How’s Your Fluids Intelligence?

What and how much you drink can have long-term impact on your brain health.

Photo by Alisha Hieb on Unsplash

As a former vice president of the United States once remarked to the United Negro College Fund, "What a waste it is to lose one's mind. Or not to have a mind is being very wasteful. How true that is."  For many years, the conventional wisdom was that, with rare exceptions, losing one’s mind was an inevitable part of aging. An inability to recall names, or proper nouns, or any nouns, can certainly fuel the fear that the loss is under way.

Now the current thinking is that we may lose one sort of intelligence as we age but gain another. There is fluid intelligence, which enables you to learn, assess, solve problems, adapt to the world, and yell out the correct answers while watching Jeopardy. It is the ability to reason, to create, and to remember. Fluid intelligence is what allows children to soak up information like sponges. It increases through the teen years, then slowly declines.

Crystallized intelligence, on the other hand, increases with age. It is information you’ve learned and stored in long-term memory. Crystallized intelligence is practical know-how, general knowledge, and wisdom, gleaned from experience and applied as needed.

Today I want to focus on fluid intelligence, and particularly on fluids that can feed it or impede it.

Caffeine

Good news for coffee and tea fans! Two different studies presented at this year’s Alzheimer's Association International Conference reported links between caffeine intake and long-term cognitive benefits. In one, people who drank two or more cups of coffee daily had a 28% lower risk of dementia than people drinking less than a cup daily. The same study found that people drinking up to two cups of tea daily had a lower risk of dementia than those who drank no tea at all. For those who drank the most caffeine, dementia risk decreased by 38%.

The second study found that daily coffee and tea intake could predict the rate of decline in fluid intelligence. The decline was slower among older adults who drank one to three cups of coffee per day and those who didn’t drink coffee. However, the rate of decline was faster among those who had more than four cups per day. For tea drinkers, one to three cups a day was a slower decline than among both those who had more than four cups and those who drank no tea at all. In either case, three cups a day seems to be the golden mean, four cups the law of diminishing returns. The results support the hypothesis that both coffee and tea intake protect the brain against cognitive decline.

Alcohol

The news about alcohol is not so rosy. There has long been a theory, popular among the drinking classes, that drinking in moderation offers some protection against developing dementia. Scientists now think the studies suggesting this protection were flawed, and will go so far as to say that the links between moderate drinking and dementia prevention are “not conclusive.” What is conclusive is that excessive drinking does increase the risk of developing dementia.

Now, a study published last year by the BrightFocus Foundation’s Alzheimer’s Disease Research program strongly suggests that even moderate drinking may accelerate the progression of Alzheimer’s. The study gave mice a choice between water and alcohol over a 10-week period to see whether voluntary, moderate, but chronic drinking impacted the pathways associated with Alzheimer’s. It did. The alcohol increased brain atrophy and caused more amyloid plaques to form. The researchers postulate that alcohol may accelerate the loss of neurons and the connections between them.

The findings may not qualify as a call for abstinence, but they do suggest caution. “If you have a healthy brain that can clear ethanol [the active ingredient in alcoholic beverages] and your consumption is minimal, maybe drinking has little impact,” says Shannon L. Macauley, the study team leader and assistant professor of gerontology and geriatric medicine at Wake Forest School of Medicine. “As we hit middle age, however, our metabolism changes, and alcohol may be something to avoid.”

Another long-standing belief is that moderate drinking is good for the heart and maybe the digestion. But a study tracking 135,000 adults aged 60 and older for 12 years found no reduction in heart disease deaths among light or moderate drinkers when compared with occasional drinkers. Light drinking was defined as up to 20 grams daily for men and 10 grams daily for women. A standard drink in the U.S. is 14 grams.

But it gets worse. Even light drinking was associated with an increase in cancer deaths among older adults. Dr. Rosario Ortola, the lead author of the study, said alcohol probably raises the risk of cancer “from the first drop.”

In other words, if you’re concerned about maintaining your fluid intelligence, apply your fluids intelligence wisely.