Indeed, in high enough dose, anything can be a poison, and everything can kill you. Oxygen causes retinopathy; water causes seizures; iron causes liver damage; vitamin D causes calcification of the heart and kidneys. Nature, however, imposes limits on our ability to ingest these substances and keeps us from getting sick. Moreover, none of these have the potential for abuse or overconsumption, and so these diseases are quite rare.
How about addictive substances? Opium poppies were used by the ancients for pain relief; only when opium was refined and mixed with tobacco in the 17th century did it become addictive. Bolivians have used coca leaves for millennia as a home remedy for aches and pains; it was only when cocaine was refined and concentrated to high doses that it became addictive and poisonous. Even marijuana has beneficial properties, e.g. preventing nausea and vomiting with chemotherapy; 18 states currently allow medicinal use, and Colorado and Washington have adopted recreational-use statutes.
What about our food? Paracelsus would argue -- real food is food, but processed food is poison. Literally. Because processed food has been overloaded, and you've been overdosed. What allows the food industry to overdose us, and why is it legal? It's called GRAS -- "generally recognized as safe." This is an FDA concept created by Congress in 1958 to distinguish substances in food it felt did not require regulation. GRAS is the straw that stirs the drink. GRAS is the enemy of the American consumer. Because "generally recognized as safe" isn't necessarily safe. Here are two reasons why.
First: A substance can become GRAS in two ways: a) "general recognition of safety through experience based on common use in foods requires a substantial history of consumption for food use by a significant number of consumers" 21 CFR 170.30(c); or b) "generally recognized, among experts qualified by scientific training and experience to evaluate its safety, as having been adequately shown through scientific procedures ... to be safe under the conditions of its intended use" 21 CFR 170.30(b). The operative phrase here is "intended use." Were the quantities of substances currently in processed food ever intended back in 1958? Even if Congress foresaw the rise of processed foods, GRAS was never intended to give the food industry free reign to add any substance in any amount to our food supply. GRAS provided a means to avoid the lengthy and expensive food additive approval process -- but only for those common ingredients backed by scientific data and endorsed by qualified experts as "safe." Changes in our diet and consumption over the decades challenge those conclusions, but GRAS has not been updated.
Second: Before 1997, a food company had to petition the FDA to get a substance on the GRAS list. Now all it has to do is convene a meeting of scientists (paid by the company -- talk about conflicts of interest) to sit in a room and declare a substance is GRAS. And they don't even have to tell the FDA they did it. Of the 10,000 items on the list, 3,000 have never undergone review, and for an estimated 1,000, the FDA was not even notified. How's that for disclosure and transparency? Worse yet, the FDA does not systematically reconsider the safety of GRAS substances as new information becomes available; and even if it wanted to, it couldn't because it has been underfunded by Congress for decades. GRAS has simply become a back door for the food industry to add substances to our food supply without FDA approval.
Why should you care? Let's look at the checkered history of three substances on the GRAS list (grandfathered in back in 1958), which have pervaded our processed-food supply.
a) Trans fats. Trans fats are the single most dangerous item in our food supply. Patented in 1902 and introduced into food (Crisco) in 1911, trans fats increase shelf life (thus, the "10 year old Twinkie"), because bacteria don't have the machinery to digest the molecular trans double-bond for energy. Our mitochondria (the subcellular factories that burn energy) are just refurbished bacteria -- we can't metabolize trans fats either! So instead of metabolizing them for energy, they line our arteries and our livers instead. We've known that trans fats are poisonous since 1988, yet they remain on the GRAS list because the food industry demands they remain. Instead of regulating trans fats, in 2006 FDA decided to require labels for trans fats in food. This effort has resulted in about a 50 percent reduction in trans fat consumption, which is better than nothing. But buyer beware -- if a food has 0.4 grams per serving or less, the food company can label the food as trans fat-free. Even today, you'd be amazed how fast you can accumulate doses of dangerous trans fats.
b) Salt. We exited the seas because our kidneys could retain salt, and we need salt for our muscles and neurons to run effectively. How much salt is really necessary? People on low-salt (0.8 grams of sodium) diets do just fine. Conversely, about 10-15 percent of the American population has salt-sensitive hypertension -- a silent killer. High salt consumption correlates with stroke and heart disease, and was tied worldwide to 2.3 million heart-related deaths in 2010. The American Heart Association has long recommended we cut back our sodium consumption to 2.3 grams/day, and 1.5 grams for vulnerable people (middle-aged, elderly, African-Americans, people with hypertension).
Yet a fight over salt has been in the news recently. The data show that on a high-salt diet, the pooled relative risk of stroke (23 percent increase) and heart disease (17 percent increase) was significant, but not necessarily actionable (set by scientists at 30 percent). That's because only those 10-15 percent with salt-sensitive hypertension will truly benefit from salt reduction. Do we change the diet of the many to help the few? Also, there appears to be no benefit in reducing salt below 2.3 grams/day.
In 2010 the FDA sponsored an Institute of Medicine report, "Strategies to Reduce Sodium Intake in the United States," which states that the U.S. government will regulate salt consumption by working with all members of the food industry (so no company has a competitive advantage) and health experts to wean us off our salt habit gradually. Yet our current average sodium consumption remains at 3.6 grams/day, with no movement whatsoever. Good luck, FDA, in getting us to reduce our salt intake.
c) Sugar. Sugar was known in India as early as 1200 BCE. However, it was only for kings, as it was more expensive than gold until the 17th century, when the pot still was invented. Sugar occupied a miniscule place in our diet portfolio until the glut of high-fructose corn syrup (HFCS), and now all forms of sugar are cheap and ubiquitous. Of the 600,000 items in the American food supply, 80 percent are spiked with added sugar. The FDA last evaluated sugar and negative effects on health in 1986, when average consumption was 51 grams/day; the data were deemed "inconclusive." Current consumption is now double that amount. My colleagues and I recently showed that sugar is the proximate cause of diabetes worldwide, and its negative effects are exclusive of calories and obesity. In other words, added sugar is "toxic" in high dose. But the FDA has never even set a Dietary Reference Intake (DRI) for sugar. In 2011, I asked Sam Kass, Michelle Obama's chef, why there was no DRI for sugar. He said, "Why would you need a DRI for something that is not a nutrient?" Indeed, sugar provides only energy, not nutrition. And that is exactly why we need a DRI, to prevent the food industry from overloading us with energy from processed sugar. Worse yet, there are 56 names for sugar, so the food industry can hide the sugar it adds in the ingredient list -- in plain sight. Lastly, the nutrition facts panel lists "total" rather than "added" sugars, so you can't tell what is naturally-occurring sugar or milk sugar (both benign) versus how much the food industry added (toxic) to compromise the product.
The GRAS system was designed to allow substances in quantities that produced no harm under intended use. Today, individual foods are tinkered with, and with impunity, by the food industry. These uses were never intended. Scientists, the Pew Research Group, the Institute for Food Technology, the journal Nature, and the Government Accountability Office (GAO) have all called for GRAS reform by the FDA, but the food industry has fought back and the FDA remains silent. Paracelsus would agree: You run fewer health risks smoking grass than eating GRAS, at least (if it hasn't been sprayed with paraquat) it's natural and you won't overdose.