Researchers at The Pennsylvania State University studied the effects of including lean beef in a heart healthy diet. The Beef In an Optimal Lean Diet Study (BOLD) , published in the American Journal of Clinical Nutrition, examined the effects of varying amounts of lean beef on the blood lipids and lipoproteins on 36 mildly hypercholesterolemic men and women. The participants consumed 4 different diets for 5 weeks each (with one week compliance breaks in between diets). The four different diets were:
1.) Healthy American Diet (HAD) – The control diet that reflected a typical American diet comprised higher in fat. Comprised mostly of full-fat cheese and dairy, more oil and butter, and refined grains.
2.) Dietary Approaches to Stop Hypertension (DASH) – The “gold standard” for a heart healthy diet consisted mainly of fruits, vegetables, low-fat dairy, and the primary protein source came from white meat and plant sources.
3.) Beef in an Optimal Lean Diet (BOLD) – Similar to the DASH diet, but the main protein source came from 4 oz/day of lean beef.
4.) Beef in an Optimal Lean Diet Plus (BOLD+) – Similar to the BOLD diet, but with higher amounts of lean beef of around 5.4 oz/day.
The full nutrient breakdown of each diet is explained in the table below. Diet adherence was monitored by daily and weekly food questionnaires, which found 93% compliance to the diets.
The results of the study found that LDL and total cholesterol was significantly lower in the DASH, BOLD, and BOLD+ diets compared to the HAD (P<0.05). Compared to the HAD, LDL cholesterol (or the “bad” cholesterol) was significantly decreased by 5.5%, 4.7%, and 4.4% by the DASH, BOLD, and BOLD+ diets, respectively. Also compared to the HAD, total cholesterol was decreased by 3.8%, 3.8%, and 4.6% by the DASH, BOLD, and BOLD+ diets, respectively. Unfortunately, HDL cholesterol (or the “good” cholesterol), was also lowered significantly by the test diets compared to the HAD (refer to the graph below). There were also no significant differences between diets in terms of serum triglycerides, glucose, or insulin levels.
So what is the bottom line? Including lean beef in a healthy diet can reduce the risk of heart disease. A 3 oz. serving of lean beef (about the size of a deck of cards) has around 150 calories and is an excellent source of protein, zinc, vit. B12, vit. B6, niacin, and selenium. The types of lean beef included in the BOLD and BOLD+ diets composed of Top Sirloin, Tenderloin, T-Bone steak, and 95% lean ground beef. However, don’t forget to follow a low saturated fat diet (<7% of calories from saturated fat) and to meet the 2010 Dietary Guidelines for Americans.
One of the reasons I am posting about this particular study is because I was personally involved with the follow-up to the original BOLD study. As a requirement for the Penn State Schreyer Honors College, I took part in the 1-year follow-up to the BOLD study for my undergraduate thesis. I was responsible for contacting participants, scheduling appointments, weighing participants in, and analyzing the data. If you want to read more, check out my undergrad thesis here!!
If you want to follow the same heart-healthy diet as the participants in the BOLD study, take a look atThe Healthy Beef Cookbook. Below is an example of a delicious and healthy recipe including Top Sirloin.