With the recent evolution of high-speed, low-cost DNA sequencing, a new variety of snake-oil salesman has found his way into society. Like his predecessors, he is selling a cure-all. However, like all the other snake-oil salesmen before him, his product is hype. He preys on the under-informed and those who know little-to-nothing about DNA.

His product, he claims, will allow you to see what evils your DNA has in store for you. It will allow you to track down all of your ancestors. With it, you can know all there is to know about yourself. And, since knowledge is power, you will be able to take control of your life and your health!

Well, if any of this sounds too good to be true, that’s because it is. Simply put, DNA is not that simple.

DNA Testing Companies Promise More Than They Deliver

The best DNA testing companies likely do not see themselves as snake-oil salesmen. To them, they are providing advanced science to consumers, to fill a demand created by consumer interest. They are Capitalists, simply operating within the bounds of the law to provide the desired product. But, scientifically speaking, DNA analysis cannot provide the answers people are looking for. For example, check out the two commonly asked questions below:

Am I going to get Alzheimer’s Disease when I am old?

Several large DNA testing companies pretend like they can help you answer this question. By testing the gene APOE, these companies claim they can predict your chance of getting Alzheimer’s in the future. But, let’s look at the actual science.

According to a 2019 report from the Alzheimer’s Association, at age 65 the general population has a 21.1% chance of getting the disease. However, certain variants of the gene APOE can increase your risk of getting Alzheimer’s. For instance, one variation of APOE can cause a three-fold increased risk of getting Alzheimer’s. That might lead the layman to understand that they have a 63% chance of getting the disease. But, that’s not how statistics work.

The 21.1% chance of getting Alzheimer’s has already measured all the variations present. For instance, while 65% of people with Alzheimer’s have the APOE variant, the other 35% with Alzheimer’s do not have a variant which increases their risk. Yet, they still got the disease. So, while having the gene variant may increase your risk, you cannot simply take a general risk and multiply it by 3. In fact, the ‘risk’ for a single person is largely incalculable.

Other factors that influence Alzheimer’s are diet, smoking, exercise, and education. Having a good diet, being a non-smoker, exercising regularly, and continuing to educate yourself throughout life can significantly decrease your risk of Alzheimer’s. Therefore, a simple look at which genes you carry is largely insignificant compared to the lifestyle you lead. While a test can tell you what variants you carry, it is almost impossible to know how these genes will interact with your environment and lifestyle. 

I was told my ancestors were Italian. Can a DNA test prove this?

While it seems simple enough to dive into your genes to find out who your ancestors were, biology is not this simple. Let’s pretend that your great-grandfather was 100% Italian. He passed 50% of his genes on to your grandfather. Your grandfather also passed 50% of his genes to your father, and your father passed on 50% of his genes to you. Simple math would dictate that you carry at least 12.5% Italian genes. But, contrary to what the snake-oil salesman is telling you, this is not the whole story.

To understand this, you must understand basic genetics. During the process of meiosis, your genes are split up randomly to create gametes (sperm and eggs) that have half of the total amount of DNA in a human. This process does not care whether genes come from your Italian side, or whether they were inherited from another source.

To understand this, let’s look at your ‘non-Italian’ history. Let’s say your great-grandmother was 100% Spanish. This means that your grandfather was 50% Italian and 50% Spanish. While it is likely that they pass on a little of each ethnicity, it is not a guarantee. All of the Spanish genes could have been packed into a sperm cell which created your father. In that case, your father would have 0% Italian genes. As such, you would also have 0% Italian genes, regardless of the fact that your great-grandfather was 100% Italian. 

Thus, the entire notion of an “Ethnicity Estimate” is entirely false. In no way can genetic testing tell you exactly who your ancestors were, and where they lived. What it can tell you is where the genes you have came from. But, as we’ve seen, this is only a small part of your total ancestry. Companies trying to sell you on the idea that you can track all of your ancestors are selling nonsense. 

Should DNA Testing Be Illegal?

Given the answers to the previous questions, the answer to this is: Maybe. DNA analysis is an enormously complex process. Not only is the science in its infant stages, but it is also vastly outside the understanding of most consumers. For the same reason that most people get a realtor when selling their house, most people should consult a geneticist when getting their DNA tested. Most companies do not offer this option. 

But, that alone doesn’t mean DNA testing should be illegal. If you consider the test a fun insight into your DNA, it is much less harmful than if you consider a DNA test a panacea to all your problems.

What DNA Testing Companies Sell Snake-Oil?

As we have seen, most companies add a large amount of ‘salesmanship’ to their product. In the age of capitalism, this is necessary for their products to even reach the market. Companies like 23andMe, AncestryDNA, and many others try to make their products sound enticing, informative, and necessary for your life. If you consider the results of these tests as a certainty, you have missed the complexities of life and will be relying on possibly false information.

If, however, you consider a DNA test a fun experiment, there is little harm that can come from getting your DNA tested. With the large majority of companies offering health and ancestry information, the Federal Food and Drug Administration monitors what the companies are selling compared to the results they actually present.

It was for this reason that 23andMe had to edit how it marketed its Breast Cancer Risk tests. This gives at least an assurance that the company is not guaranteeing you more than they can deliver. But, several smaller companies are now offering tests on the fringe of DNA science. They are the snake-oil salesmen you should be most worried about. 

However, there are several other companies which make claims so outlandish that their very premise should be questioned. Below are several examples.


In the category of ridiculous falls several companies like Vinome. Vinome is a DNA testing company which claims to be able to test your DNA to find out which types of wine you like. Apparently, by analyzing your DNA the company claims to be able to match you to wines you will enjoy. The question is: how?

Taste is a complex human feature. It depends not only on the proteins created by our DNA which can detect various chemicals in our taste buds, but also by experience, family traditions, and a certain je ne sais quoi, which can only be described as personal preference. For example, a person who has never tasted sushi may find it displeasing, until they find a sushi roll they really love. In the same way, the wine you like is a product of what you have tried, what your family drinks, and what other foods you enjoy. The most disturbing part about companies like this is that they do not even post scientific studies which back up their claims. 


This company, built around the premise that by analyzing your DNA you can become a better athlete, is similarly flawed. The company claims to offer a service which can analyze your DNA to help you determine the best workout and diet plan for becoming the ultimate athlete. 

Like other companies in this category, this claim is largely unfounded by science. While there are studies which show how different genes can affect your metabolism and muscle structure, no study has ever been done comparing these ‘DNA-specific’ plans to a more generalized plan created by a regular personal trainer. The fact is: if you want to get better at hockey, you must play hockey. A healthy diet and a good exercise plan have almost nothing to do with your genetic code. #

The Bottom Line

While DNA testing is a fun and new way to explore our world, health, and the things that may affect us, science is far behind what most companies are trying to sell us. Unfortunately, the main goal of many DNA testing companies is simply to collect and sell DNA. This, in fact, is how many companies make their money. Until science advances a considerable degree or there are more robust consumer protections against the dangers of DNA tests: users beware! DNA testing at this point is largely speculative, based on complex statistics, and has almost no regulations governing what a company can and cannot tell consumers.