For a long time, the connection between cholesterol and cardiovascular health was seemingly clear. Saturated fats, the guidelines said, led to heart disease. Turns out this compound is way more complex than experts believed.

And diet is only part of the picture with cholesterol: a recent study that compared high- and low-fat diets found that eating the low-fat diet didn’t have a significant impact on blood cholesterol levels, reported the Journal of the Academy of Nutrition and Dietetics. Weight, age and genetics arguably play a bigger role when it comes to risk factors for heart disease. Here we help you get some of the key new discoveries straight.

1. Exercise raises HDL: Exercise is good for your heart in more ways than one! Regular aerobic workouts—we’re talking moderate intensity like a brisk walk, nothing crazy—can increase HDL levels by nearly 25 percent in three months.

Why that matters: this “good” type of cholesterol grabs on to unhealthy cholesterols and ferries them to the liver, which breaks them down and clears them from your system. HDL also helps with blood-vessel health and prevents plaque buildup. So get moving, already! Your exercise Rx: 30 minutes on most days of the week.

2. Certain carbs may increase risk: That white bagel may be worse for you than the cream cheese. You thought the saturated fat in the cream cheese schmear was the main problem. But a growing body of evidence suggests that highly processed carbs—ahem, white bagel—may put you at an even greater risk for heart disease.

How those carbs hurt you? Your body rips through the highly processed carbs so quickly that your blood sugar and insulin levels climb then plummet. If you eat a lot of these types of foods, all of that roller-coastering bumps up levels of free fatty acids in your blood. In turn, that increases inflammation in the body, damages blood vessels and can jack up your cholesterol.  Healthy alternatives: Minimally processed carbs like steel-cut oatmeal (a better pick than the bagel!) don’t have this effect.

3. High-cholesterol foods aren’t the enemy: Dietary cholesterol and blood cholesterol are two different things. In other words, just because you eat foods high in cholesterol (such as shrimp and eggs) doesn’t mean your blood cholesterol levels will go through the roof.  What actually raises your cholesterol: Processed carbs, saturated and trans fats—with trans fat being the real enemy.

4. Diet does affect some people more than others: First, a biochemistry lesson. Apolipoprotein E (or ApoE) is a protein in the blood that ferries cholesterol and triglycerides to the liver. The liver then metabolizes and disposes of them. That’s a good thing. The bad news: Having particular genetic variants of ApoE can prevent your body from metabolizing fats and carbs properly. The same genetic traits can also put you at risk for high cholesterol and heart disease—as well as diabetes and Alzheimer’s disease.

What that means: If your diet is less than stellar—particularly in terms of trans fat and carbs (an excess of which gets converted to cholesterol)—your cholesterol levels could quickly become unhealthy if you have this genetic makeup.  Your doctor might order an ApoE blood test if you have a family history of heart disease or if your cholesterol and triglyceride levels are high.

Knowing what exact variants you have can help identify the most effective treatments—be it altering your diet, exercising and adding medication—to help bring your cholesterol down to a healthy level.

5. New ways to gauge heart health: Your estimated heart disease risk may be different than it was a year ago. Docs in the past would use your total cholesterol and HDL levels to determine your odds of developing cardiovascular disease.

No more. In fall 2013, a new risk calculator was released, with updated data on how factors like blood pressure, age and whether you smoke affect your 10-year and lifetime odds of developing the disease—and also, whether you should be prescribed statins. Go to heart.org to get a preview, and see your doctor for a detailed assessment.

Source www.eatingwell.com