Expert who studied brain for 15 years shares a hack for sharper memory: 'If you do just one...'

As a doctor who has spent 15 years studying the brain and five more years as a medical director of a residential memory care facility, Dr Heather Sandison always advises people to eat things that feed the brain, not harm it. Speaking to CNBC Make It, the naturopathic doctor, who specialises in neurocognitive medicine and founder of a brain optimization clinic in California, shared a tip to boost brain power and keep it healthy.

Dr Sandison strongly recommends eating "nutrient-dense, lower-carb foods". "You want to give your brain the nutrients it needs to heal, repair tissues, fight toxins, and create neurotransmitters so that it can stay young, sharp and energised for as long as possible," she told the publication.

She added that while the brain makes up only two percent of our body weight, it is responsible for over 20 percent of energy expenditure each day. Eating food rich in nutrients that can provide the building blocks, and lower carbs to help stabilise blood sugar and even out the roller coaster of spikes and drops that lead to lightheadedness, anxiety, fatigue, irritability, and an inability to focus, the brain expert said.

"If you do one thing to improve your diet to protect the brain, start raising your carb-consciousness and begin swapping out some of the carb-heavy foods you eat most often for lower-carb alternatives," she told CNBC Make It.