The DASH (Dietary Approaches to Stop Hypertension) diet has been helping people lower their risk of cardiovascular disease through decreasing cholesterol levels and blood pressure since its inception in the early 1990’s. Most recently, the DASH diet was heralded as the total diet in the 2010 Dietary Guidelines. The DASH diet is characterized by being rich in fruits, vegetables, whole grains, low fat dairy, beans, nut, and seeds. The DASH diet also is low in saturated fat, refined grains, added sugar, and red meat.
Where’s the Beef?
Traditionally red meat has been withheld from heart healthy diets as a means of controlling saturated fat. However, the need to remove red meat to reduced saturated fat is a message that has been misinterpreted by media and many health professionals. While yes, lower quality cuts and processed red meat products do contain higher levels of saturated fat. But red meat doesn’t even make the top 5 list of major contributors of saturated fat to the American diet (full fat cheese is #1). There are also 29 cuts of beef certified as lean by the USDA. These cuts have a fat content that falls somewhere between chicken breasts and chicken thighs. Some of these cuts include:
- 95% lean ground beef
- Top Round
- Shoulder Pot Roast
- Top Loin (strip) Steak
- Shoulder Petite Medallions
- Flank Steak
- Chuck Shoulder Steak
- Round Steak
- Brisket, Flat Half
- Sirloin Tip Center Steak
- And even T-Bone steaks
Survey data shows that one of the biggest barriers of entry for people to include beef in their diet is the thought that it is unhealthy and bad for your heart; despite the fact that other surveys show most Americans report enjoying beef. With that information at my disposal, 5 years ago as a nutrition PhD student, I set out with a team of researchers at Penn State to answer the question “does lean beef have a place in the DASH diet?” Today that research is being published, and after weighing, measuring, and feeding 36 different people everything they put in their mouths for almost 6 months we have a solid answer to that question.
Lean beef can be included in a DASH diet.
Participants in our study experienced a 10% decrease in their LDL cholesterol compared to the start of the study after being on both the DASH and BOLD (the DASH diet with 4.0 oz/d of lean beef) diets.
“This research sheds new light on evidence supporting lean beef’s role in a heart-healthy diet. Study participants ate lean beef every day and still met targets for saturated fat intake. This study shows that nutrient-rich lean beef can be included as part of a heart-healthy diet that improves risk factors for cardiovascular disease.” – Penny Kris-Etherton PhD, RD, distinguished professor of nutrition at PSU and the study’s principal investigator
In the study, we had a 3rd diet called the BOLD+ diet which was a higher protein (28% of calories compared to 19% as on the DASH and BOLD diets) diet that included 5.4 oz/d of lean beef. After following the BOLD+ diet participants experienced similar reductions in LDL cholesterol as with the DASH and BOLD diets. I’m sure you’re wondering what theses diets looked like? For those of you that are nutritionally inclined here is the macronutrient breakdown:
Beyond LDL and Total Cholesterol
The equivalent decreases in LDL and Total Cholesterol are the major findings in this study and the things that will be talked about most when the media picks this story up. However, there are some really interesting preliminary findings that will most likely get lost it the shuffle – they are…potential improvements in HDL cholesterol function and better responses to a cholesterol lowering diet in people with higher baseline inflammation levels. Let me talk briefly about each.
Improvements in HDL Cholesterol Function
HDL cholesterol (also known as your good cholesterol) is protective against cardiovascular disease. The higher the better. The problem, and one of the major criticisms of low saturated fat diets, is that when you decrease your saturated fat intake in an effort to decrease your LDL cholesterol (good), you’ll also get a decrease in HDL cholesterol (not good). While rectifying this problem was out of the scope of our major research question for this study, what I did discover is that after following the two diets with higher intakes of lean beef (BOLD and BOLD+ diets) the quality/function of the HDL cholesterol particles of our study participants improve. Specifically what happened was that after these diets the HDL particles of these participants had lower levels of triglycerides (if you read the paper I’m talking about Table 5, Apo C-III HS).
There is not a lot of research looking at the impact of triglycerides levels in your HDL cholesterol particles but what I was able to find is that by decreasing the triglyceride levels inside your good cholesterol you are improving how they function. Specifically making them more anti-inflammatory and improving their ability to do reverse cholesterol transport (one of the main things that makes your good cholesterol good). This was only seen in the high beef diets; I think this was potentially due to the unique fat composition of beef compared to other meats/proteins. It is something that needs to be researched further.
Inflammation and Your Response
I’ve always been fascinated by inflammation and how our diets can impact basal inflammation levels, inflammatory responses, etc. Numerous other studies have shown that having higher levels of systemic inflammation can inhibit your body’s response to a cholesterol lowering diet (which I think is fascinating). When analyzing the data for the BOLD study, I wanted to see if that phenomenon held true. It did and it didn’t.
We did see that when on the DASH diet, the people with higher baseline levels of systemic inflammation (as measured by c-reactive protein) did not see significant changes in LDL and Total cholesterol (this had been shown multiple times before in other studies). But when these people were on the BOLD and BOLD+ diets, their higher levels of inflammation didn’t prevent them from experiencing reductions in LDL and Total cholesterol (this had not been shown previously). Pretty interesting. What about beef allowed this to happen? This is something that we need to look into more as the people in our study all had low levels of inflammation to begin with. That being said, I think this is one of the more interesting findings to come out of the BOLD study.
Before I wrap this post up I wanted to share a recipe with you as all the information in the world about the fact that it is okay to eat lean beef isn’t going to help if you don’t know what kind of beef to eat and how to prepare it (two very important pieces of the puzzle)
My Favorite Lean Beef Recipe
This recipe wasn’t used in our study but beefy sweet potato hash is one of my favorite lean beef containing meals (I love this stuff).
- 12 ounces cooked beef (such as steak, roast or pot roast), cut into 1/2-inch cubes (about 2-1/2 cups)
- 1 large sweet potato, unpeeled, cut into 1/2-inch cubes
- 1 medium yellow onion, chopped
- 1 tablespoon taco seasoning mix
- 1/4 cup water
- 1 tablespoon vegetable oil
- 2 tablespoons reduced-fat or regular dairy sour cream
- 1 teaspoon hot pepper sauce
- Chopped fresh cilantro
How to Prepare:
- Combine sweet potatoes, onion and taco seasoning in large nonstick skillet over medium heat. Add water. Cover and cook 8 to 10 minutes or until crisp-tender and water has almost evaporated, stirring once. Stir in oil; continue cooking, uncovered, 4 to 6 minutes or until potatoes are tender and begin to brown, stirring occasionally.
- Meanwhile, combine sour cream and hot sauce in small bowl. Set aside.
- Add beef to potato mixture. Continue to cook 5 minutes or until beef is heated through, stirring occasionally, adding 1 to 2 tablespoons water, if needed to avoid sticking.
- Garnish with cilantro, as desired. Serve with sour cream mixture.
Take Home Message
The rigorously controlled nature of the BOLD study (the fact that we weighed and measured everything participants ate and that each participant ate each of the diets) allowed us to make the very conclusive statement that lean beef can be included in a heart healthy diet and that you can included 4-5.4oz/d of lean beef while still meeting current dietary recommendations for saturated fat intake.
Here is a link to the research paper for you to ready if you’d like.