Reprieve for red meat - OK, but with veggies
Why do nutritional guidelines flip-flop so much? Bad science.
The Institute for Health Metrics and Evaluation (IHME) is an independent global health research organisation at the University of Washington in Seattle. IHME provides rigorous and comparable measurement of the world’s most important health problems and evaluates the strategies used to address them.
IHME scientists developed a robust analytical system to better evaluate health risks, finding weak evidence for red meat's harm.
Why this to-ing and fro-ing in such an important area?
First, they swore that cholesterol was Public Enemy #1 with regard to coronary artery disease. They launched massive campaigns, costing huge sums, to educate the public about the risks of high cholesterol intake in food. The public media teemed with dietary advice about eating healthy. This went on for decades.
And then they reversed track. It’s not that bad, really. We don’t even know for sure if cholesterol is related to heart disease.
Enough is enough.
Today, our greatest health problems relate to overeating. People are consuming too many calories and too much low-quality food, leading to diseases like cancer, obesity, diabetes, and heart disease.
Nutrition research - an imperfect science
Nutritional research is inherently rife with problems and contradictions. Here are some factors:.
Nutritional research relies on observational studies. They are loaded with uncertainty. These studies have been running for years and follow large numbers of people who are already eating a certain way. We conduct periodic checks to observe, for instance, who develops the diseases under consideration.
What’s wrong with that? Sounds like a good way to make associations.
On the surface, yes. These studies, however, are rife with “confounding factors.” It could be that fish eaters are more likely to be higher-income, better-educated, or more health-conscious on average—and that's what's leading to the differences in health outcomes, not the diet. Maybe red meat eaters are more likely to eat lots of fatty foods or smoke. Maybe …
Nutritional studies find it difficult to conduct randomised, controlled trials (RCT), the gold standard for drawing conclusions from interventions.
Many studies rely on memory, such as imprecise food surveys and diaries. Chances are, you probably can't answer the questions asked with any certainty. And yet, a lot of nutrition research today rests on just that kind of information: people's self-reporting from memory of what they ate.
When researchers examined these "memory-based dietary assessment methods," they found that this data was "fundamentally and fatally flawed."
Different bodies respond differently to the same food.
One study followed 800 people for a week, continuously monitoring their blood sugar levels to see how they responded to the same foods. Every person seemed to respond wildly differently, even to identical meals. The researchers concluded, "suggesting that universal dietary recommendations may have limited utility."
Seemingly similar foods can differ wildly in their nutritional profiles. Making the same dish at home and purchasing it from a restaurant can result in significant differences.
Industrial funding and conflict of interest
The government disproportionately underfunds nutrition science, providing ample opportunity for food companies and industry groups to sponsor research. Food and beverage makers pay for many nutrition studies, with sometimes dubious results.
Industry-funded research tends to have results favourable to the sponsoring company. Health professionals and the public lose confidence in basic dietary advice.
The bottom line(s)
A consensus statement from a very diverse group of nutrition researchers, who got together to discuss what they agree on about food and health, came up with:
A healthy dietary pattern is higher in vegetables, fruits, whole grains, low- or non-fat dairy, seafood, legumes, and nuts; moderate in alcohol (among adults); lower in red and processed meats; and low in sugar-sweetened foods and drinks and refined grains.
Additional strong evidence shows that it is not necessary to eliminate food groups or conform to a single dietary pattern to achieve healthy dietary patterns. Rather, individuals can combine foods in a variety of flexible ways to achieve healthy dietary patterns, and these strategies should be tailored to meet the individual’s health needs, dietary preferences and cultural traditions.
Amen.
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