Adults who take vitamin and mineral supplements for 10 years exhibited better long-term memory skills than those who took placebos, according to a new study.

French researchers followed 4,500 French men and women between the ages of 45 and 60 for eight years, with half the group taking a daily supplement that included vitamins C and E, selenium, zinc, and beta-carotene, and half of the group taking placebo pills. After that period was up, all of the participants were given the option of taking vitamin supplements for six more years.

At the end of the six-year period, both groups were given a series of memory tests. The groups performed similarly on most of the tests, but the nutrient-taking group did better on long-term memory exercises than the placebo group.

Investigators said the findings are partly explained by chance, but noted that a well-balanced intake of “antioxidant nutrients is good for maintaining cognitive performance, especially verbal memory.”

The study was published online in The American Journal of Clinical Nutrition.