Is Fat Intake Associated With an Increased Risk of Death?
Article: Associations of fats and carbohydrate intake with cardiovascular disease and mortality in 18 countries from five continents (PURE): a prospective cohort study
Author: Dehghan et al
Journal: Lancet (November, 2017)
Objective: “To assess the association of fats (total, saturated fatty acids, and unsaturated fats) and carbohydrate with total mortality and cardiovascular disease events.”
Cardiovascular disease is a global epidemic and the number one cause of death in adults across the world. It is responsible for 17.7 million deaths each year or 31% of all deaths. In the US, cardiovascular disease accounts for 795,000 strokes, 735,000 heart attacks, and 610,000 deaths.
Prevention and risk reduction is the most important approach to decreasing the incidence of cardiovascular disease. Diet remains one of the most important modifiable risk factors, others include weight loss, exercise and tobacco cessation.
Historically, diet modification has targeted a low fat diet with limited saturated fatty and trans fat intake. These recommendations are based on smaller observational studies and some assumptions about the relationship between saturated fat, LDL cholesterol, HDL cholesterol, apolipoproteins and cardiovascular disease.
Recently, several larger studies have suggested either no association or a lower risk between saturated fat consumption, cardiovascular disease and total mortality. The authors of this study saw these findings and sought to shed more light on the association of fats with total mortality and cardiovascular disease events.
This was a large cohort study with 135,335 individuals age 35-70 followed for an average of 7.4 years.
Dietary intake was recorded using a validated food frequency questionnaire
Primary outcome: total mortality and major cardiovascular events (fatal cardiovascular disease, non-fatal myocardial infarction, stroke, and heart failure).
Secondary outcomes: all myocardial infarctions, stroke, cardiovascular disease mortality, and non-cardiovascular disease mortality
The authors found 5796 deaths, 4784 cardiovascular events
Higher carbohydrate intake (5th vs 1st quintile) was associated with a 28% increased risk of total mortality (HR 1.28, 95% CI 1.12 - 1.46, p < 0.0001) but not specifically cardiovascular disease or cardiovascular mortality.
Intake of total fat was associated with 23% lower risk of total mortality (HR 0.77, 95% CI 0.67 - 0.87, p < 0.0001).
Intake of saturated fat was associated with 14% lower risk of total mortality (HR 0.86, 95% CI 0.76 - 0.99, p < 0.0088) and 21% lower risk of stroke (HR 0.79, 95% CI 0.64 - 0.98, p < 0.0498).
Mono- and polyunsaturated fat were associated with a 19% (HR 0.81, 95% CI 0.71 - 0.92, p < 0.0001) and 20% (HR 0.80, 95% CI 0.71 - .89, p < 0.0001) lower risk of total mortality respectively.
Total fat, saturated fat and unsaturated fat were not significantly associated with a lower risk of myocardial infarction or cardiovascular disease mortality.
Comparing the high carbohydrate consumers to the lower carbohydrate consumers, there was a 28% increase in risk of total death, but not specifically stroke or heart attack.
Contrasting that, higher total fat, saturated fat, mono and polyunsaturated fat intake were associated with a lower total risk of death, non-cardiovascular disease death and stroke risk.
They were not associated with lower risk of cardiovascular disease, heart attack or cardiovascular disease mortality.
This is a large study, with over 100,000 participants across five continents and really shatters the conventional wisdom that fat is “bad”. Take in consideration to other recent studies on the subject, global dietary guidelines should be reconsidered.
Dehghan, M., Mente, A,. et al (2017). Associations of fats and carbohydrate intake with cardiovascular disease and mortality in 18 countries from five continents (PURE): a prospective cohort study. Lancet, 390 (10107), 2050-2062.