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New Ways to Lower Cholesterol with Diet

How fiber and bacteria may help lower cholesterol

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Oats are a staple of the 'Portfolio Diet,' which can be used to help reduce cholesterol.

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If you're among the 14 percent of American adults with high cholesterol, you've no doubt received the standard diet advice: lose weight; limit your intake of cholesterol-rich foods like eggs, butter, cheese, red meat and shellfish; and lower your intake of saturated fats from animal foods and hydrogenated plant oils.

Tamara Duker Freuman
Tamara Duker Freuman
[See Plant-Based Diets: A Primer.]

This standard advice is problematic. For one, many people find that cleaning up their diets of saturated fat and cholesterol isn't a surefire way to improve their lipid profile, unless significant weight loss follows. (It's common to replace those saturated fats with excessive carb portions; when that happens, cholesterol levels may not respond as favorably as one might hope.)

Another issue is that standard diet therapy emphasizes restricting, or eating less of, foods that tend to increase cholesterol levels. It doesn't tell people what they can proactively eat more of to help improve their lipid profile. It's hardly surprising that most people wind up on a statin drug to lower cholesterol when all is said and done.

But new research on complementary dietary approaches to cholesterol reduction offers promise. What if there were foods or supplements that we could consume more of, whose presence in the diet would help lower cholesterol—in some cases, by as much as some traditional cholesterol-lowering drugs do?

Indeed, there are at least two such tools that are offering new hope for the power of food and dietary supplements to help lower cholesterol, independent of weight loss. Here are some of the highlights:

• The "Portfolio Diet": Past research has focused narrowly on individual foods that have the power to help lower cholesterol—usually by small margins of a few percentage points. Individual studies have separately suggested that oats, almonds, soy and plant sterol-fortified margarines may all have a modest clinical benefit to this end.

But more recently, researchers have taken a more global approach to dietary intervention by testing a dietary pattern that included a "portfolio" of such foods in people with high cholesterol, and comparing their outcomes to others following the standard recommended diet low in saturated fat and cholesterol.

[See 5 Red Foods to Eat for Your Heart.]

Both groups started off overweight but were counseled on calorie targets to ensure they maintained their weight so that weight loss would not muddy the results.

Participants on the so-called Portfolio Diet consumed high amounts (about 11 grams per day on an 1,800-calorie diet) of viscous, cholesterol-trapping soluble fiber from both foods and supplements—like oats, barley, beans, eggplant, okra and psyllium husk fiber pills. They also ate an ounce and a half of nuts and about 1 gram of plant sterols from a fortified margarine product (like Benecol) each day. Protein sources were lean and low in cholesterol—like egg whites, soy protein, and fat-free dairy.

Portfolio dieters in this study experienced a 13 percent reduction in the LDL cholesterol levels after six months (average levels went from 171 milligrams per deciliter to 147 milligrams per deciliter). The more closely they followed the diet, the greater their reduction in LDL levels.

In my clinical practice, I've adapted this dietary approach to help my patients reduce their cholesterol levels, making modifications to liberalize food options without undermining the benefits of the diet. For example, while the research diet was vegetarian, I encourage patients who aren't interested in vegetarianism to include lean, low-cholesterol proteins like fish and skinless white-meat chicken and turkey.

With the help of a psyllium husk fiber supplement and a good oat-based breakfast, it's not terribly hard to reach target soluble fiber levels. Other Portfolio-friendly food ideas I encourage in my patients' regular rotations include mushroom barley soup, stir-fried tofu and eggplant, soy milk in their oatmeal, a generous sprinkle of chia seeds in their yogurt or cereal, beans and lentils in every possible incarnation and edamame. Not only has this dietary pattern helped many of my patients lower their cholesterol, but it helps keep them more regular than they've been in their lives!

[See Is All Fiber Created Equal?]

• "Cardioviva" probiotic (Lactobacillus reuteri NCIMB 30242): A Canadian probiotic supplement called Cardioviva is set to launch in the United States in May, and its impending arrival has generated quite a bit of buzz.

A recent study showed that participants with high cholesterol who supplemented their diets with Cardioviva twice daily experienced an average reduction of LDL cholesterol by more than 11 percent (and total cholesterol by 9 percent) in six weeks, compared to a placebo group. (By way of comparison, statin drugs can generally be expected to lower LDL levels by 40 to 60 percent; drugs like WelChol lower LDL levels by 10 to 20 percent.)

In a separate study, those who consumed the probiotic in a yogurt form experienced more modest reductions. Compared to a placebo group, their LDL levels dropped by about 9 percent and total cholesterol dropped by nearly 5 percent.

To be sure, these studies were relatively small (127 and 114 people, respectively). And it is not yet known whether using Cardioviva will actually result in a reduced risk of atherosclerosis (plaque buildup in the arteries) or cardiovascular events like heart attack or stroke. But nonetheless, the findings are promising and have understandably caught the attention of clinicians and patients looking for therapeutic options to help lower cholesterol with few—if any—known side effects.

The notion that a solution for high cholesterol might possibly be found among the bacteria in our gut is quite exciting, as it comes on the heels of a growing recognition that the health of the trillions of bacteria who call our digestive tract home may have further-reaching implications for our own health than previously understood.

[See Tending Your Inner Ecoystem.]

According to the product's developers, L. reuteri is one of several bacteria native to the human gut with the ability to produce an enzyme called bile salt hydrolase (BSH). As the name suggests, BSH breaks down bile salts, which are compounds the liver makes from cholesterol.

Bile salts help absorb cholesterol, fat and fat-soluble vitamins A, D, E and K from the diet; when they're in short supply, two things happen. One, less dietary cholesterol is absorbed. Two, the liver must divert its cholesterol production toward replenishing bile salts, instead of shipping off cholesterol into the bloodstream via LDL particles. Cardioviva is believed to work by ramping up the gut's native population of BSH-producing bacteria so that they can do what they do best.

At first glance, inducing increased BSH activity raises some concerns that deficiencies of fat-soluble vitamins could be an unintended side effect of Cardioviva. But preliminary safety data (as yet unpublished) suggest that after nine weeks on the supplement, no change in blood levels of vitamin A, beta carotene (a vitamin A precursor) or vitamin E were observed in Cardioviva users, when compared to their baseline levels. Interestingly, vitamin D levels, actually turned out to be 25 percent higher after nine weeks on the supplement. The company's founders speculate that this outcome may result from the fact that cholesterol and vitamin D actually share a common core "ingredient"; when the liver is forced to replace lost bile salts, it must also make more ingredients available to do so. Thus, more of the shared ingredient also becomes available to manufacture vitamin D.

If you are currently taking a statin medication or your doctor has recommended one, it's important to realize that statins may offer benefits beyond LDL and total cholesterol reduction alone. For example, statins can stabilize atherosclerotic plaque, which is another way in which they help prevent cardiovascular events like heart attack and stroke.

In many people, the dietary approaches outlined here may be more appropriate as complementary therapies to a statin drug—and in some cases they may facilitate a dose reduction. As promising as natural, dietary approaches to cholesterol reduction may be, never discontinue a statin drug without first discussing it with your doctor.

[See Top Cardiologists.]

Hungry for more? Write to eatandrun@usnews.com with your questions, concerns, and feedback.

Tamara Duker Freuman, MS, RD, CDN, is a NYC-based registered dietitian whose clinical practice specializes in digestive disorders, Celiac Disease, and food intolerances. Her personal blog, www.tamaraduker.com, focuses on healthy eating and gluten-free living.