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Recently I viewed a short video that recommended reducing sugar in our diets because new research suggests that sugar causes heart disease. What is the status of this research? How convincing is the evidence?
Greg Bernhardt said:Here is a study from back in April
Added Sugar Intake and Cardiovascular Diseases Mortality Among US Adults
http://archinte.jamanetwork.com/article.aspx?articleid=1819573
btw, can you post the video?
gravenewworld said:Sugar is directly linked to reprogramming the entire way your cell functions (cancer, diabetes, AZ are all characterized by abnormal glucose metabolism/consumption). I know I sound like a crazy person for constantly talking about the O-glcnac modification on these forums, but it is absolutely a thing of beauty--and I wouldn't be surprised that years from now it would be Nobel worthy.
First, some background. Protein physiology is almost always shown in cascade cartoons as being like on/off switches via phosphorylation, however it is becoming increasingly clear that this is a grossly oversimplified model. The O-glcnac modification (which is the addition the sugar N-acetylglucosamine) occurs on proteins at Ser/Thr residues in proteins and many times these Ser/Thr residues are the same exact sites where protein phosporylation occurs. If you can start to see the bigger picture, the significance of O-glcnacylation can not be understated. It behaves as a 'cap' almost to block sites from being phosphorylated on proteins. In otherwords, our models of protein physiology are vastly oversimplified because you are ignoring the fact that proteins should have multiple sites for not only phosphorylation but also for O-glcnacylation (plus mutiple combinations thereof between the two) and need to include some sort of extremely complex cycling mechanism between both phosphorylation addition/removal and addition/removal of O-GlcNAc.
Consider how many hundreds, if not thousands, or kinases and phosphatases that exist in order to regulate the phosphorylation status of the proteome. Contrast that to the O-glcnac modifcation which is controlled by only 2 enzymes--OGT which adds it to proteins and OGA which removes it, that's it (why it's mechanism and discovery is so beautiful). We now know that almost every cytosolic protein is modified by O-glcnac or is very likely to be modified by O-glcnac. O-glcnac/OGA/OGT can be viewed as a master, master regulator of almost all cellular function.
So what does this have to do with the topic? The substrate for O-glcnacylation, which is UDP-GlcNAc-- is a direct by product of glucose, and more specifically, glycolytic metabolism. In otherwords, there is a very direct link between sugar consumption and metabolism, regulation of the proteome, and disease potential through O-GlcNAc.
How could disease be possible though disturbing sugar metabolism? Well, the O-GlcNAc modification is known to regulate the function, localization, and a myriad of other things of some very, very interesting proteins.
For example, O-GlcNAc is a master regulator of writing your epigenetic code--both DNA methylation and regulation of histone dynamics:
http://www.ncbi.nlm.nih.gov/pubmed/21045127 (regulation of the histone code by O-glcnac)
http://www.cell.com/molecular-cell/abstract/S1097-2765(12)01055-6 (regulation of DNA methylation dynamics via o-glcnac)
It stands to reason that overtime, excess sugar consumption could somehow perturb how your genes are expressed, and that could possibly be through the regulation of the epigenetic code through O-glcnac (again a by product of glucose metabolism). In fact, the evidence is increasingly pointing in this direction, and it could very well be why altered sugar metabolism is a very common observation for major diseases like cancer, diabetes, alzheimer's, and heart disease.
In fact, here's a review on O-glcnac signaling in the cardiovascular system
http://circres.ahajournals.org/content/107/2/171.abstract
Also may be of interest:
http://www.ncbi.nlm.nih.gov/pubmed/20410435
Heart complications in diabetics and pre-diabetics is a well known and observed phenomenon and the link between the two could very well be sugar, and more specifically on a molecular level this could be via O-glcnac. There is a lot of very interesting emerging evidence linking sugar consumption to major disease on the molecular level.
Interestingly though, during times of stress (ischemia/reperfusion injury), maybe massive doses of sugar could be used in a cardioprotective manner since stress directly signals for the upregulation of the metabolic pathway that feeds into O-GlcNAc (but too much of a good thing overtime may be bad):
http://www.ncbi.nlm.nih.gov/pubmed/24630721
I wouldn't be surprised if 20-30 years from now we will have shown that sugar is in fact more damaging to your health than consumption of saturated fats.
One often smells ammonia on the breath as a result. This is what I experienced in heavy exertion on my bicycle.lavinia said:"Incidentally - here's what happens if you completely deprive someone of glucose: First, glycogen stores in the liver and muscle are broken down to give glucose - glycogen is a polymer of glucose and is stored in these sites. Carbohydrate loading by marathon runners is done to maximize these stores, as they are the quickest way to get glucose into the blood. Once those stores are exhausted, the process of "gluconeogenesis" becomes increasingly activated. This process allows amino acids from muscle and other proteins to be converted to glucose. Fats can also be substrates for gluconeogenesis, but that process involves far more steps. The bottom line here is that a normal individual has jealously guarded homeostatic mechanisms for maintaining blood glucose levels.
There is evidence that consuming excessive amounts of added sugar can increase the risk of developing heart disease. This is because consuming too much sugar can lead to weight gain, high blood pressure, and inflammation, all of which are risk factors for heart disease.
No, not all sugar is bad for the heart. Natural sugars found in fruits and vegetables are not associated with an increased risk of heart disease. It is added sugars in processed foods and drinks that are linked to heart disease.
The American Heart Association recommends limiting added sugar intake to no more than 25 grams (6 teaspoons) per day for women and 36 grams (9 teaspoons) per day for men. However, the less added sugar you consume, the better for your heart health.
Reducing added sugar intake can certainly have positive effects on heart health. Studies have shown that decreasing intake of added sugars can lead to improvements in blood pressure, cholesterol levels, and weight, all of which are important for heart health.
Artificial sweeteners may be a good alternative for those looking to reduce their sugar intake. However, there is limited research on their long-term effects on heart health. It is important to moderate intake of all types of sweeteners, both natural and artificial, and to focus on consuming whole, unprocessed foods as much as possible for optimal heart health.