As stated on the Nutrition Class post I created a few of days ago, I will be sharing my responses to nutrition topics. This post includes my initial response to a question posted by the professor and comments I made to others’ responses to that same question.
The professor posted the following:
“The focus of this discussion is controlling cholesterol levels. Two common initial actions for controlling cholesterol are diet modification and activity goals. For your initial post, include two of the following:
- one additional initial action/goal, and/or
- one specific dietary modification, and/or
- one specific activity modification
”
My Initial Response
[ME:] Cholesterol is ESSENTIAL for the body which is why we rely on a very sophisticated system that produces it. It is well known that dietary cholesterol has VERY little impact (if any) on cholesterol levels.
There are dietary changes that can be made, however to reduce cholesterol levels in the body. I am not referring to LDL or HDL, but actual cholesterol.
The main dietary change is an increase in fiber consumption. The liver creates bile salts and uses cholesterol delivered to it via HDLs as a precursor. Bile salts are then secreted to emulsify fat in our intestines (during lipid digestion). Because CHOLESTEROL IS ESSENTIAL (as stated earlier) to our health, the body has evolved a bile-salt reabsorption mechanism. This mechanism prevents loss of bile salt through excretion.
Soluble (unabsorbed) fiber binds these bile salts tightly making it extremely hard for them to be reabsorbed. The liver is then forced to create more bile salt and use free cholesterol (raises HDL levels because of need to deliver cholesterol to liver for this production).
A secondary change in diet would include an increase in phytosterols (plant hormone-like molecules) that are VERY similar in structure to cholesterol and compete against cholesterol in various places in the body.
And as a final dietary change, the elimination/reduction of trans/hydrogenized and saturated fats should be considered as well as an increase in polyunsaturated fats (most notably omega-3 from plant sources and ESPECIALLY from cold-water fish). DHA and EPA (only found in animals – ie: cold water fish) are predisposed to be used exclusively for anti-inflammatory, brain development, and heart health purposes.
Very few studies link consumption of cholesterol with an increase of LDL. But MANY RECENT studies directly link ingestion of trans/saturated fats with increase in LDL.
As for physical activity…
Really, ANY physical activity will have a positive effect on cholesterol levels. I am a HUGE fan of walking and strength training (no jogging, biking, etc). I enjoy jogging and biking, swimming, etc. but do not engage in them often. A recent study found that doing a series of 20m sprints over 30 seconds was just as beneficial as running nonstop for 20 mins – in regards to cardiovascular disease risk factors (one of which is LDL/HDL levels).[1] The beauty, of course, is that one can get the same result in far less time (in 15% of the time) & with about a quarter of the calories.
But really, ANY increase in physical activity will have a VERY positive effect on the body… especially heart related, including cholesterol levels.
References:
[1] http://www.medicalnewstoday.com/articles/221337.php
Discussion Based on my Initial Response
[STUDENT 1:]I agree that a diet in high saturated fats, will be a huge detriment on cholesterol levels. There are many types of healthy fats out there that would help us achieve overall well being and good health (such as Omega 3 and 6 fatty acids). But unfortunately in todays society, these foods are less commonly consumed, whereas diets high in fat are.
And I agree that any form of physical activity is good. However, I do believe that for someone with high cholesterol levels should start with cardio exercise before any strength training. Cardio exercise helps cardiovascular health which in turn would help lower cholesterol levels.
[ME:]STUDENT 1:
Great point about today’s average diet.
I also agree that cadio helps CV system, but so does weight training. Recent studies suggest weight lifting could do just as much as low-mid intensity cardio.[1][2]
No one doubts physical activity is good for our heart health, but literary reviews are inconclusive as to whether physical activity has any direct effect on cholesterol.[3] This is primarily because when one works out regularly, fat is burned & some weight is lost. It is unclear if this weight loss is a contributing factor to the reduced cholesterol.[4]
Here is an interesting quote from an article on WebMD: “Doctors used to believe it was only aerobic, endurance exercise that improved levels, but it turned out that we were wrong. A number of studies on resistance training have shown very powerful effects on cholesterol metabolism”[5]
My main point was that “ANY physical activity will have a positive effect on cholesterol levels”.
Frankly, I do not believe man was build for long distance running/jogging. There is no adaptaive advantage to it. I can’t think of a single animal on earth jogs long distances. They all walk to where they need to or run as fast as they can to get away from a predator or to catch prey. Sprinting is something we are supposed to do. This could be a possible explanation as the results of the reference I used in my original post where sprinting short distances for a few seconds resulted in the same cardiovascular benefit as jogging for 20 mins.
Reference:
[1] http://www.ncbi.nlm.nih.gov/pubmed/20885204
[2] http://www.medicalnewstoday.com/articles/213813.php
[3] http://www.unm.edu/~lkravitz/Article%20folder/cholesterol.html
[4] http://weighttraining.about.com/b/2009/02/17/does-weight-training-lower-cholesterol.htm
[5] http://www.webmd.com/cholesterol-management/features/exercises-to-control-your-cholesterol
[STUDNET 1:]You have very valid points of views. I think the main thing to remember (besides being physically active has many benefits to health) is that diet directly effects cholesterol levels (among other things). Below is a site I found for foods that are better in helping tweek cholesterol levels. Because what we eat directly effects our bodies conditions.
1.) http://www.mayoclinic.com/health/cholesterol/CL00002
[ME:] I WHOLEHEARTEDLY agree with you that our diet is DIRECTLY linked to our health.
The site you provided is inline with my belief that saturated and trans fats should be eliminated from the diet. It parallels comments I’ve made on previous posts that indicate we should all increase our fiber, DHA/EPA/omega-3, and phytosterol/phytohormone intake.
The site also tiptoes around the dietary cholesterol issue… the issue I am contesting (and have been ever since we read the chapter on fat and now the one on cholesterol). The Mayo Clinic site says “Cut back on the cholesterol and total fat — especially saturated and trans fats — that you eat. Saturated fats, like those in meat, full-fat dairy products and some oils, raise your total cholesterol. Trans fats, which are sometimes found in margarines and store-bought cookies, crackers and cakes, are particularly bad for your cholesterol levels. Trans fats raise low-density lipoprotein (LDL), the “bad” cholesterol, and lower high-density lipoprotein (HDL), the “good” cholesterol.”
Notice there it NEVER mention that cholesterol you eat increases cholesterol levels. But it does link trans and saturated fats to increased LDL levels in the blood. Harvard’s School of Public Health explains the point I’m trying to make in the following way:
“Although it is still important to limit the amount of cholesterol you eat, especially if you have diabetes, dietary cholesterol isn’t nearly the villain it’s been portrayed to be. Cholesterol in the bloodstream is what’s most important. And the biggest influence on blood cholesterol level is the mix of fats in your diet—not the amount of cholesterol you eat from food.”[1]
References:
[1] http://www.hsph.harvard.edu/nutritionsource/what-should-you-eat/fats-and-cholesterol/
My Comments on Other Students’ Initial Responses
(First Conversation)
[STUDENT 1:]Lets say I had just received results from a cholesterol blood test, and it indicated that my LDL was high and HDL was low, I would immediately make some changes! I would first modify my diet. Specifically my egg consumption. I can eat eggs daily, and since egg yolks are high in cholesterol, that would be significantly decreased. After reading the assigned chapters, I learned that egg yolks should be limited to two per week. Secondly, I would modify my physical activity, specifically cardiovascular activities. When I was reading the interactive ebook (understanding nutrition, on line vesion) on page 615 it states “Participate in at least 30 minutes of moderate-intensity endurance activity on most days of the week”. I think I would double it to 60 minutes, as often as I could just to stay extra healthy!
For my fellow egg junkies, I thought this was kind of cool:
http://www.cholesterolcholestrol.com/egg-cholesterol-cholestrol.html
[ME:]STUDENT 1:
I LOOOOOVEEE EGGS. I knew they were an awesome source of protein but was very excited to have read that they were considered to have a 1 PDCAAS.[1] It is such an awesome/recommended source that eggs were chosen as the image for chapter 6 which talks about proteins.
I stopped eating yolks, however, not because of their cholesterol content, but contaminants. Most contaminants are fat soluble. When toxicity studies are done on chickens, it is the egg yolks that are examined.
I may get a lot of heat for this comment, but I am not scared of dietary cholesterol. I completely agree with scientists who regard the limitation of cholesterol as being based on old research that is being challenged by newer research.[2]
In fact, our book says “People with high blood cholesterol, however, may benefit from limiting daily cholesterol intake to less than 200 milligrams”.[3] It also stated that an egg can have a little over 200mgs of cholesterol.
My response: In NO WAY did the book correlate that eggs were linked. In fact, it stated that “most foods that are high in cholesterol are also high in saturated fats, but eggs are an exception.”[3] It merely puts eggs into “cholesterol-containing category” and says “limit its intake”. :( not cool for “fellow egg junkies”.
Please note… I am not arguing that people w/ high cholesterol can consume >200mg of cholesterol/day; I am arguing that there is little evidence that identify eggs as an antagonist.
The body is capable of creating the cholesterol we need (or that it “thinks” it needs). Researchers, in fact, know this and is why the most popular cholesterol-lowering drugs inhibit cholesterol production by the liver. It is thought that we evolved from apes… They have a similar cholesterol requirement that we do, yet their diet consists of no cholesterol.
Cholesterol is REQUIRED by (at least) every single cellular membrane (trillions in the body) constantly. An irregular production or LDL/HDL mobilization/utilization is at the root of cholesterol issues (in my opinion).
:) That’s the beauty of science, we can all agree to disagree and be partially right.
References:
[1] Textbook Appendix D (pg D-1)
[2] http://informalscientist.com/eating-eggs-raises-your-cholesterol-or-does-it/
[3] Textbook pg 152
[STUDENT 1:]Kevin-
“:) That’s the beauty of science, we can all agree to disagree and be partially right.” <- Well said! I was of course speaking (typing) in a hypothetical sense (if my blood cholesterol was high). But until then, I enjoy my egg yolks! Yum! But overall my egg addiction is really for the egg whites, I could separate the yolk, but I would feel like I was wasting. And I feel that the chickens are here on earth to feed us, as well as their eggs. I also just read about PDCAAS, that you wrote about. Thanks for sharing that.
Now your reason for not eating the yolk is something I have not looked into. But I think I will. I had not thought of the yolk being contaminated. Interesting! And with that being the case, I can definitely agree with you for excluding them.
Thanks for sharing :)
[STUDENT 2:]STUDENT 1,
It is nice to hear someone comment about not wanting to WASTE egg yolks. I am not a fan of eggs, but AM a FAN of NOT wasting things. When I make recipes that call for egg whites, I cook the yolks and feed them to my dogs. They love the treat. (Hopefully, it does not effect their cholesterol :))
[STUDENT 1:]Hi STUDENT 2
Good idea on giving it to the dogs! I do the same thing when I, or anyone in my house, eats a can of tuna. We pour it over their dry food. Makes for a yummy treat for them, so it seems. I had not considered giving the yolks to them. It will have to be something that I try in the future! Then I wont feel like I am wasting. Good tip :)
(Second Conversation)
[STUDENT 1:]High cholesterol, specifically high LDL cholesterol, is a serious risk factor that can lead to heart disease. The two main initial actions for controlling cholesterol are diet modification and increased physical activity. I think that in addition to the two initial actions, people should focus on increasing their intake of soluble fiber. Soluble fiber reduces LDL cholesterol and increases HDL cholesterol. Higher levels of HDL cholesterol and lower levels LDL cholesterol correlate inversely with the risk of heart disease. Foods that are high in soluble fiber include; oatmeal, bran, barley, fruits and beans. There are many ways a person could increase their intake of soluble fiber. They can have oatmeal for breakfast, or a sandwich on whole grain bread, or add things like an apple or beans to their salad.
[ME:] Awesome recommendation, STUDENT 1.
Fiber really helps in the maintenance of cholesterol. Oatmeal, as you mentioned, is an excellent source of fiber. :) Luckily, so is a sweet fruit that is easy to carry along - the apple. The skin contains pectin, one of the best natural fibers in existence. The skin of one apple can contain as much fiber as a single serving of oatmeal.
An added advantage to pectin is that it serves as a prebiotic (food for intestinal flora).[1]
References:
[1] http://www.biomedcentral.com/1471-2180/10/13/abstract
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