Since John Mackey stepped down last month as CEO of Whole Foods Market, 42 years after its creation, it’s time to express our gratitude for the way Mackey and his company revolutionized food and the Natural Products Industry in America.

Grocery shopping was a dreary chore in the early days of the supermarket era. Built for efficiency, most stores were rather ugly, with bad lighting and crowded aisles. Supermarkets also were the front lines of the Better Living Through Chemistry era, when shelves were filled with highly processed, chemical-laden food.

If you were an early adopter of organic produce or pasture-raised meat, you really had to search for it. Innovation was nearly absent in the industry.

The turning point came in 1978, when John Mackey teamed up with a partner to launch Safer Way Foods, a modestly sized, natural foods supermarket in Austin, Texas. While it’s likely that you never heard of Safer Way Foods, you have surely heard of its successor: Whole Foods Market, the game-changer in providing eaters with both a pleasant shopping experience and access to better-for-people, better-for-the-planet food.

In 1980, Safer Way merged with another natural grocery in Austin, adopted the Whole Foods Market brand and opened a 10,500-foot store. It soon became the top-grossing natural food store in America, and within a very few years, spread across the nation, providing momentum to the nascent Good Food movement.

Related:Whole Foods Market co-founder and CEO John Mackey announces retirement

Today, Whole Foods' more than 500 stores are beautifully designed and well-curated, delightful to the eyes, palates and other senses. The company inspired other retailers to follow its lead, transforming the interiors of better grocery stores across America. And today, even conventional stores are filled with much healthier, tastier, and sustainably produced food.

From early on, Mackey was committed to organic food. Prior to Whole Foods, you could primarily find organic produce in the back of scruffy little health food stores. Mackey’s stores changed that. The first thing people saw upon entering a Whole Foods was gorgeous produce—much of it organic—stacked high. This spotlight on produce started a merchandising trend towards fresher, healthier food that continues today.

It's hard to believe that the entire U.S. market for organic food in 1988 was only $1 billion. Today, organic food sales exceed $62 billion.  By building a chain of large, high-volume stores across the country, Whole Foods Market played a key role in stimulating this growth.

Organic took off because Whole Foods made it hip. Organic became the food of thought leaders and influencers across the country, appealing to their interest in healthier, safer food that was more humane and better for the environment. As a result, demand for natural and organic products skyrocketed and robust supply chains followed.

Related:Replay: Conscious leadership with John Mackey

Mackey, a longtime vegan, and Whole Foods also played a key role revolutionizing livestock and seafood production. Driven by his concerns about factory farming and the inhumane treatment of animals, Mackey led efforts to create the Global Animal Partnership, a multi-step certification of animal welfare and sustainability practices now widely used in the industry. Whole Foods was also integral to the success of Marine Stewardship Council (MSC) certification, which brought a high level of transparency, sustainability and accountability to seafood production and sales.

Even prepared foods—a desultory grocery category in the pre-Whole Foods days—became a thriving sector under Mackey’s leadership, Salad bars have been an integral part of Whole Food's stores for decades. Now, customers can find sushi (with MSC-certified fish), stir-fry bars, a huge deli with numerous plant-based offerings, and many more fresh food innovations. And speaking of plant-based, Whole Foods was also the first major retailer to sell Beyond Meat, and its success launched the company as a national brand and encouraged innovation in this category.

I have my own personal and professional reasons for thanking John Mackey. I met him when he launched his first store in Chicago, and we became friends. I ran a nonprofit promoting local and sustainable food and he referred me to the Whole Foods Midwest region team to help develop their local sourcing program. We featured local farms and brands on in-store posters and our website, and the number of regional vendors they carried quickly grew.

Today, nearly every retailer is working with local brands, but Whole Foods was 15 years ahead of that curve. Whole Foods also worked with my nonprofit to launch the Good Food Accelerator, a program that supported emerging food companies with mentoring, technical assistance and, in some cases, the opportunity to sell at Whole Foods. Women and minority entrepreneurs owned many of these businesses.

On Sept. 1, Mackey retired as CEO of Whole Foods and was succeeded by Jason Buechel, the company’s long-time chief operating officer. But that doesn’t mean Mackey is done innovating in the food industry. He is partnering with a few of his former Whole Foods colleagues to launch Healthy America, plant-based restaurants paired with wellness centers. If Mackey’s success with Whole Foods is any indication, these centers might hold the key to another needed advance: linking good food with good medicine.

While I wish Mackey well in this endeavor, I acknowledge the debt we owe him and Whole Foods Market for expanding access to good food and helping to transform our industry and the way America eats.

Jim Slama is managing director of Naturally Chicago and a founding board member of the Naturally Network, the nation’s leading natural products association. He is also the founder of Good Food Catalyst, formerly FamilyFarmed, a nonprofit organization whose vision is Good Food on Every Table.