For better health, we’re told to consume less fat, salt and cholesterol. To eat more fresh fruits and vegetables. To start the day with a hearty breakfast and exercise regularly.
That’s the message federal, state and county governments propagate widely, and it’s embodied in the federal Dietary Guidelines for Americans.
However, the latest scientific research increasingly shows that a large part of the nutrition advice is not quite right, just plain wrong or downright harmful.
Medical researchers from some of the most prestigious institutions in the country fault a flawed process for judging scientific information.
Rigorous, controlled clinical trials are overlooked in favor of weaker evidence from observational studies in nutrition epidemiology. This can determine correlation, but not causation. Confusing the two is an elementary scientific error.
“Epidemiologic studies suggest that almost any nutrient can be associated with a myriad of outcomes. … Nowhere is this fact more evident than the shifting sands of opinion on the relative risks of fat, salt, cholesterol and sugar,” according to a July article in the journal Mayo Clinic Proceedings.
The new findings include:
• Eating more cholesterol won’t cause more heart disease in healthy people.
• Reducing intake of saturated fat won’t reduce the risk of heart disease.
• Salt doesn’t increase blood pressure in most people, and could even guard against infection.
And debunking another supposedly settled issue, a study in the Journal of Nutritional Science found that skipping breakfast leads to weight loss, not weight gain.
To be fair, much of the government’s advice appears to be accurate: Yes to more fruits, vegetables and exercise. Calorie-counting helps when people are trying to lose weight.
But with many other long-held beliefs now discredited, scientists such as those who wrote the Mayo Clinic Proceedings breakfast study said the whole process for judging the health value of foods needs an overhaul.
Because the government’s findings are baked into infrequently revised guidelines and enacted with laws and regulations, the bureaucracy of government has trouble keeping up with science. The most recent edition of the dietary guidelines was compiled in 2010; a revision is in the works for this year.
Along with persuasion, force is being considered. In 2010, the Institute of Medicine, an arm of the National Academy of Sciences, urged the U.S. Food and Drug Administration to mandate reductions in the salt content of foods. The American Heart Association also endorsed the plan.
But in 2013, the institute did a partial about-face, finding that extremely low levels of sodium intake endorsed by the heart association weren’t justified.
Meanwhile, dietary fat was once considered to be bad — no matter what the type. Science has now distinguished between various kinds of these substances. Certain types of fat are actually considered good, including some kinds of unsaturated fat. Others, such as saturated fats and trans fats, are still viewed as bad.
(Click here to read the full article, written by Bradley J. Fikes, SD Union Tribune)