Dairy calcium intake modifies responsiveness of fat metabolism and blood lipids to a high-fat diet.
Study Goal
The researchers aimed to determine whether the calcium content in dairy products influences the effect of dairy fat on cholesterol levels.
Results Summary
The study found that high-fat diets increased total, LDL, and HDL cholesterol, while high-calcium diets reduced total and LDL cholesterol without affecting HDL cholesterol. Dairy calcium partially counteracted the cholesterol-raising effects of dairy fat.
Population
9 subjects (specific demographics not detailed).
Effective Dosage
Four isoenergetic diets varying in calcium (700 mg/d or 2800 mg/d) and fat (25% or 49% of energy).
Duration
10 days per diet period.
Interactions
None mentioned.
| Intervention | Direction | Endpoint | Population | Dosage | Impact | Claim # |
|---|---|---|---|---|---|---|
saturated fat | increase | total and LDL-cholesterol concentrations | - | - | increases | #1 |
dairy products | decrease | incidence of CVD | - | - | inverse relationship | #2 |
HF diet | increase | concentrations of total cholesterol | Subjects (n 9) | 9% | increased | #3 |
HF diet | increase | LDL-cholesterol | Subjects (n 9) | 14% | increased | #4 |
HF diet | increase | HDL-cholesterol | Subjects (n 9) | 13% | increased | #5 |
HC diet | decrease | concentrations of total cholesterol | Subjects (n 9) | 4% | decreased | #6 |
HC diet | decrease | LDL-cholesterol | Subjects (n 9) | 10% | decreased | #7 |
HC diet | no change | HDL-cholesterol | Subjects (n 9) | - | no effect | #8 |
HC diet | decrease | total:HDL-cholesterol | Subjects (n 9) | 5% | decreased | #9 |
HC diet | increase | HDL:LDL | Subjects (n 9) | 12% | increased | #10 |
HC diet | increase | Faecal fat excretion | Subjects (n 9) | - | increased | #11 |
HF diet | increase | Faecal fat excretion | Subjects (n 9) | - | increased | #12 |
dairy Ca | decrease | total and LDL-cholesterol | - | - | counteract the raising effect | #13 |
Intervention studies have demonstrated that saturated fat increases total and LDL-cholesterol concentrations, and it is therefore recommended that the intake of high-fat dairy products be limited. However, observational studies have found an inverse relationship between the intake of dairy products and incidence of CVD. We aimed to study whether the Ca content of dairy products influences the effect of dairy fat on the lipid profile. The study had a randomised cross-over design. Subjects (n 9) were randomised to one of the sequence of four isoenergetic 10 d diets: low Ca and low fat (LC/LF: approximately 700 mg Ca/d, 25 % of energy (fat); high Ca and LF (HC/LF: approximately 2800 mg Ca/d, 25 % of energy fat); LC and high fat (LC/HF: approximately 700 mg Ca/d, 49 E% fat); or HC and HF (approximately 2800 mg Ca/d, 49 E% fat). Blood variables were measured before and after each diet period, and faeces and urine were collected at the end of each diet period. A two-way ANOVA was used to examine the effect of Ca and fat intake. Independent of Ca intake, the HF diet increased the concentrations of total (9 %; P < 0·0001), LDL (14 %; P < 0·0001)- and HDL (13 %; P = 0·0002)-cholesterol compared with the LF diet. However, independent of fat intake, the HC diet decreased the concentrations of total (4 %; P = 0·0051) and LDL-cholesterol (10 %; P < 0·0001) but not HDL-cholesterol compared with the LC diet. In addition, total:HDL-cholesterol was decreased (5 %; P = 0·0299), and HDL:LDL was increased (12 %; P = 0·0097) by the HC diet compared with the LC diet. Faecal fat excretion was increased by both the HC (P < 0·0001) and HF (P = 0·0052) diets. In conclusion, we observed that dairy Ca seems to partly counteract the raising effect of dairy fat on total and LDL-cholesterol, without reducing HDL-cholesterol.