Ruminant Trans Fats and the Risk of Cardiovascular Disease in Women

Ruminant Trans Fats and the Risk of Cardiovascular Disease in Women

While the deleterious effects of trans fat from industrial sources (iTFA) on cardiovascular health are well established, the impact of TFA from ruminants (rTFA) on cardiovascular risk factors has not been as well characterized. We have previously shown in men that a very high dietary intakes of rTFA (>3.5% of energy) leads to unfavourable changes in lipid cardiovascular risk factors that are similar to those seen with iTFA. However, our data also indicated that achievable intakes of rTFA that remain well above the current human consumption (1.5% of energy intake) had neutral effects on plasma lipids and other cardiovascular disease (CVD) risk factors in men. Other studies have also suggested that the LDL and HDL response to very high dietary intakes of rTFA (>5% of energy) in women may be different than in men.

The general objective of the study is to investigate for the first time in a double-blind randomized controlled study the impact of high but yet achievable intake of ruminant trans fatty acids on plasma LDL-Cholesterol and other risk factors for CVD in healthy women.

Ruminant trans fatty acids (rTFA) will come from an experimental butter formulated from dairy fat obtained after having modified the regimen of lactating cows. All diets will be identical in terms of menus, calories and macronutrient composition with the exception of TFA levels. All foods will be provided to study participants. Based on a 2500 kcal/day regimen, an intake of 4.1g of rTFA will represent 37 kcal/day (1.5% of energy intake) while the intake of 0.7 g of rTFA in the control diet will represent 6 calories (0.3% of energy). The 2 experimental diets will be formulated so that the percentage of daily calories from fat (33%), carbohydrates (52%) and proteins (15%) will meet the dietary recommendations of the American Heart Association and the NCEP for primary prevention of CVD.

Inclusion Criteria:

• Healthy women using or not contraceptive agents or hormone supplementation
• For pre-menopausal women: regular menstrual cycle for the last 3 months (25- 35 days)
• LDL-Cholesterol concentration between 2.5 and 4.0 mmol/L
• Stable body weight (+/- 2 kg) for 6 months before the beginning of the study
• Smoking or not

Exclusion Criteria:

• Previous history of cardiovascular disease, type 2 diabetes and monogenic dyslipidemia
• Subjects taking medications for hyperlipidemia or hypertension
• Endocrine disorders
• Body mass index > 35 kg/m2
• Food allergies
• Women with extreme nutritional habits such as vegetarism or alcohol consumption > 2 drinks/day
• Elite athletes