I am a big believer in the power of supplements to address nutritional deficiencies and to support your body's natural chemical processes, including detoxification. I've spent 15 years studying the brain, and five years as a medical director of a residential memory care facility. Nearly every patient I see leaves with a list of recommended supplements. There are five supplements that I recommend to just about everyone — although I suggest working with your healthcare provider to discuss if they are appropriate for you, dosages and possible interactions with any medications you may be taking. Some nutrients and herbs can interact with prescribed medications in potentially dangerous ways, such as nootropics and mood-stabilizing psychiatric medications.

1. Nootropics
"Nootropic" is a fancy word for a substance that supports cognitive function. They typically include a blend of vitamins, fats, amino acids, herbs and sometimes caffeine. My personal experience with nootropics is that they help with focus, mental clarity, mood and better-quality sleep. It can give you a level up on days that you haven't gotten enough rest or eaten well. I take them on days I'm giving talks or when I have a lot of work to get through and need to be on all day — they help me power through, feel productive and sleep better at night.

2. Vitamin D with K
These fat-soluble vitamins have roles all over the body, particularly in maintaining bone health, but they are also directly related to brain health. Although we don't fully understand the connection between vitamin D and cognitive functions, when people have enough vitamin D, it appears to prevent cognitive decline. Vitamin K works with D to direct calcium into the bones. Like vitamin D, having higher levels of circulating vitamin K is associated with better cognitive function.

3. Omega-3s
Omega-3 essential fatty acids are anti-inflammatory — and are believed to help reduce neuroinflammation and heart disease risk (and what's good for the heart is also good for the brain). In addition, when there are ample omega-3s on hand in the bloodstream, they become incorporated into cellular membranes throughout the body, including brain cells. Once there, they enable those membranes to stay pliable and well functioning. No matter what kind you buy, you want to store them in the fridge so that they don't become rancid — in which case they become harmful to your cells, not helpful.

4. Probiotics
Probiotics help improve your gut health, and there is a strong documented link between gut health and brain health. Your friendly gut bacteria help digest your food, making the nutrients more bio-available so that you can assimilate more of them. They also manufacture neurotransmitters, playing a crucial role in mood and mindset — which we know, thanks to research by Becca Levy, an associate professor at Yale University's School of Public Health and Psychology, have a huge influence on our dementia risk.

5. Digestive enzymes
As you age, your levels of hydrochloric acid — which helps break down your food so that you can access and assimilate the nutrients within it — decline. Taking digestive enzymes in supplement form can counteract this decline and help your body adjust to a healthier diet. There are different types of digestive enzyme supplements, and different enzymes help break down different categories of foods. For example, lipase helps break down fats, protease targets proteins, and lactase breaks down the naturally occurring sugar called lactose in dairy products. Hydrochloric acid helps digest everything, but it can aggravate acid reflux if you have it. Ideally, you'd work with a healthcare professional who can steer you toward a digestive enzyme that will help you digest your food and assimilate nutrients in a meaningful way, as well as help with bloat, indigestion and nutrient depletion.

Dr. Heather Sandison is a naturopathic doctor specializing in neurocognitive medicine and the founder of Solcere Health Clinic, a brain optimization clinic, and Marama, the first residential memory care facility to have the goal of returning cognitively declined residents to independent living. Her latest book, "Reversing Alzheimer's" is out now.

I’ve been studying the brain for 15 years—I take these 5 supplements every day for sharper memory

Dr. Heather Sandison, a naturopathic doctor specializing in neurocognitive medicine, shares her 15-year research on cognitive function and recommends five supplements for better mental clarity and focus. These include nootropics, vitamin D with K, omega-3s, probiotics, and digestive enzymes.