If you're among the 50 per cent of Canadians considered to have a high level of LDL (bad) blood cholesterol, chances are you're watching your fat intake. Eating less saturated fat – found in meat, poultry and high fat dairy products – helps to lower LDL cholesterol.
But according to a new Canadian study, you need to do more than slash saturated fat to control blood cholesterol.
People whose diets included a combination of certain cholesterol-lowering foods saw their LDL cholesterol drop considerably more than those who followed a conventional low saturated fat diet. In fact, the low fat diet had little impact on blood cholesterol.
Health professionals have always stressed the importance of diet as the primary way to improve cholesterol levels. However the introduction of statin drugs in the late 1980s highlighted the relative ineffectiveness of standard diet advice.
As a result, researchers have been busy studying other foods and food components that could boost the cholesterol-lowering power of a low saturated fat diet.
Foods such as oat bran, nuts and soy have been shown to lower cholesterol and have also been associated with lower risk of coronary heart disease. So too have foods fortified with plant sterols, compounds found naturally in nuts, vegetable oil, whole grains, fruits and vegetables.
For the past 12 years, David Jenkins, director of the Risk Factor Modification Centre at St. Michael's Hospital in Toronto, has studied the cholesterol-lowering effect of a low saturated-fat diet that also includes viscous (sticky) fibre (e.g. oats, oat bran), nuts, soy protein and plant sterols. This "portfolio" diet has been shown to cut LDL cholesterol by 28 per cent, a reduction similar to first-generation statins.
Dr. Jenkins' current research, published in this week's issue of the Journal of the American Medical Association, set out to determine if a portfolio diet could do a better job at lowering LDL cholesterol than a low saturated-fat diet.
In the multi-centre study, 351 men and postmenopausal women with mild to moderately high LDL cholesterol were counselled to either add portfolio foods – oats, barley, psyllium, soy, nuts, plant-sterol enriched margarine – to their daily diet or they were instructed to follow a control diet.
The control diet was low in saturated fat and cholesterol and included whole grain cereals, fruits and vegetables. It did not include portfolio foods.
After six months, folks on the control diet lowered their LDL cholesterol by only 3 per cent. Those following the portfolio diet, however, experienced a 13 per cent reduction in LDL cholesterol.
Participants were already following fairly healthy diets before they started Dr. Jenkins's study. Had their diets been more reflective of the typical Canadian diet, blood cholesterol levels would have declined even further.
If you have high LDL cholesterol, adding "portfolio" foods to a diet low in saturated fat can enhance its cholesterol-lowering power. Dr. Jenkins also says the more you move to a vegetarian diet, the better the results. Daily servings below are those recommended in Dr. Jenkins' portfolio diet studies and are based on a 2,000 calorie diet.
Viscous fibre: 7 servings a day
This type of fibre – plentiful in oats, oat bran, barley and psyllium – traps dietary cholesterol and fat in the digestive tract and speeds their removal from the body.
One serving is equivalent to 1/2 cup dry oat bran, 2/3 cup raw oats, 1 cup cooked barley, 1 slice oat bran bread, psyllium-enriched breakfast cereals, 1 teaspoon Metamucil and 2 teaspoons psyllium husk. Other good sources of viscous fibre include okra and eggplant.
It's possible to get 7 servings of viscous fibre by eating 2/3 cup of Kellogg's All Bran Buds at breakfast, barely soup and a sandwich on oat bran bread at lunch and supplementing with 2 teaspoons of Metamucil or 4 teaspoons of psyllium husk per day in a smoothie, juice or water.
Soy Protein: 45 grams a day
Foods such as soy beans (3/4 cup = 21 g), soy nuts (1/4 cup =14 g), firm tofu (3/4 cup = 15 g), soy burgers (1 = 12 g), soy hot dogs (1 = 9 g) and soy beverages (1 c = 8 g) contain soy protein, which helps lower blood cholesterol.
A 2,000-calorie portfolio diet is mainly vegetarian getting the bulk of its protein from soy. Two cups of soy milk, 1/4 cup of roasted soy nuts and a soy burger, or 3/4 cup chopped tofu delivers a total of 45 grams of soy protein.
Nuts: 1.5 servings a day
Studies have consistently found that nuts, packed with heart-healthy unsaturated fat, help reduce blood cholesterol.
One serving is equivalent to 28 grams worth of nuts: 24 almonds, 18 cashews, 20 hazelnuts, 28 peanuts, 20 pecan halves, 49 pistachios and 14 walnut halves.
Plant sterols: 2 grams a day
These phytochemicals compete with food cholesterol in the gut to be absorbed into the bloodstream. As a result, they have been shown to reduce the absorption of dietary cholesterol by 50 per cent.
Plant sterol-fortified foods such as margarine, yogurt, yogurt drinks and fruit juice are now available in grocery stores. Five teaspoons of Becel pro-active margarine and President's Choice Blue Menu Celeb margarine have 2 grams of plant sterols.
You can also get 2 grams of plant sterols in two 100-gram servings of Astro Biobest, two 80-millilitre servings of Danacol, two servings of President's Choice Blue Menu yogurt with plant sterols, or 2 cups of Oasis CholestPrevent juice.
For best results, consume plant sterol fortified foods two times per day rather than only once.
Heat oil in a large saucepan, over medium heat. Add onions; sauté for about 4 to 5 minutes or until soft.
Add water, beef bouillon, mushrooms, tofu, rice vinegar, balsamic vinegar, ginger root, sesame oil, pepper, kale, green onions and red pepper flakes.
Cover and simmer for 15 to 20 minutes.
From Heart Healthy Foods for Life© Leslie Beck, 2009. Reprinted by permission from Penguin Group (Canada), a division of Pearson Canada Inc.