The original Norwegian Article is written by Doctors from the Norwegian ‘Hospital Haukeland Sykehus’ part of RELIS Vest – A Manufacturer-Independent drug informant in Norway.

This Article is translated to English from the original Norwegian published Article:  “Effekt og bivirkninger av produkt med rødbetekstrakt (Stamox). Publisert: 10.01.2014. RELIS database 2014; spm.nr. 8430, RELIS Vest.

RELIS is a national network of four regional medicines information and pharmacovigilance centres in Norway. RELIS was established stepwise from 1995 on the basis of a recognised need for an independent medicines information service for health care professionals in order to achieve better use of medicines.

The centres are situated in regional university hospitals, employ both pharmacists and medical doctors, and cooperates with respective units of clinical pharmacology. RELIS is funded by an unconditional grant from the Ministry of Health and Care Services, and the information service is free of charge and independent from the pharmaceutical industry.

RELIS answers medicine-related questions from health care professionals both for individual patients and of more general character.

A doctor who works with athletes has seen that the product Stamox, beetroot extract, is being used increasingly. It is claimed to have a 15% increase in endurance, lower blood pressure, etc. The doctor asks whether there have been any side effects recorded with Stamox and whether it is objectively correct that it has medical effects and is a performance enhancer?

The Norwegian website for the dietary supplement Stamox states that it is “made only from beetroot, manufactured using a patented method that ensures that all the useful micronutrients are preserved as best as possible”. Stamox is supposed to be a tested and controlled product that provides predictable effects compared to consuming beetroot or beetroot juice, and is not supposed to be toxic (1).

Stamox is supposed to increase oxygen utilization in cells, improve blood flow, improve endurance, increase concentration, reduce blood pressure and reduce plaque formation on the inside of blood vessels (1). Beetroot is particularly rich in inorganic nitrate (2), and this is thought to be the basis for the effects that can be achieved (1).

A meta-analysis of the effects of various nitrate supplements, including beetroot preparations, on exercise performance in athletes or well-trained individuals has recently been published. 17 studies with a total of 184 participants met the inclusion criteria for the meta-analysis, and 12 of these studies used beetroot products. The meta-analysis found a small, but non-significant, effect of nitrate supplementation versus placebo on time trial performance. Regarding the effect on time to exhaustion at a given work rate, the meta-analysis of 3 studies found a moderate and significantly better effect of nitrate supplementation compared to placebo. The authors of the meta-analysis conclude that the use of nitrate supplements may provide some improvement in sports performance that may be valuable for elite athletes, but that the evidence base is currently thin and that differences in study design limit the possibilities of comparing different study results (3).

There is also a recent meta-analysis that has examined the effect of beetroot juice or other nitrate supplements on blood pressure. 16 studies with a total of 254 participants were included in the analysis. Both beetroot juice and other nitrate supplements significantly reduced blood pressure by an average of 4.4 mmHg in systolic blood pressure and 1.1 mmHg in diastolic pressure.

The authors point out, however, that the included studies were small and of short duration, and that young, healthy men were overrepresented among the participants (2). The Stamox website also refers to some published studies that indicate that beetroot may have chemoprotective effects (1), but the impression from a literature search is that research on this is at an early stage (1).

There have been no reports of adverse effects of beetroot supplements (3,4), but discoloration of urine and stool may occur (2,3).

However, dietary supplements do not have the same strict requirements for monitoring safety and quality control as pharmaceuticals and information on adverse effects may be limited. In general, contamination of preparations or addition of undeclared ingredients cannot be ruled out.

The dietary supplement Stamox contains beetroot extract, which is rich in inorganic nitrate. Some studies indicate that beetroot supplements may increase exercise performance and reduce blood pressure, but the documentation for this is currently limited. There are no known adverse effects of beetroot supplements, apart from possible discoloration of urine and stool.

1. Stamox søkkensted. www.stamox.no (read 8 January 2014).

2. Siervo M et al. Inorganic nitrate and beetroot juice supplementation reduces blood pressure in adults: a systematic review and meta-analysis. J Nutr 2013; 143: 818-26.

3. Hoon MW et al. The effect of nitrate supplementation on exercise performance in healthy individuals: a systematic review and meta-analysis. Int J Sport Nutr Exerc Metab 2013; 23(5): 522-32.

4. Natural Medicines Comprehensive Database. Beet. http://www.naturaldatabase.com/ (8 January 2014).

5. Original Article: https://relis.no/sporsmal_og_svar/?id=3-8430&fbclid=IwY2xjawJhWchleHRuA2FlbQIxMQABHpVvo9910HSi57YfDZ6UlFKcr-WVUXpD3twJzZDmr0kJhHCuJGprHWt9az7F_aem_99_AsHJnJ6BNiSflRP89-g

6. Swedish Article: https://svelic.se/utredning/?id=3-8430