This seems to be a popular subject here on BITOG, and one that often makes me smile and bite my tongue. So I thought I would jot down some thoughts for what it’s worth.
Most people’s beliefs on nutrition and healthy diet are not formed by scrutinizing volumes of gold standard studies, i.e. randomized, double blind, placebo controlled, statistically significant, peer reviewed, and published by a reputable journal. Instead our opinions are usually formed or influenced mainly by media reports and repeated headlines as this is what we have access to, and the information we glean is both dubious and ever changing.
Media makes its money by readership and so has a strong driver to sensationalize to get attention, even to the extent to intentional distortion. Any study that associates a nasty disease such as cancer with a common food, no matter how bad the study was, will generate headlines for years until it becomes an excepted fact. That is until the next study contradicts it. How many times have we heard that coffee is good for you/coffee is bad for you, wine is good for you/wine is bad for you, eggs are good for you/eggs are bad for you, margarine is good for you/margarine is bad for you, meat is good for you/meat is bad for you, etc., etc., etc. The result of this flood of profit driven information is often false, incomplete, or misleading “facts” that become imbedded in the minds of otherwise intelligent people and debated ad nauseam.
As an example, I Googled “health benefits of garlic” and in short order found 73 diseases, ailments, or conditions that garlic is purported to cure, prevent, treat, or support, ranging from nine different cancers to erectile dysfunction! This was not a surprise because if a study, any study, finds that garlic has, say, an anti-inflammatory component, no matter how small, food and supplement marketers will jump on it and connect garlic with every ailment that has ever been “associated” with inflammation. If it nudges your cholesterol down a couple of points it instantly becomes “heart healthy” and even earns (or buys) a symbol on the label to prove it. This same nonsense exists for numerous other common foods, vitamins, and supplements in an endless effort to sell or promote some product.
And this should come as no surprise. The fact is that the chemistry of our bodies, the food we eat, and the processes they undergo and interact with is extraordinarily complex, so much so that trying to isolate a single food chemical component and quantify its long term effect on health and longevity is virtually impossible. There are just far too many variables to correct for, even in most gold standard studies, making cause and effect conclusions bewildering at best and absurd at worse. A perfect playground for marketers to peddle their wares. The lack of a scientific consensus is apparent when one considers that there are literally thousands of books written by doctors on diet and health, loaded with much disagreement and conflicting information. If we actually knew the facts we would only need one book.
So what should we believe? In this complex and ever changing subject that is a difficult question. At least be sure to carefully consider the source of the information you are reading – the words “study” and “doctor” guarantee nothing, and most social media sources are infiltrated with endlessly repeated nonsense. Even apparently credible TV reports, newspapers, and magazines fall victim to the same need to gather readers for profit, and the internet seems to have more clickbait than facts. Shun testimonials, and avoid confirmation bias by reading opposing opinions. If no reasonable and scientific consensus is apparent then avoid forming and spreading unsupported opinions. Debating is useful, but preaching is not. In short, question what you read and hear, and think critically – blind faith leads to blindness. It’s okay to not know the answer to everything.
Personally I have always found my mother’s advice to be rather sensible – eat a wide variety of foods with nothing in excess. Perhaps she should have written a study! So finally, take all information you read on nutrition and healthy diet with a large grain of salt (oh wait, never mind, salt is unhealthy!).