Extreme “precision medicine” may serve your interests, and consumer DNA testing may be ineffective—or worse.
Today, you can sequence your DNA—your entire genetic code—for about $1,000, a bargain compared to the $100 million or more it cost 20 years ago. And for about a hundred dollars, you can get a partial DNA sequence. Direct-to-consumer genetic testing is “just a click away,” like 23andMe, for “ancestry, health, love… and more.” Unfortunately, many tests available today have not been properly validated. And, as a result, the consumer may buy something that is “ultimately useless.” Or, the results may just be wrong.
There is a growing public demand for direct-to-consumer genetic testing, but when tested, researchers found an “alarmingly high false positive rate.” The results of the test showed that people carry a very dangerous gene, but it was not true. And this happens 40% of the time, especially with the BRCA breast cancer gene (the one Angelina Jolie has publicly revealed she carries), which you can see below and at 1:08 in my video. Should You Get a Genetic Risk Test for You?.In addition to the 40% false positive rate, some variants that the test correctly identified were misclassified as high risk when, in fact, they were not high risk at all. You can see how it is in the interest of these companies to provide shocking results, so customers will think that the money spent was worth it and maybe pay for more tests. But false positives and false positives can have serious consequences for a person, including unnecessary stress and even unnecessary medical procedures. What if you get a preventive double mastectomy because you falsely thought you were at high risk when you don’t even have a BRCA mutation?
Yes, now, these extensive genetic association studies have identified thousands of common genetic variants that affect the risk of complex diseases, as I talked about in my video about personalized nutrition. “However, the genes found do not significantly increase our ability to predict compared to what can be achieved using information from traditional risk factors that have been known for a long time.”
Take type 2 diabetes, for example. The researchers identified about 50 genes associated with an increased risk of diabetes, but even when considered as a group, “obese people with the lowest genetic risk for diabetes were about 5 times more likely to develop the disease than normal-weight people with the highest genetic risk.” In other words, this can send the wrong message to an overweight person, giving them a false sense of security. Information about genetic predisposition to type 2 diabetes based on what we know so far “has no impact on decisions about who should be targeted for intensive lifestyle interventions.” Everyone with excess body fat, regardless of genetics, needs to lose weight to reduce their risk of diabetes.
What about the famous study that purported to show that a personalized dietary intervention can improve blood sugar response, to the extent that some commentators say it raises questions about the validity of universal dietary recommendations? But if you really read the research, the results don’t show a huge difference in people’s response to relative blood sugar; do not show the model is higher than the current methods of detecting high blood sugar; and do not demonstrate that personalized dietary advice is better than general dietary advice for managing postprandial high blood sugar responses.
But what about personal genetic risk counseling to at least encourage diabetes prevention? “In some pathetic attempt at credibility, ‘knowledge’ of an individual’s genetic risk profile has been deemed effective in motivating test subjects to commit more to appropriate disease prevention efforts….” However, again, the available evidence does not support that claim. And indeed, it did not appear to help those at risk of developing diabetes.
Researchers randomly select people to receive genetic tests that cost hundreds or thousands of dollars to reveal their subtle differences in risk for up to 40 diseases. In this case, it was Navigenics that defined its mission as empowering people with personal genetic ideas to help inspire them to improve their health. However, it didn’t work. There are no limited changes in diet or lifestyle, even in the short term.
Planning people’s personal dietary information is like deciding who would benefit genetically from eating more vegetables or eating to lower cholesterol, but when the researchers checked, there were no significant changes in diet in the sixth month compared to those who did not receive such personal information, or even in the third month. Therefore, it is not surprising that there was no difference in weight, abdominal fat, cholesterol, or any other biomarkers.
Put all the studies together, and what do we get? There are no significant benefits to tell smokers who are at particular risk of lung cancer, or who need to eat especially healthy, or who should be more physically active. Bottom line: The expectation that awareness of DNA-based risk factors will change behavior is not supported by the available evidence. However, that was the stated reason for the president’s big push for precision medicine in 2015: to empower people to take an active role in their own lives.
Not surprisingly, the theme of empowerment is discussed. It’s good for marketing, but not particularly empowering. In fact, if anything, it leaves patients even more dependent on authority, and it’s not personal since the genetic contributions we know about are so small compared to how we actually live our lives. Then why is empowerment with patience emphasized as a “primary quality”? Because it “uses appeal…to generate political and public support” for a “developing medical, industrial and scientific institution, bringing in billions of dollars worldwide.”
This is not a conspiracy theory; it’s just how the system works. “Living a healthy lifestyle threatens many powerful companies….” Eat less sugar? Eats less meat? Healthy communities, after all, only reduce the need for doctors and drugs. Seemingly willfully blind to this evidence, the United States continues to spend its health dollars lavishly on clinical care,” cleaning up the chaos caused by our way of life. Therefore, it is not surprising that we spend far too much in other countries while at the same time having very bad results. While huge new taxpayer gifts were promised for advanced medicine a decade ago, the United States had already fallen to the bottom among similar countries in terms of disease knowledge and life expectancy. “Promises of ‘precision medicine’ have been strengthened by vested interests, … justifying the exorbitant costs of our financially supported health care.” In many ways, the US health care system is the most advanced in the world, but all of our “whiz-bang technology just can’t fix what ails us.” “Let’s start with the basics. Eat your broccoli, take the stairs, and don’t worry about whether you have a 5.6 or 7.7 percent lifetime risk of a serious disease because anyway, a healthy lifestyle is the healthiest choice.”
Doctor’s Note
The video I mentioned is this Friday Favorites: How Useful Is Personalized Nutrition?.
