Last week, I wrote about the growing prevalence of genetic testing to help assess disease risk.
In that letter, I stated my deep concern that many people believe that their genes completely control their life and consequently they have very little impact on its outcome. It is natural to allow a negative genetic result to determine how you may view your life and future. However, genetic tests should be viewed in the grander context of lifestyle and family history. And perhaps most importantly, your lifestyle habits (including diet and exercise) can in many cases overcome genetic predisposition.
With that said, though, certain specific genetic mutations have and continue to emerge from the research. And this information could be extremely important in helping people begin to think about the possibility of disease—and prompt them to take preventive measures much more seriously in an effort to ward off these problems.
APOE4 for Alzheimer’s
Alzheimer’s disease is one of the most feared age-related diseases of our time. It affects more than 5 million people in our country, and that number is expected to increase 30 percent by 2025 and triple by 2050.
The gene most strongly associated with Alzheimer’s is apolipoprotein E (APOE), which has three variants. APOE2 is pretty rare and it actually appears to lower the risk of Alzheimer’s. The most common, APOE3, doesn’t seem to have any effect. The riskiest of the variants, APOE4, is strongly linked to early onset Alzheimer’s. Interestingly, APOE4 seems to affect women more than men.
In a study of 2,588 people with mild cognitive impairment and 5,496 healthy elderly individuals, women who inherited the APOE4 genetic mutation were twice as likely as non-carriers to develop cognitive impairment or Alzheimer’s. Men, on the other hand, fared only slightly worse than those who did not carry the mutation.1
Remember, not everyone who has a genetic predisposition to a certain disease will actually develop that disease. However, the APOE4 mutation does make Alzheimer’s more likely, particularly in women. This is a case where I would urge everyone, but particularly those who have a family history or genetic predisposition to Alzheimer’s, to begin preventive measures now.
Numerous studies have confirmed the importance of diet and exercise. Several studies show that people who closely follow a Mediterranean diet have reduced cognitive decline and are less likely to have Alzheimer’s disease than people who don’t follow the diet. And importantly, a 2009 meta-analysis (a review of many studies) concluded that increased physical activity reduced the risk of developing Alzheimer’s by 45 percent.3
Once a person has Alzheimer’s disease, exercise has been shown to be a powerful strategy for slowing cognitive decline. 4-6
So add 30 to 60 minutes of exercise to your day. Your brain (and the rest of your body) will benefit immediately.
Some supplements that have been studied for Alzheimer’s include curcumin and omega-3 fatty acids. One study found that omega-3s have a “protective role in mild cognitive impairment, dementia, and the risk and progression of Alzheimer’s disease in the elderly.”2
Cardiovascular Disease
Recent research has also found that a common mutation in a gene that regulates cholesterol may increase the risk of heart disease in those who carry it.
As I mentioned in my last letter, information from your genes is used to make proteins, each of which has a specific job to do in order for cells to function properly. Genetic mutations alter proteins, causing them to malfunction. In this case, the mutation is called the “rs4238001 variant,” and it alters the protein made by a gene that regulates cholesterol.
A study published in May 2015 found that this genetic mutation is “statistically significantly associated with incident coronary heart disease across a large population of multiple race/ethnic groups.” 7 Men and African Americans have the highest risk. In fact, African American men with the mutation have a nearly 50% increased risk.
Knowing whether or not you have this particular genetic mutation can be extremely helpful to doctors because it helps tailor treatment appropriately. While this research is still very new and a lot has yet to be learned, one possible treatment may include adjusting the hormones that alter cholesterol metabolism.
Additionally, with heart disease being the number one killer in the US, awareness about genetic predisposition could reinforce the importance of prevention (including following a better diet, exercising regularly, quitting/avoiding smoking, reducing stress, and taking heart-supportive supplements such as omega-3 fatty acids).
Take-Home Message
With over 63,102 tests that can look at 4,572 disorders, genetic testing has the potential to bring a lot of critical information about current and future health to the forefront. However, how you act on that information is what will really impact your future.
You can’t change your genes, but you can change your lifestyle and attitude for the better. Even in cases where genetic predisposition is strong, lifestyle and attitude can make a world of difference in whether or not a disease will actually develop, and how well you recover if it does come to be. Always be strong and courageous and don’t allow yourself to become a victim. Fight back by doing the right things, and especially by improving your diet and exercise practices.
References
- Altmann A, et al. Ann Neurol. 2014 Apr;75(4):563-73.
- Waitzberg DL and Garla P. Nutr Hosp. 2014 Sep 1;30(3):467-77.
- Hamer M and Chida Y. Psychol Med. 2009 Jan;39(1):3-11.
- Paillard T, et al. J Clin Neurol. 2015 Jul;11(3):212-9.
- van Gelder BM, et al. Neurology. 2004 Dec 28;63(12):2316-21.
- Yu F, et al. J Nurs Scholarsh. 2006;38(4):358-65.
