Dietary protein, serum albumin and health
When was the last time you thought about your serum albumin? You might have glanced at it the last time you got a lab panel at your doctor’s office, and as long as it was within the normal lab limits, you probably didn’t give it much thought. You should look at it a little more closely the next time you get a lab done because your serum albumin is a pretty good barometer of your overall health.
Albumin is the most abundant protein in blood plasma.
(Let’s take a brief digression to define a few terms so that we’re all on the same page. Blood is blood. Blood is what you get if you cut yourself. When you get your blood drawn, that dark red stuff is the blood, which includes the red blood cells,
white blood cells, and other cellular components. Plasma is what’s left over when all the cells are removed. Typically, when blood is drawn it is put into a tube, and the tube is put into a centrifuge. The whirring of the centrifuge drives all the cells to the bottom of the tube; the yellowish fluid left on top is the plasma. If you put the whole blood in a tube and let it sit, the blood clots into a big glob and drops to the bottom, the clear yellowish fluid left on top is the serum. Basically serum is plasma that has had all the clotting factors removed. For our discussion of albumin, it doesn’t really matter. Albumin is measured in the serum, and so is called serum albumin. But it is the most abundant protein in the blood other than the proteins making up all the cells.)
A number of health and lifestyle factors influence albumin levels. Malnutrition, especially protein malnutrition, liver and kidney disease, smoking, a decreased muscle mass, a loss of strength, and low levels of physical activity are all associated with lower albumin levels. More importantly, albumin is a determiner of how sick you are and how likely you are to die should you be admitted to the hospital with a severe illness. The lower your serum albumin, the greater your chances of succumbing. It’s a lab value that doctors working in intensive care units monitor very carefully.
It has generally been accepted that serum albumin falls with increasing age, which makes sense if you think about it. As you get older your muscle mass decreases, your liver and kidneys don’t work as well, and you’re not as strong: in short, you’ve got all the conditions that go along with a decreasing serum albumin. If you get sick enough to require the services of an intensive care unit, your lower albumin that goes along with your increased age marks you as less likely to survive the experience than a younger person with a higher albumin.
That has been the conventional wisdom at least. But some new research sheds light on a phenomenon that MD and I noticed in our practice: increased dietary protein intake promotes the synthesis of more albumin and raises albumin levels in the blood, even in older people.
Before we get into the specifics of the research, I want to digress once more and discuss a little about what albumin does. It doesn’t just sit there, riding along in the blood. It has a number of vital functions. Albumin attaches to and transports hormones, including thyroid hormone throughout the body. It carries free fatty acids to the liver; it transports bilirubin. Albumin also transports drugs, binds with calcium, and helps maintain the blood acidity in a narrow range. It’s most important function is that it maintains osmotic pressure, which keeps the plasma inside the blood vessels where it belongs instead of allowing it to ooze out into the tissues. How does it do this? What is osmotic pressure?
Let’s make another digression to flesh out the idea of osmotic pressure, which is one of the most important forces acting in the human body.
Imagine that you have a small aquarium. This aquarium is half full of regular old tap water. Across the middle of the aquarium you stretch a thin membrane from side to side like a tennis net. The membrane is attached on both sides and the bottom and the top. And the membrane allows water to freely flow through it, but it doesn’t allow anything else to flow through other than the water.
Now you’ve got your aquarium half full of water with a membrane dividing one side from the other. The water level is the same on both sides of the membrane. If you pour some water into one side of the aquarium, the water level in that side will rise as compared to the level on the other side of the membrane. But as water seeps through the membrane, in pretty short order the water level will be once again the same on both sides.
Let’s say that now we drop a few tablespoons of salt into the water on one side of the membrane. Remember, only water can cross the membrane, not salt. What’s going to happen? Water, as we all know, seeks its own level and will ultimately stay at the same level across the permeable membrane, i.e., there will not be a higher level on one side than the other once it equilibrates. What drives the equilibration is the pressure difference between on side and the other. When you pour the plain water in one side, the pressure rises on that side, the increased pressure drives the water through the membrane until the pressure is equal on both sides.
The same phenomenon exists with concentrations of water, and here’s where it starts to get interesting. If you mix salty water with non-salty water in the same container, the water will mix together until the concentration settles out somewhere in the middle. But if you make the water more salty on one side of the membrane stretched across the aquarium, what happens? The water can go back and forth, but the salt can’t. What ends up happening is that in an attempt to equalize the concentration of salt, the non-salty water crosses the membrane to try to dilute the salty side. As the non-salty water crosses the membrane, the level of water gets higher on the salty side. The increased water pressure then tries to drive the water back to the side with the lower level and less pressure. As you let the system come to equilibrium, the water on the salty side rises to a certain level increasing the pressure of that level. That increased water pressure becomes equal to the forces driving the water to try to equalize the concentration of salt. That pressure is called osmotic pressure.
If you pour more salt in the salty side, the level of the water rises a little bit more as compared to that on the non-salty side because you have increased the osmotic pressure.
Albumin is the substance that provides the osmotic pressure in our blood in the same way that the salt did in our aquarium experiment.
The albumin attracts the fluid in the blood and keeps it in the blood vessels. Blood vessels are porous, and without the osmotic pressure of the albumin will let the fluid part of the blood escape our into the tissues.
We’ve all seen this phenomenon in pictures of starving children. These kids don’t get enough protein, they can’t make albumin, with little albumin their blood vessels can’t retain the fluid part of the blood. It seeps out into their tissues and makes the big bellies we associate with starving kids. Their bellies are full of the fluid that should be in their blood vessels. If they are given protein to eat, their livers begin to make albumin, the albumin exerts its osmotic pressure and draws this fluid from the tissues back into the blood, and the large, protuberant bellies go away.
As you can see, albumin is extremely important, and it serves us well to make plenty of it.
The most recent edition (July 2007) of the Journal of Nutrition published a terrific study of the synthesis of albumin as a function of both protein intake and age.
Subjects of both sexes and of two age groups ( 21-43 y and 63-79 y) were given varying amounts of dietary protein after which their rates of albumin synthesis were measured. The amounts of protein were set at 125%, 94% and 63% of the recommended dietary allowance (RDA). (The RDA for protein is 0.8 gm/kg body weight/day.) 125% of RDA comes out to be 1 gm of protein per kg (2.2 lbs) body weight per day, so a person weighing 70 kg (154 lbs) got 70 gm protein, which isn’t a huge amount.
The protein in the study came from all food sources including grains, dairy, fruits and vegetables. No meat was served because – as the authors pointed out – the protein content was too high. They wanted to be able to carefully provide a precise amount of protein while keeping the calories at a substantial level. A low intake of calories inhibits the synthesis of albumin, and since they wanted to measure albumin synthesis as a function of protein intake, they gave the subjects plenty of calories. Had they used meat, they would have exceeded the protein limits they were studying.
After data analysis it turned out that male subjects made a little more albumin than female subjects across the age ranges, which goes along with the slightly higher ‘normal’ levels for males as compared to females. The most important findings were that as dietary protein increased, so did the synthesis of albumin and that these changes held across the ages of the subjects. In other words, older people who consumed as much protein as younger people made the same amount of albumin as younger people.
All this is important because it is important for elderly people to maintain their albumin levels for optimal functioning and resistance to disease. Elderly people are the very people who are the most afraid of heart disease and who get most of their information via the mainstream media. These are the people who have bought into the notion that cholesterol is dangerous, despite the mountains of data showing that – like with albumin – elderly people do better with higher cholesterol levels. The elderly are the ones who fall prey to the statin and low-fat diet pushers. As a consequence, the elderly seldom get even the RDA of protein, which the above study shows is less than adequate. And since the elderly don’t get enough protein, they can’t make the albumin they need.
For those of you (us? I just had a birthday) who are elderly, eat meat, increase your protein intake. If you don’t want to eat meat, at least drink a protein shake with a fair amount of leucine in it every day. For those of you (us?) who aren’t elderly, make sure you get plenty of protein. It’s good for you. It will increase your albumin levels, build muscle mass, and even increase your thermogenesis. And it makes you less hungry. Go for it.
Ciao Mike.
You say you eat 250g protein daily and that you weigh about 190 lbs.
In PPLP you said minimum requirement for yourself (man, weight 190 lbs.) ranges from 34 grams a meal to 40 grams a meal (that is 120 grams) depending on your height.
So your protein’s intake is more than twice your minimum requirement.
I have some questions:
1)
Could you give an example of a typical 250 grams protein menu?
It seems so difficult for me to eat 250 grams protein a day…
2)
I weigh 126 lbs. and I’m 5’8″ (174 cm.) tall.
In PPLP I’ve found minimum protein requirement PER MEAL for me is 27 (that is 81 grams daily), but what about my protein requirement if I’d like to build muscle mass (bodybuilding)?
Should I take a supplement of Leucine?
If any protein powders would help, could you suggest a brand?
Would ImmunoPro do the job?
Should I double my minimum protein requirement too?
Thanks.
Marco
p.s. – when I was a boy I was very very thin and a doctor used to give me a product: Co-carnityne B-12. It was very useful and gave me some results in getting rid of my thinness. Have you any experience with carnytine (or vitamin B-12?) in treating thinness? How does it work?
Hey Marco–
You seem to be confusing this blog with a question and answer column. The answers to your questions are way beyond the scope of the comments section.
Best–
MRE
Ok. Sorry…
No problem. I just don’t have the time to answer long, multi-part questions and write this blog and write my book and do all the other stuff I have to do. Thanks for your understanding.
Hi, I am a 22 yr old male and just had a blood test. In the kidney section on the form it said I have abnormally high levels of Albumin at 50g/l. Is this serious? Dose it mean I have a disease?
It’s difficult to tell given the limited information you have provided. Plus, I can’t give specific medical advice over the internet. But I can say that an elevated albumen doesn’t necessarily imply disease. You should have it rechecked and talk to your doctor about it.
I am a nurse and I work among the elderly. One patient had severe bilateral edema of the lower extremities, ascites and a serum albumin of 2.7. I encouraged protein supplements as well
as sharpening up the overall caloric intake. The edema went down and the patient’s health improved, but the physicians about laughed me out of the office because they felt that the
serum albumin levels did not have anything to do with the edema and that I was “milking
the situation for all it was worth”. Why is it that physicians will not recognize the severe
impact of low albumin on patient’s health?
I don’t have a clue as to why physicians wouldn’t understand that the protein in the blood (and albumin is the protein in the blood in the greatest amount) holds the fluid in the blood via an osmotic gradient. Where do they think ascites come from during starvation? Yeesh. Sorry to hear that you’re surrounded by morons.
THANK YOU FOR TAKING INTEREST IN THIS SUBJECT.
I AM 80 YEARS OLD MALE WHICH SUFFERS FROM “CELIAC SPRUCE”. I HAVE LOST 6O LBS IN A YEAR. I ALSO HAVE ASCITES VERY BAD. I NEVER CONSUMED ALCOHOL,BUT WAS SLIGHTLY EXPOSED TO AGENT ORANGE WHILE IN THE ARMY. IN ADDITION TO THIS I ALSO BEEN DIAGNOSED WITH “SGO GREN SYNDROME. I HAVE EDEMA OF THE LEGS AND ALSO SUFFER FROM CRONIC DIARREAH AND ANEMIA.
in addition to the above reply,i must add that the physicins now wants to do biopsies of the liver and remove nine inches of my small intestine, because according to them, i been also diagnosed with CARCINOSIS OF THE SMALL BOWEL.I refuse the surgery.
I hope that you people realize that Dr. Mike, even if he really is a doctor, is not qualified to provide nutritional counseling. Registered Dieticians are the legally and medically recognized source for nutrition.
Especially since Dr. Mike is rather obviously trying to sell his books.
Your articles are excellent. I could learn many things from it. I have the foll. queries, kindly guide:
1) Kindly inform the vegetarian dietary sources of Albumin
2) Is a dietitian eligible to prescribe protein powders for patients
3) Kindly inform some topics and areas where biochemistry and nutrition-Dietetics is linked i.e. where both the knowledge can be used simultaneously (for research)
4) Under what cases the patient should be advised protein supplementation via I.V. infusion, in addition to dietary protein
Kindly reply.
There are no vegetarian sources of albumin. The liver makes albumin from other protein. If protein intake is adequate and liver function is good, the albumin is no problem.
Anyone is able to prescribe protein powders because protein powders are non-prescription.
I don’t understand #3. Nutrition is nothing more than applied biochemistry.
#4 is beyond the scope of an answer to a comment.
Dr Mike
My serum albumin is 7.1 (vs lab ref 3.2-5.5), should I worry? What kind of diseases could be related?
(I am 30 and generally in good health except currently a diplopia driven by a 3rd cranial nerve palsy – after 2 weeks of hospital tests doctors don’t know what I have… could it be related to high albumin levels?)
Looking forward for your reply,
Eric
Without knowing a whole lot more, I couldn’t possibly comment. It could be nothing at all. You may just be one of those people whose normal albumin runs a little high. Or it could be a lab error.
Hi: I have been diagnosed as having Bisalbuminemia. My Dr. has never heard of it and I can’t find info on it. What should be in or not in my diet. I also have type 2 diabetes which I control strictly with diet and exercise. Could you help me out? Thanks Joan
Bisalbuminemia is a genetic oddity (like having one brown eye and one blue one) without any health consequences.
Hi Mike,
I wonder did the dread Convention Unit(US) vs SI Unit (EUR) gremlin strike in one of the comments above.
I noticed Seb quote 50 g/l which I read as g/L (SI) not Conventional g/dL.
The reference levels i have from TDL lab in London are: Albumin g/L ( 34 – 50 ) SI
and hence Albumin g/dL ( 3.4 – 5. ) Conventional
I have printed out “SI units for Clinical Dat”a which gives Conversion factors (Conventional – SI) for Acetominophen to Zinc. I refer to these 5 plus pages quite regularly. The source is JAMA Author Instructions on http://www.unc.edu Reference Rowlett.
Regards
Desmondo
I don’t really understand, I am sorry for that.
I had nearly seven litres of fluid drained from my tummy and had two infusions of Albumin (night have wrong spelling sorry)
But I am swelling up like a ballon.
can you in simply terms please explain what albumin is / does please
Hi. My 4th lab results in about 10 months came back. And my bilirubin went from 1.4 to 1.5 to 1.1 to 1.3, total protein went from 7.4 to 7.9 to 7.9 to 8.5, and finally my albumin went from 4.9 to 5.0 to 5.0 to 5.6, which was out of range, as all of these levels are either at the upper end of the scale, or slightly elevated. Since these three seem vaguely connected- what’s going on here, and why, over the course of almost a year, are they slightly increasing? I’m a 33 year old male, not overweight, decent amount of exercise…
Since you’re not my patient, and I don’t know your medical or dietary history, I don’t have a clue.
Hi Doc, I have had iron overload for 25+ years and it was only recently diagnosed…after it did considerable damage to my liver…ascites, micro-nodular cirrhosis…to the point where I now have a TIPS installed. I am doing remarkably well but my albumin is still at 0.9. Yes, you saw that right. I take lactulose to mitigate any hepatic encypholophy (none has occurred) and spronolactone (diuretic) for edema. It was bad for a while until the TIPS was installed but I have gained my weight back and muscle mass. I can’t determine if I am carrying around excess weight in my thighs as water or fat at the moment…
In any case as I understand it the lactulose ‘interrupts’ the protein breakdown in the gut so that ammonia is not produced to prevent the hepatic encypholophy. But wouldn’t this affect the amount of protein being made available to the liver to manufacture albumin? It has been almost 2 years since the TIPS was installed. AST is still elevated even though I have taken milk thistle and Liv52 to help protect the liver…I do phelobotomies approximately every 6 weeks to get the iron out…my Doctor allows the hemoglobin to be as low as 10.5 to take blood out. Trying to stay away from all red meats and other high iron content foods…
I may have low protein intake because of lactulose but I have built muscle mass back…
So I don’t know what to think or do to help the albumin go up. Any comments or suggestions?
Thanks…
Since albumin transports insoluble bilirubin to the liver for removal, thus preventing jaundice: could a pregnant woman eating a high protein diet especially during the last trimester of pregnancy potentially decrease the likelihood of her baby developing jaundice?
Likewise, could a breastfeeding mom of a baby with jaundice help her baby to clear away excess bilirubin by increasing the protein in her diet?