Nutritional Biochemistry and Supplementation Flashcards

Which dietary polyphenol found in grapes and red wine has been studied for activating sirtuins and mimicking caloric restriction effects?

Answer: Resveratrol

Resveratrol activates SIRT1 (a deacetylase sirtuin) and AMPK, producing effects similar to caloric restriction including improved mitochondrial function and metabolic regulation.

What is the role of chromium as an essential trace mineral in glucose metabolism?

Answer: Potentiates insulin signaling by facilitating insulin receptor binding, improving glucose uptake

Chromium in the form of chromodulin (low-molecular-weight chromium-binding substance) amplifies insulin receptor tyrosine kinase activity, enhancing peripheral glucose utilization.

Curcumin, the active compound in turmeric, has poor bioavailability. Which approach most effectively enhances its absorption?

Answer: Combining with piperine (black pepper extract), which inhibits glucuronidation and increases absorption by up to 2,000%

Piperine inhibits intestinal and hepatic phase II metabolism (glucuronidation and sulfation) of curcumin, dramatically increasing its systemic bioavailability in both human and animal studies.

What is the proposed mechanism by which intermittent fasting promotes autophagy?

Answer: Lowered insulin and mTOR activity during fasting periods trigger cellular self-cleaning and organelle recycling

During fasting, reduced insulin and nutrient sensing decrease mTOR (mechanistic target of rapamycin) activity, de-repressing ULK1 kinase and initiating autophagosome formation for cellular cleanup.

Which nutrient is essential for the synthesis of glutathione, the body's master antioxidant, alongside glycine and glutamate?

Answer: Cysteine

Glutathione is a tripeptide composed of glutamate, cysteine, and glycine; cysteine provides the critical thiol (-SH) group for glutathione's antioxidant and detoxification functions.

Inositol supplementation has the strongest clinical evidence for which condition?

Answer: Polycystic ovary syndrome (PCOS), improving insulin sensitivity and ovarian function

Myo-inositol and D-chiro-inositol supplementation improve insulin resistance, reduce androgen levels, restore menstrual regularity, and support ovulation in women with PCOS.