By Simon J. Evans, PhD

The title question may be a bit of a stretch, but you only need to connect a couple of research dots to get from childhood obesity to reduced brain fitness in older age.

Belly Fat and Brain Fitness are Related

First, a recent meta-analysis from researchers at Johns Hopkins University verified that the odds of getting Alzheimer’s and other types of dementia increase as you gain weight. A meta analysis takes all previous studies on a particular topic and looks at them together to improve the statistical power over any one study by itself. This particular meta analysis looked at all studies that evaluated whether or not risk for Alzheimer’s or other types of dementia is increased in obese individuals.

Some studies evaluated obesity status of people in their mid-forties, others looked at people in their mid-sixties or seventies. In any case, obesity in mid-life or late life increased odds of getting Alzheimer’s disease or other dementias anywhere from 10 to 30 years later. Importantly, researchers controlled for socio-economic status, lifestyle choices, genetic factors and other illnesses so that the condition of obesity itself, seemed to be the culprit.

Adolescent Weight Problems Lead to Adult Weight Problems

The second dot to connect is that being overweight in childhood dramatically increases the odds of battling a weight problem throughout adulthood. So giving in to your kids’ demands for cakes, cookies and sugared cereals now, is not doing them any favors down the road.

There are really two ways to pack on the pounds. One is to make more fat cells, and the second is to store more fat in the fat cells you already have. An important study from the Karolinska Institute in Sweden, discovered that the number of fat cells you will carry throughout your adult life is really set during your adolescent years. After the age of 20, your number of fat cells will stay about constant.

Obviously, this doesn’t mean that your weight is set after age 20. You can still lose weight or dramatically gain weight. It’s not uncommon to gain weight in your 30s and 40s, as your activity level and metabolism slow down, especially if your food intake doesn’t change. You can always lose or gain fat in the cells that you already have. However, if you gain too much weight in adolescence, when you are actively making more fat cells, you are going to set yourself up for a tough battle for the rest of your life. So as parents, we should do everything possible to regulate our kids weight while it’s still somewhat in our control.

If you connect these two lines of research, you can see that increased weight gain in childhood predicts increased obesity in adulthood; and increased obesity in adulthood boosts your odds of Alzheimer’s and dementia in your 70s and 80s. There have not been any research studies following kids all the way from adolescence to old age to look directly at the relationship between childhood weight and dementia, but they will come eventually. Personally, I won’t be surprised if these studies find increased odds of dementia with childhood obesity.

It’s difficult to think of our kids as old people, but that is who they will become. We must think proactively and do everything we can to boost their odds of life-long cognitive success. If you have concerns about your own children’s weight, work with your pediatrician to design a diet and exercise program and get it under control while you still can. If you struggle with a weight problem yourself, don’t give up. The more effort you put in to bringing your weight under control, the better your odds of a fit brain down the road. Even if you only drop some of the weight you want to lose, every little bit helps boost those odds.

References:

Nature (2008) Jun, 453(7196):783-7

Obesity Reviews (2008) May, 9(3):204-18

By Simon J. Evans, PhD

Does your job have anything to do with your odds of getting Alzheimer’s disease down the road? Studies have come out recently linking intellectually challenging careers to reduced risk of dementia. Other studies link education level to cognitive health in later years. Overall, people with more education have lower rates of Alzheimer’s disease than those with less education.

This really isn’t that surprising if you think about it. We know that the more you use your brain, the stronger it gets. Just like muscles in your arms and legs, the brain gets more fit when you work it out. Higher education usually means more mentally stimulating jobs and that keeps your brain fit.

But that doesn’t mean that you have to go to graduate school to stay mentally active. Big studies look at large groups of people. On average, when you look at lots of people those with higher levels of education have more intellectually challenging jobs. So overall, they have lower rates of dementia. However, you can be a high-school drop out and still do what’s necessary to keep your brain fit. Just don’t be average.

You can maintain an active mind by committing yourself to life-long learning. It doesn’t take a formal education to teach yourself new skills, read new books and continually challenge your mind – it ain’t rocket science.

There is, however, a flip-side to this coin. Even though higher education predicts lower odds of getting Alzheimer’s disease, those with higher education who do get Alzheimer’s, decline much more rapidly and die sooner than those with less education. Remember, again, this is based on big number averages and is not necessarily predictive for any one person. Still, on average if you have an intellectually challenging career, your odds of getting dementia are lower, but if you do get it, your odds of rapid decline are greater.

At first, this might seem paradoxical. But I think there is a likely explanation for these seemingly odd data. It all relates back to the cognitive reserve theory, which we have discussed in the past.

Essentially, cognitive reserve is something you create throughout your life. The more you learn and the more you experience, the more you create cognitive reserve. This is like ‘extra’ brain circuits to accomplish intellectual tasks.

Think of it like a city building multiple bridges across a river. If you only have one bridge to cross the river and it gets knocked out by a freak storm, you can’t get traffic to the other side. If, however, you’ve created reserve routes to cross the river with multiple bridges and one gets knocked out, you can divert traffic across the other bridges.

This is the same with brain circuits. If you’ve created multiple circuits through a variety of experiences you have different ways to accomplish the same task. If one takes a hit due to age-related damage, you can divert thoughts through different circuits and not really notice a problem.

So people with higher education and more challenging jobs may have reserve brain circuits. That means that even though we may all experience the same age-related damage, someone with more cognitive reserve will show less cognitive decline. There are also ways to minimize the age-related damage through healthy living, but that’s another topic.

So why would people with more reserve show more rapid decline once dementia sets in? Again, this makes sense if you think about it. People with high levels of reserve who get dementia must have experienced severe damage that took out all their bridges. Damage of this severity will take them down quickly.

However, it’s an illusion. Since studies only compare people diagnosed with dementia, they may be comparing apples to oranges. On average, the people with high reserve (mentally challenging careers in these studies) who have Alzheimer’s disease have likely experienced a lot more damage than, on average, the people with low reserve who have Alzheimer’s.

This would explain why people with more challenging careers would have fewer cases of Alzheimer’s; and also why people with higher levels of education who do get Alzheimer’s, decline much more quickly.

Overall, it’s better to boost your odds of not getting dementia in the first place by doing what’s necessary to challenge your mind on a daily basis. Commit yourself to life-long learning and stay mentally active to build more bridges. Couple this with quality nutrition, plenty of exercise and enough sleep, and you will also minimize the storms that create the damage that can damage your bridges.