According to a new study published today in Hypertensiona peer-reviewed journal of the American Heart Association.
Nearly half of the US population suffers from hypertension or high blood pressure – one of the major contributors to cardiovascular disease. When left untreated, high blood pressure damages the circulatory system and is a major contributing factor to heart attacks, strokes, and other health problems.
“Nutrition can be an easily accessible and effective measure to combat hypertension. Along with fats and carbohydrates, protein is one of the three basic macronutrients,” said study author Xianhui Qin, MD, from the National Kidney Disease Clinical Research Center in Nanfang. Hospital, Southern Medical University in Guangzhou, China.
There is a strong association between a poor quality diet and an increased risk of cardiovascular disease and death from cardiovascular disease. In its 2021 dietary advice for improving cardiovascular health, the American Heart Association advises people to eat healthy sources of protein, primarily from plants and may include seafood and low-fat or fat-free dairy products. , and, if desired, lean cuts and unprocessed forms of meat or poultry. The American Heart Association recommends eating one to two servings, or 5.5 ounces, of protein daily.
The study authors analyzed health information from nearly 12,200 adults living in China who were part of at least 2 of 7 rounds of the China Health and Nutrition Survey from 1997 to 2015 ( surveys carried out every 2 to 4 years). The participants’ initial survey was used as a baseline, while data from their last round was used as a follow-up for comparison. The participants were on average 41 years old and 47% were men. The survey measured food intake in three consecutive 24-hour food recalls and a household food inventory. A trained interviewer collected 24-hour dietary information on 3 days of the same week during each survey cycle.
Participants were given a protein “variety score” based on the number of different protein sources consumed out of 8 reported: whole grains, refined grains, processed red meat, unprocessed red meat, poultry, fish, eggs, and legumes. One point was assigned for each protein source, with a maximum variety score of 8. The researchers then assessed the association for the onset of new hypertension against the protein variety score.
New-onset hypertension was defined as systolic blood pressure (top number) greater than or equal to 140 mm Hg and/or diastolic blood pressure (bottom number) greater than or equal to 90 mm Hg, taking antihypertensive medication or self-reporting that a physician has diagnosed high blood pressure since their last survey visit. The mean follow-up time was 6 years.
The analysis found:
- More than 35% of the approximately 12,200 participants developed new high blood pressure during follow-up.
- Compared to participants with the lowest variety score for protein intake (less than 2), those with the highest variety score (4 or more) had a 66% lower risk of developing high blood pressure.
- For each of the 8 protein types, there was a window of consumption amount where the risk of hypertension was lower. The researchers described this as the appropriate level of consumption.
- When the total amount of protein intake was taken into account, the amount consumed was divided into five categories (quintiles), from the lowest intake to the highest intake. People who consumed the least total protein and those who consumed the most protein had the highest risk of new onset hypertension.
“The heart health message is that consuming a balanced diet with protein from different sources, rather than focusing on a single source of dietary protein, can help prevent the development of hypertension,” says Qin.
A limitation of the study is its observational design. Because the researchers used previous health information, they could not definitively prove that protein intake, regardless of type or amount, caused or prevented the onset of new hypertension.
The study was funded by the National Natural Science Foundation of China, Nanfang Hospital Outstanding Youth Development Program, Nanfang Hospital Clinical Research Program and Southern Medical University.