Most would agree that milk is an important part of a child’s diet, but the value of dairy doesn’t diminish as we get older. Recent research conducted at the University of Kansas Medical Center and published in the journal Frontiers of Nutrition highlighted the benefits milk also has on the brains of older adults.
The research team found that drinking three cups of milk a day can boost the level of glutathione (GSH) in the brain of adults between the ages of 60 and 89 years old. Glutathione is a powerful antioxidant that helps protect the brain from some of the damage that comes with aging and age-related diseases.
Free radicals and other oxidants are released when the brain coverts nutrients into energy. Over time, this oxidative stress builds up and is believed to be a major contributor to aging the brain along with neurodegenerative diseases such as Alzheimer’s. As people get older, the level of GSH in the brain tends to fall.
The University of Kansas Medical Center had the ability to use a novel magnetic resonance imaging technique to measure the levels of antioxidants in the brain. In their original work, the researchers found that milk was highly correlated with GSH concentrations in the brain. More recently, they looked to see if improved consumption would show even more benefit.
A group of adults 60 to 89 years old who typically ate less than 1.5 servings of dairy a day were assigned to one of two groups. The first group was the control and maintained their current milk intake. The other group upped their intake to three cups of milk per day for three months. Brain scans were conducted before and after the study.
While there was no change in GSH brain levels in the control group, positive results were found in the other participants. Those who drank three cups of milk each day had their brain GSH levels rise on average by almost 5% overall and by 7% in the parietal region of the brain. Earlier studies have shown that GSH levels can be about 10% lower in older adults, so milk consumption could help fill this gap.
The research team focused on milk because it seems to elevate GSH levels more than dairy products like cheese and yogurt. They also noted that a GSH vitamin supplement does not have the same effect because it will not enter the brain. The brain must be able to synthesize three amino acids — glycine, glutamate, and cysteine — to make GSH. Luckily, milk is a fantastic source of those amino acids. The researchers plan to do follow up studies to determine the optimal level of milk consumption and to see if other milk, like goat of sheep milk, or plant-based alternatives have similar benefits.
Even through the U.S. Dietary Guidelines recommend that adults drink three cups of milk per day, data from the Centers for Disease Control and Prevention show that the average American adult over 60 years old drinks less than two cups daily. This recent research supports that recommendation of three cups of milk per day as a great way to keep some negative effects of an aging brain away.