Sodium caseinate, whey protein and blood sugar responses in adults
What it found
Sodium caseinate and whey protein lowered blood sugar peaks by 21% and raised insulin by 96% in prediabetic adults.
The two proteins worked the same way.
What they found
Studies in people
Blood sugar and insulin
Both proteins lowered peak blood sugar by 21% compared with the carbohydrate drink alone in prediabetic adults. Peak insulin rose by 96% after either protein drink in that group.
Stomach emptying speed
The researchers found no evidence that stomach emptying differed between the sodium caseinate and whey protein drinks. They measured this using markers added to the beverages.
Gut hormone GIP
In healthy volunteers, the whey protein drink raised peak levels of a gut hormone called GIP by 56%. Sodium caseinate did not cause this rise in the healthy group.
Amino acids in blood
Differences in amino acid levels in the blood matched the different amino acid makeups of the two proteins. The authors say digestion speed did not explain these differences.
What the authors conclude
- They conclude that sodium caseinate and whey protein reduced blood sugar rises similarly when taken with carbohydrates.
- They found no evidence that the body processed the two proteins differently under their test conditions.
- The authors note that both proteins caused comparable effects on hormones and blood sugar control.
How it was done
Scientists wanted to know if sodium caseinate and whey protein affect blood sugar differently when taken with carbohydrates. Casein is thought to digest more slowly than whey, which might change hormone responses.
Fifteen healthy men and fifteen prediabetic adults drank test beverages on three separate days at least two days apart. The drinks contained a carbohydrate alone or mixed with 50 g of whey protein isolate or 50 g of sodium caseinate. Blood was drawn over 240 minutes to measure hormones and metabolites.
What it can’t tell you
- This trial tested single large doses of 50 g of protein in a lab setting.
- It cannot show what happens when smaller amounts are eaten as part of everyday meals.
Who paid
- Authors work at
- Central Institute for Nutrition and Food Sciences, and; Technische Universität München, Germany
The paper
- Title
- Metabolic responses of healthy or prediabetic adults to bovine whey protein and sodium caseinate do not differ
- Type
- Randomised controlled trial
- Evidence
- Studies in people
- Summarised from
- Full text
- Cite
- Hoefle AS, Bangert AM, Stamfort A, et al (2015). Metabolic responses of healthy or prediabetic adults to bovine whey protein and sodium caseinate do not differ. The Journal of nutrition. doi:10.3945/jn.114.199190Free full textPubMed 25733461DOI
Summary written 1 Oct 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error