Cardiovascular diseases (coronary heart disease, stroke and peripheral vascular disease), are the primary cause of death worldwide. A key public health recommendation for reducing the risk of developing CVD is to lower dietary saturated fats (SFA) intake to <10% total dietary energy. At present, the best nutrient to replace SFA in our diets is unclear.
Unsaturated fats (found predominantly in vegetable oils) are considered more beneficial than carbohydrates, although no guidance exists on whether polyunsaturated or monounsaturated fatty acids are optimal. Furthermore, the links between SFA and CVD have been questioned recently, which has caused considerable public confusion regarding the impact of SFA intake on health.
A comprehensive dose-response meta-analysis was conducted to examine linear and non-linear associations between milk and dairy products with all-cause mortality, coronary heart disease (CHD) and cardiovascular disease (CVD) using existing prospective cohort studies of adequate quality.
Outcomes and Impact
- When MUFA replaced SFA, night-time blood pressure was reduced on average by 5 mmHg. On a population level this reduction is considered clinically relevant as a 3 mm Hg reduction in blood pressure is linked to a 5% reduction in coronary heart disease risk
- Levels of LDL-cholesterol, were reduced by 11-14% when SFA was substituted with either MUFA or n-6 PUFA, which is equivalent to a 17-20% reduction in heart disease risk
- Levels of LDL-C increased by on average 10 % on a high SFA diet compared with baseline pre-intervention concentrations
- There was no significant effect on measures of endothelial function (blood vessel health).
These findings reinforce the current UK government guidelines to reduce intakes of SFA and to replace them with unsaturated fats to lower our risk of CVD.
Professor Julie Lovegrove, Professor of Metabolic Nutrition, Head of the Hugh Sinclair Unit of Human Nutrition, University of Reading
Professor Parveen Yaqoob, Professor of Nutritional Physiology, Pro-Vice Chancellor (Research & Innovation), University of Reading
Dr Kim Jackson, Senior Research Fellow & QAR Manager, Food & Nutritional Sciences, University of Reading
Replacement of saturated with unsaturated fats had no impact on vascular function but beneficial effects on lipid biomarkers, E-selectin, and blood pressure: results from the randomized, controlled Dietary Intervention and VAScular function (DIVAS) study