Dietary changes limiting certain amino acids may help slow disease progression in pulmonary hypertension, researchers say.
- About
1% of the world’s population lives with pulmonary hypertension, which
currently has no cure.
- Researchers
say dietary changes that limit the amino acids glutamine and serine may
help slow disease progression and improve the effectiveness of current
medications.
- Scientists
have also developed a new noninvasive diagnostic test for pulmonary
hypertension based on their findings.
Researchers estimate
that about 1% of the
world’s population lives with pulmonary hypertension —
a condition causing high blood pressure in
the blood vessels in the lungs.
There is currently no cure for pulmonary hypertension. Treatment options —
medication, surgery, and lifestyle changes — can help manage symptoms and
prolong a person’s life.
Now, new research has
examined the effects of dietary interventions on pulmonary hypertension.
A recent mouse study
published in Cell Metabolism shows that dietary
changes limiting the amino acids glutamine and serine may
help slow disease progression in pulmonary hypertension and improve the
effectiveness of current medications.
Stephen Y.
Chan, MD, PhD, co-senior author of the study and Vitalant Chair in
vascular medicine and professor of medicine in the Division of Cardiology at
the University of Pittsburgh School of Medicine, told Medical News Today:
“Contrary
to a popular misconception, pulmonary hypertension is a prevalent condition
with often limited therapeutic options. As such, there is still a 50% mortality
rate within 5 to 8 years of diagnosis. While there are new exciting therapies
recently approved for the treatment of pulmonary hypertension, we are far from
a cure, and our patients are desperate for better therapies to improve
mortality rates and quality of life.”
Effects of amino acids on pulmonary
hypertension
Chan said they decided
to look for a link between diet and pulmonary hypertension when they observed
that diseased cells called fibroblasts of
the lung blood vessels in pulmonary hypertension are surprisingly “hungry” for
the amino acids glutamine and serine.
“Our data later showed
that this hunger comes from the need (for) fibroblasts to increase collagen production and
deposition in and around the blood vessels to stiffen them in disease,” he
continued.
“When we cut off that amino acid supply or prevented
the use of these amino acids for collagen production, we could reduce collagen
production, vessel stiffening, and worsening of pulmonary hypertension.”
Chan and his team used a
mouse model to test their theory. When the mice were administered drugs that
lowered their cellular uptake of glutamine and serine, the pulmonary hypertensive
blood vessels were relieved of their craving.
Additionally,
researchers found the lack of glutamine and serine stopped the production of
excess collagen, which would lead to lung blood vessel stiffening and impaired
function.
New diagnostic test for pulmonary
hypertension
Through the research
team’s findings regarding serine and glutamine, they were also able to develop
a new diagnostic test for pulmonary hypertension.
The test uses positron
emission tomography (PET) scan technology and a glutamine
imaging tracer to track where glutamine goes in the body. Cells
“hungry” for glutamine distinguish themselves on the PET scan, helping doctors
with making a diagnosis.
“One of the crucial
obstacles in managing pulmonary hypertension is that the diagnosis requires an
invasive test called cardiac
catheterization, where a long hollow tube is inserted into the blood
vessels of the neck,” Chan detailed.
“That catheter is then
threaded all the way down into the heart and lungs to measure pressure
directly. Not every medical center has this capability, particularly those in
more rural or isolated settings, and this limits the ability to appropriately
identify and treat patients with this disease.”
“While we use some
noninvasive imaging studies like MRI and ultrasound in
managing the disease, they are not sufficient to make the diagnosis,” he
continued. “Thus, accurate and early diagnosis of pulmonary hypertension is
crucial, and there is a clear unmet need for developing better noninvasive
diagnostic technology.”
“Our
data was only performed in animals with experimental pulmonary hypertension,”
Chan added. “We are actively recruiting for a clinical trial at our institution
that is testing this new PET technology in patients with pulmonary
hypertension.”— Stephen Y. Chan, MD, PhD, co-senior study author
What foods help with pulmonary
hypertension?
Chan said that for the
first time, researchers have proof that specific dietary adjustments — reducing
glutamine and serine consumption, in particular — may serve as an effective way
of treating pulmonary hypertension.
“It opens up a new way
that we could manage this disease, because now — instead of just relying on
medications and transplantation — there are possibly effective lifestyle
interventions,” he continued.
“For patients with pulmonary hypertension, avoiding
foods rich in serine and glutamine, or eating foods with these amino acids
depleted, might improve symptoms, reduce disease progression, or bolster the
effectiveness of current medications,” Chan explained.
However, Chan did urge
caution in over-interpreting their findings at this stage.
“Our work fully restricted
all glutamine and serine from the rodent diets which led to improvement of
pulmonary hypertension,” he said.
“We view this finding as
(an) important proof-of-concept that dietary maneuvers can be effective as
therapies in this deadly disease. However, this level of absolute restriction
would not be feasible in a normal human diet, and we certainly do not recommend
that our patients attempt to do so at this time.”
“More work is needed to
determine if lower levels of amino acid restriction have the same therapeutic
effect and/or if more feasible and safe dietary maneuvers could bolster current
treatments to promote even better improvement of (the) disease,” Chan added.
More
studies on diet and pulmonary hypertension needed
After reviewing this
study, Cheng-Han Chen, MD, a board certified interventional
cardiologist and medical director of the Structural Heart Program at
MemorialCare Saddleback Medical Center in Laguna Hills, CA, told MNT that a
dietary approach to improving pulmonary hypertension is a novel approach that
could be more accessible to people with pulmonary hypertension as a form of
treatment.
“Pulmonary hypertension
is a complex disease that could have many different causes,” Chen explained.
“Many of the causes are
not easily treatable with our current therapies. This type of research has the
potential to provide new targets for medications that could improve the
prospects for our patients with pulmonary hypertension.”
However, Chen said we are not yet at the point where
people should adjust their diets specifically for glutamine and serine based on
the results of this study.
“I
advise all patients to eat a well-balanced, heart-healthy diet. The next step
should be to see if these findings apply in humans, not just in mice. They
probably will be looking at clinical studies to evaluate the effects of diet,
specifically glutamine and serine intake, on pulmonary hypertension in those
individuals.”— Cheng-Han Chen, MD, cardiologist
Should people with pulmonary
hypertension adjust their diet?
MNT also spoke with Monique
Richard, a registered dietitian nutritionist and owner of
Nutrition-In-Sight, about this study.
Richard explained that
amino acids are the building blocks of protein. Foods rich in amino acids
include animal and plant proteins,
grains, and legumes with the richest sources, most bioavailable — meaning the
body can use efficiently.
“In practice, we often
observe an excess intake of animal proteins from those who have hypertension, cardiovascular disease risk, chronic obstructive
pulmonary disease (COPD), and other related conditions, as well as
contributory factors related to lifestyle choices such as minimal
activity, smoking,
alcohol intake, poor sleep hygiene,
(and) hydration status,” she said.
For those worried about their glutamine and serine
intake, Richard advised meeting with a registered dietitian nutritionist (RDN)
to fully assess diet composition and intake appropriate for an individual’s
needs.
“An RDN will also assess
(the) overall balance of dietary and lifestyle factors that influence health in
conjunction with the person’s genetics and current physical state allowing for
specific and personalized recommendations to be given,” she continued.
“There
are a lot of apps and tech platforms that can help assist in deciphering amino
acid profile intake, but once we start reducing intake down to building blocks
of protein, micronutrients,
and that level of scrutiny, we begin to lose sight of the bigger picture and
all the factors that beautifully harmonize to produce the symphony of health
and vitality.”— Monique Richard, registered dietitian nutritionist.
No comments:
Post a Comment