Age Wise

Long before you routinely forget where you left the keys or why you walked into a room, the wheels of cognitive decline could be turning in your brain, setting you on a course to eventual dementia.

But dementia is not inevitable, experts say.

Several new and recent studies strengthen the case for prevention strategies that you can employ starting right now — no matter how old you are — to improve your chances of staying sharp down the road.

“The underlying process related to cognitive decline starts in early adult life, and probably even earlier,” Walter Willett, MD, a professor of epidemiology and nutrition at the Harvard T.H. Chan School of Public Health, tells me. “Thus I don’t think we can start too soon.”

Before you know it

For reasons still somewhat mysterious, brain cells sometimes stop working, and connections between brain centers weaken, leading to poorer memory and thinking ability at the root of most forms of dementia. (One particular type, vascular dementia, is brought on by a stroke or other event that restricts blood flow to the brain.)

In any case, dementia is not considered a normal part of aging. Proof exists in so-called superagers I recently wrote about — people in their sixties and older whose brains inexplicably look and function just like people in their twenties.

Yet for other people, the seeds of dementia can sprout frighteningly early in life.

Signs of Alzheimer’s disease, the most common form of dementia, typically start to appear in a person’s mid-sixties, if they show up at all. More than 6.2 million Americans over 65 deal with Alzheimer’s as do more than 50 million people globally. But the gradual accumulation of damage in the brain is thought to begin 10 years or more before symptoms appear.

Early-onset Alzheimer’s, a less common type that seems to have a stronger genetic component, can begin to show up in a person’s thirties.

Regardless of when it starts, dementia’s early signs can be subtle and hard to distinguish from brain farts we all experience now and then: forgetting a name or an appointment or struggling to pull up just the right word we know is buried somewhere in the mind. As these symptoms increase, a person is likely to struggle with reason and judgment, all of which can lead to frustration and intense negative emotions.

The many potential causes of dementia

There is no cure for Alzheimer’s or other forms of dementia, and scientists are in the early stages of figuring out all the causes. Heredity is known to affect but not entirely determine dementia risk. By one estimate, albeit one that’s not fully supported by data, about a third of all dementia cases could be prevented by improving various health, lifestyle, and societal risk factors, including physical activity, diet, depression, education, and loneliness.

Last month, researchers published in the journal Stroke a list of so-called “modifiable risk factors” for dementia:

• Depression
• Hypertension
• Physical inactivity
• Diabetes
• Obesity
• Hyperlipidemia (high level of fats in the blood)
• Poor diet
• Smoking
• Social isolation (loneliness)
• Excessive alcohol use
• Sleep disorders
• Hearing loss

“Dementia is not inevitable,” said panel member Deborah Levine, MD, a primary care provider at the University of Michigan Health. “Evidence is growing that people can better maintain brain health and prevent dementia by following healthy behaviors and controlling vascular risk factors.”

To be clear, if you have a parent or sibling with dementia, your odds of getting it are around 70% higher than someone without that genetic risk. But even then, you can reduce those odds significantly by pursuing healthy lifestyle options like those mentioned above, according to preliminary research presented earlier this year at an American Heart Association meeting.

“When dementia runs in a family, both genetics and nongenetic factors, such as dietary patterns, physical activity, and smoking status, affect an individual’s overall risk,” said that study’s leader, Angelique Brellenthin, PhD, an assistant professor of kinesiology at Iowa State University.

Along with addressing the above risk factors, the latest research suggests three solid ways to help prevent or at least stall dementia.

Increase physical activity

Among the most important steps you can take to lower your risk of dementia is to up your level of physical activity — from wherever it is now to more of it. Moderate physical activity, such as a brisk daily walk, has been shown to promote good overall physical and mental health, improving sleep, lessening symptoms of depression, and promoting good cognitive functioning.

Ample research argues for starting ASAP no matter how old you are.

Poor health in middle age — measured by lack of physical activity, poor diet, and high blood pressure — more than doubles the risk of dementia later in life.

In one study, sedentary adults started a six-month exercise program, after which they took cognitive tests. Compared to a control group that stayed sedentary, the 40-year-olds in the exercising group tested as though they were 30 years old, and the 60-year-olds tested as though they were 40.

Other research finds that people who were in relatively poor health when they were 18 to 30 years old — with high blood pressure, blood sugar, and cholesterol — scored worse on cognitive tests in their forties and fifties, compared to people who were healthier as young adults. Exercise is known to improve all those markers of health.

Challenge your mind

Some studies have suggested that challenging yourself mentally can help maintain good memory and thinking skills, but experts say more research is needed on this front. So here you go:

New findings published July 14 by the journal Neurology involved 1,978 people who were 80 years old, on average, and did not have dementia at the start of the study. During a seven-year monitoring period, 457 of them developed symptoms of Alzheimer’s disease. But overall, staying mentally active — by such things as writing letters, doing puzzles, playing card games, or reading — was linked to a five-year delay in the onset of symptoms.

“It’s never too late to start doing the kinds of inexpensive, accessible activities we looked at in our study,” says the study’s lead author, Robert Wilson, PhD, a clinical neuropsychologist at Rush University Medical Center in Chicago.

Choose colorful food

You might’ve heard about flavonoids, widely touted as powerful antioxidants that could help keep the mind sharp. Cause-and-effect is always difficult to determine with nutrition research, particularly when it relies on self-reporting of consumption. So again, more research is needed. Okay, then:

New research, published July 28 in Neurology, finds people who eat at least half a serving per day of food high in flavonoids have a 20% lower risk of cognitive decline compared to those who consume few flavonoids. The high-flavonoid foods are a colorful bunch: apples, blackberries, blueberries, celery, cherries, grapefruit, oranges, pears, peppers, and strawberries. The strongest apparent protective effect came from yellow and orange fruits and vegetables, which contain high levels of a particular flavonoid called flavones.

“There is mounting evidence suggesting flavonoids are powerhouses when it comes to preventing your thinking skills from declining as you get older,” says Willett, the Harvard nutrition expert and a member of the study team. “Our results are exciting because they show that making simple changes to your diet could help prevent cognitive decline.”

The study, involving 77,335 middle-aged adults who were then monitored for 20 years, evaluated cognitive decline, not dementia, but other research shows cognitive decline is directly linked to the diagnosis of dementia, Willett notes.

While no single lifestyle change guarantees you won’t get dementia, the science has never more strongly suggested that you can exert some control over where your mind goes as you age.

“It’s never too late to start,” Willett says about improving your diet, “because we saw those protective relationships whether people were consuming the flavonoids in their diet 20 years ago or if they started incorporating them more recently.”