by Marion Nestle

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Nov 27 2009

Fad diets make people fat?

It’s post-Thanksgiving so I suppose I must say something about overeating.  Fad diets contribute to obesity, says the president of the British Society of Gastroenterology.  He singles out Atkins, Raw, Hallelujah (fruits and seeds mentioned in the Book of Genesis), and Grapefruit diets for particular scorn.  Why?  He doesn’t say.  His otherwise sensible conclusion: “The problem facing society is not the content of our diet but it’s the quantity we are consuming and the consequential impact of obesity.”

Ah yes, quantity.  Probably best not to mention it this week.  Enjoy the weekend!

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Nov 25 2009

The latest on too much salt

The British Medical Journal has a new meta-analysis of 13 studies of the health effects of high salt intake.  Its conclusion:

High salt intake is associated with significantly increased risk of stroke and total cardiovascular disease. Because of imprecision in measurement of salt intake, these effect sizes are likely to be underestimated. These results support the role of a substantial population reduction in salt intake for the prevention of cardiovascular disease.

In commentary, the authors insist that regulation is needed.  The effects of salt are large:

a 5 g reduction in salt intake at the population is associated with a 23 per cent difference in stroke rates, and a 17 per cent difference in total cardiovascular disease….eating less salt could avert 1.25 million deaths from stroke and almost 3m deaths from cardiovascular disease – and these projections are…conservative because of imprecision in assessing salt intake.

Why regulation?  Because nearly 80% of salt enters the diet through processed and pre-prepared foods.  The rest is about equally divided between naturally occurring salt in foods and salt added at the table.   To reduce salt, food manufacturers and restaurants need to cut down, and all of them have to do it.

This is because the taste for salt depends on how much is eaten.  On a low salt diet, even lightly salted foods taste salty.  But if you are used to eating a lot of salt, it takes even more to taste salty.  So the object needs to be to reduce salt in the diet across the board.

I’m hearing a lot these days about how federal agencies are getting interested in the salt issue.  Stay tuned on this one.

And have a safe, healthy, delicious, and lightly salted thanksgiving!

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Nov 24 2009

The news from China: two executions

Remember last year’s scandal about the 300,000 Chinese infants who developed kidney disease after being fed infant formula laced with melamine?  That anyone would put melamine into infant formula was shocking on its own (although the previous year’s scandal over melamine in pet food ought to have been fair warning, as I explained in my book, Pet Food Politics).

Even more shocking is that the Sanlu infant formula company knew about problems with its milk long before it issued a recall, in part because it did not want to embarrass the country just prior to the start of the Olympic games in Beijing.

Now, Chinese authorities have executed two men deemed responsible for adding melamine to the milk powder sold to Sanlu.  The Sanlu manager was given a life jail sentence, and 18 others involved with the Sanlu company also have been jailed for up to 15 years.

One can always debate whether the punishment fits the crime but a BBC press account quotes a lawyer who laid the blame on

an inadequate regulatory system…It’s hard to understand why these people are give such harsh punishment because generally speaking… there is a lack of monitoring and regulation…It’s the food supervision and inspection authorities that are responsible for this.

Congress, take notice: pass that food safety bill now!

Nov 23 2009

You heard it here: the hot trend is cupuaçu (?)

What, you may well ask, is cupuaçu?  I confess never having heard of it but thank heavens for Wikipedia, which explains in somewhat limited detail that it is a chocolate-like tree with a sweet fruit.  Botanically, it is a Theobroma in the chocolate family.

Mintel, the market research firm, identifies it as the newest antioxidant-rich fruit craze.  It says this fruit is not only rich in antioxidants, but also in vitamins, essential fatty acids and amino acids.  Well, yes, but so are all fruits to a greater or lesser extent.  But never mind.  Anything this exotic has to be a marketers’ dream “superfruit,” no?

Can’t wait to taste it.  If you know anything about this, do say, especially about how it might taste.

Mintel has six other predictions for upcoming hot trends:  sweet potato, cardamom, rose water, hibiscus, and Latin spices. Yum.  Aren’t you happy to be the first to know?

Nov 20 2009

Europe “clarifies” basis for health claims

European food manufacturers continue to file thousands of petitions for approval of health claims for their products.  The European Food Safety Authority (EFSA) takes a dim view of most of them, arguing that the claims are poorly substantiated by scientific evidence, if at all.

Now EFSA is attempting to clarify what manufacturers have to do to gain approval for their claims.  I say “attempting” because EFSA’s statements often are models of bureaucrat-speak.

EFSA, for example, says it is willing to consider evidence for claims based on studies performed in people with a particular disease:

For studies in groups (e.g. subjects with a disease) other than the target group (e.g. general population) for a claim EFSA considers whether scientific conclusions can be drawn for the substantiation of the claim on a case by case basis…For example, for claims on reducing gastro-intestinal discomfort (in the general population) evidence in patients with irritable bowel syndrome may be accepted.

OK.  I get that.  Then it offers further clarification:

For claims on maintenance of normal joints (in the general population, evidence in osteoarthritis patients is not accepted as osteoarthritis patients are not considered to be representative of the general population with regard to the status of the joint tissues.  In its evaluation, EFSA considers that where a health claim relates to a function that may be associated with a disease, subjects with the disease are not the target for the claim.

EFSA explains its overall philosophy for deciding which claims to approve.  It does not use a pre-established formula for the type or number of studies.  Instead, it weighs:

All the evidence from the pertinent studies (i.e, studies from which scientific conclusions can be drawn for substantiation of the claim)…with respect to its overall strength, consistency and biological plausibility, taking into account the quality of individual studies and with particular regard to the population group for which the claim is intended and the conditions of use proposed for the claimed effect.

As with all scientific evaluations, EFSA’s judgments are subjective.  It considers animal studies, but grants more weight to studies in humans.  These, it says, are “central for the substantiation of the claim.”

Food manufacturers also view the evidence subjectively, but tend to be less scientifically rigorous in their interpretation of benefit, especially when their own products are involved.   Hence: conflict.

At the moment, EFSA is holding a hard line on health claims.  FDA: take notice!




Nov 19 2009

Supplement woes, again

The supplement industry has its hands full these days trying to keep up with negative publicity about taking vitamins.    Its latest damage-control efforts are aimed at some Norwegian studies published in this week’s Journal of the American Medical Association (JAMA).  Norway does not fortify foods with folic acid and investigators evidently wanted to know if the vitamin was safe.  They gave various combinations of vitamin supplements to heart disease patients.  Oops.   Patients taking folic acid and vitamin B12 had higher death rates than those taking no supplements or vitamin B6.  The excess deaths were generally from cancer, mostly of the lung.

Implications?  Like all such studies, this one requires interpretation.  The supplement industry has one interpretation.  Others are likely to follow.

But maybe it’s time to think more carefully about adding folic acid to the food supply?  We add folic acid to flour in the U.S. in an effort to reduce prenatal risks for neural tube disease (NTD).  Rates of NTD have decreased with folic acid fortification, but they might have done so anyway.  Maybe taking single vitamins is not such a good idea?  Maybe we need a whole lot more research on mechanisms of action?  Do vitamins promote the growth of cancer cells, for example?  Are people with heart disease especially susceptible to excessive vitamin intake?  And maybe we need stronger regulation of dietary supplements?  What a concept!

For the supplement industry, these kinds of studies mean bad news.  Nutrition Business Journal worries about how such research will affect sales.  Watch the industry spin on this one.

Nov 18 2009

Chocolate milk redux: Nutrifluff vs. Policy

First, the “Nutrifluff,” my term for research with results that are intriguing but of unknown clinical significance.  I thank everyone who sent me links to the New York Times account of the new study linking chocolate milk to reduced inflammation.  It quotes the lead author:  “Since atherosclerosis is a low-grade inflammatory disease of the arteries, regular cocoa intake seems to prevent or reduce [it].”   But the giveaway is the next magic words that cover all bases: “more studies needed.”

The study suggests – but in no way proves – that drinking chocolate milk reduces the risk of coronary artery disease.  Inflammation is an intermediate marker of suggestive but unconfirmed clinical implications.  More research is needed, indeed.

Next, policy.  Recall the fuss over chocolate milk (see previous post on the topic)?   Marlene Schwartz of the Rudd Center at Yale has posted an explanation of her views on the matter.

The “chocolate milk controversy” story this week is not about nutrition; it’s about marketing…They explain that “more than half of all flavored milk is sold in schools,” and “the importance of flavored milk goes beyond the school market because it is a key growth area for milk processors.”

They are trying to sell their product. There is nothing wrong with that as long as their marketing efforts are not misleading. Chocolate milk is not the nutritional equivalent of regular milk. It is significantly higher in calories, sugar (often high fructose corn syrup), sodium, and usually contains artificial colors and flavors.

In the promotional video on YouTube, expert dieticians acknowledged that chocolate milk has about 60 more calories per serving than regular milk, but then quickly added that “in the grand scheme of things, that’s nothing compared to the amount of nutrients they are going to be getting.”

That sounded really familiar.

“In the grand scheme of things, these calories don’t count” is exactly what we heard from David Mackay, the CEO of Kellogg in his defense of marketing his company’s high-sugar cereals: “Twelve grams of sugar is 50 calories. A presweetened cereal as part of a regular diet for kids is not a bad thing.”

50 calories here, 60 calories there, and pretty soon we are talking about real weight gain.

Our research has found that children will eat low-sugar cereals and drink white milk when these are the foods that are served. We also found that most children will also eat a piece of fruit if you prompt them to take it. School cafeterias are the perfect place to reinforce the nutrition lessons that begin at home and promote nutrient-dense foods.

If chocolate milk were the only treat children were exposed to in schools, it would not be nearly as much of a problem.  But it is not.  In many schools, kids are offered sweet treats all day long (birthday celebrations, rewards from teachers, etc) or exposed to those readily available from vending machines.  So sweet foods have become the norm.  Norms are hard to change, but let’s at least not make them worse.

Nov 17 2009

Want safe meat? Make USDA do its job!

The New York Times reports that the company selling contaminated ground beef responsible for killing two people and making 500 others sick, “stopped testing its ingredients years ago under pressure from beef suppliers.”

Recall that since 1994, the USDA bans E. coli 0157:H7 in ground meat.  It encourages, but does not require, meat companies to test for the pathogen. Why don’t they test?  Because they don’t have to.

If they did test, they might find toxic E. coli and have to cook or destroy the meat.  As the Times reported in depth last month, Testing puts meat companies in “a regulatory situation.”  As one food safety officer put it, slaughterhouses do not want his packing company to test for pathogens: “one, I have to tell the government, and two, the government will trace it back to them. So we don’t do that.”

Instead of requiring safety testing, the USDA uses a “restrained approach.”  As Dr. Kenneth Petersen, an assistant administrator with the USDA’s Food Safety and Inspection Service, told the Times, USDA has the power to require testing but doesn’t use it because it has to take the companies’ needs into consideration: “I have to look at the entire industry, not just what is best for public health.”

The moral?  Meat companies will only produce meat safely if forced to.  As we saw yesterday, oyster companies will only produce safe oysters if they have to.  That’s why we need a food safety system in which all foods have to be produced safely.  What will it take to get Congress to act?