Nutrition can be confusing. Fad diets make headline news, and we're bombarded with flip-flopping reports about what to eat. The constant changes can make it tricky to plan a nutritious diet.
To separate fact from fiction, a panel of physicians and researchers did a deep dive into the nutritional science, and Monday they published their findings in the Journal of the American College of Cardiology. In the review, they examined the attention-grabbing controversies related to heart health and drilled down to give the most current, evidence-based advice. Here's what they recommend.
• Which oil should I buy?
For heart health, liquid vegetable oils (olive, canola, etc.) are better than hard fats such as butter, margarine and coconut oil. But if you've read anything lately about the magic of coconut oil, you may be doubting this advice. The panel sifted through the science and concluded that the cardiovascular benefits of coconut oil are unsubstantiated and that its use should be discouraged. They even point to a study that shows that coconut oil raises cholesterol levels, which is not helpful for heart health.
What should you pick up instead? Extra virgin olive oil gets top marks in the review, because it has been the subject of the most comprehensive research and the clearest evidence of being beneficial for the heart.
• Is cholesterol from eggs still a concern?
Maybe you added eggs back into your diet after last year's announcement that cholesterol is not a nutrient of concern. But the panel says this advice is not one-size-fits-all. Although saturated and trans fats (in butter and meat) have a larger impact on raising blood cholesterol than eggs do, consuming high-cholesterol foods may still be problematic for the 15 to 25 percent of people who hyper-respond to it. The amount of cholesterol we absorb from food differs from one person to another based on overall diet as well as genetic factors. Hyper-responding means you experience an almost threefold greater response to dietary cholesterol compared with the rest of the population.
"Egg whites are unlimited in my view," said Michael Miller, a professor at the University of Maryland School of Medicine, author of "Heal Your Heart" and a co-author of the review. "They are a great source of protein. But I recommend some patients have just one yolk per every two egg whites, to minimize the impact on cholesterol."
• Can I eat leafy greens if I take blood thinners?
Leafy greens such as kale and spinach are nutritional powerhouses, with an array of beneficial vitamins, minerals and antioxidants. One study showed that people who consumed three daily servings of leafy greens had a 24 percent lower risk of cardiovascular disease. The panel gave a thumbs-up.
If you're taking blood-thinning medication, you may have been advised to avoid leafy greens because their high amounts of vitamin K may affect blood clotting. But it turns out that doctors can establish the right dose of medication based on consumption of leafy greens.
"Leafy greens can be eaten when taking blood thinners, but the amount consumed needs to be consistent daily," Miller said in an interview. "If your daily intake of greens changes, let the doctor know so medication can be adjusted accordingly."
• Do I need a gluten-free diet?
Gluten is a protein found in wheat, rye and barley. People who have been medically diagnosed with celiac disease, non-celiac gluten sensitivity or wheat allergy require a gluten-free diet. But if you do not have one of those conditions, there is no reason to follow a gluten-free diet. The panel says that there is no evidence that this diet should be used to promote weight loss or boost heart health.
• What else do I need to I know?
It was the consensus of the panel that:
• Nuts are beneficial for cardiovascular disease, but also that portion control is key. "Aim for an ounce of nuts, then hide the bag to prevent overconsumption," Miller advised.
• Antioxidants in berries are beneficial for heart health. But be wary of antioxidant supplements, which don't offer the same health benefits and can cause harm in high doses.
• If you want to prevent heart disease, look to the Mediterranean diet and plant-based vegetarian diets.
• The "Southern diet", an eating pattern that includes fried food, processed meats, fats and sugar-sweetened beverages, is detrimental to heart health and should be avoided.
• Juicing is not a magical pathway to health. Juice provides concentrated energy, making it easy to take in too many calories. Eating whole foods is recommend over juicing.
Of course, we could spend forever sifting through the minutiae of every single nutrient. Or we could be more practical and focus on the big picture, by looking at the whole diet instead of each individual food. Miller's takeaway advice? "A generous amount of veggies and fruits, a moderate amount of whole grains and nuts, supplemented with your favorite protein sources of legumes, fish, poultry and lean meats, is a heart-smart, healthy eating plan."