Plasma Ketone and Medium Chain Fatty Acid Response in Humans Consuming Different Medium Chain Triglycerides During a Metabolic Study Day

Abstract

Background: Medium chain triglycerides (MCT) are ketogenic but the relationship between the change in plasma ketones and the change plasma medium chain fatty acids (MCFA)—octanoate, decanoate, or dodecanoate—after an oral dose of MCT is not well-known. An 8 h metabolic study day is a suitable model to assess the acute effects on plasma ketones and MCFA after a dose of tricaprylin (C8), tricaprin (C10), trilaurin (C12) or mixed MCT (C8C10). Objective: To assess in healthy humans the relationship between the change in plasma ketones, and octanoate, decanoate and dodecanoate in plasma total lipids during an 8 h metabolic study day in which a first 20 ml dose of the homogenized test oil is taken with breakfast and a second 20 ml dose is taken 4 h later without an accompanying meal. Results: The change in plasma acetoacetate, β-hydroxybutyrate and total ketones was highest after C8 (0.5 to 3 h post-dose) and was lower during tests in which octanoate was absent or was diluted by C10 in the test oil. The plasma ketone response was also about 2 fold higher without an accompanying meal ( P = 0.012). However, except during the pure C10 test, the response of octanoate, decanoate or dodecanoate in plasma total lipids to the test oils was not affected by consuming an accompanying meal. Except with C12, the 4 h area-under-the-curve of plasma β-hydroxybutyrate/acetoacetate was 2–3 fold higher when no meal was consumed ( P < 0.04). Conclusion: C8 was about three times more ketogenic than C10 and about six times more ketogenic than C12 under these acute metabolic test conditions, an effect related to the post-dose increase in octanoate in plasma total lipids.

Ketosis After Intake of Coconut Oil and Caprylic Acid—With and Without Glucose: A Cross-Over Study in Healthy Older Adults

“…Our results are in line with previous findings on changes in ketosis after intake of different fatty acids (11,12), but adds information on their relative contribution in relation to fasting ketosis, and also expands the evidence to include an older sample. Extension of the non-carbohydrate window of an overnight fast-by replacing breakfast with coffee plus any of the tested fatty acids-induced a mild ketosis in the same range as the additional effect of 20 g C8 (on AUC/time).…”

“…Another strength of our study is the complete collection of rich data, assessed under well-controlled conditions. Previous studies (11,12) have reported that coconut oil, C12 and C8 were associated with different ratios between the two blood ketones BHB and AcAc, raising interesting questions on potential variations in their metabolism. If such a difference is present, interpretations may be biased when only BHB is used to assess ketosis, as for the primary outcome of our study.…”

“…Also, the agreement between BHBv and BHBp was satisfactory (Lin's concordance coefficient of absolute agreement = 0.91) (21). A divergence in the ratio between BHB and AcAc has been reported after intake of C8 vs. coconut oil (11,12), which could potentially induce bias when only BHB is measured. We therefore analyzed if a divergence could be observed in our data.…”

“…A recent intervention study investigated the acute ketogenic response to coconut oil and different MCFA-combinations, including ≥91% concentrations of C8, C10, and C12. Comparisons of the arms have been reported in two articles (11,12), concluding that C8 increased blood ketones during a few hours, while the ketogenic Abbreviations: BHBv, β-hydroxybutyrate in venous whole blood; BHBp, βhydroxybutyrate in plasma; AcAc, acetoacetate; Glu, glucose; Coc, coconut oil; C8, caprylic acid; C10, capric acid; C12, lauric acid; Suf, sunflower oil; AUC, area under the curve; MCFA, medium-chain fatty acids; MCT, medium-chain triglycerides; LCFA, long-chain fatty acids; BMI, body mass index. response to the other MCFA and coconut oil was weak.…”

Metabolic and Immunological Effects of Intermittent Fasting on a Ketogenic Diet Containing Medium-Chain Triglycerides in Healthy Dogs

“…However, the main medium-chain triglyceride constituent in coconut oil is dodecanoic acid (lauric acid, C12), with decanoic acid (capric acid, C10) and octanoic acid (caprylic acid, C8) as the great remainder (100). When given in equal amounts, intake of decanoic acid and octanoic acid leads to a greater ketone production postprandially then dodecanoic acid (101,102). Thus, to increase the effect of medium-chain triglycerides on ketogenesis, a concentrated oil with a higher quantity of decanoic and octanoic acid can be given instead of coconut oil.…”