The burgeoning wellness industry, fueled by popular health podcasts and personal tracking devices, often makes claims that are not supported by robust scientific evidence, according to doctor and broadcaster Xand van Tulleken.
In his book, "Make Me Well," van Tulleken, who has two decades of experience as a health professional, investigates the efficacy of numerous popular health products, from supplements like NMN and glutathione to continuous blood-glucose monitors and red-light therapy. He found that for many of these, the purported benefits do not align with rigorous scientific research.
The Vitamin Paradox
Van Tulleken highlights the common belief that daily vitamin supplements are essential for optimal health, particularly given modern diets. However, he points to extensive research, including meta-analyses of numerous randomized trials, which consistently show that multivitamin supplementation does not prevent chronic diseases like cancer and cardiovascular disease in the general population, nor does it decrease the risk of premature death. Some studies even suggest a potential increase in mortality risk associated with certain antioxidant supplements, such as vitamins A, C, beta-carotene, and selenium.
Despite the wealth of scientific data, including large-scale trials like the COSMOS study, which found no significant reduction in cancer, cardiovascular disease, or all-cause mortality from multivitamin use, public behavior often remains at odds with the evidence. This disconnect, van Tulleken suggests, is exacerbated by media reporting that frequently overstates the benefits of these studies, making it difficult for the public to discern between hype and scientifically validated claims.
Complex Systems vs. Simple Fixes
The complexity of the human body is a recurring theme in van Tulleken's critique. He uses the analogy of motorways leading into London to explain why interventions targeting a single pathway may not yield the expected results. Just as closing one road doesn't solve London's traffic problems because people will use alternative routes, the body's intricate systems mean that adding more of a single nutrient may not produce a desired outcome. Furthermore, he notes that what one person perceives as a problem (like traffic) might be essential for another aspect of the system (like the economy).
This complexity makes it challenging to isolate the precise functions of nutrients like vitamins, which often serve multiple roles in the body. Van Tulleken argues that the wellness industry often promotes simple solutions for complex health issues, which are unlikely to be effective.
Questioning Health Trackers and Vitamin D
Continuous blood-glucose monitors (CGMs), while providing data, have a significant margin of error and their results may not always translate into actionable health improvements. Similarly, the widespread enthusiasm for Vitamin D supplementation, driven by observational studies linking low levels to numerous health problems, has not been consistently supported by large-scale randomized controlled trials. While these trials did not demonstrate benefits for cancer, cardiovascular disease, or cognitive function, van Tulleken notes that supplements are still advisable for specific groups to prevent deficiency diseases like rickets and osteomalacia, aligning with NHS advice for certain populations.
Van Tulleken concludes that while supplements can be beneficial when prescribed for specific medical conditions, such as iron for anemia or vitamin B12 for vegans, the broader claims made by the wellness industry often lack substantial evidence. He suggests that focusing on improved diet and other lifestyle factors may be more effective than relying on the products commonly marketed as wellness enhancers.