Ask Dr. Keith Roach M.D
What is LDL cholesterol’s relation to longevity?
DEAR DR. ROACH: I recently saw an article about how higher cholesterol levels (especially LDL) actually contribute to a longer life. I think that means if you don't have high blood pressure, diabetes, etc. I went online, and there are a few articles about this. Since I and some of my offspring have genetic high cholesterol (high HDL, and mine is borderline high LDL), I wonder what you think of these articles and studies. The article I read also says that very low LDL levels contribute to a shorter lifespan and that statins, as much as they are prescribed these days, are a scam of the pharmaceutical companies. I realize that some of this might be hype, but I'm not totally skeptical about this, either. I wonder about your take. — E.L.
ANSWER: I have read a great deal about the history of medicine, and have never thought that Western medicine has all the answers, nor even that everything we learn in medical school is correct. There have been too many times where a substance or procedure thought to be beneficial actually has been harmful, or vice versa, for a person with a sense of history to feel certain he or she possesses the truth. However, the evidence that high LDL levels are associated with increased risk of heart disease and decreased lifespan is so overwhelming that I feel comfortable saying that, for most people, higher LDL levels do not contribute to a longer lifespan, but the reverse.
Statins have been shown, in many different studies with many different populations, to have a net benefit, as long as the population is at high risk for the development of coronary artery disease.
There certainly are many opinions available on the Internet. Where I become very skeptical is when I see the opinions provided with a link to purchase supplements that do not have the weight of scientific consensus. That has so high a conflict of interest that I recommend being exceptionally wary.
DEAR DR. ROACH: I would like to know if collagen hydrolysate is really beneficial to joints and safe to take. Thank you. — N.L.
ANSWER: Collagen is an important structural protein in many tissues, including the cartilage that lines the joints. Breakdown in cartilage is a component of several diseases, so at first glance it might make sense that eating collagen, or taking a collagen supplement, could help this. There is some data to support this: Two small trials showed minimal benefit over placebo in improving joint function from taking hydrolyzed collagen.
Unfortunately, I really don't believe it. Collagen supplements are only a little bit of extra dietary protein, and the amount of collagen in a supplement is small compared with a good dietary source of collagen (chicken soup is a classic example, or bone broth, if you are trendy). The proteins are broken down into their amino acids and absorbed. (Hydrolysis is the process of breaking down proteins. Your body is very, very good at it due to the strong acids and enzymes in the stomach.) One study suggested that people who don't eat animal protein might get more benefit from collagen supplements than those who do. This suggests that there might be a role for relative deficiencies of amino acids present in collagen (lysine and proline are suggested in the literature on this subject), but I can't recommend collagen supplements based on physiology. *** Dr. Roach regrets that he is unable to answer individual letters, but will incorporate them in the column whenever possible. Readers may email questions to ToYourGoodHealth@med.cornell. edu or request an order form of available health newsletters at 628 Virginia Dr., Orlando, FL 32803. Health newsletters may be ordered from www.rbmamall.com.