For example, since the early 20th century, we've been told that lard – rendered and clarified pig fat – is an unhealthy substance that should be replaced with vegetable oils.
Well, guess what? The truth is nearly the opposite. It's true that lard intake should be limited, but frying foods in lard is far more healthy than doing so in most vegetable oils, according to more recent studies.
In fact, when heated to frying temperatures, many vegetable oils actually release toxic substances which can cause a range of serious health problems, including cancer, dementia and heart disease.
Professor Martin Grootveld of De Montfort University at Leicester, whose field of expertise is bio-analytical chemistry and chemical pathology, was recently asked to conduct a study to determine which cooking oils are the healthiest.
His findings challenged the common wisdom regarding the use of saturated fats versus polyunsaturated fats. We have long been told that polyunsaturated fats, such as the ones found in sunflower oil, for example, are healthier than the saturated fats found in butter and lard.
From an article posted on the De Montfort University website:
When fats and oils are heated the molecular structure changes, producing chemicals called aldehydes that may cause heart disease and cancer.
Professor Grootveld's team found sunflower oil and corn oil produced aldehydes at levels 20 times higher than recommended by the World Health Organisation.
Grootveld and his team found that foods cooked in rapeseed oil, butter, goose fat or olive oil produced far less of the toxic aldehydes found in sunflower oil, corn oil and other commonly used vegetable oils.
So how did lard get a bad reputation?Lard is only one of the foods we've been warned away from, and as with many supposedly "unhealthy" foods, the real reason is that someone wanted to sell us a replacement.
In the case of lard, we were lied to by Procter & Gamble, who wanted to sell its new product – Crisco – which was invented in a lab way back in 1907.
The short version of the story is this:
In 1906, Upton Sinclair's novel, The Jungle was published. The book was a somewhat sensationalist expose of the meat industry and conditions in the slaughterhouses of Chicago. It was technically a work of fiction, but his description of workers falling into boiling vats of lard was enough to seriously turn stomachs.
However disgusted by the thought of eating lard the public may have been after reading the book, there was no viable replacement on the market until Procter & Gamble began marketing vegetable shortening.
The company was interested in finding a way to sell the cottonseed oil it owned in vast quantities since the market for the candles it sold was shrinking due to the invention of the electric light bulb.
In 1907, a German chemist, E.C. Kayser, showed up at Procter & Gamble headquarters in Cincinnati with a marvelous invention. It was a ball of fat. It looked like lard. It cooked like lard. But there was no pig involved. It was hydrogenated cottonseed oil."
The company was able, through clever marketing, to convince an already "queasy" public (due to Sinclair's book), that its lab-created product was cleaner and healthier.
Procter & Gamble... launched an ad campaign that made people think about the horrible stories of adulterated lard. The ads touted how pure and wholesome Crisco was. The company packaged the product in white and claimed "the stomach welcomes Crisco."
The rest is history. In the 1950s, scientists further diminished lard's reputation by claiming that saturated fats caused heart disease. By that point, lard was becoming widely shunned.
The moral of this entire story is that whenever you are told that a product made in a lab is better for you than a natural substance that has been used for thousands of years, a bit of healthy skepticism may be in order...