Tuesday, October 25, 2022

Higher Cancer Rates in Men and Alzheimer Rates in Women Due to Genes

It's interesting to read the following two articles together:

Higher Cancer Rates in Men Likely Due to Biological Differences
X Chromosome-Linked Enzyme May Explain Women’s Higher Alzheimer’s Incidence

While men and women have different health-related characteristics, they don't account for the large differences in cancer and Alzheimer incidence rates. This implies that regardless future progress in medical sciences (barring significant gene editing), there will always be more women than men in a high-age group, and at the same time, more of these women suffering from Alzheimer than men unless this disease is completely eliminated.

Monday, May 2, 2022

Acupuncture, TCM, or alternative medicine in general will be fully deciphered

M.D. Anderson (MDA) Cancer Center, the best cancer hospital in the US, posted a message to Facebook, "Pressing pressure points and energy channels that we can’t see may help with headaches, nausea and anxiety." Most readers cheer for or agree with the message. But one reader, a former MDA employee and also cancer survivor, criticized MDA for bringing alternative medicine into its toolbox when even the terminology used by alternative medicine is unscientific, thus tarnishing the image of MDA as a prestigious hospital. He says "What energy channels? What basis is there for the existence of these channels? I note that “Qi” is always placed in quotes. Why? If it’s something that can truly be manipulated, it ought to have an actual name and evidence of its existence. If not, then MD Anderson ought not be promoting something that has no basis in fact."

As usual, this type of questioning leads to a hot debate, and the original poster (MDA) decides to filter out all messages except this reader's initial message and MDA's direct response. My long response to the reader's message is among those filtered out as well. But I'd like to present it below.

The terms "qi", "energy channels" etc. indeed sound pre-scientific. But lack of understanding of the real mechanisms and temporarily using these terms should not blind us from tried-and-proved efficacy of acupuncture to improve certain symptoms, most notably pain. Your attitude is very understandable, and I'd like to compare that to Einstein's toward the probabilistic nature of small particles such as electrons; his "God does not throw dice" implies that he believes the true, non-probabilistic, definite time and place of any particle will eventually be revealed and the quantum phenomena are just one stage in the history of science. Well, we don't know if he'll eventually be proven right on that but we're quite sure many pre-scientific-sounding terms and the theories associated with them in alternative medicine are being rendered unnecessary. Just like we no longer say four humors of a human body, we're gradually substituting pharmacological findings for TCM's classification of herbs into hot-cold-mild-sweet-... The latter can still be retained for pedagogically convenient tools or mnemonics. As to acupuncture, for some reason, the study of the mechanism is far slower than pharmacology. (I recall reading an article about a Chinese Academy of Science biophysicist's research in 1980's.) But just because we don't know the true nature of it doesn't mean we should stop using it if it doesn't cause serious side effects and it works most of the time. (For instance, one pressure point, called 风池--I have to look up the English name--has remarkable reproducibility in temporarily relieving headache.)

The gold standard of double or single blind trials has its limitations, particularly when it comes to pain management (and I think one more field, psychiatry). It's almost impossible for the trial participant to not know if he's in control or intervention group. Instead of blindly blaming reported effects of acupuncture as placebo effect, other strategies such as N-of-1 trials may be adopted. For all its shortcomings, N-of-1 bypasses the said problem of blind trials and most importantly, tests a specific individual's response. When it comes to pain relief, psychiatric treatment, and probably more, it's a norm not exception for one intervention to be valid for John but not for Jack. Acupuncture falls into this category.

(By the way, I'm sorry to hear that you had cancer but I'm glad it was cured or is in remission. I think it's you that I worked with 16+ years ago on the leukemia project. Back then MDA probably did not have integrative medicine. But I think it's a welcome addition, because it helps relieve certain symptoms.)

Sunday, August 29, 2021

How to read medical statistics correctly?

The Bright Light News website claims to be "Shining a light on the Covid-19 narrative. Investigate. Facts matter." An article on the website dated August 23, based on statistics from the British government, is titled "More Fully Vaccinated Dying of Delta Variant Than Unvaccinated". This conclusion is surprising, and on the surface of it, is difficult to explain. I checked the original data of the British government website (see the small print after Source for the URL), and found that the Bright Light article quoted the data correctly (see Table 5 on pp.22-23): In the survey, 57.1% of the people who died of the Delta variant of the coronavirus in England were completely vaccinated, and 32.8% of those have not been vaccinated. So where is the problem?

The reality is that the vast majority of the people in the UK, about 90%, are fully vaccinated. Therefore, the ratios 57.1% and 32.8% cannot be compared in isolation. If the former were 90% and the latter 10%, i.e. matching the ratios of the vaccinated and unvaccinated population, and if there is no other factor that confounds the matter, we would be able to conclude that vaccination does not increase or decrease death rate; if the former were to exceed 90%, the latter less than 10%, then it would be that vaccination will increase the chance of dying. In case this is not clear enough, let's see another example. Imagine you have 1000 apples, 900 of them being red and 100 green. If there are a total of 10 apples that have gone rotten, 9 of them red and 1 green, and suppose there are no other confounding variables related to rotting of apples (e.g., some apples are kept in the refrigerator and others are not), then we can say that the color of the apple is unrelated to whether it rots, but we cannot say "Look! Red apples are more likely to rot than green apples, in fact by 9 times more likely!" If 6 out of 10 rotten apples are red and 4 green, we can't say that the color of the apple is unrelated to whether it's going bad or not. On the contrary, we should say that red ones are less likely to go bad, even though 6 is greater than 4!

Medical students must receive formal training in epidemiology. I have read such a textbook, in which there're plenty of such logical questions. But the case above is much simpler than the exercises in this type of textbook, and no special training is required to draw correct conclusions. Sadly, the website that claims "Shining a light" is lacking in basic logical thinking and misleads gullible people into vaccination rejection.

Saturday, March 6, 2021

Choline helps reduce Alzheimer's risk for certain people: a new study

The following is a bullet-point summary of a recently published research. Specifically, this is a layman's summary of a medical news article, "APOE4 Alzheimer’s Risk Could Be Abated by Common Dietary Supplement", published on ClinicalOMICS magazine, supplemented with other information such as that on Wikipedia.

  • The primary authors of the published research article work for MIT.
  • People carry APOE (Apolipoprotein E) genes, which are involved in the metabolism of fats. The APOE2 variant is good, 3 neutral, 4 bad in terms of risks for late onset Alzheimer, as well as cardiovascular diseases. 14% of the general population, but almost half of Alzheimer's patients, have APOE4. Most people have APOE3.
  • The Wikipedia page for choline states that "[s]tudies observing the effect between higher choline intake and cognition have been conducted in human adults, with contradictory results". And WebMD article says "Insufficient Evidence for ... Alzheimer disease". But the authors of this new study said "those trials were not targeted specifically to people with the APOE4 gene".
  • "[C]holine supplementation ameliorated the APOE4-induced lipid defects... [M]ost people don’t consume that much [of recommended choline]... [P]eople who carry the APOE4 gene may benefit from taking choline supplements... The APOE4 carriers are more susceptible to choline deficiency."
  • According to Wikipedia, beef liver contains the most choline per unit weight, 418.22 mg/100g, followed by chicken liver (290.03 mg/100g), hen egg (251.00), "wheat germ, toasted" (152.8), bacon (124.89), soy bean (115.87), pork loin (102.76). Vegetables are not rich sources of choline; the highest are brussels sprout (40.61) and broccoli (40.06), followed by cauliflower (39.10).
  • Choline is not considered vitamin. Multivitamins you may be taking do not contain choline. Severe deficiency, which is unlikely, "causes muscle damage and non-alcoholic fatty liver disease" according to Wikipedia.

Thursday, July 16, 2020

African/African-American and Non-Finnish European populations more susceptible to COVID-19

According to New insights into genetic susceptibility of COVID-19: an ACE2 and TMPRSS2 polymorphism analysis published on 15 July 2020 in BMC Medicine by Cleveland Clinic researchers,

"the distribution of deleterious variants in ACE2 differs among 9 populations in gnomAD (v3). Specifically, 39% (24/61) and 54% (33/61) of deleterious variants in ACE2 occur in African/African-American (AFR) and Non-Finnish European (EUR) populations, respectively (Fig. 1b). Prevalence of deleterious variants among Latino/Admixed American (AMR), East Asian (EAS), Finnish (FIN), and South Asian (SAS) populations is 2–10%, while Amish (AMI) and Ashkenazi Jewish (ASJ) populations do not appear to carry such variants in ACE2 coding regions"

If needed, Figure 1b can be viewed here. This research of course mean Latinos or Asians can take it easy when it comes to prevention. In fact, the outbreaks in Brazil and India appear to contradict this research. But this research is about genetic susceptibility, not considering the social factors that may play a greater role, such as whether people wear face masks and keep social distancing.