Helen Pearson has an NSU article about recent calls for a ban on trans-fatty acids such as those found in vegetable oils and margarines used extensively in processed and packaged foods.

Such fats are preferred by industry because they are versatile and last longer. But nutrition experts say trans-fats are disastrous for your health. Whereas saturated fats raise both 'bad' low density lipoprotein cholesterol (LDL) and 'good' high density lipoproteins (HDL), trans-fats boost LDL without affecting HDL, increasing the risk of heart disease.

Nutritional guidelines have long advocated cutting back on the saturated fatty acids found in meat and dairy products, and boosting unsaturated fats abundant in nuts, seeds and vegetable oils.

But trans-fats have taken longer to attract attention because their effects on health were less clear.

If you have been paying any attention at all to nutrition you're aware of the failures of the conventional dietary advice symbolized by the FDA food pyramid and associated recommendations. Obesity, diabetes, heart disease and a number of other subtle insults to health and longevity have grown to worrisome proportions and motivated rethinking of conventional wisdom. There have been dissenters all the while, but they were ignored, and newer research that dared to question dietary orthodoxy has increasingly exposed defects.

The effectiveness and safety of low-carbohydrate diets have been confirmed for periods up to one year. They may well be safe for longer periods but the data is not yet available except for anecdotes. The high-carb establishment still clings to hopes of long term problems for low-carb diets to help them save face and diminish culpability for current health problems.

Fatty acids are much better understood due to research findings in recent years. There are different kinds of dietary fats and the volume of intake isn't as important as their balance so long as there is sufficient dietary fat. In the earlier post Functional Foods polyunsaturated fatty acids (PUFAs) called omega-3 and omega-6 were cited for their health benefits in brain development and protection against heart disease and rheumatoid arthritis. Eye as well as brain development is diminished for developing country children with very low levels of fats in their inadequate, mostly grain diets deficient in both fats and oil soluble vitamins such as vitamin A.

It's interesting that those who were vilified as cranks and quacks a few years ago have been increasingly vindicated by new information, attitudes and practices. This isn't the first time Helen Pearson has written an NSU article on the subject. This article from the spring of 2002 discusses concepts advocated by evolutionary thinkers about human adaptedness to a palaeolithic diet.

Fifteen thousand years ago, cheeseburgers and chicken wings weren't on the menu. Before the advent of agriculture, humans ate whatever meat and fish they could catch, plus seeds and plants that they gathered.

Humans were healthier for it, claims Lauren Cordain of Colorado State University in Fort Collins. He and his colleagues have shown that meat from wild elk, deer and antelope contain more beneficial types of fat than meat from today's grain-fed cattle1.

Reverting to our ancestor's diet might help to fight the global spread of obesity and associated diseases, Cordain thinks. "We should try and raise our meat so it emulates wild meat," he says...

Palaeodiet advocates think that humans evolved to eat and live as hunter-gatherers did, and have not had time to adapt to the modern lifestyle of factory foods and sloth. "We believe there's a discordance between environmental conditions we were selected for and those we live in now," says Cordain.

There is still strong opposition to evolutionary diet ideas. Though the health claims of these opponents have been under increasing pressure as noted above they now base their case on agronomic claims that it is impossible to produce sufficient food for the large and growing human population without reliance on high-carb diets. For some there is hope in Techno-Vegetarianism, the production of new cultivars of common food plants altered to be more nutritious.

Meat from pasture-grazed cattle resembled wild meat more closely than did meat from cows that were intensively raised on grains such as corn and sorghum. But some argue that less intensive farming techniques will not produce sufficient meat to feed the world's population. "There's no way you can support six billion people on that kind of diet," says Bogin.

The agronomic arguments of high-carb advocates is as weak as their now discredited health arguments. In both cases they lack useful knowledge of the system. Grain feeding doesn't produce more meat, it produces more fat, exactly contrary to the objectives of palaeodiet advocates. Most of that fat is "bark", a layer of back fat that is trimmed away and rendered for industrial use rather than as food. Bark is the price paid to achieve marbling, the intra muscular fat that is comparatively low in volume but is thought to add flavor and tenderness to commercial beef. Such cattle are fed high-carb diets for about 4 months prior to slaughter to fatten them after having achieved full frame growth on a diet of fresh, green pasture grasses and/or hay (grass/lucerne).

Much less grain is needed to produce the pastured meats prized by palaeodiet advocates. In the US 70% of the maize produced is used for animal feed. Not all of that is for cattle, hogs and chickens get a lot of it too, but a significant amount of prime farm land could be converted to pasture and directly produce lean beef. This would benefit the environment as well as human diets. Erosion from cultivation would eliminated, far less fertilizer would be used and no herbicides or pesticides are needed. Far less water is used, far less fossil fuels are burned, and pastures grow ever more fertile as they draw down massive amounts of carbon from the atmosphere and sequester it in humic acids and glomalin in the soil.

Much of the wisdom of pasture production is still anecdotal but formal research is increasing. There is great opposition by the well established and well funded grain producers, animal rights extremists, vegetarians and others heavily invested both financially and philosophically in conventional foods. It isn't yet clear how things will develop, but it seems as if the carb establishment is crumbling, undermined by good science and populist rebellion as people are increasingly sick of being sick.

» Fatuous Food from Crumb Trail
There's another rant at M&M, Fat Chance, about agricultural leanings. If you have been paying any attention at all to nutrition you're aware of the failures of the conventional dietary advice symbolized by the FDA food pyramid and associated recommend......[read more]
Tracked: May 19, 2004 12:22 PM