Cardiovascular Nutrition: Facts vs. Myths

The potential cardiovascular benefits of several trending foods and dietary patterns are still incompletely understood. However, a number of controversial dietary patterns, foods, and nutrients are given significant media exposure, making consumers vulnerable to unsubstantiated health benefit claims, according to a review published in Journal of the American College of Cardiology.

See Also: High Amounts of Saturated Fats Increase Heart Disease Risk

"There are important challenges to establishing the scientific evidence base in nutrition, in part because of the complex interplay between nutrients and confounding by other healthy lifestyle behaviours associated with changes in dietary habits," study authors note.

The review addresses some of the more popular food trends and dietary patterns that are promoted for cardiovascular (CV) health to provide clinicians with accurate information for patient discussions in the clinical setting.

Healthy Dietary Patterns and ASCVD Risk

Current evidence strongly supports the Healthy U.S. Dietary Pattern, the Healthy Mediterranean-Style Dietary Pattern, and the Healthy Vegetarian Dietary Pattern for atherosclerotic cardiovascular disease (ASCVD) risk reduction and improvement in ASCVD risk factors for adults and children 2 years of age and older. Healthy dietary patterns emphasise high intake of fruits, vegetables, whole grains, legumes, and nuts in moderation, and may include limited quantities of lean meat, fish, low-fat and nonfat dairy products, and liquid vegetable oils. These dietary patterns are also low in saturated, trans, and solid fats; sodium; added sugars; and refined grains.

In addition, energy intake and physical activity appropriate for maintaining a normal weight, and achieving nutrient adequacy are also recommended.

Nutrition Hypes and Controversies

Eggs and dietary cholesterol: Dietary cholesterol increases blood cholesterol concentrations. Nonetheless, the 2015 Dietary Guidelines Advisory Committee reported that “available evidence shows no appreciable relationship between consumption of dietary cholesterol and serum cholesterol”. This statement was widely reported in the press and resulted in significant consumer confusion. It remains prudent to advise patients to significantly limit intake of dietary cholesterol in the form of eggs or any high-cholesterol foods to as little as possible.

Vegetable oils: Vegetable oils vary greatly in the content of SFAs, monounsaturated fatty acids (MUFAs), and polyunsaturated fatty acids (PUFAs). The tropical oils, coconut oil and palm oil, are high in SFAs. In contrast, canola, olive, and sunflower oils are high in MUFAs.

Solid fats (at room temperature), including coconut oil and palm oil, have deleterious effects on ASCVD risk factors. Current claims of documented health benefits of the tropical oils are unsubstantiated and use of these oils should be discouraged. In contrast, liquid vegetable oils have beneficial effects on lipids and lipoproteins. The evidence base for olive oil is the most comprehensive, with clear evidence for a benefit in ASCVD risk reduction.

Berries and antioxidant supplementation: Currently available evidence suggests that fruits and vegetables are the healthiest and most beneficial source of antioxidants for ASCVD risk reduction. There is no evidence of ASCVD benefit with the addition of high-dose antioxidant dietary supplements. Further investigation will be necessary to better define the role of antioxidant supplements in health promotion.

Nuts and CV health: The fatty acids in nuts are predominantly unsaturated, with oleic acid being the most abundant. Nuts also contain complex carbohydrate and fibre, protein, tocopherols, nonsodium minerals, phytosterols, and polyphenols. Nuts may be included for ASCVD risk factor improvement and ASCVD risk reduction as part of a heart-healthy dietary pattern. Portion control is necessary to avoid excess calorie consumption. Clinicians must provide guidance to incorporate nuts isocalorically in the diet by substitution for other foods, preferably those that provide “empty calories.”

Juicing: Until comparative data become available, whole food consumption is preferred, with juicing primarily reserved for situations when daily intake of vegetables and fruits is inadequate. Guidance should be provided to maintain optimal overall caloric intake and to avoid the addition of sugars (e.g., honey) to minimise caloric overconsumption.

Source: Journal of the American College of Cardiology