Cholesterol levels; Statins and Exercise

Is one better than the other? Are they interchangeable? How do they interact? Is a multiple approach the answer? As with anything to do with biology, the answer is “it’s complex”.

Statins have been one of the most prescribed drugs to lower high cholesterol in the US since their introduction in the early 1990s. Let’s start with understanding cholesterol , why should it be lower in many people, and ways to approach it.

Our livers make a daily genetically-determined amount of cholesterol. It is necessary as a cell membrane stabilizer, a precursor of sex hormones, vitamin D and bile, and as part of the fatty-acid transport system in our blood. Animal foods add a dietary source of cholesterol, but whether dietary cholesterol is actually worrisome has been debated for years (current thoughts -> less problematic, but stay tuned...) We manage cholesterol levels internally with a recycling mechanism that recaptures some, and we also lose some through our gut. The liver uses cholesterol to create bile acids which are secreted into the intestine to facilitate absorption of dietary fats. Some of these bile acids are lost in the feces.

Handy food tips: eating high fiber foods causes more bile to be swept out of the intestine, indirectly lowering your cholesterol. Certain plant foods, (avocado, flax, peanuts) contain phytosterols, which compete with cholesterol for reabsorption sites in the intestine, thus increasing cholesterol elimination. Take home tip: eat higher fiber foods like apples, oats, beans, lentils, leafy greens and consider including avocado, flax and peanuts.

It gets a bit more complicated because you’ll hear about more than one type of cholesterol (total cholesterol reflects the sum of LDL and HDL in lipid profile blood work). Vastly simplified, LDL is a blood-borne vehicle which carries lipids and cholesterol (sloppily) out to the perifery for use in cellular metabolism and repair. The HDL vehicle returns to the liver picking up scraps of cholesterol stuck to the insides of blood vessel walls on the way. Higher HDL levels are good, because it correlates with decreased heart disease risk (you’ll want it high, remember H for high HDL). If one’s levels of LDL creeps up, this is concerning because more cholesterol and fatty acids could get dropped in the blood vessels. Narrowing and hardening of arteries due to plaques, drive up blood pressure and risk of atherosclerotic events such as heart attack and stroke. (So you want it low: remember L for low LDL). Make sure that you know your ratio of HDL to LDL (different for men vs women, but around 3.5 is good). Total cholesterol is a less precise number.

There are a number of tactics to decrease risk of atherosclerosis and improve one’s health span. The simplest one is to go on statins, also known by the following terms: atorvastatin (Lipitor), fluvastatin (Lescol XL), lovastatin (Altoprev), pitavastatin (Livalo), pravastatin, rosuvastatin (Crestor) and simvastatin (Zocor). Statins are a class of pharmaceuticals that block the creation of cholesterol in the liver, thus decreasing their overall level in the blood. They have been researched to be effective in their short-term goal of cholesterol reduction, but they are a life-long commitment of medication. Many question their side effects (myalgia, or muscle pain for some, low tolerance in others) contraindication in pregnancy, and a possible blinding effect to more overarching issues like poor nutrition or a sedentary lifestyle.

If the simplicity of taking a drug can distract us from making decisions that lead to longer term health, what happens when we choose not to use it any more? What habits are we grooming? Perhaps different lifestyle choices can be used collaboratively with statin drugs, to reduce dependence on Big Pharma and turn our attention back to creating our own healthy lifestyle. Enter: Exercise. Free, no negative side effects and many additional benefits.

Exercise and effects on Cholesterol:

We have a love-hate relationship with exercise (OMG why?!) More on this in another post, but for now let’s look at how exercise affects cholesterol levels. I’ll define exercise here as “movement to increase heart rate and respiration to meet increased activity-induced metabolic demands”.

Mechanisms are a bit murky, but it seems that exercise changes the size of LDL to make them less likely to stick on vessel walls, and increases transportation of LDL to the liver, expediting elimination. A metastudy suggests protective results of exercise are seen when folks exercise for at least 150 min/week, 5 X a week. This is a bare minimum. I suggest at least double that. Sitting is the new smoking - actually, don’t do either, they are both associated with increased risk of atherosclerosis.. (I recognize the irony of sitting to type this, I am looking forward to getting off my butt and going cross country skiing). Also, more intense exercise is more health-protective than moderate intensity, and both aerobic and resistance training are effective modalities in changing cholesterol levels.

“But I don’t have time to exercise…”

Actually, No - you don’t have time to be sick.

Though it’s much easier to take a pill than change your lifestyle and priorities, statins have a long list of inconvenient side effects (common ones are headache, muscle ache, flushing, drowsiness, dizziness, GI upset, rashes, and less common ones include hair loss, inflammation and sexual dysfunction). Plus there’s cost, medical appointments and insurance involved. Increased activity is free, available to everyone, and have very convenient side effects such as improved sleep, muscle tone, mood, bone mass, resilience, immunity, lower weight, blood pressure and stress levels, among many others. Reprioritizing to include more vigorous activity in your life is a choice that will have many long-lasting positive effects on your health.

From where I stand, if you are dealing with a diagnosis of dangerous cholesterol levels, statins are an effective and safe-enough-for-most quick fix. But it’s not the best long-term choice. Updating priorities and habits to add vigorous enjoyable movement to your life will have effects above and beyond cholesterol levels. And this is only one side of the coin - healthy food choices (a few quick tips above) are also very important.

Brainstorm about how to add more enjoyable vigorous playtime to your life to create your own joyful healthy lifestyle, minimize dependance on pharmaceuticals, and enjoy energetic spill-over of all the healthspan benefits statins cannot offer.

A heart-felt commitment: Exercise

Well ‘tis the week of Valentine’s Day, and all it’s hearty associations. Here are some ways to show love to the most important heart in your life - your own.

How does exercise improve our heart health? In so many ways. Here are three biggies.

Cardio means heart, and vascular means vessel. Therefore, the cardiovascular system includes both the heart muscle itself, and all the vessels (arteries, veins and capillaries) through which the blood flows. Exercise affects many things that improve the function of this system of pumps and tubes, and the hormonal milieu in which it works.

We’ll start with the main pumping station - the heart itself. Made of specialized muscle - cardiac muscle - composed of cardiomyocytes (cardio = heart, myo = muscle, cyte = cell), spontaneously generate their own electrical impulses. Heart cells in Petri dish will beat by themselves, and when they grow to touch each other, they beat in synchrony by sharing their electrical waves across their cell membranes. In our own hearts, we have an inner pacemaker poetically called “The Bundle of His” and the “Purkinje fibers”. Go and nerd out on these terms , but for now, I’ll simply say these structures coordinate our cardiomyocytes and keep our heart beating regularly day in, day out until we die (or need an artificial replacement pacemaker). Fibrillation is when our inner pacemaker loses control and all the cardiomyocytes start beating independently. The heart just quivers uselessly, and the owner suffers a heart attack. A defibrillator shocks and resets the inner pacemaker to reorganize synchronicity, keeping the owner alive until the paramedics get there. This is why first aid classes now involve training on an AED or an Automated External Defibrillator.

Strong muscles are more efficient and squeeze more powerfully. By performing aerobic (with air/oxygen) exercise that challenges us past our comfort zone, we forcibly require our cardiac muscle to pump more blood through the lungs and thence to outlying tissues meeting the increased oxygen and nutrient requirements. The heart, like any muscle, will rise to repeated challenges and hypertrophy (become larger). Unchallenged muscles atrophy (become smaller), and cardiac muscle is no different. Cardiac atrophy is not a good idea, so regular exercise is needed to maintain cardiac muscle mass and performance. A general indicator of good heart health is a low resting heart rate (50 - 60 beats per minute), indicative of powerful and efficient cardiac muscle. Take your resting heart rate when you have just woken up and are still lying in bed - here’s how, and here’s a comparison chart. There are exceptions due to medications like beta blockers and various medical conditions.

Take home message #1; perform daily aerobic exercise that challenges your heart muscle to maintain it’s size and efficiency.

The other part of the system are the blood vessels. Arteries move oxygenated and nutrient-filled blood outwards to the peripheral tissues. Capillaries in the tissues are so delicate that O2 and nutrients filter out toward the cells and cellular waste products and CO2 diffuse back in. Veins collect blood with CO2 and waste products and return to the core for purification via lungs, kidneys and liver. Then the whole process starts again. This is a massively simplified overview of course, but you get the idea of circulation.

As with any system of pipes, restriction of flow causes problems, so maintenance of smooth healthy vascular tubing is crucial. Your arteries are muscular (a variety called “smooth muscle”) and complex triple-layered tubes that contract, dilate and secrete slippery substances to keep their inner walls clean. Exercise increases the level of nitric oxide in the arteries, maintaining a flexible and open lumen, thus enhancing blood flow. Aerobic exercise causes the heart to push more blood through the tubes and flushes the system, cleaning the insides of the vessels and reducing risk of build-up. What might build up? Sticky substances like Low Density Lipoproteins (LDL), platelets (clotting factors) and trapped blood cells may collect inside the vessels if they are damaged due to inflammation. Consistent flushing helps keep things flowing. These principles apply especially to the little arteries that feed the heart muscle itself - the coronary arteries. Constriction of the coronary arteries is called Coronary Artery Disease, or CAD and can lead to heart attacks. Exercise decreases this risk.

Take home message #2: daily exercise boosts blood flow by flushing our blood vessels and increases the presence of nitric oxide which keeps vessels open and slippery.

A more general effect of exercise on our system involves stress reduction. Exercise is shown to reduce the amount of stress humans typically perceive. Whether is it’s due to a reorganization of our hormonal response (cortisol/adrenaline) or simply the feeling that we have “done something” (which is mentally relieving) is still up for debate. Our sleep improves when we physically tire our bodies from regular exercise, and sleep is when we repair ourselves to become stronger and more able to face our challenges; mental, physical and emotional. Stress hormones released during negatively stressful situations can depress the nitric oxide in our arteries and increase other inflammatory substances that may rub away at our inner vessel linings to increase the risk of cardiovascular injury and events.

Take home message # 3: daily exercise is a way of inhibiting stress-response chemicals, lowering the risk of damage to our cardiovascular structures.

Make a daily date for 30 - 60 minutes of heart-rate boosting exercise for a long, happy and heart-felt commitment to your cardiovascular system.

Every day is Valentines Day when it comes to your heart!

That's a stretch...

Ahhh, stretching. That thing that feels so good, but no one has time for.

As a Fitness Professional, I’ve witnessed countless times when folks work their butts off in class, sweating and strengthening, and then disappear before the end (citing ‘lack of time’) avoiding the post-workout cool-down and stretch. The last part of the workout is sacrificed by a perception that it is less necessary. (I’d argue that it’s not ‘lack of time’, but ‘lack of time-management’ that’s truly the culprit, but hey…) Hence the second part of my career as Massage Therapist - stretching people back out, after they have contracted themselves into a state of pain and injury. We can get away with the perception that stretching is unnecessary for only so long (usually our 30’s), until our bodies become less elastic and start to give us musculo-skeletal clues that a lifetime of contraction without extension isn’t beneficial. Joint issues, imbalances, uneven tendon and ligament wear and tear, low back pain and more all stem from a lack of elasticity and length in the tissues. Although you’ll probably never be able to put your leg behind your head again like you did when you were 8, boosting your flexibility will make life activities more easy and fluid, enhance balance and increase active range of motion.

What is stretching? For the purpose of this post, I’ll define it as an activity or movement that returns a part of the body to a lengthened and extended resting position. For example after sitting for many hours at a computer our hip flexors (muscles that bring our leg toward our chest) have been held in a shortened position. Because they attach to our anterior lumbar vertebrae, if they are not lengthened back out, we increase the risk of low back pain.

How does it benefit us? More flexible tissues allows our life more lightness and ease. It’s wonderful to have the shoulder mobility to reach backwards for something, or lift our foot up to clamber over a boulder on a hike without worrying about it. Stretching creates more mobility around joint, reducing wear and tear and the risk of injury. Decreased pain and tightness during activities, and increased reach and ability ripples out into our life, reducing our stress levels and boosting our health span.

Why is stretching so uncomfortable? You may be overdoing it. The discomfort comes from pain receptors in the muscle when it is overstretched. Muscles are also attached to tendons and tendons should not stretch, so being aware of how to address stretching correctly and safely is important. Dehydration can also be a factor. (see my previous post).

How do I stretch pleasurably? Warm up a bit first. Think of your muscles like uncooked spaghetti. Cooked spaghetti is much more mobile. Even 5 minutes of movement will increase the metabolism in the muscle and move some blood through. Irrigated and warm tissues are pliable and more willing to accept length. Use the idea of green-, yellow-, and red-flag pain markers. Move yourself slowly into the yellow-flag stretchy-discomfort feeling, and then slow down your breath to access your calming parasympathetic nervous system. Don’t let yourself go into red-flag pain - your muscles will contract to protect themselves. Moving slowly bypasses the muscle spindle reflex - a reflexive contraction in your muscles that protects from damage due to a sudden unexpected lengthening. Hold the stretch for 30 seconds. Stretch after your work out, it’s not so important before.