The supplement market pitches longevity to anyone willing to pay. The largest controlled trials to date say the promise does not hold up.
What the major studies find
In 2007, Bjelakovic and colleagues published a meta-analysis in JAMA covering 47 low-bias randomised trials and 180,938 participants. Antioxidant supplements (beta-carotene, vitamin A, and vitamin E) were associated with a statistically significant increase in all-cause mortality: RR 1.05 (95% CI 1.02-1.08). Broken down by substance: beta-carotene RR 1.07, vitamin A RR 1.16, vitamin E RR 1.04. Vitamin C and selenium showed no significant effect. The finding: antioxidants in supplement form do not extend life; at higher doses, several raise mortality.
The US Preventive Services Task Force reached a similar verdict in 2022 after reviewing 84 studies. It found insufficient evidence that multivitamins prevent cardiovascular disease or cancer in well-nourished adults, and it explicitly recommends against beta-carotene supplementation because of documented harm and against vitamin E because no benefit has been demonstrated. The review was restricted to adults without an established nutrient deficiency, the population segment that most supplement marketing targets directly.
The COSMOS trial, published in 2022, followed 21,442 participants in a randomised, placebo-controlled design. Multivitamin supplementation did not significantly reduce cancer incidence, cardiovascular events, or all-cause mortality. Two substudies (COSMOS-Mind and COSMOS-Web) found a moderate benefit for cognitive function and memory in older adults. The Physicians' Health Study II found an 8 percent reduction in overall cancer incidence among older male physicians on daily multivitamins, a modest signal that did not extend to other health outcomes. These trials together represent the strongest positive evidence for multivitamin use, and the effects are confined to specific subgroups.
When supplementation is backed by evidence
The research supports targeted supplementation in people with documented shortfalls. Vitamin D deficiency is common in populations with limited sun exposure, and replenishment where deficiency is confirmed is evidence-based. Vitamin B12 becomes a genuine concern on strictly plant-based diets, where dietary sources are absent. Folate supplementation before and during early pregnancy reduces neural tube defect risk, one of the clearest causal relationships in nutritional medicine. Patients after bariatric surgery, people with malabsorption disorders, and older adults with diagnosed micronutrient deficits are further groups where supplementation shifts from optional to indicated.
The shared logic is targeted correction of a measured gap. Observational data repeatedly show supplement users appearing healthier than non-users, but controlled trials consistently explain this away as healthy-user bias: people who take supplements tend to have generally healthier habits. Taking a broad nutrient stack as a hedge against ageing, without an established deficiency, is not supported by the clinical record.
The EU regulatory frame
Under Directive 2002/46/EC, dietary supplements are classified as foods, not medicinal products. They may not claim to prevent, treat, or cure any disease. Health claims on packaging are governed by Regulation (EC) No 1924/2006: only claims approved by the European Food Safety Authority (EFSA) may appear. EFSA has evaluated more than 4,000 health claim applications and rejected roughly 80 percent of them, a rate that reflects the gap between marketing assertions and demonstrated physiological evidence. The approximately 250 approved claims cover specific nutrients with established functions. Phrases such as 'anti-aging', 'immune boost', or 'nutrient transport to the cellular level' have no place in that approved vocabulary.
What this means for products like FitLine
Broad multi-nutrient formulas are built for market appeal, not for documented individual need. The FitLine product PowerCocktail , combining vitamins, minerals, fibre, and caffeine in a single powder, is a representative example of this category. The NTC concept (Nutrient Transport Concept) carries no EFSA-approved health claim. A trademark on the name is not evidence of a mechanism; the German utility model covering piperine as an absorption enhancer expired in 2015.
Germany's consumer advisory body, the Verbraucherzentrale, has flagged FitLine products for synthetic ingredients and what it describes as exaggerated health claims. Independent analyses note that the underlying micronutrients in broad-spectrum powder formulas are available at pharmacies and drugstores for a fraction of the price. The premium reflects the brand and distribution model, not a differentiated ingredient profile.
For anyone asking whether a broad supplement stack protects against ageing, the clinical record gives a consistent answer: it does not, and in some cases it causes measurable harm. The question worth asking before taking any supplement is not 'which brand?' but: 'Have I documented a deficiency, and has a clinician confirmed it?'
This article is editorial reporting, not medical advice. Consult a qualified healthcare professional for personal health decisions.