Monday, December 18, 2006

Now for the GOOD trans fats!

Well, as with so much in science, there are caveats. And there's a big one with the trans fats. Although the vast majority of these fats are unhealthy, there is a minority that are fine to eat and may even prove beneficial.

Known as conjugated linoleic acids (CLAs), some of these trans fats occur naturally in dairy products and meat, especially milk and butter. Others form as a result of chemical processing or cooking. A growing number of studies have demonstrated that, at least in animals, these unusual fats fight a host of chronic health conditions from heart disease to diabetes to cancer. Most recently, several CLAs have shown promise in moderating the runaway inflammation that underlies arthritis, asthma, and even lupus.

A new line of research now aims at naturally increasing the concentrations of these unusual trans fats in foods such as milk and cheeses. Michael W. Pariza of the University of Wisconsin-Madison, who discovered the beneficial alter ego of CLA trans fats more than 2 decades ago, suspects that one day they may even be added to foods to fortify their healthiness. At present, however, most people take in minimal amounts of CLAs.

Nevertheless, data on the potential benefits of these unusual trans fats have been so compelling that the Food and Drug Administration exempted them from the new trans-fat labeling law that went into effect this year. That law had been intended to steer people away from bad fats...

There is one more important caveat about CLAs: As fats, they're high in calories. That means that, as with all energy-dense foods, consumption of their food sources should be kept within moderation.


This reminds me of the old cholesterol scare. Once all cholesterol in your diet was bad and then it was decided that there is good and bad cholesterol. Then later again it was decided that dietary cholesterol was largely irrelevant to the amount of cholesterol in your blood (the body makes its own cholesterol). As one large study concluded "There was no association between intakes of saturated or c/s-monounsaturated fatty acids, linoleic or linolenic acid, or dietary cholesterol and the risk of coronary deaths". So cholesterol in your food was not really much of a problem after all. Most dietary cholesterol in Western countries comes from eggs so do big egg-eaters die younger? There is no clear evidence that they do. Amusing how the trans fats scare is following the same trajectory. It will take a few years, though

How green is your organic lettuce?

Even an apparently obvious claim-that organic food is better for the environment than the conventionally farmed kind-turns out to be controversial. There are many different definitions of the term "organic", but it generally involves severe restrictions on the use of synthetic pesticides and fertilisers and a ban on genetically modified organisms. Peter Melchett of the Soil Association, Britain's leading organic lobby group, says that environmental concerns, rather than health benefits, are now cited by British consumers as their main justification for buying organic food. (There is no clear evidence that conventional food is harmful or that organic food is nutritionally superior.)

But not everyone agrees that organic farming is better for the environment. Perhaps the most eminent critic of organic farming is Norman Borlaug, the father of the "green revolution", winner of the Nobel peace prize and an outspoken advocate of the use of synthetic fertilisers to increase crop yields. He claims the idea that organic farming is better for the environment is "ridiculous" because organic farming produces lower yields and therefore requires more land under cultivation to produce the same amount of food. Thanks to synthetic fertilisers, Mr Borlaug points out, global cereal production tripled between 1950 and 2000, but the amount of land used increased by only 10%. Using traditional techniques such as crop rotation, compost and manure to supply the soil with nitrogen and other minerals would have required a tripling of the area under cultivation. The more intensively you farm, Mr Borlaug contends, the more room you have left for rainforest.

What of the claim that organic farming is more energy-efficient? Lord Melchett points out for example that the artificial fertiliser used in conventional farming is made using natural gas, which is "completely unsustainable". But Anthony Trewavas, a biochemist at the University of Edinburgh, counters that organic farming actually requires more energy per tonne of food produced, because yields are lower and weeds are kept at bay by ploughing. And Mr Pollan notes that only one-fifth of the energy associated with food production across the whole food chain is consumed on the farm: the rest goes on transport and processing.

The most environmentally benign form of agriculture appears to be "no till" farming, which involves little or no ploughing and relies on cover crops and carefully applied herbicides to control weeds. This makes it hard to combine with organic methods (though some researchers are trying). Too rigid an insistence on organic farming's somewhat arbitrary rules, then-copper, a heavy metal, can be used as an organic fungicide because it is traditional-can actually hinder the adoption of greener agricultural techniques. Alas, shoppers look in vain for "no till" labels on their food-at least so far.

What about Fairtrade? Its aim is to address "the injustice of low prices" by guaranteeing that producers receive a fair price "however unfair the conventional market is", according to FLO International's website. In essence, it means paying producers an above-market "Fairtrade" price for their produce, provided they meet particular labour and production standards. In the case of coffee, for example, Fairtrade farmers receive a minimum of $1.26 per pound for their coffee, or $0.05 above the market price if it exceeds that floor. This premium is passed back to the producers to spend on development programmes. The market for Fairtrade products is much smaller than that for organic products, but is growing much faster: it increased by 37% to reach _1.1 billion ($1.4 billion) in 2005. Who could object to that?

Economists, for a start. The standard economic argument against Fairtrade goes like this: the low price of commodities such as coffee is due to overproduction, and ought to be a signal to producers to switch to growing other crops. Paying a guaranteed Fairtrade premium-in effect, a subsidy-both prevents this signal from getting through and, by raising the average price paid for coffee, encourages more producers to enter the market. This then drives down the price of non-Fairtrade coffee even further, making non-Fairtrade farmers poorer. Fairtrade does not address the basic problem, argues Tim Harford, author of "The Undercover Economist" (2005), which is that too much coffee is being produced in the first place. Instead, it could even encourage more production.

Mr Bretman of FLO International disagrees. In practice, he says, farmers cannot afford to diversify out of coffee when the price falls. Fairtrade producers can use the premiums they receive to make the necessary investments to diversify into other crops. But surely the price guarantee actually reduces the incentive to diversify?

Another objection to Fairtrade is that certification is predicated on political assumptions about the best way to organise labour. In particular, for some commodities (including coffee) certification is available only to co-operatives of small producers, who are deemed to be most likely to give workers a fair deal when deciding how to spend the Fairtrade premium. Coffee plantations or large family firms cannot be certified. Mr Bretman says the rules vary from commodity to commodity, but are intended to ensure that the Fairtrade system helps those most in need. Yet limiting certification to co-ops means "missing out on helping the vast majority of farm workers, who work on plantations," says Mr Wille of the Rainforest Alliance, which certifies producers of all kinds.

Guaranteeing a minimum price also means there is no incentive to improve quality, grumble coffee-drinkers, who find that the quality of Fairtrade brews varies widely. Again, the Rainforest Alliance does things differently. It does not guarantee a minimum price or offer a premium but provides training, advice and better access to credit. That consumers are often willing to pay more for a product with the RA logo on it is an added bonus, not the result of a formal subsidy scheme; such products must still fend for themselves in the marketplace. "We want farmers to have control of their own destinies, to learn to market their products in these competitive globalised markets, so they are not dependent on some NGO," says Mr Wille.

But perhaps the most cogent objection to Fairtrade is that it is an inefficient way to get money to poor producers. Retailers add their own enormous mark-ups to Fairtrade products and mislead consumers into thinking that all of the premium they are paying is passed on. Mr Harford calculates that only 10% of the premium paid for Fairtrade coffee in a coffee bar trickles down to the producer. Fairtrade coffee, like the organic produce sold in supermarkets, is used by retailers as a means of identifying price-insensitive consumers who will pay more, he says.

As with organic food, the Fairtrade movement is under attack both from outsiders who think it is misguided and from insiders who think it has sold its soul. In particular, the launch by Nestle, a food giant, of Partners' Blend, a Fairtrade coffee, has convinced activists that the Fairtrade movement is caving in to big business. Nestle sells over 8,000 non-Fairtrade products and is accused of exploiting the Fairtrade brand to gain favourable publicity while continuing to do business as usual. Mr Bretman disagrees. "We felt it would not be responsible to turn down an opportunity to do something that would practically help hundreds or thousands of farmers," he says. "You are winning the battle if you get corporate acceptance that these ideas are important." He concedes that the Fairtrade movement's supporters are "a very broad church" which includes anti-globalisation and anti-corporate types. But they can simply avoid Nestle's Fairtrade coffee and buy from smaller Fairtrade producers instead, he suggests.

Besides, this is how change usually comes about, notes Mr Pollan. The mainstream co-opts the fringe and shifts its position in the process; "but then you need people to stake out the fringe again." That is what has happened with organic food in America, and is starting to happen with Fairtrade food too. "People are looking for the next frontier," says Mr Pollan, and it already seems clear what that is: local food.

"Local is the new organic" has become the unofficial slogan of the local-food movement in the past couple of years. The rise of "Big Organic", the large-scale production of organic food to meet growing demand, has produced a backlash and claims that the organic movement has sold its soul. Purists worry that the organic movement's original ideals have been forgotten as large companies that produce and sell organic food on an industrial scale have muscled in.

This partly explains why food bought from local producers either directly or at farmers' markets is growing in popularity, and why local-food advocates are now the keepers of the flame of the food-activism movement. Local food need not be organic, but buying direct from small farmers short-circuits industrial production and distribution systems in the same way that buying organic used to. As a result, local food appears to be immune to being industrialised or corporatised. Organic food used to offer people a way to make a "corporate protest", says Mr Pollan, and now "local offers an alternative to that."

Buying direct means producers get a fair price, with no middlemen adding big margins along the distribution chain. Nor has local food been shipped in from the other side of the country or the other side of the world, so the smaller number of "food miles" makes local food greener, too. Local food thus appeals in different ways to environmentalists, national farm lobbies and anti-corporate activists, as well as consumers who want to know more about where their food comes from.

Obviously it makes sense to choose a product that has been grown locally over an identical product shipped in from afar. But such direct comparisons are rare. And it turns out that the apparently straightforward approach of minimising the "food miles" associated with your weekly groceries does not, in fact, always result in the smallest possible environmental impact.

The term "food mile" is itself misleading, as a report published by DEFRA, Britain's environment and farming ministry, pointed out last year. A mile travelled by a large truck full of groceries is not the same as a mile travelled by a sport-utility vehicle carrying a bag of salad. Instead, says Paul Watkiss, one of the authors of the DEFRA report, it is more helpful to think about food-vehicle miles (ie, the number of miles travelled by vehicles carrying food) and food-tonne miles (which take the tonnage being carried into account).

The DEFRA report, which analysed the supply of food in Britain, contained several counterintuitive findings. It turns out to be better for the environment to truck in tomatoes from Spain during the winter, for example, than to grow them in heated greenhouses in Britain. And it transpires that half the food-vehicle miles associated with British food are travelled by cars driving to and from the shops. Each trip is short, but there are millions of them every day. Another surprising finding was that a shift towards a local food system, and away from a supermarket-based food system, with its central distribution depots, lean supply chains and big, full trucks, might actually increase the number of food-vehicle miles being travelled locally, because things would move around in a larger number of smaller, less efficiently packed vehicles.

Research carried out at Lincoln University in New Zealand found that producing dairy products, lamb, apples and onions in that country and shipping them to Britain used less energy overall than producing them in Britain. (Farming and processing in New Zealand is much less energy intensive.) And even if flying food in from the developing world produces more emissions, that needs to be weighed against the boost to trade and development.

There is a strand of protectionism and anti-globalisation in much local-food advocacy, says Gareth Edwards-Jones of the University of Wales. Local food lets farming lobbies campaign against imports under the guise of environmentalism. A common argument is that local food is fresher, but that is not always true: green beans, for example, are picked and flown to Britain from Kenya overnight, he says. People clearly want to think that they are making environmentally or socially optimal food choices, he says, but "we don't have enough evidence" to do so.

What should a shopper do? All food choices involve trade-offs. Even if organic farming does consume a little less energy and produce a little less pollution, that must be offset against lower yields and greater land use. Fairtrade food may help some poor farmers, but may also harm others; and even if local food reduces transport emissions, it also reduces potential for economic development. Buying all three types of food can be seen as an anti-corporate protest, yet big companies already sell organic and Fairtrade food, and local sourcing coupled with supermarkets' efficient logistics may yet prove to be the greenest way to move food around.

Food is central to the debates on the environment, development, trade and globalisation-but the potential for food choices to change the world should not be overestimated. The idea of saving the world by shopping is appealing; but tackling climate change, boosting development and reforming the global trade system will require difficult political choices. "We have to vote with our votes as well as our food dollars," says Mr Pollan. Conventional political activity may not be as enjoyable as shopping, but it is far more likely to make a difference.


Cure closer for diabetes

A Canadian-led research team has uncovered the trigger for Type 1 diabetes, a "breakthrough" that allowed them to cure the disease in mice. Researchers at Toronto's Hospital for Sick Children, University of Calgary and the Jackson Laboratory in Maine published the findings in the December 15 issue of the journal Cell.

Type 1 diabetes is an auto-immune disorder that affects millions of people worldwide -- about 10 per cent of diabetes cases. It arises when certain cells responsible for insulin production become inflamed and are ultimately destroyed, making it impossible for the body to produce insulin.

Most studies on Type 1 diabetes had focused on the immune system, but the Canadian-led team found a link between the disease and the nervous system. The group discovered that abnormal nerve endings in insulin-producing pancreas islet cells sparked a chain of events that caused Type 1 diabetes in mice. When they removed the sensory neurons, it prevented inflammation of the cells and the mice did not develop the disorder. "We have created a better understanding of Type 1 and Type 2 diabetes, with new therapeutic targets and approaches derived for both diseases," study collaborator Pere Santamaria, of the University of Calgary, said.

The researchers said treatment was now being tested for Type 2, or obesity-related diabetes, in which insulin resistance was even more severe, with "strong evidence" so far it would work.



Just some problems with the "Obesity" war:

1). It tries to impose behavior change on everybody -- when most of those targeted are not obese and hence have no reason to change their behaviour. It is a form of punishing the innocent and the guilty alike. (It is also typical of Leftist thinking: Scorning the individual and capable of dealing with large groups only).

2). The longevity research all leads to the conclusion that it is people of MIDDLING weight who live longest -- not slim people. So the "epidemic" of obesity is in fact largely an "epidemic" of living longer.

3). It is total calorie intake that makes you fat -- not where you get your calories. Policies that attack only the source of the calories (e.g. "junk food") without addressing total calorie intake are hence pissing into the wind. People involuntarily deprived of their preferred calorie intake from one source are highly likely to seek and find their calories elsewhere.

4). So-called junk food is perfectly nutritious. A big Mac meal comprises meat, bread, salad and potatoes -- which is a mainstream Western diet. If that is bad then we are all in big trouble.

5). Food warriors demonize salt and fat. But we need a daily salt intake to counter salt-loss through perspiration and the research shows that people on salt-restricted diets die SOONER. And Eskimos eat huge amounts of fat with no apparent ill-effects. And the average home-cooked roast dinner has LOTS of fat. Will we ban roast dinners?

6). The foods restricted are often no more calorific than those permitted -- such as milk and fruit-juice drinks.

7). Tendency to weight is mostly genetic and is therefore not readily susceptible to voluntary behaviour change.

8). And when are we going to ban cheese? Cheese is a concentrated calorie bomb and has lots of that wicked animal fat in it too. Wouldn't we all be better off without it? And what about butter? It is just about pure fat. Surely it should be treated as contraband in kids' lunchboxes! [/sarcasm].

Trans fats:

For a summary of the weak science behind the "trans-fat" hysteria, see here. Trans fats have only a temporary effect on blood chemistry and the evidence of lasting harm from them is dubious. By taking extreme groups in trans fats intake, some weak association with coronary heart disease has at times been shown in some sub-populations but extreme group studies are inherently at risk of confounding with other factors and are intrinsically of little interest to the average person.


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