Ask The Doctors: January 2019
Q: I have always used low-fat dairy products, but recently read that whole-dairy may be better for the heart. Should I switch?
A: I would not advise it. Recently, a large multinational study that examined the impact of seven food types on health confirmed beliefs that higher consumption of fresh fruits, vegetables, nuts and legumes and lower consumption of refined carbohydrates reduced overall mortality and cardiovascular (CVD) events. The study also found that higher intake of dairy and unprocessed meats also appeared to be protective. An offshoot study that focused on dairy alone found that more than two servings a day of milk or yogurt-high-fat or low-fat-was linked to a 17 percent lower risk of death and a 23 percent lower risk of all cardiovascular diseases combined, compared to no dairy consumption at all. However, it did not prevent heart attack.
Before you binge on high-fat dairy, consider a few caveats: Observational studies such as this one detect associations, not causality. Specific dietary interventions, including the effects of high-fat versus low-fat dairy, were not assessed in a controlled fashion. The predominance of low- to middle-income countries represented in this international study may render the results less applicable to an affluent Western population, which includes other sources of protein and fat in the diet. In lower-income countries, dairy consumption is often low, and daily caloric intake comes primarily from refined carbs. When these bad carbs, which are associated with diabetes, hypertension and high triglyceride levels, are replaced with foods that have better nutritional value, the overall diet may benefit-even if whole-fat dairy products are added.
The quantity and type of fats from all sources should be individualized to your own medical history and diet. It would be wise for you to continue gaining the nutritional benefits of dairy as part of a heart-healthy diet. However, I would recommend you continue using lower-fat products, particularly if your cholesterol is high, other sources of saturated fat are included in your diet or you have coronary artery disease.
Q: Peripheral arterial disease (PAD) limits my ability to walk. Do I need a cardiac rehab program, or is exercising at home okay?
A: Structured, supervised exercise programs have been shown to improve symptoms and walking distance in individuals with PAD. Nevertheless, frequent visits to a rehab center may be difficult for some people.
A recent study examined whether an at-home exercise program that included phone coaching and Fitbit-type monitoring would improve walking performance, compared with no exercise. After nine months, no differences were seen in walking time or measures of impairment or physical functioning.
This finding contrasts with previous studies that showed similar behavioral interventions designed to increase at-home exercise were effective and improved six-minute walk tests. Why was this study different? Those in the exercise group reported more leg pain, likely due to increased attempts at activity. This is normal for patients with PAD and often causes them to avoid activity that provokes it. For exercise interventions in PAD to be successful, participants must repeatedly push themselves to walk until they feel pain. This is often hard to do on one's own, and on-site coaching in the rehab setting helps them exercise to the level necessary to achieve success.
Cardiac rehab programs also include counseling on nutrition, smoking cessation, stress management and medication adherence. These lifestyle modifications treat the underlying vascular disease. A cardiac rehab program will help you walk further with less pain and may also reduce the risk you'll have a heart attack or other cardiovascular event.