Abstract
Cardiovascular diseases (CVD) are the main leading cause of death worldwide. A reduction in low
density lipoprotein cholesterol (LDL-C) is considered a key target for prevention and treatment of
CVDs. Beyond increased LDL-C, low high density lipoprotein cholesterol (HDL-C), high fasting
and postprandial insulin and triacylglycerols (TAGs), high blood pressure (BP), and small, dense
LDL particles may contribute on their own to increased CVD risk. In several countries, the CVDrelated
dietary guidelines proposed by health authorities focus on reducing the intake of saturated
fatty acids (SFAs), especially from food categories such as dairy. Thus, low-fat dairy products are
advocated in most dietary guidelines to reduce the intake of cholesterol-raising SFAs found in
regular-fat dairy foods. However, these recommendations remain controversial to many, as
evidence from observational data found no detrimental association between dairy intake and CVDrelated
outcomes. Cheese intake, in particular, has been suggested to have a neutral or even
beneficial association with CVD-related outcomes and type 2 diabetes (T2D). Still, there is a key
research gap concerning the effect of regular-fat cheese intake compared with reduced-fat cheese.
The overall objective of this PhD thesis was to investigate the effects of regular-fat cheese with an
equal amount of reduced-fat cheese and carbohydrate-rich foods on CVD and T2D-related
outcomes including fasting blood lipids, LDL particle size distribution, and postprandial
insulinemia and lipidemia. The thesis is based on one large 12-week human intervention study
(paper I-III). The intervention was designed as a parallel-arm randomized, controlled intervention
study.
The objective of paper I was to compare the effects of regular-fat cheese versus an equal amount of
reduced-fat cheese and an isocaloric amount of carbohydrate-rich foods on LDL-C concentrations
and risk factors for the metabolic syndrome (MetS). A total of 150 subjects of the 164 randomized
subjects were included in the statistical analyses. We found that daily consumption of 64–112 g
regular-fat cheese for 12 weeks did not modify LDL-C concentrations or MetS risk factors
differently than equal amounts of reduced-fat cheese. The same was true when regular-cheese was
compared with carbohydrate-rich foods, although regular-fat cheese tended to increase HDL-C
concentrations compared with carbohydrate-rich foods (paper I).
The objective of paper II was to compare the effects of long-term cheese consumption on
postprandial insulinemia and lipidemia. A 4h postprandial meal test was conducted after the 12-
week randomized controlled trial in a subgroup of 37 subjects. Postprandial concentrations of
glucose, insulin, TAG, and free fatty acids (FFAs) were measured before and 30, 60, 90, 120, 180
and 240 min after breakfast commenced. We found that long-term consumption of regular-fat
cheese did not result in increased postprandial glucose and insulin concentrations, but resulted in
elevated postprandial TAG concentrations at 240 min compared with an equal amount of reducedfat
cheese (paper II).
The objective in paper III was to compare the effect of regular-fat cheese versus reduced-fat
cheese and carbohydrate-rich foods on LDL particle size distribution. In paper III, fasting plasma
was collected at week 0 and week 12 from a total of 85 subjects of the 164 subjects included in the
main intervention. In paper III, we found that regular-fat cheese did not modify LDL particle size
distribution compared to reduced-fat cheese after a 12-week intervention. However, our results
suggested that lipoprotein response is gender-specific. In men, regular-fat cheese intake reduced
total LDL particle number compared with reduced-fat cheese, whereas regular-fat cheese
consumption tended to increase total LDL particle number compared with reduced-fat cheese in
women.
Overall, the data from the large human intervention study presented in the current thesis do not
support the dietary recommendation that consumption of reduced-fat cheese is less atherogenic than
consumption of regular-fat cheese. Our results suggest that for most individuals with risk factors of
the metabolic syndrome, it is reasonable to include regular-fat cheese as part of a healthy diet.
density lipoprotein cholesterol (LDL-C) is considered a key target for prevention and treatment of
CVDs. Beyond increased LDL-C, low high density lipoprotein cholesterol (HDL-C), high fasting
and postprandial insulin and triacylglycerols (TAGs), high blood pressure (BP), and small, dense
LDL particles may contribute on their own to increased CVD risk. In several countries, the CVDrelated
dietary guidelines proposed by health authorities focus on reducing the intake of saturated
fatty acids (SFAs), especially from food categories such as dairy. Thus, low-fat dairy products are
advocated in most dietary guidelines to reduce the intake of cholesterol-raising SFAs found in
regular-fat dairy foods. However, these recommendations remain controversial to many, as
evidence from observational data found no detrimental association between dairy intake and CVDrelated
outcomes. Cheese intake, in particular, has been suggested to have a neutral or even
beneficial association with CVD-related outcomes and type 2 diabetes (T2D). Still, there is a key
research gap concerning the effect of regular-fat cheese intake compared with reduced-fat cheese.
The overall objective of this PhD thesis was to investigate the effects of regular-fat cheese with an
equal amount of reduced-fat cheese and carbohydrate-rich foods on CVD and T2D-related
outcomes including fasting blood lipids, LDL particle size distribution, and postprandial
insulinemia and lipidemia. The thesis is based on one large 12-week human intervention study
(paper I-III). The intervention was designed as a parallel-arm randomized, controlled intervention
study.
The objective of paper I was to compare the effects of regular-fat cheese versus an equal amount of
reduced-fat cheese and an isocaloric amount of carbohydrate-rich foods on LDL-C concentrations
and risk factors for the metabolic syndrome (MetS). A total of 150 subjects of the 164 randomized
subjects were included in the statistical analyses. We found that daily consumption of 64–112 g
regular-fat cheese for 12 weeks did not modify LDL-C concentrations or MetS risk factors
differently than equal amounts of reduced-fat cheese. The same was true when regular-cheese was
compared with carbohydrate-rich foods, although regular-fat cheese tended to increase HDL-C
concentrations compared with carbohydrate-rich foods (paper I).
The objective of paper II was to compare the effects of long-term cheese consumption on
postprandial insulinemia and lipidemia. A 4h postprandial meal test was conducted after the 12-
week randomized controlled trial in a subgroup of 37 subjects. Postprandial concentrations of
glucose, insulin, TAG, and free fatty acids (FFAs) were measured before and 30, 60, 90, 120, 180
and 240 min after breakfast commenced. We found that long-term consumption of regular-fat
cheese did not result in increased postprandial glucose and insulin concentrations, but resulted in
elevated postprandial TAG concentrations at 240 min compared with an equal amount of reducedfat
cheese (paper II).
The objective in paper III was to compare the effect of regular-fat cheese versus reduced-fat
cheese and carbohydrate-rich foods on LDL particle size distribution. In paper III, fasting plasma
was collected at week 0 and week 12 from a total of 85 subjects of the 164 subjects included in the
main intervention. In paper III, we found that regular-fat cheese did not modify LDL particle size
distribution compared to reduced-fat cheese after a 12-week intervention. However, our results
suggested that lipoprotein response is gender-specific. In men, regular-fat cheese intake reduced
total LDL particle number compared with reduced-fat cheese, whereas regular-fat cheese
consumption tended to increase total LDL particle number compared with reduced-fat cheese in
women.
Overall, the data from the large human intervention study presented in the current thesis do not
support the dietary recommendation that consumption of reduced-fat cheese is less atherogenic than
consumption of regular-fat cheese. Our results suggest that for most individuals with risk factors of
the metabolic syndrome, it is reasonable to include regular-fat cheese as part of a healthy diet.
| Original language | English |
|---|
| Place of Publication | Copenhagen |
|---|---|
| Publisher | Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen |
| Number of pages | 135 |
| ISBN (Print) | 978-87-93476-93-6 |
| Publication status | Published - 2016 |
