There’s a good chance that someone you know—maybe even a loved one—suffers from dementia, a debilitating disease that affects memory, thinking, and the ability to do many day-to-day tasks. Someone is diagnosed with dementia every three seconds and, unfortunately, the disease is on the rise. It’s estimated that the number of people worldwide living with dementia (currently more than 55 million) will actually double every 20 years.

Like many chronic health issues, dementia gets worse over time and, while it mostly affects older people, research suggests that its initial onset may be earlier than we once thought. One study published in the journal Neurology shows that certain cognitive impairments can show up 18 years before an individual receives a clinical diagnosis of dementia. 

Here, experts break down some key contributors to cognitive decline, warning signs that something is off, and a few everyday actions that can support healthy brain function for years to come.

• About Our Experts: David Perlmutter, M.D., is a board-certified neurologist and a fellow of the American College of Nutrition. David Friedman, N.D., D.C., is a naturopathic doctor and clinical nutritionist. Dale Bredesen, M.D., is a neuroscience researcher and an expert in neurodegenerative diseases.

Culprits Behind Declining Cognition

Several factors can influence the gradual deterioration in functions like memory, attention, problem-solving, language, and decision-making. The most common, of course, is aging; however, lifestyle habits such as poor nutrition, lack of physical activity, excessive alcohol consumption, and smoking can all contribute to early cognitive decline, too, notes board-certified neurologist David Perlmutter, M.D., a fellow of the American College of Nutrition and author of Drop Acid. 

“Certain medical conditions like diabetes, high blood pressure, and heart disease can also contribute to cognitive decline by affecting blood flow to the brain,” Perlmutter says. “Diabetes, specifically, may compromise the ability of the brain to use glucose, its primary fuel.”

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Not to mention, exposure to environmental toxins, such as heavy metals, air pollution, pesticides, and chemical solvents, has also been associated with cognitive decline, notes naturopathic doctor and clinical nutritionist David Friedman, N.D., D.C. 

“Heavy metals like lead and mercury can accumulate in the brain, disrupting neurological function and impairing cognitive abilities,” he says. “Pesticides and insecticides, too, can interfere with neurotransmitter systems and induce oxidative stress, contributing to cognitive deficits. Industrial solvents, such as gasoline and trichloroethylene, may disrupt brain function and damage neurons, leading to memory deficits and attention problems.” 

Sleep deprivation is another potential factor here. “When we consistently get less than the recommended seven to nine hours of sleep, our cognitive processing speed slows down, which hampers executive functions, such as decision-making and problem-solving, and disrupts emotional regulation,” Friedman explains. This has a big impact over time, with research suggesting that poor sleep is a risk factor for declining cognition. 

Early Warning Signs Of Declining Cognition

Though every individual’s experience is different, a handful of early shifts could tip you off to potential cognitive issues to come.  

1. Mild and frequent forgetfulness

One of the earliest signs of cognitive decline is often trouble with forgetfulness. This can involve forgetting important dates or events, and repeatedly asking for the same information, according to Perlmutter. “It’s important to note that occasional forgetfulness can be a normal part of aging and doesn’t always indicate a serious problem,” he adds. If you’re noticing it on a more frequent basis, however, don’t disregard it.

2. Trouble performing Familiar tasks

If you notice that you’re having difficulty with a task that once felt routine or easy to perform, it may be a sign of early cognitive decline. “This could include forgetting the steps in a recipe you’ve made many times, having trouble driving to a familiar location, or forgetting the rules of a favorite game,” Perlmutter says. When difficulty with familiar tasks goes beyond regular forgetfulness and disrupts your daily life, it can become a problem.

3. Difficulty recalling pertinent information

One of the earliest signs of cognitive decline often involves changes in episodic memory, particularly delayed or difficult recall of information after time has passed. In fact, delayed recall is one of the key attributes that’s looked at in the Modified Mini-Mental State Test, a resource used to diagnose early-onset Alzheimer’s disease.

4. Changes in mood or personality

Cognitive decline can often lead to changes in a person’s mood or personality—and these shifts might start occurring gradually pretty early on. “An individual may become more confused, suspicious, depressed, fearful, or anxious and might also become upset more easily, especially when they’re out of their comfort zone,” explains Perlmutter.

5. Calling objects By The Wrong Name

Forgetting common words or phrases that you typically use all the time is another potential sign of early cognitive decline, warns Dale Bredesen, M.D., neuroscience researcher and neurodegenerative disease expert. “Substituting the wrong words, for example saying ‘carpool’ when you really meant to say ‘conference call,’ or calling your dogs the wrong names and mixing up the names of relatives are common signs,” he says. 

6. Losing focus or having difficulty concentrating

While an inability to concentrate can be the result of several things, early cognitive decline is one of them, notes Friedman. “People can become easily distracted, have trouble multitasking, or find it challenging to follow instructions,” he says. “They might struggle with maintaining concentration during conversations or while engaging in activities that previously held their attention.”

5 Everyday Ways To Keep Your Mind Sharp

Since lifestyle plays a key role in how your brain functions over the years, a few simple actions now can make a big difference down the line. Consider the following must-do’s. 

1. Engage in regular exercise 

Research shows that any kind of physical exercise, from aerobic workouts to strength training, improves cognition. “Exercise increases blood flow and oxygen delivery to the brain, promoting the growth of new neurons and enhancing cognitive function,” explains Friedman. He recommends a combination of aerobic exercises (like jogging, swimming, or cycling) and activities that challenge coordination and balance (like yoga or dancing) for optimal brain health. 

2. Maintain a healthy, nutrient-rich diet

Consuming a healthy diet is one of the best things you can do for overall brain health. Friedman recommends emphasizing antioxidants (think fruits and vegetables) to help reduce oxidative stress and inflammation in the brain, as well as omega-3 fatty acids (think fish, nuts, and seeds), which help the body manage inflammation, support healthy blood flow, and promote the function of neurotransmitters that allow the brain’s cells to communicate.   

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A healthy diet is also one that promotes healthy blood sugar levels, adds Perlmutter. “Keeping blood sugar levels normal ensures that your brain receives a steady supply of energy to help it function optimally,” he says. “Moreover, maintaining normal blood sugar can prevent conditions like diabetes, which is a risk factor for dementia.” 

3. Keep your brain active and engaged 

For long-term brain health, mentally stimulating activities such as reading, solving puzzles or crosswords, learning a new skill or instrument, playing strategy games, or engaging in creative pursuits should be a regular part of your routine. “This can help maintain cognitive function and promote neuroplasticity, or the ability of the brain to change and adapt its structure and function in response to experience,” Friedman explains. “Continuously learning and exposing yourself to new experiences can support brain health and cognitive vitality.”

4. Get consistent quality sleep

Getting sufficient and deep restorative sleep goes a long way for your health. In fact, getting the recommended amount of sleep each night can help reduce your risk of myriad diseases, including obesity, type 2 diabetes, heart disease, and high blood pressure, per the CDC. “Sleep is crucial for memory consolidation, cognitive processing, and overall brain health,” Friedman shares. “Establish a regular sleep routine, create a relaxing sleep environment, and practice good sleep hygiene habits, such as avoiding TV and smartphone screens before bed.”

5. Supplement appropriately

A number of supplements can help you provide your brain with key nutrients and support function. Just a few Friedman often recommends: coenzyme Q10, alpha lipoic acid, ginkgo biloba, phosphatidylserine, and acetyl-l-carnitine.

One that Perlmutter considers a top priority: DHA (docosahexaenoic acid). “DHA is an omega-3 fatty acid that makes up a large portion of the gray matter in the brain and is essential for neural functioning,” he explains. “Some research suggests that taking DHA supplements can help maintain brain health.”

Experts recommend that healthy adults consume 250 to 500 milligrams of DHA (combined with another omega-3, EPA) each day.