My Q and A column in the San Francisco Chronicle appears on the first Sunday of every month.  This one is about safety problems with tuna scrape.

Q: I had no idea that the tuna in my sushi roll was scraped off the bones in India, ground up, frozen, and shipped to California. Is this another “slime” product? Can I eat it raw?

A: No sooner did the furor over lean, finely textured beef (a.k.a. “pink slime”) die down than we have another one over sushi tuna. On April 13, the Food and Drug Administration said Moon Marine USA, an importing company based in Cupertino, was voluntarily recalling 30 tons of frozen raw ground yellowfin tuna, packaged as Nakaochi scrape.

Centers for Disease Control and Prevention investigations linked consumption of Nakaochi scrape sushi to about 250 diagnosed cases and an estimated 6,000 or so undiagnosed cases of illness caused by two rare strains of salmonella. Among the victims who were interviewed, more than 80 percent said they ate spicy tuna sushi rolls purchased in grocery stores or restaurants.

Scrape refers to the meat left on fish skeletons after the filets are cut off. This is perfectly good fish, but difficult to get at. I once visited an Alaskan salmon packing plant and asked what happened to the delicious looking meat between the bones. The answer: pet food. (Lucky cats.)

A hot commodity

But tuna is too valuable to leave behind, and companies in India use special devices to scoop out the meat, combine it with scrapings from many other fish, chop the mixture, freeze it in blocks, and ship it to importers in the United States. Unlike “pink slime,” tuna scrape is not treated with ammonia or anything else to kill harmful bacteria.

Nevertheless, it is supposed to be safe. The FDA requires producers of imported foods to follow established safety plans. Although the United States imports about 80 percent of seafood sold domestically, the FDA only inspects 1 or 2 percent.

This means we have to rely on the diligence of international food producers in following safe-handling procedures, and of U.S. importers in verifying safety through pathogen testing. But even well-intentioned producers can make safety errors, especially when dealing with high-risk foods.

Tuna scrape is very high risk. Its supply chain is long, complicated and international, leaving many opportunities for contamination. And it is eaten raw.

This tuna scrape came from a single processing plant in India owned by Moon Marine International of Taiwan. Tuna are plentiful off the Indian coast, and the tuna processing industry is expanding rapidly. India has dozens, perhaps hundreds, of fish processing facilities, but most are relatively small and their number, size and geographical dispersion make monitoring difficult.

Safe handling issues

The frozen scrape blocks are supposed to be held at subzero temperatures throughout shipping. Even so, they pose a safety risk. They combine the scrapings from many fish. One contaminated scraping can contaminate the entire lot.

And subzero freezing may kill some salmonella, but large fractions can survive, remain viable, and multiply when the blocks are thawed.

Once the tuna scrape arrived in America, I’m guessing it was trucked to Cupertino and from there to retailers and distributors who further trucked them to restaurants and grocery stores. There, sushi chefs thawed the scrape and used it to make spicy tuna rolls.

Tuna scrape is used in supermarket-grade sushi, not the fancy stuff. Sushi used to be – and still is, in places – an art form requiring exceptional skills. In Japan, sushi chefs can train for as many as 10 years to learn how to recognize the freshest, safest and most delicious fish. Sushi served by such chefs is made to order. It is never pre-prepared. It can be breathtakingly expensive.

But in America, sushi has gone mainstream. You can find prepackaged sushi rolls at practically any supermarket or convenience store, at a cost equivalent to hamburger.

Cheap sushi is made with cheap ingredients – hence, Nakaochi scrape – by chefs with far less training. A typical certification program for sushi chefs in this country can be completed in two or three months. Some offer certification online. Although these programs address safe food-handling procedures, the training is necessarily superficial.

What are the odds?

Sushi aficionados argue that while raw fish is never perfectly safe, the safety odds are much better when the chef is well trained, and the fish are freshly caught and cut to order in front of you. By their standards, tuna scrape is suitable only for pet food, which is at least cooked to kill pathogens.

If anything, the tuna scrape outbreak teaches why it is so important to know where food comes from and how it is made. Caveat emptor.

Nutrition and public policy expert Marion Nestle answers readers’ questions in this monthly column written exclusively for The Chronicle. E-mail your questions to food@sfchronicle.com, with “Marion Nestle” in the subject line.

Addition, May 14:  Bill Marler reports that the FDA “483 Inspection Report” on the Indian tuna processing facility is now available.  Here are excerpts from the most revealing section:

Tanks used for storage of process waters have apparent visible debris, filth and microbiological contamination…There is no laboratory analysis for water used in ice manufacturing at the [redacted] facility to show the water used to make ice is potable…Apparent bird feces were observed on the ice manufacturing equipment at Moon Fishery; insects and filth were observed in and on the equipment…Tuna processed at your facility, which is consumed raw or cooked, comes in direct contact with water and ice.

I was honored to give the keynote address to this weekend’s splendid Food Book Fair (for information, travel directions, and schedule, click here).

The Fair features the work of groups listed in the poster.  It encompasses an unusually broad vision of food studies in action.

The venue, the Wythe Hotel at 12th street in Brooklyn, is an architectural wonder and worth the trip on its own.  It’s just a short walk from the Bedford Street subway stop on the L line.

Check out the schedule.  Check out the terrific selection of books at the bookstore–all on food in its many dimensions.

Come!

Paul Kindstedt, Cheese and Culture: A History of Cheese and its Place in Western Civilization, Chelsea Green, 2012.
Kindstedt, a professor of food science at the University of Vermont and co-director of its Institute for Artisan Cheese, has organized his history by time period and region, from the Paleolithic origins of cheese to current attempts to regulate raw milk.  His material is well referenced and the book is full of facts and observations that will delight cheese lovers.

Seamus Mullen, Hero Food: How Cooking with Delicious Things Can Make Us Feel Better, Andrews McNeel, 2012.

I don’t usually blurb cookbooks but I couldn’t resist this one from Seamus  Mullen, the chef-owner of Tertulia in lower Manhattan.

This gorgeous book proves without a doubt the point I’ve been making for years: healthy food is delicious!  Take a look at what Seamus Mullen does with vegetables, fruit, grains and everything else he cooks.  I can’t wait to try his 10 Things to Do with Corn.  His food can’t guarantee health, but will surely make anyone happy!

Ordinarily I find government plans of this type to be soporific but this one is especially well written and well thought out (with some caveats).

The report is a statement of FDA commitment to what it is going to do in the next four years in food areas that affect people and animals.  It includes many promises, among them this one of particular interest: 

Program Goal 4: Provide accurate and useful information so consumers can choose a healthier diet and reduce the risk of chronic disease and obesity

Objective 1. Update the Nutrition Facts label.

• Publish proposed rules updating the nutrition facts label and serving sizes [OK, but by when?].
• Publish final rules updating the nutrition facts label and serving sizes [Ditto].

Objective 2.  Implement menu and vending machine labeling regulations.

• Publish final menu and vending machine labeling regulations [OK, but by when?].
• Collaborate with states, localities and other partners to ensure high rates of compliance.

Objective 3.  Improve consumer access to and use of nutrition information.

• Explore front‐of‐pack nutrition labeling opportunities [Explore?  See comment below].
• Collaborate with public/private sector parties on nutrition education [Collaborate?  See comment below].
• Implement updated standards for the labeling of pet food including nutrition and ingredient information [How about a Pet Facts label for pet foods that someone might actually be able to understand?].
• Implement standards for animal feed ingredients.
• Publish final rule defining and permitting use of the term “gluten free” in the labeling of foods.

Goal-setting processes usually include dates by which the objectives are to be completed.  These do not, which suggests that the FDA can continue to delay action until 2016. 

I also do not understand what is meant by “Explore front‐of‐pack nutrition labeling opportunities.”  Explore?  The FDA has already sponsored two Institute of Medicine reports on front-of-pack labeling.  Does this mean the agency is ignoring them and intends further research?

And “Collaborate with public/private sector parties on nutrition education?”  What does the FDA have in mind for the content of such education?  You can bet that no collaborative campaign can focus on “don’t drink your calories.” 

FDA needs to deliver on these items, and sooner rather than later.  This year?  I’m not counting on it.

My Tuesday question from student readers of NYU’s Washington Square News:

Question: How can we determine our individual caloric, vitamin, carbohydrates, fats and other intake requirements per day based on our own individual weight, height and lifestyle?

Answer: You can’t. You will have to be satisfied with estimates based on measurements performed years ago on a small number of study subjects.

We require calories and nutrients — 40 to 50 separate substances that our bodies cannot make, we must get from food. Because these interact, studying one at a time gives results that may well be misleading.

Early nutrition scientists got “volunteers”— in quotes because study subjects often were prisoners — to consume diets depleted in vitamin C, for example. They waited until the subjects began to develop scurvy, a sign of vitamin C deficiency. Then they fed the subjects the smallest amount of vitamin C that would eliminate symptoms.

Because individuals vary in nutrient requirements, scientists used this data to estimate the range of nutrient intake that would meet the needs of practically everyone.

The Institute of Medicine compiles such data into Dietary Reference Intakes and presents the estimates by sex and age group. You can look up your requirements in DRI tables. DRIs account for the needs of 98 percent of the population. If your requirements are average, you will need less.

Few American adults show signs of nutrient deficiencies, but if you are worried about your own intake of nutrients, you can take a multivitamin supplement. Note, however, that we have no evidence to show supplements make healthy people healthier.

You can estimate calories by looking up everything you eat or drink in food composition tables, but it is easier to weigh yourself at regular intervals. If you are gaining weight, you are eating too many calories for your activity level.

With nutrition, it’s best to get comfortable with estimates and probabilities.

Fortunately, eating a healthy diet takes care of nutrients without your having to give them a thought. Eat your veggies!

A version of this article appeared in the Tuesday, May 1 print edition. Marion Nestle is a contributing columnist. Email her questions at dining@nyunews.com.

A question from a reader:

Q.  I was wondering if you could comment on the recent article in the New York Times which questions the link between food deserts and obesity.

A.  Sure.  Happy to.  The article talks about two recent studies finding no relationship between the types of foods children eat, what they weight, and the kinds of foods available within a mile and a half of their homes.

These finding seem counter-intuitive in light of current efforts to improve access to healthier foods in low-income communities.

Obesity is more common among the poor than among those who are better off.   Poor people must be eating more calories than they expend in physical activity.

Eating more calories means eating more of foods high in calories, especially fast food, snacks, and sodas.  Kids who are heavier have been found to eat more of those foods than those who are not.

I can think of several reasons why this might be the case:

• Access: healthier foods are less available
• Cost: healthier foods cost more
• Skills: healthier foods require preparation and cooking
• Equipment: cooking healthier foods requires kitchen facilities, pots, and pans
• Transportation: even if stores are available, they might be too far away to walk to
• Quality: even if stores sell fruits and vegetables, they might not be fresh
• Marketing: fast foods, snacks, and sodas are heavily marketed in low-income areas
• Peer pressure: eating high-calorie foods is considered the norm

I can think of ways we might try to improve any of these factors, but I’m guessing that cost is the critical factor for people with limited means.  The Department of Commerce reports that the indexed price of fresh fruits and vegetables has increased by 40% since 1980, whereas the indexed price of sodas has declined by about 30%.

Fast food, snacks, and sodas are cheap.  Fruits and vegetables are not.

Without access to healthful foods, people cannot eat healthfully.  But access alone cannot reverse obesity.

The real issue is poverty.  Unless we do something to reduce income inequality, and to make healthier foods more affordable, fixing the access problem is unlikely to produce measurable results on its own.

Posted from the World Public Health Association annual meeting, World Nutrition 2012, in Rio.

I am in Brazil at meetings of World Nutrition Rio 2012 but was deluged yesterday by links to a lengthy Reuters’ Special Report: How Washington went soft on childhood obesity.

In an e-mail, Reuters explains that its report is about how food and beverage companies dominate policymaking in Washington, doubled lobbying expenditures during the past three years, and defeated government proposals aimed at changing the nation’s diet.

• The White House, despite First Lady Michelle Obama’s child obesity campaign, kept silent as Congress killed a plan by four federal agencies to recommend reductions to sugar, salt and fat in food marketed to children.
• Corporate lobbying last year led Congress to declare pizza a vegetable to protect it from a nutritional overhaul in the school lunch program.
• The Center for Science in the Public Interest, widely regarded as the lead lobbying force for healthier food, spent about $70,000 lobbying– roughly what companies opposing stricter food guidelines spent every 13 hours.
• The food and beverage industry has a near-perfect record in political battle even while health authorities link unhealthy food to the child obesity epidemic.
• During the past two years, each of the 24 states and five cities that considered “soda taxes” has seen the efforts dropped or defeated.

Reuters Investigates also has a video about how the food industry fought back when the White House sought healthier school lunches and Congress directed federal agencies to set nutrition standards.

Readers of this blog may recall my post last December fretting about the White House pullback, and the vigorous denial the next day by White House senior food policy advisor Sam Kass.

I attributed White House caution to the upcoming election.  Reuters does too, apparently, and so does the New York Times. 

If the First Lady is to make real progress on Let’s Move, she needs all the support she can get.  This might be a good time to send a note to the White House strongly encouraging more vigorous action on methods to address childhood obesity.

Politics does indeed make strange bedfellows. 

The American Enterprise Institute, a conservative (to say the least) think tank, has just issued a report on reforming the farm bill to ensure a safer food system.  Its stunning conclusion:

More feasibly, in the short to medium term, changes in food safety regulation should aim at correcting inconsistencies or loopholes that exist in US food safety laws.

For example, policymakers could merge the FSIS and the FDA to allow for a better allocation of resources and exploit potential return to scales.

Standardizing states’ detection systems for food-borne illnesses and collecting better data about the incidence of food-borne illnesses would make firms more accountable and help construct better food safety policies.

Merge the food safety functions of USDA and FDA?  This, of course, is precisely what food safety advocates and the Government Accountability Office have been urging since the early 1990s. 

Now, maybe, it has a chance?