Pursuit of Happiness and Aging

Pursuit of Happiness and Aging

I was listening to Terry Gross interview David Linden on Fresh Air about his book The Compass of Pleasure, and something kept nagging at the back of my thinker throughout the interview. Something familiar. Something that seemed to connect with all the reading and writing I’ve done on Alzheimer’s and the brain this past year.

So I re-listened to the Fresh Air segment today, then did some quick digging through articles I’ve seen online on the brain, stirred it all around, let it simmer some more, and here is the reduction I got.

Maybe our addiction to the pursuit of happiness is contributing to brain aging. It’s not an umbrella cause, of course. You would never have been able to say that Mom led a hedonistic lifestyle. And Ronald Reagan pursued a lot more things than happiness. But still… The connection between what Dr. Linden was saying and what I’ve read makes me suspicious.

In David Linden’s Compass of Pleasure, he talks about the pleasure area of the brain as being that part that–in response to certain activities or substances–produces dopamine. Dopamine is the “feel good” neurotransmitter in the brain. It is activated when we engage in certain activities or thought processes, but it is also activated when we injest/inject food, alcohol, narcotics.

Some things that produce dopamine are completely healthy. Like a good run, the enjoyment of friends, reading a stimulating book.

Some things are borderline good. Like food. Everybody needs it. The pleasure of good food produces dopamine. But when pleasure is sought after for pleasure’s sake, “the brain’s dopaminergic circuitry gets blunted. In all cases of producing pleasure in the brain, it takes increasing levels [of a thing] to produce the same level of pleasure” (quoting Dr. L). So with food, you eventually get overweightness if the pleasure of food is pursued beyond the body’s need for it. Obesity is contributing to an epidemic of Diabetes, which is strongly linked to brain aging. By indirect means, then, the pursuit of a happy palate can lead to brain aging.

Then there are things that produce dopamine (or cause its production) that are not healthy. Like alcohol, nicotine, cocaine. This falls in with the acetaldehyde hypothesis I wrote about in Does Alzheimer’s Take Guts. Alcohol, cocaine, and especially cigarette smoke have–at some point in their metabolic breakdown–the toxic aldehyde acetaldehyde. Very destructive to the brain. Dopamine is produced as the end-process of breaking down harmful aldehydes into harmless acids. It’s the brain’s “Yahoo!” after saving the day from the bad guys. That “Yahoo!” may be a good thing, but again, in order to get it a second, third, and nth time, you have to increase the attack on the body. [Interestingly, Disulfiram‘s use to treat alcohol and cocaine addiction works by inhibiting ALDH2 (aldehyde dehydrogenase) which is the enzyme that metabolizes acetaldehyde. It lets the toxin do its full work rather than disabling it by metabolizing it into a harmless acid. So the brain does not get its “yahoo!” And if you get no yahoo, you don’t repeat the action.]

The problem with focusing on happiness above all else is that we may end up using the short-cut and more harmful methods of getting that dopamine high.

Dr. Linden’s solution? “Try to take your pleasures broadly: exercise, meditate, learn, have moderate consumption of alcohol, moderate consumption of food.”

I would add: pursue friendships, do charitable work, tend a garden, read a good book (get more ideas at Changing Aging).

As Captain Kirk once said, “There are a million things you can have and a million things you can’t have. Choose the million you can.”

See also:
Ethanol and acetaldehyde action on central dopamine systems: mechanisms, modulation, and relationship to stress.

Age-Dependent Neurodegeneration Accompanying Memory Loss in Transgenic Mice Defective in Mitochondrial Aldehyde Dehydrogenase 2 Activity