Ask Me Anything

with Sigma Nutrition Premium

Ask a question

Omega 3 Supplmententation worthwhile?

Is there any evidence that otherwise healthy people should be consuming Omega 3 supplements? It's almost blanketly recommended as a staple for most, but are there any benefits in non clinical dosages?

Vitamin C and Low-Carb diets

A former guest Mike Sweeney RD, had an interesting recent interview on a Keto podcast: https://m.youtube.com/watch?v=8fGQ8mU3TGo The claim is at timestamp 46:20. It was interesting to hear a registered dietitian with such *ahem* different views, but I wanted to focus on one particularly interesting claim which I have dug into myself because I previously heard the same claim within the last year. You can listen above for his exact words but the basic claim is this: "Those on low carb diets require less vitamin C than those on high carb diets. This is because Vitamin C and Glucose have a shared transporter (GLUT#). The more carbohydrate in the diet, the more glucose, the more glucose, the higher the vitamin C requirement as they compete for the same transporter. On low-carb, there is less glucose, thus less competition for the transporter, thus a lower Vitamin C requirement." I have heard that this means the RDA for Vitamin C is "irrelevant" and "doesn't apply" to low carb dieters ..... I see a couple of significant problems: (1) Competition for the transporter would only be relevant if either Vitamin C or Glucose were sufficiently high in those areas where the transporters do their job. I believe in the case of hyperglycaemia, there can be an issue with Vitamin C uptake. But where is the evidence that high carbohydrate diets, of themselves result in sufficiently high levels of glucose to make competition for these transporter an issue that would affect Vitamin C requirements? (2) Why would cell requirements for Vitamin C be lower? Rummaging in "Nutrient Metabolism: Structures, Functions and Genes" (Martin Kohlmeier), carbohydrate metabolism does not seem to require Vitamin C. Maybe he is saying that although cell Vitamin C requirements are the same, because of high glucose levels, more vitamin C is needed to outcompete the glucose and reach the cells? It all sounds pretty sketchy so would love to hear you guys take it apart.

Organic Produce versus Conventional

How do herbicides, pesticides, and other chemicals used in conventional farming affect the human body.

Monounsaturated Fat: Good, Bad or Indifferent

I've seen a couple articles lately from what look like reasonable sources and I've seen Monounsaturated Fat applauded as the healthiest, as fairly neutral, and I've seen it lumped in with Saturated Fat. What are your thoughts?

Dietary iron-absorption enhancers

Hi gents, love your work. Do we need Dietary iron-absorption enhancers? I commonly hear dietitians say that you must eat vit c with non-heme iron foods, or you must avoid eating non-heme iron foods with calcium, phytates etc. But....does this actually impact iron status? Thanks!! - Paul