I’ve lost count of the number of people who’ve told me healthy eating doesn’t work to lower their blood cholesterol. Indeed, some people’s cholesterol is resistant to diet. Yet more often than not, when I ask what they’ve tried, it’s “a low-fat diet.” The good news: If that sounds like you, you haven’t begun to see the impact of a broad-based strategy of healthy choices on your blood cholesterol and overall heart disease risk.
Relying on a “low-fat diet” to reduce your blood cholesterol and heart disease risk is like leaving for vacation with just one thing in your suitcase. Broader strategies have been proven to potentially drop LDL cholesterol as effectively as the starting dose of the powerful statin medications, and can address other heart health risks to boot. Don’t worry, a broader strategy doesn’t have to be harder, and it can pay off with broader health benefits.
Low-fat?
Not all fat affects blood cholesterol equally. Target two specific types: Trans fat from partially hydrogenated oils and saturated fat. The 2010 Dietary Guidelines for Americans recommend reducing saturated fat to no more than 10 percent of calories and then working down to no more than 7 percent. For the average American, that means cutting about 12 grams of saturated fat from current daily intake.
Why saturated fat recommendations are less than crystal clear
Not all saturated fat is the same. One type – stearic acid – does not raise cholesterol. However, most foods contain a mixture, so the only food that’s really “off the hook” despite its listed saturated fat content is chocolate. About 30 percent of the fat in either dark or milk chocolate is stearic acid, and studies repeatedly show that neither chocolate raises blood cholesterol.
Not all LDL cholesterol is equally bad, according to emerging research that divides LDL into small, medium and large subclasses. Small LDL is what studies now link to heart disease, probably because it gets into blood vessel walls easily and stays there longest producing damage.
Early studies suggest that if you replace saturated fat with carbohydrate, although total LDL may drop, the damaging small LDL may increase. However, in studies showing this, about half the carbohydrate was in the form of sugars rather than nutrient- and fiber-rich foods like whole grains and vegetables. Replacing saturated fat with poly- and monounsaturated fat doesn’t pose this concern. More research is needed.
If you’re overweight and don’t replace the saturated fat you cut with anything else, the calorie cut will lead to weight loss that may independently slash both blood cholesterol and other heart risk factors.
Strategies that add healthy foods
An approach known as the portfolio diet, which is low in saturated fat and adds foods that help lower blood cholesterol, offers impact far beyond the drop in LDL from even substantial cuts in saturated fat alone. It has slashed LDL by 30 percent, comparable to starting doses of statin medications, in controlled laboratory conditions. People following the portfolio diet living on their own dropped LDL levels a less dramatic nearly 15 percent. Still, about a third of people in one such study achieved at least a 20 percent drop in LDL levels. Importantly, this drop in LDL includes a drop in high-risk small LDL.
The portfolio approach includes daily targets for soy foods, soluble (or “viscous”) fiber, nuts and compounds called plant sterols.
Soluble fiber in the portfolio diet studies came from oats, barley, eggplant and okra, as well as added psyllium. You can also get soluble fiber from fruits, dried beans and some other vegetables.
Nuts in the portfolio diet studies were almonds, although research shows walnuts, pistachios and other nuts also lower LDL cholesterol.
Plant sterols occur naturally in a variety of plant foods, but the large amount (about 2 grams/day) used in portfolio diet studies requires foods such as certain margarines with added sterols. For some people, increasing sterols is among the easiest swaps in the portfolio diet, although it may not be among the most effective.
Create your own portfolio
Other research shows additional healthy foods you might add for further drop in LDL cholesterol and heart disease risk.
Olive oil, avocado and other monounsaturated fat, also known as MUFA or omega-9 fat: In one study, versions of the portfolio diet with and without increased MUFA reduced LDL cholesterol equally well. However, those with extra MUFA showed more improvement in other markers of heart health, including more than a 56 percent drop in a marker of inflammation.
Whole grains, vegetables, fruits: The DASH diet, a low-fat diet rich in these foods, has produced drops in LDL cholesterol in several studies. Importantly, it can also decrease inflammation and improve blood sugar control in people with diabetes.
Blood cholesterol as marker not goal
Since tests differentiating between types of LDL are not widespread in medical care yet, LDL is still an important benchmark. Just remember that it’s exactly that – one important marker of the true target, which is decreasing development of heart disease and promoting overall health. That means you want choices that also reduce inflammation and promote healthy levels of HDL (“good”) cholesterol, triglycerides, blood sugar and insulin.
Studies discussed above focus on lowering cholesterol in people with mild to moderately increased blood cholesterol. People, often predisposed by genetic traits, with severely high cholesterol need separate consideration.
Cholesterol-lowering medications provide powerful help in fighting heart disease. Yet some people cannot take them, and whether or not you pay for them personally, the medications and the necessary monitoring for side effects are expensive to our health care system. That’s why it’s great news that if “low-fat diets” haven’t improved cholesterol levels, there’s still plenty you can try.
Take-home ideas for today
Don’t switch from chocolate or nuts to fat-free cookies and pretzels to cut fat. Do choose leaner meat and poultry, and eat more seafood (that’s not deep-fried or batter-coated). Switch from donuts to oatmeal. Add barley to soup instead of white rice or refined pasta. Add beans to soup and mixed dishes instead of sausage. If you’re overweight, reduce meat portions and ice cream and don’t eat more of something else.
Resources
To see which foods you commonly eat are highest in saturated fat, check this summary from the US Dept of HHS, or a complete listing from the USDA National Nutrient Database.
To look beyond LDL cholesterol, researchers and doctors calculate overall heart disease risk using the Framingham 10-year coronary heart disease risk calculator by totaling points for a variety of risk factors. You can check yours here.
References
Report of the Dietary Guidelines Advisory Committee on the Dietary Guidelines for Americans, 2010. Part D, Section 3: Fatty Acids and Cholesterol.
Siri-Tarino, PW et al. Saturated fatty acids and risk of coronary heart disease: modulation by replacement nutrients. Curr Atheroscler Rep, 2010.
Jenkins, DJ et al. Direct comparison of a dietary portfolio of cholesterol-lowering foods with a statin in hypercholesterolemic participants. Am J Clin Nutr, 2005.
Jenkins, DJ et al. Assessment of the longer-term effects of a dietary portfolio of cholesterol-lowering foods in hypercholesterolemia. Am J Clin Nutr, 2006.
Jenkins, DJ et al. Adding monounsaturated fatty acids to a dietary portfolio of cholesterol-lowering foods in hypercholesterolemia. CMAJ, 2010.
Azadbakht, L et al. Effects of the Dietary Approaches to Stop Hypertension (DASH) eating plan on cardiovascular risks among type 2 diabetic patients: a randomized crossover clinical trial. Diabetes Care, 2011.
Karen Collins, MS, RD, CDN is a Registered Dietitian who promotes healthy eating as a syndicated nutrition news columnist, speaker and consultant, bringing special expertise in cancer prevention and how it fits within overall wellness efforts. Karen can be contacted about speaking engagements at karen@karencollinsnutrition.com. For more information, please visit http://www.karencollinsnutrition.com
The articles written by guest contributors are the sole responsibility of the individual writers in terms of factual accuracy and opinion and do not necessarily reflect the views of the publisher of this blog.
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