Carbohydrates Can be Bad and Good for You

Health Writer

You drink a smoothie a day that's brimming with high-carb fruit assuming it's a really healthy habit. Others may opt for a low carb weight loss diet assuming it's the best choice for their diabetes. Which one is actually right? Two studies have examined these choices, and the findings may come as surprising.

Studies from Vanderbilt University Medical Center and the University of Alabama at Birmingham aimed to test the impact of a high carbohydrate smoothie on heart health. A second study examined the impact that a high carbohydrate weight loss diet versus a low carb weight loss diet might have on the psychological well-being of patients with Type 2 diabetes. Here we’ll cover what they found in result.

Smoothies are a way of life

In preface, smoothies have become the mainstay of a number of consumer diets. They’re a meal that can be eaten on the run, and can be customized from a slew of ingredient options. Most people think smoothies are super healthy and a great meal replacement or snack. Even parents assume they're a great way to get their kids to eat fruits and vegetables. For those whose lifestyle includes strenuous athletic activity, carb-loading before a workout is often a go-to technique - so a giant fruit smoothie is a popular dietary choice associated with a positive health payoff.

High-carb shake is hard on the heartFor the study, researchers from the universities monitored 33 individuals who were fed a carbohydrate-heavy smoothie (264 Kcal shake). Timed blood samples were taken from the subjects over a six-hour period. Researchers were especially interested in a hormone that the heart produces,** ANP** (atrial natriuretic peptide), which normally helps the body to get rid of excess salt and helping to reduce blood pressure.

Researchers already knew that ANP levels tend to be lower in people diagnosed with obesity. This can predispose a person to salt retention and high blood pressure. However, the study was searching for indications that a heavy carbohydrate load might suppress ANP, which would not only be a big problem for individuals with obesity, but also a problem in healthy individuals._The Result _

Drinking the high carb shake was found to reduce ANP production by 25 percent. The primary driver of the phenomenon was increased blood glucose levels. We know from previous studies that glycemic load does lead to cardiac problems, so this study further suggests that drinking a shake that’s high in glucose can directly and acutely impact heart health. Understanding these findings should be a wake-up call to individuals of all ages to possibly re-think those high carb “healthy” drinks.

When it comes to type 2 diabetes and mental health, is there an optimal weight loss diet plan?

Another recent study looked at 115 obese adults, ranging in age from about 51 to 65, and with BMIs that ranged from about 32 to 38.9. Patients in the study were randomly selected to eat a low calorie/low carb/higher fat diet, or a low calorie/higher carb/low fat diet for one full year.

Both groups also engaged in supervised exercise, three times a week. During the study, researchers monitored body weight, psychological mood and overall well-being using several assessment tools.

Weight loss in both groups was similar, and hovered around 9 pounds. Both groups also saw improvements in a variety of psychological areas, including feelings about diabetes control, anxiety and worry, sexual functioning, fatigue-inertia, tension-anxiety, depression-dejection, anger-hostility. Despite the dramatic differences in the dietary composition, both diets achieved weight loss and improvements in mood and affect. Essentially, low carb and high carb restricted-calorie diets that are accompanied by an exercise program and followed strictly by patients, provide weight loss and can also support and even improve mental health.

Understanding carbsCarbohydrates, particularly refined carbohydrates, have been slammed recently because of their dangerous impact on blood sugar levels. Certainly “drinking your carbs,” as in juices or high calorie, fruit-based smoothies, may not be healthy as a regular habit.** Smoothies can be improved by adding protein powder or silken tofu to mitigate the sugar content of the drink, but watch overall calories.** It’s clear that the cardiac implications described above should give you pause if you regularly juice or drink high carbohydrate smoothies.

In terms of diabetes, the second study suggests that there may be other diet options for individuals who need to lose weight and struggle with following a very low carbohydrate diet.

Patients need personalized therapeutic options

The worst thing a health practitioner can do is to only offer one approach to treat disease. If the goal is weight loss and reversing lifestyle-induced diabetes, then this low carb/high carb study suggests that if you have a compliant and committed patient, and add exercise as a regular habit, there may be some leeway in using a weight loss diet with a slightly higher carbohydrate component. The diet should however, from my perspective, utilize fruits, vegetables, beans and whole grains as the primary carbohydrate choices, and carb-counting and portion control must be emphasized.


Journal of the American College of Cardiology

Science Daily


Amy Hendel, also known as The HealthGal, is a Physician Assistant, nutritionist and fitness expert. As a health media personality, she's been reporting and blogging on lifestyle issues and health news for over 20 years. Author of The 4 Habits of Healthy Families, her website offers daily health reports, links to her blogs, and a library of lifestyle video segments.