Foods to Choose to Improve Heart Health, Lower Diabetes Risk

With Alice Lichtenstein, DSc, Diane McKay, PhD, Gaoxing Ma, PhD student, Shirin Pourafshar, PhD, and Amy Hess-Fischl, MS, RD, LDN, CDE

Here's some good news about foods to improve diet and your health, just to change things up from the usual gloom and dietary doom. Making certain food choices may actually help you fight disease and lower your risk of developing chronic diseases such as diabetes, heart disease, and obesity.

For better heart-health, a heart diet will include eggs, mushrooms, and nuts.

Making sure you include four disease-fighting foods in your diet is highly recommended based on a trio of studies1-3 being presented at the American Society for Nutrition meeting this week in Boston and a fourth study4 published in Nutrition & Diabetes.

What foods may elicit better health? Mushrooms, eggs, pecans, and plant sterols (found in plants, but more commonly found as a margarine spread).1-4

But first some perspective: "It's important to keep in mind if you want to improve your diet to substitute rather than add," says Alice Lichtenstein, DSc, Gershoff Professor of Nutrition Science and Policy and director and senior scientist at the Cardiovascular Nutrition Laboratory at Tufts University in Boston. She was not involved in the studies but reviewed them for EndocrineWeb.

What Can We Learn from These Food Studies?

Eggs Are Actually Good for our Heart and Overall Health

Reinforced by the results of this study,1 and supported by a growing body of evidence,5,6 eggs not only do not boost blood cholesterol as has been thought for decades, rather eating eggs seems to improve blood glucose as well as lead to increased low-density lipoprotein (LDL, the type of cholesterol known to clog arteries), and increase high-density lipoprotein (HDL, the blood cholesterol that protects against cardiovascular disease.)

One large egg a day actually appears to reduce the risk of diabetes without driving up your serum cholesterol,1 says Shirin Pourafshar, PhD, a National Institutes of Health postdoctoral fellow in nephrology at the University of Virginia, Charlottesville.

She randomly assigned 42 adults, ages 40 to 75 years, who had either prediabetes or type 2 diabetes, to eat one large egg a day or an equivalent amount of egg substitute for 12 weeks. Blood samples were analyzed for changes in levels of blood cholesterol and blood glucose.At the end of the three months, the group eating eggs had a 4.4% reduction in blood glucose.1 They also showed less insulin resistance, which is a good response indicating improved control over blood sugar levels.

Dr. Pourafshar said that participants’ blood was also evaluated for a protein carried in high-density lipoprotein (HDL), the heart-protecting cholesterol, finding the group eating a daily egg had a higher level of this circulating protein, which adds to the good news. And there were no negative effects on total cholesterol or low-density lipoprotein,1 the type of blood cholesterol that leads to clogged arteries.The Egg Nutrition Center funded the egg-related study but had no role in the data analysis.

Adding back the eggs: The egg, ideally, should be boiled, not fried, says Dr. Pourafshar. When eggs are scrambled or used to make an omelet or frittata, either olive oil or avocado, which are both high in heart-promoting monounsaturated fats, should be used. And resist the urge to add bacon or ham, adding instead vegetables.

Taking Dr. Lichtenstein advice—eating eggs should be done in place of breakfast foods, like cold cereals or sugary energy bars.

Snack on Pecans to Lessen Diabetes Risk, Improve Heart Health

Eating a handful of pecans a day, about 1.5 ounces (or 21 halves) appears to help people with overweight or obesity reduce their risk of heart disease and improve their insulin levels,2 according to a second study.

"We are suggesting that you swap [nuts]'' for other snacks, such as chips or salami, says Diane McKay, PhD, FACN, program director and assistant professor of nutrition at Tufts University, who led the study.

She and her research team asked 26 men and women who were diagnosed with overweight or obesity to eat a handful of pecans in place of less heart-healthy snack for four weeks, then to eat the regular diet provided to them without the nuts for the next four weeks.2 The researchers provided all the food for the study participants over the eight weeks. Funding for the study was provided by the National Institutes of Health and a pecan industry group donated the nuts but had no role in the study.

Adding the pecans produced better outcomes, says Dr. McKay. "We did see a statistically significant improvement in their insulin levels, and less insulin resistance," she says. She suspects it has to do with the type of fat in pecans, which like olive oil, is mostly monounsaturated fat, which is known to protect against cardiovascular disease.  

Advice: Choose a handful of pecans instead of, but not in addition to, those potato chips or tortilla chips, she says, that is easy to grab to satisfy your mid-afternoon hunger, or consider adding a handful of chopped pecans to your salad and drizzle with lemon juice or balsamic vinegar and avocado oil, instead of the creamy salad dressing. This is a better way to balance the flavors and calories in choosing a source of heart-healthy fat, protein, and fiber instead of a fat-laden dressing to improve your health.

Add Some Mushrooms to Reduce Inflammation

Mushrooms may reduce excess inflammation in your body,3 which is a very a good thing as it is linked to thyroid problems, heart disease, and other health ailments.8,9

Gaoxing Ma, a PhD student at Nanjing Agricultural University in China, isolated two complex carbohydrates—PPEP-1 and PPEP-2—which are fiber-like substances, from edible mushroom genus Pleurotus eryngli.3 In the lab, he stimulated cells to become inflamed, and then exposed them to these specialized mushroom polysaccharides. This study is the first to introduce the potential for the complex carbohydrates in edible mushrooms to be singled out as part of a healthy heart diet.

"In the lab, cells exposed to two polysaccharides from edible mushrooms had less inflammation," he tells EndocrineWeb.

Advice: The study is preliminary,3 he says, but adds to the growing evidence that mushrooms may be a functional food (prebiotic) that promotes good gut health, thereby reducing overall inflammation.10,11

Some May Benefit from Adding Plant Sterols for a Cardiovascular Health

Plant sterols, which occur naturally in foods but are particularly in high in vegetable oils (eg, canola, olive)—as well as nuts (particularly in almonds), wheat germ and wheat bran, and Brussels sprouts—are added to margarine spreads (ie, Promise, Benecol), and seem to lower LDL-cholesterol,4 according to findings reported in Nutrition & Diabetes.

The researchers gave 151 participants, all with either type 2 diabetes or at increased risk of diabetes, a spread with either added plant sterols or no plant sterols After six weeks those eating the plant sterol-fortified spread, with 2 grams of the plant sterols, showed a 4.6% reduction in LDL-cholesterol compared to the group eating a margarine without the added plant sterols.4

Advice: Remember that ''plant sterols cannot take the place of statins," says Amy Hess-Fischl,  MS, RD, LDN, BC-ADM, CDE, a certified diabetes educator and transitional program coordinator at the Kovler Diabetes Center in Chicago, Illinois, who was not involved in the study.

"The evidence is clear that these sterols do provide a benefit, but most people will be unable to get the 2 grams of plant sterols in their diet without using fortified products like these types of margarine," she tells EndocrineWeb. Two tablespoons have 2 grams, she says, for those who want to consider switching out their usual spread for one that provides a cholesterol-lowering boost.

According to the European Atherosclerosis Society Consensus Panel on Phytosterols,12 plant sterols have a clear lipid-lowering effect without any adverse effects. However, the use of products like the fortified margarine is best used by those who at low to moderate risk for cardiovascular disease but cannot take a statin and those with an inherited form of hyperlipidemia.

The study was supported by Unilever (which makes Promise margarine).4

Will It Matter if You Eat More of These Heart Healthy Foods?

While including eggs, pecans, mushrooms, and possibly plant sterols, might improve your diet and ultimately your health, proceed with caution about these findings, Dr. Lichtenstein advises.

Adding mushrooms to your diet to fight inflammation doesn't mean to sauté them in butter, for instance. Similarly, eating salted or honey-coated nuts will defeat the purpose, too, she tells EndocrineWeb.

It’s all in the way you choose to incorporate these foods by choosing these types of foods in place of foods that prompt increases in blood glucose, blood cholesterol, and increasing body fat, such as salami, most cold cereals, milk chocolate, and snack foods that add sugar, salt, and empty calories.

"When you see these studies, it may not be what is added to the diet, but what is removed from the diet," she adds. It's crucial to remember these studies are mainly talking about replacing unhealthy fare with healthier choices.

For the overall diet, Dr. Lichtenstein advises one with plenty of fruits and vegetables, whole grains, legumes, fish, low-fat dairy, lean meat and poultry and liquid vegetable oil.

"No one food has the magical properties to improve or fix our health," Hess-Fischl adds. "We need to focus on the meal as a whole, which is not a new concept, but is one that needs to be embraced by everyone."

None of the experts interviewed had any financial conflicts to disclose. 

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