By Sarah McKay, Ph.D

I’ve been writing this brain health blog since April, and very quickly it has become one of my life’s great passions—my “north star.” I wake up every morning buzzing with excitement and feeling so blessed I’m doing what I love.

Besides trying my hardest to be the best Mum and wife I can be, my passion is writing about neuroscience. My goal is to provide impeccably researched, evidence-based stories that are told in a simple, fun, and compelling way.

Your purpose in life, your north star, your passion, your bliss, your inner voice, your wisdom, your calling. What do you call it?

I believe what Mastin Kipp from The Daily Love says: “Your bliss and your purpose are the same thing.”

Chris Crowley, the author of Younger Next Year, calls it a “kedge,” which is his term for ordinary people doing extraordinary things.

Whatever word you choose to call it, people who have meaning and purpose in their life have lower risk of Alzheimer’s disease and cognitive impairment in later life. Dr. David Bennett, director of the Memory and Aging Unit at the Rush Medical Centre in Chicago, published this finding in a paper in the Archives of General Psychiatry in 2010. The project studied more than 900 community-dwelling older people (i.e. people living in aged care facilities or residential communities) without dementia who were enrolled in the Rush Memory and Aging Project.

Purpose in life was defined as:

The psychological tendency to derive meaning from life’s experiences and to possess a sense of intentionality and goal directedness that guides behaviour.

Purpose in life is linked to many positive health outcomes, including:

• better mental health
• less depression
• happiness
• satisfaction
• personal growth, self-acceptance
• better sleep
• longevity

To measure “purpose in life,” the team asked participants to rate their level of agreement from one to five, to each of the following statements:

• I feel good when I think of what I have done in the past and what I hope to do in the future.
• I live life one day at a time and do not really think about the future.
• I tend to focus on the present because the future nearly always brings me problems.
• I have a sense of direction and purpose in life.
• My daily activities often seem trivial and unimportant to me.
• I used to set goals for myself, but that now seems like a waste of time.
• I enjoy making plans for the future and working them to a reality.
• I am an active person in carrying out the plans I set for myself.
• Some people wander aimlessly through life, but I am not one of them.
• I sometimes feel as if I have done all there is to do in life.

Scoring for the negatively worded items was flipped and item scores were averaged to give a total “purpose in life” score for each person, with higher scores indicating greater purpose in life. All of the scores were adjusted (a statistical technique that takes into account other factors and “levels the playing field”) for depressive symptoms, neuroticism, and chronic medical conditions.

In the seven years of the study, 155 of 951 people (16.3%) developed Alzheimer’s disease. Statistical analysis showed that greater purpose in life was associated with a substantially reduced risk of Alzheimer’s disease. Specifically, a person with a high purpose in life score was approximately 2.4 times more likely to remain free of Alzheimer’s disease than was a person with a low purpose in life score.

A high purpose in life score was also linked to less “mild cognitive impairment.”  Mild cognitive impairment is a long preclinical phase during which people may transition before they show sufficient symptoms be diagnosed with Alzheimer’s disease.

A high purpose in life score was also linked to a slower rate of cognitive decline in old age. And purpose in life was related a decline in semantic memory, followed by episodic memory, then perceptual speed, and working memory.

What is the biological basis of the association of purpose in life with brain health?

As yet it remains unknown. We do know that lack of purpose in life is associated with high levels of the stress hormone cortisol, markers of inflammation, low high-density lipoprotein cholesterol levels (the “good” cholesterol), and abdominal fat—all factors that are associated with poor general health.

So, science might not yet have all the answers as to how purpose in life exerts an effect on the brain. But they have provided some pretty compelling evidence to foster your purpose/passion/ bliss/wisdom, or to find your north star.

How do your find your life’s purpose?

This article was original published on Your Brain Health: Everyday Neuroscience for Brain Health and Wellness, by Sarah McKay, Ph.D.