Cardiovascular disease is the leading cause of death
world-wide. Efforts to prevent cardiovascular disease can have a major impact
on global cardiovascular disease mortality. This presidential advisory from the
American Heart Association reviewed the scientific evidence of multiple studies
regarding the impact of dietary saturated fat on cardiovascular disease. It
strongly concludes that reducing dietary intake of saturated fat and replacing
it with unsaturated fat, especially polyunsaturated fat, will reduce the rate
of cardiovascular disease. The following are key points to remembers.
1-
Multiple randomized
clinical trials, meta-analyses, prospective observational studies, and animal
studies all support the concept of replacement of dietary saturated fats with
unsaturated fats to reduce cardiovascular disease. Reducing dietary saturated
fat and replacing it with polyunsaturated vegetable oil reduced cardiovascular disease
by around 30%. Similar to results from statin therapy. Prospective
observational studies showed that reducing saturated fat and replacing it with polyunsaturated
or monounsaturated fat caused 25% and 15% reductions in coronary heart disease
(CHD), respectively. Mortality overall and from other causes was also reduced.
2-
Replacing dietary saturated
fats with carbohydrates, especially refined carbohydrates, does not reduce
cardiovascular disease, Substitution with refined carbohydrates causes a 1%
increase in CHD; substitution with whole grain carbohydrates caused a 9%
reduction.
3-
Both polyunsaturated fats
and monounsaturated fats are effective in reducing cardiovascular disease. The
effect is greatest for polyunsaturated fats.
4-
Studies in which saturated
fats were replaced by carbohydras resulting in a low-fat diet did not reduce
cardiovascular disease.
5-
Animal studies have shown
that a diet high in saturated fats raises low-density lipoprotein (LDL) cholesterol
and increase coronary atherosclerosis, and a diet low in saturated fat but high
in polyunsaturated fat has the reverse effect.
6-
Replacement of saturated
fat with polyunsaturated fat, monounsaturated fat, or carbohydrates results in
a reduction on LDL cholesterol; the reduction is greatest for polyunsaturated
fats and least for carbohydrates.
7-
Coconut oil increases LDL
without known beneficial effects. Diary fat increases LDL; substitution by
polyunsaturated fats causes a 24-25% lower risk of cardiovascular disease and
stroke. Trans-unsaturated fats increase cardiovascular disease. Omega-3
vegetable oil is associated with a lower risk of fatal but not overall CHD,
possibly due to antiarrhythmic properties.
8-
Randomized clinical trials
of a Mediterranean diets in conjunction with substitution of polyunsaturated or
monounsaturated fats for saturated fats resulted in significantly reduced
cardiovascular disease in the intervention arms but not in controls groups
assigned to a low-fat diet.
The American heart Association Presidential
Advisory strongly concedes that reducing dietary intake of saturated fat and
replacing it with unsaturated fat, especially polyunsaturated fat. Will reduce cardiovascular
disease incidence. Reduction in total fat i.e.; a low fat diet) is not
recommended. This dietary shift should occur concurrently with the adoption of
an overall healthy diet such as the Dietary Approaches to stop Hypertension
diet or mideterranead diet.
