Nutrition
Evidence-informed coverage of food supplement ingredients - green coffee extract metabolism, guarana, L-Carnitine, Vitamin B6, Zinc and more. Written for UK readers.
Understanding EFSA Nutrient Function Claims
The European Food Safety Authority (EFSA) evaluates claims made about nutrients in food and food supplements. Only claims that have passed EFSA's scientific review process may legally appear on product labels within Great Britain and the EU. These are called authorised nutrient function claims.
When The Riverstone Review states that a nutrient "contributes to normal energy-yielding metabolism" or "contributes to normal macronutrient metabolism", these are EFSA-authorised statements - not marketing language. They describe a specific, evidence-reviewed physiological role for that nutrient when consumed at the stated reference amount.
They do not mean the product will produce a particular health outcome, cause weight loss, or treat any condition. Food supplements are not medicines.
Vitamin B6
Contributes to normal protein and glycogen metabolism. NRV: 1.4 mg/day.
Vitamin C
Contributes to normal energy-yielding metabolism. NRV: 80 mg/day.
Zinc
Contributes to normal macronutrient metabolism. NRV: 10 mg/day.
Caffeine (from guarana)
Contributes to normal cognitive function and helps reduce tiredness and fatigue at ≥75 mg per serving.
Green Coffee Extract & Metabolism - What We Know
Green coffee bean extract - derived from unroasted Coffea arabica or Coffea robusta beans - has been the subject of considerable nutrition research interest over the past two decades. Here is a balanced summary of what the evidence currently supports.
What green coffee extract contains
Unroasted beans retain higher concentrations of chlorogenic acids - a family of naturally occurring polyphenolic plant compounds - compared to roasted coffee. These are the primary phytochemicals of research interest.
Regulatory status in the UK
Green coffee extract is used as a food supplement ingredient in the UK. EFSA has not issued a general authorised health claim for green coffee extract specifically; products carrying it are regulated under food supplement rules by the Food Standards Agency.
What this means in practice
Products containing green coffee extract may refer to its traditional use in wellness routines. No authorised claim exists stating it causes weight loss or reduces body fat. The Riverstone Review does not make such claims in our coverage.
L-Carnitine: Role in Normal Metabolism
L-Carnitine is an amino acid derivative found naturally in animal-source foods including red meat and dairy. The human body also synthesises it from the amino acids lysine and methionine. It plays a role in the transport of long-chain fatty acids into the mitochondria, where they are used in energy-yielding metabolic processes.
As a food supplement ingredient, L-Carnitine carries the EFSA-authorised function claim that it "contributes to normal energy-yielding metabolism". This is an authorised nutrient function statement - it describes the nutrient's established physiological role, not a promised health outcome.
In Wellaray Coffee, L-Carnitine is included at 500 mg per sachet - a typical dose found in the food supplement market for this nutrient.
Natural food sources of L-Carnitine
- Beef and lamb (highest concentrations)
- Pork and chicken
- Full-fat dairy products
- Cod and other fish (lower concentrations)
- Plant foods (very low - relevant for those following plant-based diets)