Scientists say your brain suddenly ages at 57, 70, and 78. Here are 5 ways to curb mental decline.

• A new study found waves of brain aging occur at ages 57, 70, and 78.
• Some healthy habits can combat mental decline by improving memory and cognition.

Brain aging accelerates at three specific points in your life, according to a recent study.

The researchers looked at brain images of over 10,000 healthy adults, then tracked blood protein changes in half of them to look for "brain age gap" (BAG), a sign of cognitive aging.

Their findings, published in Nature, suggest that most people experienced peaks in brain aging at three ages: 57, 70, and 78.

At 57, there were protein changes related to wound healing and metabolism; at 70, with brain-cell function that could increase the risk of dementia; and at 78, with immunity and inflammation.

There are steps you can take to reduce your risks of mental decline.

Here are some science-backed habits that scientists believe have strong cognitive benefits, from improving memory to clearing out toxins from the brain.

Eat lots of protein and leafy greens

Eating enough protein, such as fatty fish or sardines, can boost memory and protect against cognitive decline. Nuts, beans, whole grains, and yogurt are also great sources of protein.

Leafy greens, such as spinach and kale, contain important nutrients like iron and magnesium that are vital for optimal brain health.

Other great foods to incorporate for cognitive health include berries, herbs, and tea.

Move often

The hippocampus and prefrontal cortex both deteriorate as we age, but regular movement can boost neuron growth and improve memory.

It doesn't mean you have to hit the gym every day, either: Even short bursts of exercise have loads of health benefits — just one minute of squats can improve concentration and decision-making.

The Blue Zones project reports that people who rely on walking as their main form of movement throughout the day live longer.

See your friends

Chronic loneliness affects your physical health in multiple ways, including your heart function and immune system. It can also impact your memory, even contributing to cognitive decline and dementia.

Joining groups is a great way to make new friends even in your 70s. It's also good to seek out deeper relationships to avoid feeling lonely in a crowd.

Get enough deep sleep

Quality sleep is crucial for brain health. Deep sleep, in which your brain wave frequencies slow down, is responsible for clearing toxins from your brain. It accounts for less than a quarter of your sleep cycle, so you should be getting between 55 to 97 minutes of deep sleep every night.

You can get more deep sleep by exercising enough during the day and reducing caffeine before bed, so that you can properly enter deep sleep.

Challenge yourself

Jason Shepherd, an associate professor of neurobiology at the University of Utah, previously told Business Insider that trying new things keeps the brain healthy. It can include traveling or taking up new hobbies.

"I think a lot of us get into routines and habits where we're doing the same old thing each day," he said. "But learning new things helps with brain plasticity."