Can Lifestyle Overcome Genetics?
Author: Dr. Stephen Chaney
Will a healthy diet help prevent Alzheimer’s disease?
Alzheimer’s disease and other forms of dementia are among the most feared diseases of aging. What use is it to have a healthy body, a loving family, and a successful career if you can’t remember any of it? You should be able to enjoy your Golden years, not see them slip through your fingers.
If you have a family history of dementia or have sent your DNA off for testing and learned you are genetically predisposed to dementia, you are probably worried. You are not alone.
According to the World Health Organization:
- 50 million people worldwide have dementia.
- Alzheimer’s Disease accounts for 60-70% of all dementia cases.
According to the Alzheimer’s Association:
- 8 million Americans are currently living with Alzheimer’s Disease.
- 1 in 3 seniors will die from Alzheimer’s or another form of dementia.
- The number of Americans with Alzheimer’s Disease is expected to increase to 14 million by 2050.
Perhaps the scariest thing about Alzheimer’s is that the medical community has no answers. There are no drugs to prevent or cure Alzheimer’s and brain transplants are out of the question. Some medical professionals will tell you nothing can be done, but is that true?
Studies have suggested that a healthy lifestyle can help reduce your risk of developing Alzheimer’s and other forms of dementia. But what about genetics? Will a healthy lifestyle only reduce your risk of dementia if your genetic risk is low or will it be equally effective when your genetic risk is high? Can lifestyle overcome genetics?
This study (I Lourida et al, JAMA, 322: 430-437, 2019 ) was designed to answer that important question.
How Was The Study Done?
This study used data collected from the UK Biobank study, which was designed to assess the effect of genetics and lifestyle on health outcomes. The UK Biobank study enrolled more than 500,000 participants between 2006 and 2010.
At the time of enrollment, UK Biobank participants were given a physical exam. Blood samples were taken and preserved for subsequent genetic analysis. They also completed an online questionnaire and were interviewed about lifestyle, medical history, and nutritional habits.
This study used a subset of the UK Biobank data, consisting of 196,383 people who were 60 years or older and free of cognitive impairment or dementia at the time of enrollment. They were followed for an average of 8 years.
The authors created the following scoring system to assess the effect of genetics and lifestyle on Alzheimer’s disease and dementia:
The Genetic Risk Score represents the combined effect of all genetic variants known to increase the risk of Alzheimer’s disease and dementia. [Note: There is no single gene that determines whether you will develop Alzheimer’s and other forms of dementia. There are multiple gene variations that affect your risk.]
The Healthy Lifestyle Score was based on 4 well-established dementia risk factors (smoking status, physical activity, diet, and alcohol consumption). The risk factors were defined as follows:
- Smoking status was categorized as current or no current smoking.
- Regular physical activity was defined as meeting the American Heart Association of:
- ≥ 150 minutes of moderate exercise per week – OR –
- ≥ 75 minutes of vigorous activity per week.
A healthy diet was defined as meeting at least 4 of these 7 criteria.
- ≥ 3 servings/day of fruit.
- ≥ 3 servings/day of vegetables.
- ≥ 2 servings/week of fish.
- ≥ 3 servings/day of whole grains.
- ≤ 1 serving/week of processed meats.
- ≤ 1.5 servings/week of red meat.
- ≤ 1.5 servings/day of refined grains.
Moderate alcohol consumption was defined as:
- Up to one drink a day for women.
- Up to two drinks a day for men.
Finally, the diagnosis of Alzheimer’s Disease or dementia was obtained from the centralized databank of the UK National Health Service.
Will A Healthy Lifestyle Help Prevent Alzheimer’s Disease?
Here are the results from the study:
- People at high genetic risk were almost twice as likely to develop dementia as those at low genetic risk.
In other words, genetics matter. If you have “bad” genes, your risk of developing dementia is increased significantly.
- A healthy lifestyle decreased the risk of developing dementia by about 40% for both people at high genetic risk and for people at low genetic risk.
In other words, lifestyle also matters. You can significantly decrease your risk of developing dementia, no matter what your genetic risk.
- People at high genetic risk and an unhealthy lifestyle were almost three times more likely to develop dementia than people at low genetic risk and a healthy lifestyle.
In other words, the combination of a high genetic risk and an unhealthy lifestyle is the worst of all possible worlds.
- People at low genetic risk and an unhealthy lifestyle were just as likely to develop dementia as people at high genetic risk and a healthy lifestyle.
In other words, bad genetics does not doom you to Alzheimer’s and dementia. A healthy lifestyle can cut your risk almost in half. Conversely, good genetics is not a “Get Out of Jail Free” card. You can squander the advantage of good genetics with an unhealthy lifestyle.
Simply put, both genetics and lifestyle influence the risk of developing Alzheimer’s Disease and dementia. However, the take-home lesson from this study is that:
- A healthy lifestyle can partially offset the effect of bad genetics.
- A healthy lifestyle can enhance the effect of good genetics.
- An unhealthy lifestyle can negate the benefit of good genetics.
Can Lifestyle Overcome Genetics?
This study clearly suggests that a healthy lifestyle can significantly reduce the effect of “bad” genetics on your risk of developing Alzheimer’s and other forms of dementia as you age. Considering that the medical profession has no other answer for preventing or treating Alzheimer’s Disease, this is really good news.
In the words of Dr. John Haaga of the U.S. National Institute on Aging: “No one can guarantee you’ll escape this awful disease, but you can tip the odds in your favor with clean living.”
The main strength of this study is its very large size. It is also supported by many smaller studies that have come to similar conclusions.
Moreover, a recent intervention study has been performed in Scandinavia in which one group was enrolled in a healthy lifestyle program while the other group continued with their previous health habits. That study also concluded that healthy habits could help prevent mental decline. The Alzheimer’s Association also has a similar intervention study in the United States. We should have more definitive information on this important subject very soon.
Finally, Alzheimer’s Disease may not be unique. Another recent study found that a healthy lifestyle can partially overcome a high genetic risk for developing heart disease.
The Bottom Line
A recent study looked at the effect of genetics and lifestyle on developing Alzheimer’s Disease and other forms of dementia. Here are the results from the study:
- People at high genetic risk were almost twice as likely to develop dementia as those at low genetic risk.
In other words, genetics matter. If you have “bad” genes, your risk of developing dementia is increased significantly.
- A healthy lifestyle decreased the risk of developing dementia by about 40% for both people at high genetic risk and for people at low genetic risk.
In other words, lifestyle also matters. You can significant decrease your risk of developing dementia, no matter what your genetic risk.
- People at high genetic risk and an unhealthy lifestyle were almost three times more likely to develop dementia than people at low genetic risk and a healthy lifestyle.
In other words, the combination of a high genetic risk and an unhealthy lifestyle is the worst of all possible worlds.
- People at low genetic risk and an unhealthy lifestyle were just as likely to develop dementia as people at high genetic risk and a healthy lifestyle.
In other words, bad genetics does not doom you to Alzheimer’s and dementia. A healthy lifestyle can cut your risk almost in half. Conversely, good genetics is not a “Get Out of Jail Free” card. You can squander the advantage of good genetics with an unhealthy lifestyle.
In the words of Dr. John Haaga of the U.S. National Institute on Aging: “No one can guarantee you’ll escape this awful disease, but you can tip the odds in your favor with clean living.”
For more details on the study and how a healthy lifestyle was defined in this study, read the article above.
These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.