I just found this in the latest edition of Medscape. For those who are resistant to taking drugs for cholesterol management...
Diet May Lower Cholesterol as Much as Statins CME
News Author: Laurie Barclay, MD
CME Author: Charles Vega, MD
July 22, 2003 — Adding soy protein, viscous fiber, and nuts can be as effective for lowering cholesterol as adding a statin to a low saturated fat diet, according to the results of a randomized controlled trial published in the July 23/30 issue of The Journal of the American Medical Association.
"Current dietary recommendations focusing on diets low in saturated fat have been expanded to include foods high in viscous fibers (eg, oats and barley) and plant sterols," write David J. A. Jenkins, MD, from St. Michael's Hospital in Toronto, Ontario, Canada, and colleagues. "These guidelines, together with additional suggestions to include vegetable protein foods (soy) and nuts (almonds), appear to reduce LDL-C [low-density lipoprotein cholesterol] levels similarly to the initial therapeutic dose of a first generation statin."
In this four-week study, 46 healthy, hyperlipidemic adults, including 25 men and 21 postmenopausal women (average age, 59 years; average body mass index, 27.6), were randomized to one of three diets. The control diet was very low in saturated fat, based on milled whole-wheat cereals and low-fat dairy foods, such as skim milk, fat-free cheese, and yogurt. The statin group received the same diet plus lovastatin, and the dietary portfolio group received a diet high in plant sterols (1g/1,000 kcal), soy protein (21.4 g/1,000kcal), viscous fibers (9.8 g/1,000kcal), and almonds (14 g/1,000 kcal).
LDL-C decreased by 8.0% in the control group, 30.9% in the statin group, and 28.6% in the dietary portfolio group. C-reactive protein decreased by 10.0%, 33.3%, and 28.2%, respectively. The significant reductions seen in the statin and dietary portfolio groups were significantly different from changes in the control group, and the efficacy of the dietary portfolio treatment was not significantly different from that of the statin treatment.
"In this study, diversifying cholesterol-lowering components in the same dietary portfolio increased the effectiveness of diet as a treatment of hypercholesterolemia," the authors write. "Using the experience gained, further development of this approach may provide a potentially valuable dietary option for cardiovascular disease risk reduction in primary prevention."
The Canada Research Chair Endowment of the federal government of Canada, the Canadian Natural Sciences and Engineering Research Council of Canada, Loblaw Brands, Ltd., the Almond Board of California, and Unilever Canada supported this study. Dr. Jenkins holds a Canada Research Chair funded by the federal government of Canada, and he has received research grants and/or other financial support from the Almond Board of California, Loblaw Brands, Ltd., Yves Fine Foods (now Hain-Celestial Group), Unilever Canada, and Protein Technologies, Inc. (now Solae).
In an accompanying editorial, James W. Anderson, MD, from the University of Kentucky in Lexington, emphasizes the importance of dietary management in treating all common lipid disorders.
"Dietary management is an essential part of the treatment for lipid disorders, although adherence to strict and intensive dietary interventions requires motivation by patients, encouragement by physicians, and, perhaps, counseling by dietitians and nutrition experts," he writes. "For most patients, dietary intervention should be the first line of therapy (perhaps for six to 12 weeks) before introducing pharmacotherapy for hyperlipidemia."
Clinical Context
Dietary modification should be part of the treatment plan for every patient with hyperlipidemia. According to the authors of the present study, dietary intervention in and of itself can result in a reduction of cholesterol by 4% to 13% compared with 28% to 35% reductions of LDL-C seen in most trials of HMG CoA reductase inhibitors (statins). Therefore, many physicians are quick to add statin therapy to help patients reach their target LDL-C levels.
Certain plant sterols and fibers seem to have lipid-lowering properties. In the introduction to the current study, the authors describe how plant sterols inhibit cholesterol absorption and can reduce LDL-C levels by up to 13%. Viscous fibers, such as psyllium, increase bile acid losses of bound cholesterol and can reduce LDL-C by 6% to 7%. Soy proteins reduce hepatic cholesterol synthesis and may also increase biliary uptake of cholesterol. Finally, almonds can lower LDL-C levels because they contain a plant sterol-rich oil and are high in monounsaturated fat.
The authors of this study sought to determine if a combination of the above products in a dietary portfolio could compare with the HMG CoA reductase inhibitor lovastatin in reducing LDL-C levels as well as C-reactive protein, a serum marker of inflammation implicated in promoting myocardial infarction.
Study Highlights
55 otherwise healthy patients with hyperlipidemia (LDL-C >158 mg/dL) were recruited to participate, and 46 patients completed the study. All patients came from a referral clinic in Canada and had previously expressed reluctance to start statin therapy, which explains in part the excellent compliance to diet during the study.
All participants were started on low-saturated-fat diets for one month prior to randomization. They were then randomized to 1 of 3 interventions: a control diet group with an emphasis on very low-saturated-fat diary and whole-grain cereal diet, a group with the same diet plus lovastatin 20 mg/day, or a diet rich in plant sterols, viscous fiber, soy protein, and almonds.
Specifically, the diet portfolio group received the following totals of food per day per 1,000 kcal of diet: 1.0 g of plant sterols (via a plant-sterol margarine), 9.8 g of viscous fiber (via oats, barley, and psyllium), 21.4 g of soy protein (via soy milk and soy meat analogs), and 14 g of almonds.
The main outcome measures of the study were cholesterol and C-reactive protein levels. These were measured over a 4-week period.
Weight loss varied between 0.2 - 0.4 kg in all groups over the 4-week study period.
LDL-C levels were 8.0% lower in the control group, and 30.9% and 28.6% lower in the lovastatin and diet portfolio groups, respectively.
The LDL-C to high-density lipoprotein cholesterol (HDL-C) ratio increased in the control group, but it decreased by 28.4% in the lovastatin group and 23.5% in the diet portfolio group.
C-reactive protein fell by 10% in the control group, 33.3% in the lovastatin group, and 28.2% in the diet portfolio group.
Lovastatin and the diet portfolio were statistically better in all study outcomes than the low-cholesterol diet alone, but there was no significant difference between the lovastatin and diet portfolio groups. This significance persisted on intention-to-treat analysis of the data.
There was no difference between sexes with regard to treatment efficacy.
Blood pressure was slightly reduced among all treatment groups.
40% of subjects in the dietary portfolio group thought the diet needed no modifications, but an equal number advocated for a greater variety of foods. 27% thought that the volume of food was too great. These findings, along with the selection of a group of motivated patients for this research, call into question the applicability of the study's findings in the general population.
Pearls for Practice
Viscous fiber, plant sterols, and almonds can have a positive effect on serum lipid levels in patients with hyperlipidemia through a variety of mechanisms. Dietary recommendations for hyperlipidemic patients should include foods rich in these items.
When viscous fiber, plant sterols, and almonds are incorporated into a dietary portfolio, the consequent reduction in LDL-C, LDL:HDL ratios, and C-reactive protein levels can equal those found with lovastatin treatment. |
