Nutrition Research Center at Tufts University. Writing in the Journal of the American Medical Association, they recommend focusing not on the specific nutrients in nutrition supplements, but instead on healthy eating patterns in foods. They advise, “other factors in food or the relative presence of some foods and the absence of other foods are more important than the level of individual nutrients consumed.” That, in a nutshell, is the same nutrition perspective I hear from the Good Food Movement.
The conference has more excitement in the air than I would have expected in advance. It's not because of my panel! Michelle Obama is the keynote speaker this morning.

Scientific American on SNAP (food stamp) improvements

From Lynne Peeples at Scientific American Online:
A growing number of local programs from Boston to San Diego are trying to make healthier foods more appealing and affordable for low-income families—the population of Americans who are most reliant on food stamps, and most likely to be obese. Meanwhile, public health researchers are looking hard at the federal food stamp program itself, now known as the Supplemental Nutrition Assistance Program (SNAP). They're questioning why the long-standing strategy for helping the hungry may, in some cases, actually be hurting their health by packing on extra pounds. But could a few simple changes transform SNAP into a powerful vehicle for curbing obesity?
One of the possible changes -- worth study in a pilot, I should say, not necessarily full rollout -- is twice monthly benefit delivery through the Electronic Benefit Transfer (EBT) card:
Participants themselves have suggested that the change could help them spread out their grocery shopping and keep adequate food around through the month, notes Parke Wilde, an agricultural economist at Tufts University's Friedman School of Nutrition Science and Policy in Boston and lead author of the shopping cycle paper. "It's just a little change in the environment that still gives people freedom [to shop as often as they want], yet gives them a slightly different sense of the default behavior," he says. "I'm always surprised that there's not more interest in the idea."