Does spinach make you strong? Ask Popeye -- and science

(CNN)If you were a kid raised anytime between the 1930s and the 1970s -- or raised by someone who was raised then -- chances are good that you grew up with the idea that spinach was a muscle builder par excellence.

We owe that notion to a comic-strip cartoonist named Elzie Crisler Segar, who created a character that he based on a rough-edged, hard-drinking local from his Illinois hometown. Segar christened the character "Popeye," a sailor who debuted in a strip in 1929.
By 1933, when he began to appear as one of the lead characters in an animated cartoon series called "Thimble Theatre," Popeye was getting instant strength from spinach.
    And he needed it, thanks to an assortment of enemies on the high seas and terra firma alike. Whenever the diminutive mariner downed a can of spinach, muscles inflated, enabling him to pound the stuffing out of his archnemesis -- a piratical sailor called Bluto -- who was much larger and sturdier, but lacking that secret green rocket fuel.
      The legend of Popeye -- and the source of his superpower -- long outlasted the character. But, experts say, answering the question of whether spinach really does make us stronger takes some complicated turns.

      The science of spinach

      One point that could support the spinach-strength connection is that it contains plenty of nitrates, "which might improve muscle endurance," said Norman Hord, chair of the University of Oklahoma's Department of Nutritional Sciences. These nitrates are rapidly depleted during exercise or physical exertion and replenishing them "increases force production in exercising skeletal muscle."
        "More research is being done now to determine if increased nitrate in muscle translates to increase muscle strength and improved athletic performance," Hord added.
        Fitness and exercise guru Timothy Ferriss (born in 1977 and perhaps too young to have caught the Popeye bug) does not cite the ack-ack-acking sailor when, in his book "The 4-Hour Chef: The Simple Path to Cooking Like a Pro, Learning Anything, and Living the Good Life," he recommends a "slow-carb" diet of eggs, meat, fish, lentils and spinach as the quickest path to weight loss as well as overall fitness.
        This jibes well with Hord's observation that spinach contains plenty of vitamin K, which helps lower blood pressure and the risk of cardiovascular disease. Unless it's cooked beyond recognition, spinach is also a good source of vitamin C. It has no cholesterol or fat.
        Harold McGee, the dean of culinary science, argued that there are better sources of strength-building minerals. "Despite Popeye, spinach is not remarkably rich in iron, though it is a good source of vitamin A," he wrote in his now-classic book "On Food and Cooking: The Science and Lore of the Kitchen."
        Though the iron of the pumping-iron set isn't what McGee means, it's iron that you want for sculpting bulging biceps and an admirable six-pack.

        How to get the benefits of spinach

        Atlanta-based nutritionist Rahaf Al Bochi touts the vegetable's overall health benefits.
        "I recommend adding spinach to your eating pattern as it is loaded with antioxidants and vitamins such as folate, magnesium, and vitamin A, as well as fiber, which are important for reducing risk for chronic diseases," Al Bochi said.
        It's also loaded with other substances that boast a variety of benefits. Spinach has plenty of lutein, which is believed to support eye health and reduce the incidence of macular degeneration, a concern mostly of people 55 or older. The level of lutein drops substantially as spinach is cooked but is increased if used in liquefied form, so to gain this benefit, it's best eaten in a smoothie. according to a 2019 study published in Food Chemistry.