Good article on MUFA and PUFA by Dr. MAKI

MUFA and PUFA by Dr Maki link


Highlights:

The results from this and other dietary intervention trials suggest that reductions in LDL-C, non-HDL-C, and apo B occured when MUFAs replaced SFAs in the diet.47, 48, 49

When MUFAs replace carbohydrates in the diet, TG, very low-density lipoprotein-C, high-sensitivity C-reactive protein, and blood pressure decrease, while HDL-C and apo A1 increase.48, 49

These changes suggest that increased MUFA intake should reduce the risk of cardiovascular events.

However, caution is warranted because results from studies in nonhuman primates and mice, as reviewed by Dr. Rudel, have suggested that dietary MUFA compared to SFA intake may not protect against the development of coronary artery atherosclerosis, despite favorable changes in serum lipoprotein lipids.40, 42

There is little clinical trial evidence available regarding MUFA intake and CHD outcomes, but in epidemiological studies researchers have examined this relationship.

In the Nurses’ Health Study, modeling an isocaloric replacement of 5% of energy from SFA with carbohydrate was associated with a nonsignificant reduction in CHD risk (Fig. 5).10

When carbohydrates were substituted for MUFAs, CHD risk was increased, whereas when MUFAs were substituted for SFAs there was an apparent reduction in risk.

However, such results are challenging to interpret because MUFA intake is highly correlated with SFA intake (correlation coefficient of 0.81 in the Nurses’ Health Study data) and is moderately correlated with intakes of PUFA (correlation coefficient 0.30) and trans-fatty acids (correlation coefficient 0.55).

Other factors should also be taken into account when considering the relationship between MUFA intake and atherosclerotic CVD risk.

1-For example, MUFAs coexist with SFAs in many foods.

2-In addition, cis- and trans-isomers of MUFAs were sometimes categorized together in epidemiological studies.

3-Studies that specifically assessed trans-fatty acid intake sometimes characterized them poorly, which may have led to residual confounding.

4-Possible effects of the other nutrients in foods being replaced and what is substituted for the displaced foods also have to be considered.

5-Furthermore, the specific food sources of MUFA may influence the results.

For example, relatively unrefined olive oil retains several lipophilic components, whereas highly refined olive oil has a low level of some of these potentially bioactive compounds.

6-The net effect of a particular dietary change may also be modified by characteristics of the population being studied. Individuals with

1-insulin resistance,

2-metabolic syndrome,

3-diabetes, or

4-dyslipidemia

may respond differently from those who do not have these conditions.

Therefore, in light of the uncertainty regarding the relationship between consumption of specific fatty acids and CVD risk, the most prudent recommendation in the author’s view is a dietary pattern that emphasizes whole grains, legumes, nuts and oils, fruits, vegetables, fish, lean meats, and low-fat dairy products, with sparing consumption of refined grains, white rice, potatoes, stick margarines, shortenings, sugar-sweetened sodas, confectionary products, desserts, high-fat meat and high-fat dairy products.52, 53