In a study conducted by three researchers from UCLA 11 obese men spent three weeks at the Pritikin Longevity Center in Santa Monica on a low-fat, high-fiber program combined with exercise to determine what effect that program would have on their blood pressure and cholesterol. While the subjects' weight loss was not significant during this brief study period, the decrease in both blood pressure and cholesterol levels was dramatic.
The eleven men ranged in age from 38 to 72 and were considered obese with a body mass index of at least 30. A body mass index (BMI) of 25 or more is considered overweight. According to medical experts, body mass index has a strong correlation with risk of heart disease.
Researchers Christian K. Roberts, Nostratola D. Vaziri, and R. James Barnard of the University of California Los Angeles placed the eleven men on a low-fat, high-fiber diet and combined it with 45 to 60 minutes of brisk walking on a treadmill daily for three weeks.
The results were significant, not so much in weight loss but in reducing blood pressure, cholesterol, insulin levels, and glucose. The participants lowered their cholesterol by an average of 19% and blood pressure by 14%. The insulin levels dropped 46% and glucose fell 7%.
By the end of three weeks seven of the men who initially had high blood pressure were able to reduce their blood pressure to the normal range. Their levels of nitric oxide, a blood compound that keeps blood vessels clear and helps dilate them, rose by 28%.
"This the first study to show that this type of diet and exercise can reduce oxidative stress, lower blood pressure, and improve risk factors for other chronic diseases in a very short time," said Dr. Barnard, a professor of physiological science at UCLA. "A high-fat, refined sugar diet increases free radical formation to oxidative stress. This may be the underlying cause of the health problems we see in this country and as we show in this paper, can be reduced by diet and exercise."
The participants lived at the Pritikin Longevity Center for 21 days and were served a diet of 10% calories from fat, 15 to 20% protein, and 70 to 75% carbohydrates. Protein came primarily from plant sources but did include nonfat dairy (up to 2 servings daily), fish or fowl served in 3 1/2 oz. portions one day a week, and soups or casseroles two days each week. Meals were served buffet style and participants were free to eat as much as they wanted. No alcohol, tobacco, or caffeinated beverages were allowed.
Were limitations placed on salt and sugar content in the food?
Yes. For sugar and other refined sweeteners, Pritikin Program recommendations are 1 tablespoon for every 1,000 calories consumed. We encourage our participants to become accustomed to and enjoy the subtler, natural sweetness of fresh fruits, and, indeed, virtually all learn how during their stay at the Pritikin Longevity Center. At breakfast, for example, they love the fresh raspberries, strawberries, and bananas we offer as toppings for their oatmeal. Dessert in the evening is often a delightful combination of sweet, exotic fruits, like fresh mango with papaya salsa.
For salt, Pritikin Program recommendations are no more than 1,600 mg of sodium daily. By the end of their stay, many participants have found that their taste buds have adapted extraordinarily well to this lower salt intake. And they enjoy the natural flavor enhancers, like fresh lemon juices and combinations of pungent herbs, that our chefs expertly prepare. In the last few days of their stay, some of our participants are even asking, "Are you adding salt to the food?" In just a week or two, their taste buds have discovered the flavors of fresh, unsalted foods.
What types of dairy foods were included in the diet?
The dairy foods included in the Pritikin Eating Plan are nonfat milk, nonfat yogurt, and nonfat ricotta cheese. It's astonishing what our chefs can prepare using these nonfat dairy products -- entrees like creamy pastas and risottos, desserts such as chocolate mousse, and rich salad dressings. It's not easy, I assure you, but we've been in the business of preparing heart-healthy foods for close to 30 years, so we know what we're doing.
Did the soups and casseroles contain animal protein?
Very few of the soups and casseroles contain animal protein other than chicken stock and clam juice. For the participants in the study, we did occasionally serve a meatloaf flavored with very small amounts of lean turkey breast. The vast majority of our food is plant-based. The Pritikin Eating Plan is predominately fruits, vegetables, legumes, and whole grains. Many of our participants are vegetarians. In cooking school at the Center, they learn many creative ways to cook with richly satisfying plant proteins like tofu, beans, and nuts.
What legumes were included in the diet?
The Pritikin Eating Plan includes all sorts of legumes--beans, peas, lentils, and soybeans. Often, while the participants in Dr. Barnard's study were at the Center, our chefs use them in savory soups, chilies, and stews, like our spicy tomato bean chowder, black bean stew, and golden split pea soup. The participants learned how filling and delicious a bean-rich soup or chili is--as a snack or entrée. In cooking school, they learned how easy it is to prepare these soups, stews, and chilies at home.
What desserts were available?
At the Pritikin Longevity Center, participants enjoyed a wide variety of desserts, including fresh raspberries, balsamic strawberries and apples, bananas flambé, chocolate mousse, apple-pear-apricot compote, orange-pineapple sherbet, and rum raisin bread pudding.
It sounds like the participants could not have all they wanted of the animal protein. Is that true?
Yes. When participants graduate and return home, they may opt--once their blood lipids have dropped to healthy levels--to follow a maintenance version of the Pritikin Eating Plan: they may eat up to 3 to 4 ounces a day of animal protein, preferably cold-water seafood, rich in omega-3 fatty acids. At the Center, however, one of our primary goals is reducing risk factors for heart disease, including those affected by animal protein intake, such as cholesterol and triglycerides. We, therefore, keep animal protein intake to a minimum--no more than two to three servings per week, and two of those servings are seafood.
The results are phenomenal, as you ascertained from Dr. Barnard's study. Other studies have found similar results. In an analysis of 4,687 participants in the three-week program at the Pritikin Longevity Center, both total and LDL cholesterol dropped, on average, 23 percent; triglycerides plummeted 33%. (Archives of Internal Medicine, 151:1389, 1991.)
Researchers at UCLA have also found that the Pritikin Program dramatically improves coronary blood flow. They studied participants before and after a six-week evening program at the Pritikin Longevity Center and found significant improvement in coronary artery blood flow. (Circulation, 92:197-204, 1995)
Were you able to observe whether people reduced the quantities of foods they consumed as the study progressed?
They had no need to reduce the quantities of food. The beauty of the Pritikin Program is that you can eat a lot of food and not gain weight. That's because most of the food is very low in calorie density. Our participants eat 6 and 7 times a day, meals and snacks that are filling, but not fattening. Indeed, many say they feel "stuffed"; they're eating more than they ever have, yet they're losing weight at the same time.
What foods did the participants like best? What foods were unpopular?
This is a difficult question because each participant is different. Each has his or her favorites from the menu. Our soups are often very popular. Participants love their savory, homemade richness, especially selections like gingered winter squash soup and garlic leek soup. Dr. Barnard's participants also enjoyed our salad dressings and sauces. They had no idea that nonfat, sugarless, low-sodium salad dressings and sauces could taste so good.
Some favorites of the participants in Dr. Barnard's study were country mustard vinaigrette and balsamic basil vinaigrette. The participants were also surprised at how flavorful entrees without animal protein can be. Some favorites were black beans and rice copacabana, white bean and vegetable stew, mushroom tofu stroganoff, and grilled vegetable polenta. Participants also learned that just a little meat, 1 to 2 ounces per serving, can go a long, flavorful way. They learned, in effect, how to eat like Asian people, using meat as a condiment, a flavor enhancer. Favorites were chicken primavera stir-fry, salmon shiitake mushroom risotto, and paella with clams, lobster, and scallops.
Were there any complaints about the food?
Again, each participant is different. Many loved the food, from breakfast to dinner. Others started out with complaints, understandably so. Their taste buds, groomed from years on Big Macs and French fries, need some time to adapt to the fresh, natural flavors of foods from the earth. It's amazing, though, how quickly their palates changed. Participants who, in the first two days of the stay, turned up their noses at oatmeal were, by the end of their stay, telling us that they really liked the nutty texture of it now. They intended to eat oatmeal every day when they returned home.
Were any snacks available or was the group limited to three meals a day?
Snacks were VERY available. In fact, participants at the Pritikin Longevity Center are encouraged to snack two and three times daily. Numerous studies have found that frequent eating throughout the day helps maintain steadier insulin and blood sugar levels, reduces hunger and fat storage, decreases cholesterol levels, and enhances and maintains weight loss. Favorite snacks included hearty, rich soups, fresh fruits and vegetables, salads such as a fiesta corn salad and Indonesian rice salad, and fruit salsas.
What efforts were made to prevent cheating?
No efforts were made to prevent cheating because, by and large, no efforts were needed. Because food was always available, as snacks or as main meals, participants felt very satisfied with the food--and the quantities of food--offered to them.
When the participants were not eating or exercising, how did they spend their time? Did the program include any lifestyle education classes?
The participants spent their time attending a large variety of lifestyle education classes, all taught by world-renowned experts in the fields of nutrition, cooking, stress management, and lifestyle change. Our faculty includes dietitians, physicians, exercise physiologists, and lifestyle counselors. Their goal: to transform peoples' lives. Their approach: "Let's do it with a whole lot of fun." From morning till night, participants enjoyed a program that truly was transforming. They were actively involved, working together to build successful strategies to help them maintain their success at home.
In cooking classes taught daily, participants learned how to recreate the dishes they were enjoying in our dining room. In nutrition classes, they learned how to travel, how to socialize, how to order in restaurants, and how to enjoy a wide variety of foods. They even learned how to "cheat": how to blend calorically-light foods, like vegetables, with a touch of the calorically-rich, like a teaspoon of olive oil or a dollop of guacamole. The end result? Some of the most delicious food, the participants told us, that they ever tasted, but at no cost to their waistline.
In education and lifestyle workshops, the participants learned how the Pritikin Program affected their overall health and well-being--their blood pressure, their cholesterol and triglycerides, their energy levels, their weight. The workshops also provided sound, practical guidelines for everyday living. Some of the workshops included:
Is it possible to obtain a copy of the menus for those three weeks?
We do not have copies of the menus for those specific three weeks, but we do have menus we are currently using at the Pritikin Longevity Center, and they follow the exact same dietary guidelines used for the participants in Dr. Barnard's study. If you would like copies of our current menus, just let me know, and I will forward them to you.
We were interested in learning more about the funding for the study. Can you tell us about the L-B Research/Education Foundation? Who supports this organization?
It is a private foundation that donates to medical research and education
Was the Pritikin Longevity Center involved in the funding?
Why was the Pritikin Longevity Center selected as the locale for the study?
They were close to UCLA and were willing to make their participants available. I have done numerous studies at the Pritikin Center which unfortunately has closed in Santa Monica but still operates in Florida
What were the roles of each of the three people who conducted the study?
All were involved
Why did the study have no female participants?
Too hard to get 24 hour urine samples
Is there a plan to expand the study to more participants?
Not at this time but we are doing other studies.
Did you ask the Pritikin Longevity Center to make any changes in their normal program? If so, what changes were made?
No changes were made in the normal program
Other researchers like Dr. Dean Ornish have suggested that a similar program with a maximum of 10% calories from fat and no dairy or animal protein could reverse heart disease and atherosclerosis? What are your views on Dr. Ornish's program?
I am doing a research project with him at the present time