As we covered recently, current evidence suggests that not many things can help prevent cognitive decline with aging, but there’s good news: There may something you can do, and it might be as simple as eating. In fact, a recent study has shown that a daily helping of leafy greens can slow down memory loss as you age.

What Researchers Found

Researchers at Rush University Medical Center asked 960 elderly people how many leafy greens—such as spinach, kale, and Swiss chard—they ate for about five years. What did they find? People who ate 1.3 servings (about one and one-third cup) per day had the cognitive ability of someone 11 years younger than their age! This effect seemed to correlate with the amounts of certain plant ingredients, called phytochemicals, that people were getting—things like lutein, folate, and nitrate, all of which are present in leafy greens.

This is all good news, but keep in mind that this is an observational study. What does that mean? Well, instead of the researchers performing a trial in a controlled situation, they simply observed or recorded what these people did (how many greens they ate) over the years that they followed them. The drawback here is that it doesn’t allow us to rule out other factors that may have contributed to their increase in memory, such as having more money to spend on better quality greens. We recently covered a similar story about how drinking more coffee is associated with longer lifespan (again, you can’t conclude cause-and-effect here).

Eat Another Helping of Greens

Nevertheless, this does at least suggest that when your mom told you to eat your greens, she was right! Even though there is no stone-cold proof that eating 1.3 cups of leafy greens daily will make your brain 11 years younger, leafy greens are definitely part of a healthy diet, which we know is important for brain function. And in case you’re interested, another food that is associated with greater brain function is fish, and there’s also good evidence that people who follow the Mediterranean diet (which is high in fish and greens) stay sharper into old age.