Certain diets can work to lower risk of heart disease
Dear Dr. Roach: Which diet styles in particular are associated with a lower risk of heart disease? Many people are confused about what actually is a healthy diet. Is a Mediterranean diet easier than an extreme low-fat diet?
D.H.H. There are several styles of diet that have been proven to be healthier than a typical North American diet. Two of the best that have been studied are the ones you mentioned — the extreme low-fat diet and the Mediterranean-style diet.
In a landmark study published by Dr. Dean Ornish in 1998, intensive lifestyle changes reduced the amount of heart disease (measured by blockages in the heart arteries) more than those in the control group without medication. This remarkable result required a diet that was mostly vegetarian (egg whites and 1 cup of milk a day only) and no more than 10% fat (the average American diet is 30% to 35% fat).
In addition to diet, participants performed aerobic exercise (three hours per week), stress management (1 hour per day) and group psychosocial support (four hours twice a week), and they also had a 100% smoking cessation rate. It is unclear how much of the benefit is due to diet and how much is due to other beneficial behaviour changes, or whether they all worked together (which seems likely to me).
The Mediterranean diet, when studied, also reduced risk of heart disease, with a roughly 30% relative-risk reduction in heart attack, stroke or death due to heart disease. This diet is characterized by:
• an abundant use of olive oil
• high consumption of plant foods (fruits, vegetables, legumes, cereals, nuts and seeds)
• frequent but moderate intake of wine (especially red wine) with meals
• moderate consumption of fish, seafood, fermented dairy products (yogurt and cheese), poultry and eggs
• low consumption of red and processed meat as well as sweets
The Mediterranean diet is much easier for most to comply with. The two diets haven’t been compared, so I can’t say which is better, but I more commonly recommend the Mediterranean diet. However, I do not recommend drinking wine for any kind of health benefit. Exercise, stress management and psychosocial support would be likely to improve outcomes with any kind of favourable dietary change.
The DASH diet — a lower-salt diet with four to five servings of fruit, four to five servings of vegetables and two to three servings of low-fat dairy per day, with less than 25% of daily caloric intake from fat — has been shown to reduce blood pressure. It’s also easy to maintain.