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    How We Select the Blood Biomarkers in Our Tests

    By Michelle Cawley, MS, March 16, 2020

    insidetracker scientist testing blood biomarkersThe science we use to back up our recommendations for food, exercise, supplementation, and lifestyle changes is held to the highest standard possible. In order for a study to make its way into our system, it needs to come from a non-industry funded, peer-reviewed journal and use human subjects. And even when those standards are met, we still carefully sift, read, and critique hundreds of journal articles to ensure a study's findings are strong enough. And it's this high threshold that is often the answer to a common question we hear: "Why don't you test for 'X' biomarker?" So, here's a breakdown of some of the key biomarkers that have and haven't made it into our tests, and how we keep up with the ever-evolving science.


    We test multiple biomarkers with similar implications

    We offer a few different tests, but our most comprehensive test—the Ultimate—consists of 43 biomarkers, which can be broken into nine groups: energy and metabolism; strength and endurance; bone and muscle; brain and body; oxygen and performance; inflammation; minerals; liver; and complete blood count.

    We create these groups because, often times, a single biomarker is most useful when considered in the context of others like it. Though individual biomarkers within a group are very similar, their nuances help to widen what we can see about your health—and, therefore, what you can do to improve it. Here are a few of the carefully-researched biomarker groups we include in our tests and how their constituents add up:

    Sugar group

    We test both fasting blood glucose and hemoglobin A1c (HbA1c) to provide a more rigorous view of your blood sugar levels—blood glucose provides a short-term measure, while HbA1c paints a picture of your average blood glucose over a longer period of time. The combination of both is often used to obtain a more comprehensive view of your blood sugar. For a complete breakdown between the two, read this blog.

    Lipid group

    We measure total cholesterol, as well as its subtypes, LDL ("bad") cholesterol and HDL ("good") cholesterol. When combined with triglycerides—the main type of fat circulating in your bloodstream—we can see a more complete picture of your heart health. Read about how these three adults improved their health health using InsideTracker here.

    Inflammation group

    We measure high-sensitivity c-reactive protein (hsCRP) and a variety of white blood cells (WBC) to determine levels of inflammation in the body. hsCRP is a protein that rises and falls in response to increases and decreases in inflammation — giving a reliable depiction of full-body inflammation. White blood cells act as infection fighters in the immune system making them better indicators of acute inflammation. By measuring both, we can get a more targeted and specific view of the inflammation in your body.

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    inflammation group-insidetracker

    Why we don't test certain biomarkers you might hear about

    It’s important to remember that the premise of InsideTracker is to help individuals monitor, improve, and ultimately optimize their well-being. Our platform offers personalized recommendations to improve health via food, supplements, exercise, and lifestyle. And if a particular biomarker isn't scientifically proven to be affected through those four channels, regardless of whether they're popular in the news or the literature, we won't test them.

    Here are some examples of biomarkers we are frequently asked about, but currently don't test:

    Thyroid group

    This includes thyroid stimulating hormone (TSH), reverse T3, free T3, and free T4. Currently, there aren’t enough research-backed interventions (via nutrition or lifestyle) that would move the needle on these markers. While we agree that they're important markers of health, at this point, the research suggests that medication is the only actionable step someone can take to change them. And since we're not a clinical or diagnostic service, we don't give medical recommendations.

    Female reproductive hormone group

    More specifically: estrogen, follicle-stimulating hormone (FSH), luteinizing-hormone (LH) and T4. Similar to the thyroid group, medication is presently the only intervention that can meaningfully change them, therefore, we don't test them either. In addition, the levels of each of these hormones fluctuate greatly each month due to a woman's menstrual cycle. For a clearer, more stable picture of a woman's reproductive health, we test sex hormone-binding globulin (SHBG) and an estrogen precursor called DHEAS. You can read more about each of these biomarkers in this blog post

    Food sensitivity tests

    Food sensitivities are receiving a lot of air time right now, but truthfully, current commercially-available tests are unsatisfactory. These tests do not fully represent the physiologic impact of a food on your body and their accuracy has yet to be validated by scientific research.

    In general, these biomarkers are not included in our product because a result outside of the normal range would prompt either a diagnosis or a consultation with a medical professional, which we cannot provide. 

    Why we dont test a biomarker-grid (1)

    We've evolved with the science—and are committed to continuously doing so

    If you’re reading this blog, you likely care about nutrition and try to be informed on the latest science. So, you should know about the challenges and criticism nutrition science often faces. Diets and fads come and go, social media perpetuates misleading information, reputable news sources report conflicting recommendations, scientific studies have a hard time attributing outcomes to a single dietary intervention alone...the list can be extensive and overwhelming. For nutrition scientists, this is just part of the job. But for someone with a different background, this can be incredibly confusing—and nearly impossible to distill.

    That’s why we do the hard work for you. We know that this field is richer than ever before, and with that, new information and ways to access it are becoming available. So, we are constantly investigating new biomarkers to add to our products and keep InsideTracker on the cutting edge of personalized nutrition.

    Here are a few biomarkers that we’ve recently added to enhance the information you receive from your tests:

    Hemoglobin A1c (HbA1c)

    Unlike fasting glucose tests, your HbA1c value reflects your average blood glucose concentration over the previous three to four months. We recently added this biomarker to our tests because we've identified lifestyle changes that have positive impacts on its levels.

    Red Blood Cell Magnesium

    This test measures the magnesium concentration of your red blood cells, which is about three times higher than it is in your serum. This test is therefore more sensitive and can more accurately reveal a magnesium deficiency.

    Complete Blood Count (CBC)

    The CBC provides insight into the different cells in your blood—both red and white. Adding this to our tests has given us additional insight into how your lifestyle, nutrition, and training affect your body.


    We're always here to answer your biomarker questions

    InsideTracker remains the one place where you can take control of your health with personalized recommendations to optimize your wellness. Our goal has always been to digest the dense world of scientific research and provide our users with the actionable steps to live healthy lives. As the science transforms, so does InsideTracker. We'll continue to bring you the most up-to-date and cutting edge research and help you understand how to apply it to your life. Ever want to reach us with a biomarker-based question? You can always chat with us on our website or email us at

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