If you have high cholesterol, the American Heart Association's low-cholesterol, low-saturated fat diet will fail you. Even when applied conscientiously, it achieves a disappointingly modest reduction in LDL cholesterol of approximately 7%. Starting at an LDL cholesterol of 150 mg/dl, for instance, you would drop to 139. It's no surprise that many people turn to alternative diets (Ornish, Pritikin, Zone, etc.) to get a bigger bang. And no surprise that many physicians go directly to statin agents for their nearly effortless 35% or greater reduction.
The Adult Treatment Panel-III (ATP-III) is a committee of experts charged with developing guidelines for cholesterol treatment for Americans. The latest ATP guidelines suggest the use of fibers for a nutritional advantage in lowering cholesterol. Despite the ATP-III's endorsement, however, there has been no "real-world" data that documents the LDL-lowering effectiveness of combinations of fibers and other foods added to an AHA Step II low-fat diet (fat 30% of calories). Dr. David Jenkins from the Clinical Nutrition & Risk Factor Modification Center at St Michael's Hospital, Toronto has therefore explored such a multi-ingredient program, reported in the Journal of the American Medicine Association1. He calls this program the "dietary portfolio," highlighting the inclusion of several different healthy foods combined to achieve the goal of lowering cholesterol.
The study enrolled 46 adults (25 men, 21 post-menopausal women) with a mean age of 59 years. All participants were free of known heart disease, diabetes, and none were taking any cholesterol-lowering agents. Baseline LDL cholesterol was 171 mg/dl for all participants. Three groups were designated: 1) Viscous fiber, phytosterols, and almond diet, the so-called "dietary portfolio"; 2) Control diet (AHA Step II); and 3) Control diet with lovastatin 20 mg/day (a cholesterol-lowering statin drug). Cholesterol panels were reassessed after a four week period in each arm. All diets had equal calorie content.
The dietary portfolio provided 1.0 g of phytosterols (a soy bean derivative) per 1000 kcal; 9.8 g viscous fibers (as oat bran and oat products, barley, and psyllium seed) per 1000 kcal; 21.4 g soy protein per 1000 kcal; and 14 g (around 12 almonds) per 1000 kcal. A typical 2400 kcal diet would therefore provide 2.4 g phytosterols (2 tbsp Take Control or Benecol), 24 g viscous fiber, 51 g soy protein, and 34 g of almonds (around 34 almonds). Average fiber intake for participants was an impressive 78 g/day. (The average American takes in a meager 14 g/day.)
The control diet was also abundant in fiber at 57 g/day, but contained little of the viscous variety, as the primary fiber sources were whole wheat products which lack viscous fibers. The diet was otherwise very similar to the dietary portfolio in fat and cholesterol content, protein, and total calories.
The dietary portfolio achieved an impressive 28% reduction in LDL cholesterol. Unexpectedly, there was also a 30% reduction in C-reactive protein (CRP), a popular measure of inflammation. The results achieved with the dietary portfolio were virtually identical to the results obtained with lovastatin. The control diet achieved a paltry 8% reduction in LDL and a 10% reduction in CRP. Interestingly, a third of the participants in the dietary portfolio group reported that there was too much food (given the satiety-effect of fiber rich foods). This was the group that lost the most weight, though only a modest 1 lb.
Conclusion:
Dr. Jenkins' portfolio of fiber-rich foods had the same effects on LDL cholesterol and CRP as a moderate dose of lovastatin. This is quite remarkable, given the relative failure of the diets usually prescribed to improve cholesterol values. Conventional diets, in fact, have been so ineffective that some physicians have abandoned the use of dietary recommendations in their practices.
The fiber-rich foods used in the dietary portfolio are readily available and inexpensive. Though the specific components used in the study have each been shown to lower LDL cholesterol when used independently, the combination has not been examined. Many would likely have predicted that, in view of the similar mechanisms of LDL-reduction among the various components of the portfolio, the LDL lowering effect would not exceed 15%. (Soy protein is the only component with a significantly different mechanism of action--suppression of liver synthesis of cholesterol.)
Instead, this powerful combination achieved an impressive 28% reduction, as good as the prescription agent lovastatin. (In our experience with this approach, LDL cholesterol typically drops 30 to 50 points, sometimes more.)
The high-fiber approach of the dietary portfolio significantly exceeds the fiber intake of the average American. As a practical matter, people who elect to follow this program should introduce each component gradually and drink plentiful water, as constipation can result if hydration in inadequate.
To reproduce the LDL and CRP benefits of the dietary portfolio, a practical combination would be:
o Oat bran--1/4 cup (uncooked) + 3 tsp psyllium seed
o Soy protein powder--6 tbsp/day
o Almonds--34 or approximately 2 handfuls/day
o Take Control or Benecol 2 tbsp/day
Jenkins DJA, Kendall CWC, Marchie A, et al. Effects of a dietary portfolio of cholesterol-lowering foods vs. lovastatin on serum lipids and c-reactive protein. JAMA. 2003 290:502-10.
William Davis, MD is a practicing cardiologist, author and lecturer. He is author of the book, Track Your Plaque: The only heart disease prevention program that shows you how to use the new CT heart scans to detect, track, and control coronary plaque. He is author of the soon-to-be released new book, What Does My Heart Scan Show?, available by May, 2005 at trackyourplaque.com trackyourplaque.com
No comments:
Post a Comment