Eating a predominantly vegetarian diet focused on lowering cholesterol — and getting advice on how to do so effectively — can drop LDL levels more than a diet focused only on reducing saturated fat, researchers found.[1]
A diet rich in cholesterol-lowering foods dropped LDL by 13% to 14% over six months, depending on the level of accompanying counselling, compared with a drop of just 3% for patients on a control diet.
Our data demonstrate the cholesterol-lowering potential of a dietary portfolio intervention that counsels participants to increase consumption of cholesterol-lowering foods denoted by the FDA to have a heart-health benefit,” stated the authors.
Foods with known cholesterol-lowering properties — such as nuts, soy, and barley — have been shown to be effective in lowering serum cholesterol in metabolically controlled conditions, the researchers said.
So they assessed whether eating a diet consisting of these foods decreased LDL cholesterol compared with a control diet that emphasised eating fibre and whole grains.
They enrolled 351 patients with hyperlipidaemia at four centres across Canada, who were given one of three diet plans: a “dietary portfolio” that emphasised plant sterols, soy protein, viscous fibres, and nuts with either two counselling sessions or seven sessions over six months, or a control diet focused on lowering saturated fats without counselling. Control patients were not allowed to eat foods in the intervention portfolio.
The 51 patients who were taking statins before the study had discontinued them at least two weeks prior.
Mean LDL cholesterol at baseline was 171 mg/dL.
In the modified intention-to-treat analysis of 345 patients, the researchers saw significant reductions in LDL cholesterol only for patients in both arms of the portfolio diet:
- a 13.8% reduction for those who had intensive counselling and a
- 13.1% drop for those with “routine” counselling (P<0.001 for both)
- Compared with a non-significant 3% drop for those on the control diet.
The authors stated that the LDL reductions were “approximately half those observed with early statin trials, that were associated with 20% reductions in coronary heart disease mortality.”
“Further study is needed to determine whether cholesterol reduction using these portfolio components is associated with lower rates of coronary heart disease events”
They also noted that more frequent visits to the clinic appear to be unnecessary in achieving significant reductions in LDL.
“The near maximal effectiveness of only two clinic visits enhances the suitability of this dietary approach for clinical application”
The portfolio diet also improved the ratio of total cholesterol to HDL cholesterol;
- Dropping 8.2% for the routine counselling and
- Dropping 6.6% for the intensive counselling (P<0.001 for both).
Those reductions were significantly greater than those for the control diet, but weren’t significantly different from each other, the researchers said.
The cholesterol-lowering diet also reduced the calculated 10-year heart risk by:
- 10.8% for those on routine counselling and by
- 11.3% for those on intense counselling, which was significantly greater than
- the non-significant 0.5% drop in risk for those on the control diet.
“Convincing people to change dietary patterns is difficult, much less convincing them to become vegetarians,”
But it can be done, motivation comes from many sectors, and not everyone is motivated by the reduction of end risk, but most are. the nutritional counselling represents a very important part of this study and demands that Nutritional Therapists commit a great deal of effort in the preparation of their patients for the inevitable complex and confusing changes that switching eating habits creates.
Cautionary notes
The study was limited because the intervention was complex and lipid-lowering effects couldn’t be pegged to specific components. Also, the authors cautioned about its high overall dropout rate of 22.6%, though they noted this is an attrition rate common to dietary studies at these levels of intensity.
As well, the study may lack generalisability because its population was predominantly white, with low-to-intermediate risk of cardiovascular disease, and may not translate to those with a higher risk of disease.
Still, they concluded that “a meaningful 13% LDL reduction can be obtained after only two clinic visits of approximately 60- and 40-minute sessions.
Reference
[1] Jenkins DJA, et al “Effect of a dietary portfolio of cholesterol-lowering foods given at two levels of intensity of dietary advice on serum lipids in hyperlipidemia” JAMA 2011; 206(8): 831-839. View Full Paper
