Only 5% of Highly Fit Women Got Dementia
That's the good news. The not-so-good news is that 25% of women with average fitness developed dementia.
These statistics come from a new report in Neurology journal by Helena Hörder, Lena Johansson, XinXn Guo and others. Their research concluded that it's important for women to stay fit to reduce the risk of developing dementia later in life.
In 1968, Swedish scientists began a 44 year study of 1,462 women. A smaller, representative group of 191 of these women were tested for cardiovascular fitness.
- This test was given once to the women during mid-life. Some women were 38, and some were 60, but the average age at the time of the fitness test was 50 years old.
- These fitness tests monitored the women's hearts as they rode a stationary bike at peak exertion. The researchers followed these 191 women's lives and health for four decades.
How much does exercise reduce the risk of Alzheimer's and dementia? 88%
Women who exercise and maintain high levels of fitness are 88% less likely to get dementia. Here is the breakdown:
Of the 191 women who were tested at mid-life, 23% developed dementia in the ensuing 44 years.
Sorting these into fitness levels, researchers determined that:
- 32% of the low-fitness women developed dementia
- 25% of the average-fitness women developed dementia
- Only 5% of the high-fitness women developed dementia -- and they got dementia 9.5 years later in life.
What's the health difference between exercising a little and a lot?
There is tremendous benefit to women who are very fit in mid-life. Women with higher fitness levels at mid-life were 88% less likely to develop dementia compared to women with average fitness levels.
Among the 5% of fit women who did develop dementia, they were diagnosed 9.5 years later than the low-fitness women.
Those with lower fitness levels had 41% higher risk of developing dementia than women with an average fitness level.
In the study cited here, physiotherapists at the University of Gothenburg in Sweden, measured cardiovascular fitness in the women. This research provided input on how well their blood circulation was feeding their hearts and brains. They found that when the heart is healthy, so is the brain.
As it turns out, being out of shape strains the heart and is unhealthy for the brain. Researchers were surprised that there was such a correlation between fitness and dementia. But it seems there is a clear link between staying fit and keeping your brain fit as well.
What Does it Mean to be Fit?
In measuring fitness, the women rode stationary bikes that measured their pedaling output in watts. First, the women pedaled easy for six minutes, at speeds and gearing (or tension) to produce 32 watts, and then 64 watts. By comparison, fast walking produces 100 watts of energy.
After this warm up, the women rested for five minutes. Then, they started the "peak workload test." The women pedaled as hard as they could until they were exhausted and had to stop -- typically at six minutes. If a woman could pedal longer than six minutes at her maximum speed, the researches increased the tension on the bicycle, until she had to stop pedaling.
- Low-fitness women, on average, produced 80 watts at their peak workload.
- Average-fitness women produced 88 to 122 watts at peak workloads.
- High-fitness women, on average, produced 120 watts or more at peak workload.
Today, many stationary bicycles at a modern gym measure output in watts. You can test your own fitness with a 2-Stage VO2 Max Test.
Regular Exercise May Help Prevent Alzheimer’s
Current thinking suggests we get at least 30 minutes of moderate exercise at least three times a week. This is good for the heart and the brain. You want to feel tired but not exhausted.
If you have not been active in a while, start with shorter exercise sessions of 10 or 15 minutes a day. Start by walking on flat terrain. As this becomes easier, include routes that require walking up hills. As you become more fit, you can start interval training. This involves combining a few minutes of intense activity with a few minutes of less intense exercise, like stretching.
While the Swedish study focused on the value of cardiovascular fitness, it also reported that strength training and building muscle are important. This is especially true as people get older.
It isn't clear at what age fitness makes a difference in preventing dementia; more research is needed on that front. In the Swedish study, the women ranged in age from 38 to 60. For this group, fitness seemed to slow or prevent dementia.
No doubt, genetics can work against you. But it seems that exercising and keeping your body healthy and fit can help prevent cognitive decline.
Improving Brain Health
Many factors can contribute to dementia – some of which are beyond our control. Studies indicate that what’s good for your body is usually very good for your brain as well. Keeping your heart and lungs healthy can also keep your brain healthy.
In addition to exercise, managing blood pressure and controlling cholesterol are important health factors. Keeping blood sugar normal and eating a brain-healthy diet also make a difference. Losing extra weight and not smoking, can also keep your brain healthy and prevent cognitive decline.
The brain needs adequate blood flow to function optimally. Blood brings oxygen to the brain. With less oxygen, brain tissue can become damaged, leading to dementia. Anything that interferes with good blood flow can damage the brain. This includes high blood pressure, cholesterol, high blood sugar or heart disease.
Continuing education, social interaction, and other forms of mental stimulation are also important to ensure brain health. Even something fun like a dance class can help. You'll be getting some good exercise, as well as learning a new skill and interacting with others.
What is a healthy brain? A brain that can pay attention, can learn and remember. A brain that can communicate, solve problems, make decisions.
Take time this month to assess your lifestyle. Are you living a brain healthy life? Consider taking a long walk (that would be exercise!) with a loved one and talk about it. Everyone agrees it’s never too soon or too late to start making lifestyle changes that can preserve and improve brain health.
Read the full study here, in Neurology:
7 Ways to Keep Your Brain Sharp As You Age, Time Magazine