Last year, I wrapped up the year in food and nutrition stories with a detailed chronological summary. This time, I want to highlight four of the year’s most significant events in the realm of food, food politics, and nutrition — and the lessons they imparted.

1. Glue, Scrape, and Slime. 2012 was the year where disturbing ingredients in our food supply — with particularly heinous food safety implications — came to light. There was tuna scrape in sushi. And who can forget “meat glue”? As alarming as those stories were, this year will forever be remembered as the year of “pink slime” (also known as mechanically separated meat, or — as Beef Products Inc. refers to it — “lean finely textured beef”).

This ammonia-treated scrap meat — the same one phased out by fast-food giants — has been widely used since the early 1990s and was a staple in school cafeterias despite its shoddy food safety reputation. A petition drafted by blogger Bettina Elias Siegel to eliminate pink slime from school cafeterias quickly earned over 250,000 signatures.

In a victorious epilogue, 47 states did not purchase pink slime for the 2012-2013 school year, and ground beef processors saw production of the controversial ingredient — and its sales — plummet.

Just days ago, the pink slime saga reawakened when a former BPI employee — and author of a recently-released book on “pink slime” — sued ABC News, Diane Sawyer, and Siegel, among others, for defamation. Stay tuned.

The Lesson: These slimes, scrapes, and glues are further evidence that the industrialized food system is, more often than not, a food safety terror, barely held together by a deeply flawed model that continually puts our health at risk. They also demonstrate the importance of regulating food safety and gaining an understanding of where the food we eat comes from. The strong rejection of “pink slime” was also a testament to food activists’ grassroot efforts.

2. Proposition 37. Food activists around the world kept a close eye on California this past November when the time came to vote on Proposition 37 — a ballot initiative to label genetically modified organisms in food.

Although it was a close race, Prop 37 did not pass (as renowned public health lawyer Michele Simon pointed out, it was in large part due to Big Ag’s lies, dirty tricks, and seemingly bottomless pockets).

The Lesson: The concern over genetically modified crops will only continue to increase in the United States — especially since 50 countries already have labeling laws in place.

Proposition 37 served as a conduit for individuals throughout the “good food” movement to put dietary preferences aside and band together for a common cause. The defeat of Proposition 37 was also a wake-up as to just how powerful of machines Big Food and Big Ag are, and their ability to fund a battle against sound public health policy. In the meantime, states like Washington and Vermont are working on GMO labeling initiatives.

3. Hostess Shuts Down. After years of dismal finances and organizational musical chairs, Hostess Brands declared bankruptcy and shut down operations after an 80-year run (in an incredible display of hubris, the company blamed unionized workers).

While some lamented the demise of the Twinkie (an icon of processed food, if there ever was one), it was the blatant examples of corporate greed — like putting employee pensions toward executive pay — that turned this story into a cautionary tale of business gone wrong (and unethical).

The Lesson: While Big Food is often cited for its constant production of highly processed and minimally nutritious foods, it is just as important to keep an eye on its corporate structures that propagate, and worsen, issues of income and social inequity.

4. The Toxic Food Environment. Conversations about food, nutrition, and health must also touch on environmental factors. This year, arsenic in chicken feed — and rice — understandably caused concern. The health risks of pesticides, meanwhile, (finally!) received acknowledgement from even relatively conservative health organizations, like the American Academy of Pediatrics.

The Lesson: The health of our food and agricultural system is entirely dependent on the health of our environment. It is crucial to have effective environmental policies in place that allow us to produce foods that do not come with added public health risks.

As the famous saying goes, “Those who do not learn from history are doomed to repeat it.” For the sake of the health of our planet and fellow beings, may this year’s food lessons be remembered and well-integrated as we move forward.

This post originally appeared on the Huffington Post.