Today a study was published in the American Journal of Clinical Nutrition, touting the benefits of a diet rich with plant sterols, almonds, and soy - Assessment of the longer-term effects of a dietary portfolio of cholesterol-lowering foods in hypercholesterolemia - that concluded "More than 30% of motivated participants who ate the dietary portfolio of cholesterol-lowering foods under real-world conditions were able to lower LDL-cholesterol concentrations more than 20%, which was not significantly different from their response to a first-generation statin taken under metabolically controlled conditions."
Wow - so 70% of motivated participants apparently didn't have the same "beneficial" outcome.
But, let's see just how the data in this study bears out, shall we?
At baseline, the profile of the participants shows they were consuming well within the "heart healthy" guidelines already, consuming on average, 25.2% total fat, just 6.8% saturated fat, just 141.3mg of cholesterol daily on average (89.5mg/1000 calories, 1579 calories a day average) and the requisite 55% carbohydrate (54.6%).
The cholesterol at baseline - one word - horrible, even with their "heart healthy" eating habits:
TC = 261
LDL-C = 173
HDL-C = 48
TG = 203
TC/HDL Ratio = 5.76 (actual as reported by the researchers)
So, then, what happened at the end of a year?
Well, there was improvement in their cholesterol:
TC = 234
LDL-C = 150
HDL = 49
TG = 175
TC/HDL Ratio = 5.03 (actual reported by researchers)
First let me say - these "improvements" were unimpressive - on average the group still had borderline high total cholesterol, LDL-C and triglycerides and only minor movement with their HDL-C. Their TC/HDL ratio remained way too high.
The researchers concluded that it was the dietary portfolio of almonds, soy, oats and other foods with plant sterols that was responsible for the improvement.
I wondered, did anything else change?
Interestingly, the percentage of saturated fat in their diets did decrease, but the actual amount eaten remained exactly the same at one-year as it was at baseline because they increased their calorie intake over the year.
Not only did they increase calories, they increased fiber, fat, polyunsatured and monounsaturated oils, and significantly decreased their intake of cholesterol.So the question begs - were the results due to the "dietary portfolio" of almonds, oats and soy, or the other dietary modifications that occured? Or, something else?
Sadly, the researchers don't explore the confounding variables in their data. They also failed to have a control group to compare the dietary intervention group against and instead compared results the effect of statins for cholesterol reduction. Also noteworthy is the study is one-year and cannot accurately predict long-term outcomes or even show long-term outcomes from such a diet - will a diet like this reduce heart attacks, will it reduce all cause mortality over the long-term?