You might think that the impact of your diet on heart health is obvious. And yet, the information we see in the news and on social media can often be conflicting and confusing.

Are high-cholesterol foods still a killer? Is sugar really the villain? Is red wine the way to go? With so many diet plans and changing recommendations, it’s hard to know what’s what anymore.

So as a practicing cardiologist, I advise my patients to stick with the evidence. Here’s what I tell them about what the research really shows:

1. What science says about … the Mediterranean diet

As you probably know, the Mediterranean Diet is a food plan rich in olive oil, nuts, fresh fruits and vegetables, fish and seafood, legumes, white meats, and optional wine with meals.

The PREDIMED study published in the New England Journal of Medicinein 2013 demonstrated that among those with high cardiovascular risk, a Mediterranean diet supplemented with extra-virgin olive oil and nuts reduced the incidence of major cardiovascular events (stroke, heart attack, and death). Secondary studies showed that it was also effective inpreventing the development of type 2 diabetes, and consuming nuts was associated with a significantly reduced risk of death over a five-year period.

Plus, a 1999 study in the journal Circulation looked at men and women who had already suffered a heart attack who were placed on a Mediterranean-type diet supplemented with omega-3-rich margarine. After four years, the study showed that the Mediterranean-type diet was effective at preventing recurrent heart attacks or death from heart disease.

Several other studies on the Mediterranean diet have also shown it to be effective in reducing metabolic syndrome, helping glycemic control, and even delaying or reducing the need for drug therapy in patients with newly diagnosed type 2 diabetes.

Bottom line: If you’re looking for a heart-healthy diet, research shows the Mediterranean diet works.

2. What science says about … the DASH diet

DASH stands for Dietary Approaches to Stop Hypertension. We know that hypertension is a major risk factor for heart disease. While we have excellent medications to treat high blood pressure, of course most patients prefer trying lifestyle and diet modifications to reduce their blood pressure.

The DASH diet consists of fat-free or low-fat milk and dairy foods, fruits, vegetables, lean meat, fish, poultry, nuts, seeds, and legumes. The pivotalstudy published in the New England Journal of Medicine in 1997 showed that the DASH diet substantially reduced blood pressure. This was supported by a study in the journal Hypertension in 2001 that proved the DASH diet to be effective as first-line therapy in Stage 1 isolated systolic hypertension.

Bottom line: If you’d like to manage your blood pressure, try the DASH diet first.

3. What science says about … sugar

There’s no disputing that added sugars are bad for your health. A large prospective study in the Journal of the American Medical Association in 2014 looked at the relationship between added sugars and cardiovascular risk. Added sugars were defined as all sugars used in processed or prepared foods, such as sugar-sweetened beverages, grain-based desserts, fruit drinks, dairy desserts, candy, ready-to-eat cereals, and yeast breads, but not naturally occurring sugar, such as in fruits and fruit juices.

They found that most U.S. adults eat more added sugars than recommended for a healthy diet and found a significant association between added sugar intake and cardiovascular risk.

Bottom line: Keep added sugars to less than 10 percent of your daily calories.

4. What science says about … coffee

Yes, please! While the data seems all over the map as it relates to coffee and health benefits, a 2014 meta-analysis in Circulation of 36 studies and over 1.2 million people found that moderate coffee consumption (three to five cups per day) was associated with lower cardiovascular risk. Plus, heavy coffee consumption (more than five cups per day) was not associated with any increased risks.

Bottom line: If you’re a coffee drinker, your heart certainly won’t hurt—and could even benefit—from the habit.

5. What science says about … wine

Contrary to what you might have heard, there’s still no clear evidence that drinking alcohol is good for your heart. (Sorry!)

Certain antioxidants present in red wine may help increase HDL (good cholesterol) and reduce LDL (bad cholesterol) in your blood. Resveratrol, an antioxidant found in red wine, may be linked to reduced inflammation and blood clotting.

Bottom line: As it stands, drinking alcohol of any kind is not advised to improve heart health.

6. What science says about … chocolate

There’s plenty of data to suggest that cocoa and chocolate may actually be good for your heart. Cocoa products contain flavonoids and other antioxidants that likely promote cardiovascular health.

A prospective study published in Heart in 2015 of nearly 21,000 men and women showed that higher chocolate intake was associated with a lower risk of future cardiovascular events. Multiple other studies have demonstrated that chocolate intake decreases risk of heart failure, blood pressure, insulin resistance, and even death from heart disease and stroke.

Bottom line: A moderate amount of dark chocolate might actually help your heart.

7. What science says about … cholesterol

We know that we want our total cholesterol and LDL (bad) cholesterol to be low and our HDL (good) cholesterol to be high. But what can we eat?

There has actually been a change in the recommendations for dietary cholesterol. We now believe that only about 20 percent of your blood cholesterol levels come from what you eat. The 2015 guidelines do not restrict dietary cholesterol. But sticking to omega-3 fatty acids and plant oils and avoiding trans fats is still advised.

Bottom line: Cholesterol doesn’t need to be feared as much as it once was, but don’t overdo it.