As government agencies in places like New York seek a greater hand in shaping diets, the next set of federal nutrition guidelines, to be published this year, could prove controversial — for growing scientific evidence suggests that some federal recommendations have simply been wrong.
The crux of the controversy is the quantity of fat and carbohydrates we consume and how it influences cardiac health. As Scientific American recentlypointed out, ever since the first set of guidelines in 1980, Americans heard that they had to reduce their intake of saturated fat by cutting back on meat and dairy products and replacing them with carbohydrates. They dutifully complied. Since then, obesity has increased sharply, and the progress that the country has made against heart disease has largely come from statin drugs.
In an analysis of the daily food intake of some 350,000 people published this year in The American Journal of Clinical Nutrition, researchers found no link between the amount of saturated fat that a person consumed and heart-disease risk. Harvard researchers also recently released an analysis of data from 20 studies around the world, concluding that those who eat four ounces of fresh red meat a day face no greater risk of heart disease.
According to Scientific American, growing research into carbohydrate-based diets has demonstrated that the medical establishment may have harmed Americans by steering them toward carbs. Diets rich in carbohydrates that are quickly digestible give people an insulin boost that raises the risk of diabetes and makes them far more likely to contract cardiovascular disease than those who eat moderate amounts of meat and fewer carbs.
Though federal guidelines now emphasize fiber-rich carbohydrates, which take longer to digest, the incessant message to substitute carbs for meat appears to have done much damage. And it doesn’t appear that the government will change its approach this time around. The preliminary recommendations of a panel advising the FDA on the new guidelines urge people to shift to “plant-based” diets and to consume “only moderate amounts of lean meats, poultry and eggs.”
The public-health establishment has been slow about reversing course before. Starting in the 1970s, the American Heart Association advised people to reduce drastically their consumption of eggs to limit total cholesterol intake. The recommendation, seconded by government and other public-health groups, prompted a sharp drop in the consumption of eggs, a food nutritionists praise as low in calories and high in nutrients. In 2000, the AHA revised its restrictions on eggs to one a day (from a one-time low of three a week), but it also recommended reducing consumption of other cholesterol-heavy foods to compensate.
Yet a 2004 Journal of Nutrition article that looked at worldwide studies of egg consumption noted that the current restrictions on eating eggs are “unwarranted for the majority of people and are not supported by scientific data.”
More and more, the history of dietary guidelines that our public-health authorities promulgate resembles the Woody Allen comedy “Sleeper,” in which the main character, awaking from a centuries-long slumber, learns that every food we once thought bad for us is actually good, starting with steak and chocolate. In 2006, New York City passed the nation’s first ban on the use of trans fats by restaurants, and other cities followed suit, though trans fats constitute just 2 percent of Americans’ caloric intake. Now the Bloomberg administration is trying to push food manufacturers nationwide to reduce their use of salt — and the nutrition panel advising the FDA on the new guidelines similarly recommends reducing salt intake
Yet Dr. Michael Alderman, an Albert Einstein College of Medicine hypertension specialist, observed in The New York Times that because sodium is an essential component of our diets, the city’s effort amounts to a giant, uncontrolled public-health experiment that could have unintended consequences. In 2006, Harvard Medical School professor Norman Hollenberg concluded that evidence “is too inconsistent and generally too small to mandate policy decisions at the community level.”
As medicine focuses on tailoring therapies to individual needs, sweeping public pronouncements on health have become outdated at best and dangerous at worst. The best advice that government can give citizens is to develop their own diet and exercise regimes, adapted to their own physical circumstances, after consultation with their doctors.
Adapted from City Jour nal, where Steven Malanga is senior editor.