- Almost half of adults in the United States have high blood pressure, or hypertension.
- Current evidence suggests that dietary changes can reduce blood pressure, but more investigation is necessary.
- A recent study in China shows that eating a balanced diet including protein from a variety of sources may help adults lower their risk of developing high blood pressure.
Hypertension can lead to cardiovascular disease, stroke, and illnesses that affect the kidneys and the brain.
Scientists believe that hypertension occurs due to a combination of environmental and lifestyle factors. Current advice is that eating more healthily can reduce high blood pressure.
Lately, there has been a growing interest in the role of protein as a possible approach to preventing hypertension.
The present study, led by Dr. Xianhui Qin, M.D., at the Southern Medical University in Guangzhou, China, investigated the link between the variety and quantity of protein in the diet and new-onset hypertension.
The study authors found that eating protein from a variety of sources could help lower the risk of high blood pressure. Their findings appear in the journal Hypertension.
Tracy Parker, senior dietitian at the British Heart Foundation, told Medical News Today, “This study adds to the evidence that eating a moderate amount of protein from a variety of foods is an important part of a healthy diet.”
“Although this study was observational, it suggests that eating a selection of both plant- and animal-based proteins in your diet can help control your blood pressure and benefit your heart. Further research is now needed to help understand this, including in different population groups with different dietary intakes.”
The team took data from the China Health and Nutrition Survey, a collaborative project between the University of North Carolina at Chapel Hill and the Chinese Center for Disease Control and Prevention (CCDC).
The survey collected data between 1989 and 2015 and covered more than 47% of the Chinese population. The collection of data took place in waves every 2–4 years. In the 2009 wave, researchers collected blood samples.
The present study used data collected from 1997 to 2015, excluding participants who already had a hypertension diagnosis, who had not completed two rounds of the survey, or whose dietary data were insufficient.
Trained nutritionists collected information about food intake during face-to-face interviews. This entailed 24-hour dietary recalls over 3 days of the same week, together with a household food inventory. From this information, the scientists then calculated the nutrient intake.
The team looked at the variety and quantity of protein intake from eight major food sources: whole and refined grains, processed and unprocessed red meat, poultry, fish, eggs, and legumes. They then generated protein scores based on the number of protein sources a person consumed, awarding one point for each source.
Over an average follow-up of 6.1 years, the researchers captured information about new hypertension diagnoses. The final analysis included a total of 12,177 participants.
The average age of the participants was 41, and approximately 53% were female. During the study, just over 35% of the participants developed hypertension.
The researchers found that the participants with the greatest variety of protein in their diet had less than half the rate of new-onset hypertension than those with a protein variety score of less than 2.
The total quantity of protein showed a U-shaped curve in relation to hypertension onset. This means that those with the least variety and the most protein intake had the highest risk of new-onset hypertension.
For each type of protein, the researchers identified specific levels where the risk of hypertension is lower.
Dr. Qin told MNT that he was not surprised by the results. “We speculated that consuming greater variety of proteins in proper quantity could guarantee the intake of different essential amino acids, which may correlate with better nutritional status, microbiota richness, and diversity.”
“The heart health message is that consuming a balanced diet with proteins from various, different sources, rather than focusing on a single source of dietary protein, may help prevent the development of high blood pressure,” Dr. Qin says.
Dr. Qin told MNT that future work should include participants of other ethnicities and from other regions. “Randomized trials are needed to further examine the associations between the variety and quantity of protein intake from different food sources and the risks of hypertension and other health outcomes.”
“Moreover, we should further define the appropriate amount of the intake of each protein in different populations.”
Parker added: “To keep your heart healthy, you should focus on eating more fruit, vegetables, fish, pulses, and whole grains and cutting down on foods high in salt, sugar, and saturated fat, like cake, biscuits, and sweets. Lifestyle factors, such as exercising regularly, quitting smoking, and maintaining a healthy weight, are also important ways to reduce your risk of heart and circulatory diseases.”