Superfoods Research & Evidence-Based Practice 3

Question 1

Which type of study design is most prone to 'healthy user bias' when evaluating superfood consumption?

Accepted Answer

Prospective cohort studies

Answer

Prospective cohort studies cannot fully control for the fact that people who eat superfoods often also exercise, avoid smoking, and follow other healthy behaviors that independently reduce disease risk.

Question 2

Sulforaphane bioavailability from broccoli is substantially reduced by boiling compared to lightly steaming. This finding best illustrates which research consideration?

Accepted Answer

Preparation method critically alters phytochemical content

Answer

Boiling leaches water-soluble glucosinolates and inactivates myrosinase (the enzyme that converts glucosinolates to sulforaphane), so preparation method is a key variable in superfood research.

Question 3

The Women's Health Initiative Dietary Modification Trial failed to show that a low-fat diet reduced breast cancer risk. What does this illustrate about superfood/diet research?

Accepted Answer

Short intervention periods and imperfect adherence can mask true long-term effects

Answer

Despite a large sample, the trial's 8-year follow-up may have been too short and dietary change too modest to detect effects on cancer incidence, highlighting limitations of large dietary RCTs.

Question 4

A researcher measures resveratrol blood levels after participants eat red grapes. This type of measurement is called a:

Accepted Answer

Pharmacokinetic bioavailability study

Answer

Measuring plasma concentrations of a compound over time after ingestion is a pharmacokinetic study, which determines how much is absorbed, how quickly, and how long it persists.

Question 5

Which methodological issue is most common in cell culture (in vitro) studies of superfood antioxidants?

Accepted Answer

Concentrations used far exceed what is achievable in human blood after normal food intake

Answer

In vitro studies often expose cells to antioxidant concentrations 10–100× higher than physiological levels, making results difficult to translate to dietary recommendations for humans.

Superfoods Practice Test

Superfoods Practice Test

Superfoods Research & Evidence-Based Practice 3