These studies may have nothing to do with you at all. The problem with basing recommendations on such studies ignores the fact that they don't ultimately account for YOU as an individual.
For example, although smoking is strongly linked to lung cancer and other lung related diseases, it doesn’t equally affect all smokers. That doesn’t mean smoking is ever good for you, but for some it actually is harmless. (Today, as there is no way to know if you are at real risk, it’s still best to avoid.)
While some people have a disease (Celiac) that absolutely requires them to avoid gluten and others have an intolerance to it, there are still many that are not affected, whether it’s genetically modified or not. The same can be said for sugar and simple carbohydrates. There is no doubt that for some the consumption of sugar is lethal as it leads to deadly weight gain, diabetes, heart disease, etc., while there are others completely unfazed by consumption of large amounts. I have a friend Steve that consumes it non-stop with no apparent consequence. He has no family history of diabetes and his blood sugar is not elevated above normal levels despite his relentless consumption. He is also very physically active and that may explain his apparent immunity.
Now I’m not saying that just because you don’t know for sure whether or not something is bad for you it’s okay to throw caution to the wind and ignore the statistics. Rather, I’m saying that you really have to pull together all the clues your body is giving you to try to make sense of what is and is not right for you.
Those clues include family history, genetic testing, blood work, the mirror, how you feel, etc.
None of these clues in and of themselves carry absolute weight.
You are not your parents or your siblings. First, you inherit two sets of genes, one from each parent. Second, factors such as mutations and environmental exposures affect if these genes turn on or off. At this point, science cannot predict except in very rare circumstances how one’s genes will ultimately affect your overall health. That’s because it’s a complex, multifaceted hormonal and transcriptional system that’s at play.
Complicating the matter further, over the span of one’s lifetime, genes can change the way they act or even actually change in what are called somatic mutations. That may explain why something that was never a problem suddenly becomes one and vice a versa. The science of how the environment affects our genes is called epigenetics and it is still a fledgling field.
What about genetic tests? They have yet to become mainstream and for good reason. Genetic tests only identify the genes we know and understand and potentially ignore many other genes that we don’t fully understand their roles and how they may affect the genes we do seem to understand. More importantly, gene therapy is still in its early stages and so identifying a gene problem for which there is no practical solution today could best be described as a frustrating exercise in futility for the current sufferer. While there is great promise in what lies ahead, genetic testing today plays at best a marginal role. Yes, it may induce a woman with a family history of breast cancer and a known BRCA gene mutation to undergo mastectomy, but it may not have been necessary if we had a better grasp of what other factors, such as the presence or absence of other genes or gene mutations, would change the risk profile and eliminate the need for surgery.
Blood tests provide good, but also imperfect information. Their results are generally markers, rather than causes of diseases. I generally favor them as more information is usually better than less, but even that’s not always the case. The Prostate Specific Antigen test for prostate cancer is a case in point. Reasonable doctors can disagree if and when having such a test is indicated as so many men pursue further expensive, invasive, and unnecessary testing based on misleading results.
The mirror is my favorite clue. How do you look? The most specific clue is do you look your age. Again, not the perfect clue because you can look great and still have underlying disease or even trouble pending. That’s also true for how do you feel. Feeling good is obviously better than the alternative, but it’s no guarantee of good health.
My point is that although no clue in isolation should give one complete peace of mind, taken collectively they offer a decent roadmap when reviewed by someone capable of properly making such a determination.
Now you may say that all this concern about clues about health is much ado about nothing because there is actually very little you can do to change anything--and you may actually be right. Until we know more, no one can answer that question with certainty, or what is certain today may not be tomorrow
However, to the extent that you continue to seek advice about the best foods to eat, what supplements you need, what form your exercise should take, etc., please be aware that unless the person giving you such advice knows a lot about you such as your family history, your blood results, your genetic profile, your state of mind and body, such advice is merely general and generic. That’s because at the end of the day it’s all about what does/will affect you as an individual and not some statistic. Don’t chase or accept unsolicited advice from people who don’t know YOU or your history. Such advice is usually not meaningful and may lead to bad results.
By the way, this does not apply to medical advice given by a health professional following a proper consultation. That’s more a question if you trust the professional’s knowledge and judgment (a whole topic on its own).
Nevertheless, you don’t need to be a narcissist to realize that when it comes to your health and the best approach, it really is all about YOU.