Down to a science
December 5th 2018, 15:29
It's hopefully not a case of wishful thinking that another big fat nail has been driven into the coffin of the system that's been issuing faulty nutritional advice to the public for years. The advice hasn't been just slightly wrong—it's been killing people prematurely.
It's also at the heart (excuse the pun) of the preventable chronic disease spiral that includes cardiovascular disease, obesity and type 2 diabetes. Not only have these conditions unnecessarily harmed millions of families, they've also brought Western healthcare systems close to the breaking point. You heard it: unnecessarily.
The 'nail' comes in the form of a paper written by Professor John Ioannidis from Stanford University, published in one of the world's most influential medical journals, the Journal of the American Medical Association.1 Ioannidis has spent over 20 years on the scientific front lines, speaking out about what's wrong with modern research.
His first international claim to fame was telling the scientific community that most published science was false,2 and his analysis has been sufficiently robust to ensure it stands to this day without any effective challenge.
Now he's turned his attention to the two main types of studies that carry the most weight in developing public health advice—prospective cohort studies and randomized controlled trials—and how they are prone to delivering findings that have little relevance to most people, most of the time.
His target is a small but highly influential group of epidemiologists who have taken the lion's share of funding in the field of nutrition research aimed at informing the public about the healthiest ways to eat.
Faceless public health scientists employed by government agencies in the US, UK and other Western countries usually don't know enough about the details to determine if the latest research study is good, bad or indifferent. They accept it at face value, or worse, they accept the spin that's put on the findings by national media, which is well-known to be in the back pocket of Big Pharma and Big Food.
The net result is that government agencies then dish out advice to the public, allegedly on the basis of the "best available scientific evidence," that is actually lethal. This is exactly what's happened with over three decades of advice on low-fat eating guidelines that have caused people to become ever more dependent on sugars and other refined carbs.
Ioannidis complained that these scientists often misrepresent statistical associations as causations. It might not sound too important, but let's say you find that people who consume more vegetables and fruits live longer with less disease. That doesn't necessarily mean that the types of fruit and veg people are eating are improving their health. It could be that they also consume less food that's harmful to them, such as foods with additives and pesticides, something that's generally not assessed.
Conversely, some studies have shown that those who eat more red meat may have worse health outcomes. Again, it's not necessarily red meat itself that's harming them. There's plenty of evidence showing that how animals are raised and how meat is prepared can dramatically affect our health.
Some undercooked meats may increase our risk of food-borne bacteria and other pathogens, while 'incinerating' meat using high-temperature cooking methods like frying and grilling creates compounds that can give you cancer.
Ioannidis' list of complaints also includes wrongly assuming that the things we eat most (like carbohydrates or fats) have the greatest influence on our health. The unspoken implication of this assumption is that the things we eat in tiny amounts, like food additives and pesticides, are unimportant. Any reading of the science on carcinogens tells us otherwise.
Furthermore, while nutritional epidemiological studies might include tens of thousands of people, the findings are only as good as the data plugged in. Most use self-reported questionnaires, which are demonstrably inaccurate.
Studies of studies, known as meta-analyses, that pull together many different investigations are the latest fad. But they're a melting pot of so many different types of data that you end up with nothing more than what Ioannidis describes as "weighted averages of expert opinions." This kind of desk-based research is entirely divorced from clinical reality.
The US and UK governments still issue flawed nutritional advice that tells us not to consume more than 35 percent of our energy from fats, and to get around 55 percent of our energy from carbohydrates. This advice got another plug by a recent prospective cohort study, which generated headlines claiming that those on low-carb diets might die prematurely. 3
The reality is that it presented not one shred of definitive evidence to this effect. It was a classic piece of scientific spin designed to maintain the status quo, which keeps the wheels of Big Pharma, Big Food—and Big Research—spinning.
This is the very type of research and media circus that Ioannidis and a growing number of scientists, clinicians and members of the public are railing against. But let's not give up—it's just a matter of time before good science wins.
1 JAMA, 2018; 320: 969-70
2 PLoS Med, 2005; 2: e124
3 Lancet Public Health, 2018; 3: e419-28