You’ve likely heard about how an apple a day keeps the doctor away. But have you heard about the benefits of an avocado a day? According to a new study performed at Tufts University, eating one whole, fresh avocado each day can contribute to better eye and brain function in older adults who are otherwise healthy.

The researchers followed 40 health adults aged 50 years and older as they ate one avocado each day for a period of six months. The participants in the control group ate either one cup of chickpeas or a medium potato each day. The control group foods have approximately the same number of calories as an avocado, but with less nutritional benefits, like monounsaturated fats and lutein.

Lutein, a pigment found in some fruits and vegetables, builds up in the bloodstream, eyes, and brain. It can work as an anti-inflammatory agent and an antioxidant. In the group that ate a whole avocado each day, researchers found a 25% increase in lutein. The same participants had better results on cognition tests that measured processing speed, attention levels, and memory.

The lutein levels more than doubled in the eye when compared to the control group. Elizabeth Johnson, the study’s lead investigator, indicated that a balanced diet that includes avocados could be a strategy for improving cognitive health.

A typical daily serving is only one third of an avocado, so more research is needed to see if the same results can be achieved by consuming less than one whole avocado. However, the research does reinforce research that shows that the avocado has health benefits.

The Hass Avocado Board commissioned the research, and the results were published in the journal Nutrients.