Which High-Protein Diet Lowers Risk of Death?

 

A number of years ago, a colleague of mine tried a high-protein diet for weight loss because he’d met someone special in another state on an online dating site — only he’d posted pictures of himself when he was 30 to 40 pounds lighter.
Unfortunately, a regular meal schedule is a luxury few doctors get. Most physicians eat on the run when there’s an opening in their schedule, which often leads to weight gain from poor food choices.
My colleague’s interstate romance grew through correspondences, and he agreed to travel to the woman’s hometown for a meeting. The only trouble was that he wanted to lose weight quickly.
Like many others, he started a high-protein, low carbohydrate diet; his consisted almost entirely of animal proteins, along with a few strawberries. More than 80 percent of his diet came from animal proteins.
I’m happy to report that he lost the desired weight, and the online romance ended in marriage.

Should You Try a High-Protein Diet?

Many people use high-protein diets such as Weight Watchers or the South Beach Diet, among others, to quickly lose weight. And once they reach a certain weight goal, many will transition to a more balanced diet.
But some people stay on a diet long term to maintain their weight loss. And weight loss through diet certainly has significant benefits, including lowering your risk of developing high blood pressure, heart disease, diabetes, some cancers, and sleep apnea.
Numerous high-protein diets are available: When I searched for new books on the topic, the online bookstore yielded more than 100 options.
Most people I ask about a high-protein diet think of eating more meat and eggs. But protein is abundant in many other food sources.
Animal products high in protein include most forms of meat, eggs, seafood, dairy, cheeses, and whey protein.
Plant products high in protein include beans and legumes, such as lentils, chickpeas, soybeans, and black-eyed peas — also known as pulses. Other plants that contain protein include some vegetables (broccoli and spinach, for example), most nuts (like almonds, cashews, pistachios, and many nut butters), and seeds like chia, sunflower, poppy, quinoa, and many more.

Why Food Sources Matter in a High-Protein Diet

Given these facts about protein, here are two questions you may want to ask yourself before you embark on a high-protein diet:

1. Is the high-protein diet a healthy long-term option?
2. Should you switch from animal-based proteins to plant-based proteins in your diet?

A study published in October 2016 in JAMA Internal Medicine shed some light on these questions as they related to long-term risk of death from heart disease and cancer.
The study included 131,342 participants, of whom 85,013 were women; the average age was 49. These people were evaluated every two years with regard to their lifestyle and diet, and they were followed for more than 20 years.
Researchers compared people in groups based on the percent of protein in their daily diets:

• Animal protein (less than 10 percent, 12 to 15 percent, or greater than 18 percent)
• Plant protein (less than 3 percent, 4 to 5 percent, or more than 6 percent)

The study participants were not assigned to a particular diet, but instead reported on what they chose to eat. This study’s findings reflected broad dietary patterns and various protein sources:

• For each 10 percent increase of dietary animal protein, participants had an 8 percent increase in risk for heart disease-related death.
• For each 3 percent increase in dietary plant protein, participants had a 12 percent decrease in heart disease-related death.

The people who reported high levels of animal protein consumption and were most at risk for death from heart disease were also overweight, more sedentary, consumed alcohol, or smoked.

The Health Advantages of Plant-Based Proteins

If plant proteins are healthier, what happens when you substitute plant protein for animal protein in your diet?
Researchers found that for every 3 percent substitution of plant proteins in place of animal protein, there was a 34 percent reduction in mortality (risk of death) from heart disease. These benefits were seen in both active and inactive people. The best animal protein source to swap for a healthier plant protein source, according to this study, was processed red meat.
And for every 3 percent substitution of plant protein in place of animal protein, cancer-related death in study participants dropped by 17 percent. In this analysis, the best animal protein sources to swap for plant proteins were, again, processed red meat products — but also eggs.

High-Protein Diets Preserve Muscle Mass 

A second, smaller study published in October 2016 in Cell Reports highlights the need to consider transitioning to a well-rounded diet once you’ve achieved your desired weight loss goal.
A healthy diet is primarily derived from fruits, nuts, vegetables, and very few processed foods. In this study of postmenopausal women who had developed prediabetes, researchers looked at the influence of a high-protein diet on glucose (sugar) levels.
Approximately 60 women with prediabetes participated and were assigned to a low-calorie, rapid weight loss diet or a high-protein weight loss diet. Both diets resulted in a loss of 8 to 10 percent of body weight.
But women who followed a high-protein diet preserved much more lean muscle mass. Essentially, most of their weight loss was loss of fatty tissue. One caveat: Their high-protein diet did very little to improve their muscles’ natural sugar intake, so some of the prediabetes condition persisted.

Small Diet Changes, Big Health Benefits

If you get your protein from animal sources like meat, eggs, and dairy, the first study is great news. When you make small changes to your diet and swap out some of the animal products for plant protein, you may get a tremendous benefit in lowering your risk of death from heart disease and cancer. These health dividends were observed when people substituted plants for animal products in just 3 percent of the diet. Few other things you can do will pay off so well.
If you keep a diary of your daily diet over a week, you should be able to find a few animal protein sources to eliminate; in particular, it’s helpful to substitute plant-based proteins for processed red meats.
You may not be considering a diet change to prepare for the love of your life like my colleague, but when you look at the evidence, it seems most of us could use more plant protein in our diets.

A number of studies have suggested that a diet high in protein is beneficial for health, boosting metabolism, and aiding weight loss. For older women, however, a high-protein diet may be more harmful than helpful; researchers suggest it may raise their risk of heart failure, particularly if the majority of protein comes from meat.

Researchers have linked a high-protein diet to increased risk of heart failure among older women.

Heart failure occurs when the heart is no longer able to pump enough oxygen-rich blood around the body to support other organs.
According to the Centers for Disease Control and Prevention (CDC), around 5.7 million American adults have heart failure, and in 2009, heart failure contributed to around 1 in 9 deaths in the United States.
A diet high in fat, cholesterol, and sodium is known to raise the risk of heart failure, but according to study co-author Dr. Mohamad Firas Barbour, of Brown University Memorial Hospital of Rhode Island, and colleagues, a diet high in protein may be just as harmful.
The researchers recently presented their findings at the American Heart Association's Scientific Sessions 2016, held in New Orleans, LA.
Protein is found in foods such as meat, poultry, dairy products, seafood, beans, peas, and nuts, and it is considered essential for healthy bones, muscles, and skin.
While some studies have suggested a diet high in protein may aid weight loss by suppressing appetite, other research has cited the downfalls of a high-protein diet.
A 2014 study published in the journal Cell Metabolism, for example, suggested a link between a high-protein diet and greater risk of cancer, diabetes, and all-cause mortality.
Such studies claim animal-derived proteins are more to blame for negative health implications than plant-derived proteins, and the new research is no exception.

Heart failure risk higher for women who eat more meat protein

The researchers came to their findings by analyzing data of 103,878 postmenopausal women aged 50-79 years who were part of the Women's Health Initiative (WHI).
As part of the survey, participants were required to complete a food frequency questionnaire that assessed their daily intake of around 125 different food items between 1993-1998. The researchers looked at subjects' total daily protein intake, as well as the total amount of daily protein consumed from meat and vegetables.

Fast facts about heart failure

• Fatigue, shortness of breath, and weight gain with swelling in the stomach, feet, legs, or ankles may be signs of heart failure
• Around 50 percent of people with heart failure die within 5 years of diagnosis
• Heart failure costs the U.S. around $30.7 billion annually.

Learn more about heart failure

The researchers note that self-reported dietary data can be inaccurate, so they also used biomarker data to get a more reliable indication of participants' protein intake. This involved assessing subjects' urinary nitrogen and doubly labeled water levels - a measure of metabolism.
All women were free of heart failure at study baseline, and heart failure development was monitored until 2005.
A total of 1,711 of the women in the study developed heart failure, the team reports.
Compared with women who had low total protein intake, those who had a higher total protein intake were found to be at much greater risk of heart failure. The risk was greater among women who consumed most of their protein from meat.
The results remained after accounting for age, race/ethnicity, education level, high blood pressure, coronary heart disease, anemia, and arterial fibrillation.
The researchers did uncover an association between high intake of vegetable proteins and lower risk of heart failure, but when the team accounted for body mass index (BMI), this result was not statistically significant.
The team warns that the findings should be interpreted with caution and further research is required, but they do suggest a high-protein diet may be linked to heart failure.

"Higher calibrated total dietary protein intake appears to be associated with substantially increased heart failure risk while vegetable protein intake appears to be protective, although additional studies are needed to further explore this potential association."

Dr. Mohamad Firas Barbour

"Heart failure is highly prevalent, especially in postmenopausal women; therefore, a better understanding of nutrition-related factors associated with heart failure is needed," adds Dr. Barbour.
Read about a study linking certain nonsteroidal anti-inflammatory drugs to greater heart failure risk.

Written by Honor Whiteman