PORTFOLIO DIET
A recent Canadian study showed that a rigorous diet with specific food included can lower cholesterol almost as mush as statins with no side effects. The diet is almost but not quite vegetarian.
What did the study do?
What were the results of the study?
What do we learn from the study?
Do I throw away my statin prescription?
Footnotes
What is cholesterol? Who needs it? Why do we have it if it is so bad?
What did the study do?
They compared three groups:
- very low saturated fat diet
- very low saturated fat diet + statin (lovostatin)
- "portfolio diet": so called because of the "portfolio" of foods previously shown to lower bad cholesterol (LDL cholesterol.)
- high soluble fibre - oatmeal and barley: psyllium powder: vegetable sources - okra and eggplant. Cholesterol in the bowel sticks to the fibre and is carried to the outer world. (More in footnotes)
- plant sterols: they used margarine with sterols added. Sterols act like cholesterol in the small bowel and compete with the lining of the bowel for absorption. The bowel wall prefers the sterols and the cholesterol passes through to the stools. (more in footnotes.)
- soya based foods. Countries where soya is a major source of protein rather than meat have lower cholesterol. At first the effect on cholesterol was thought to be through isoflavones but now this is being questioned and the effect is probably from soya protein.
What were the results of the study?
LDL cholesterol fell with all three diet regimens.
Very low saturated fat diet: LDL cholesterol fell by 8.5%.
Very low saturated fat diet + statin: LDL cholesterol fell by 33.3%
Portfolio diet: LDL cholesterol fell by 29.6%
What have we learned?
- Do not eat foods that make cholesterol: foods that contain:-
- saturated fat
- trans fats
- Do not eat foods with cholesterol: this is much less important than removing saturated fat and transfats from the diet. Only about 10% of the cholesterol in the diet is absorbed, and plant sterols can prevent even that amount from being absorbed. So do not be afraid of the occasional egg!
- Eat foods that have a lot of soluble fibre. This will carry the cholesterol out through the bowels without beoing absorbed.
- Eat soya based products. Substitute soya milk for cows milk. Substitute soya protein for meat protein: soya burgers, soya hot dogs, tofu, soya cheese, spun soya protein in chile etc.
Do I throw away my statin prescription?
NO!
Diets that are radically different from your normal diet are seldom followed exactly and permanently. That is why weight loss diets fail after an initial success.
Incorporate the portfolio diet as much as is feasible.
Life has a bad habit of getting in the way of even the best intentions. We all stumble and fall. We are social animals and eat socially, so often we have little or no control of what food is offered. When we eat at home we can follow the diet assiduously. At social gatherings we do just the best we can, and make the wisest choices. Only people who are already almost vegetarian will find it easy to adapt completely and consistently.
Stay on your statins.
While adopting the diet as best we can, we should stay on the statins.
Have your cholesterol checked regularly.
Check your cholesterol initially every month. Your cholesterol will fall slowly.
Check with your physician before discontinuing statins.
When you reach perfect scores for cholesterol, ask about reducing or stopping statins.
Footnotes
What is cholesterol?
Cholesterol is a waxy kind of fat. Being a wax, it is not soluble in water or blood.
How does it travel in the blood?
Cholesterol is wrapped in a protein (lipo-protein = fat-protein) which is soluble, so the combined fat-protein complex is soluble. (See HDL - LDL below).
Why do we have it?
Cholesterol is made into hormones including sex hormones. It is also an ingredient in the walls of cells of our body. It is part of the scaffolding that holds our brain cells together. ALL VERY IMPORTANT JOBS!
Where does it come from?
Most of our of our cholesterol we make ourselves from fat in the diet. A little we absorb as cholesterol in food. Some we re-absorb from the bowel after the liver tries to get rid of it.
Process: The body makes cholesterol in the liver from fat in the diet. It attaches it to a lipo-protein and sends it off through the bloodstream to wherever it is needed: the adrenal glands for hormones, the brain for brain cell walls and scaffolding to hold the cells up and to all the cells of the body as they replace themselves.
The extra cholesterol comes back to the liver on its lipo-protein for destruction.
Why do we make so much?
We all have a cholesterol on-off switch. It is inherited. When cholesterol levels reach a certain level the liver stops production. In some people it is set high, some lower. Genetics also controls how much HDL-LDL we make.
How does the liver get rid of it?
The liver released the excess cholesterol from its lipo protein and passed it into the gall bladder, a pouch that sits just below the liver on the right side of the abdomen. The gallbladder has a tube (bile duct) that leads to the small intestine. The cholesterol is dissoved in bile. Bile is used in digestion to break up the fat in our diet into tiny globules small enough to be absorbed. When we eat a fatty meal the stomach releases a hormone to tell the gall bladder to contract and squeeze out some bile to break up the fat. The bile carries the cholesterol into the small bowel, the part of the bowel that absorbs most of the nutrients in our food. So intead of getting rid of the cholesterol, the body re-absorbs some of it.
Bile contains bile acids or pigments. If your cat has ever thrown up on a rug you know why they are called pigments: they stain fibre. That is how fibre in the diet works. The bile + cholesterol sticks to the fibre and is removed from the body through the bowels. Plant sterols work at this level. They compete with cholesterol for access to the transport mechanism in the small bowel wall that carries fat from the bowel to the blood. The transport mechanism can absorb the sterols but cannot pass them on, and they clog up the system. Any cholesterol has to pass by to the outside world. The transport system is like an old fashioned train: there are first class and second class tickets. When the train arrives at the station the first class passengers get on first. As mentioned above, sterols have difficulty passing through the transport system, so once on, they don't get off! If there is any room left the second class citizens get on: if not, they miss the train! Plant sterols have the first class tickets. Cholesterol is second class.
What is HDL - LDL (and VLDL) ?
These are proteins that carry cholesterol. They vary in size. HDL is a transport truck: it is large, and carries the cholesterol inside. None sticks out to catch in a cholesterol receptor in the artery wall. LDL is a pick-up truck. The cholesterol rides in the back but is partly exposed to the receptors in the artery wall. Some gets pulled off and sticks in the arteries causing arteriosclerosis. VLDL is a wheel barrow: the cholesterol is really exposed and falls out the easiest.
If your cholesterorol is carried on HDL, you are safe. HDL- GOOD!
I want more HDL! How do I get it?
Genetics plays the biggest role. However we can increase HDL through exercise.
How does exercise help?
Lipo-proteins carry all kinds of fat, not just cholesterol, including triglycerides and free fatty acids. When you exerise first your muscles use sugar from the blood. When that runs low e.g., after a few minutes of jogging, the muscles start burning glycogen. Glycogen is sugars strung together like pearls on a string. The muscles pop a sugar off as they need it. Glycogen is stored in muscles and liver. As the muscles run low they send to the liver for new supplies. When that runs low e.g., after 10-15 minutes jogging, the muscles start using fat for energy, triglycerides and free fatty acids. These are stored in the liver and fat cells of the body. They need trucks to take them from the fat storage area to the muscles. The more you exercise the more trucks you need. Long distance runners often have double the average amount of HDL.
Exercise takes a while to result in a rise in HDL. The body does not change rapidly, indeed it resists change. That is why you often feel bad in the first 10-21 days of an aerobic exerise program. You are asking for energy that the body does not want to give up.
How much exercise is needed?
You need to do aerobic exercise - fast walking, jogging, cycling: anything that gets your heart rate into the aerobic range. You don't start burning fat for about 10-15 minutes so you must do longer than that to have an effect on HDL. Consult an exerise specialist about this if you are young and do not have health problems. If you are older or already have cardiovascular problems, consult a doctor and cardiac exercise kinesiologist. You may need a stress cardiogram before starting.
