Tuesday, September 11, 2012

Intermittent fasting

Improvements in coronary heart disease risk indicators by alternate-day fasting involve adipose tissue modulations.
16 obese subjects instituted an alternate-day fasting program (eat for 24 hours, then fast for 24 hours). Subjects lost Body weight (average loss: 5.7 +/- 0.9 kg) but not Lean body mass. They had lower LDL cholesterol levels & reduced Waist circumference.

Alternate-day fasting and chronic disease prevention: a review of human and animal trials.
Human trials support beneficial effects on HDL & Triglycerides. Animal studies support beneficial effects on Diabetes incidence, Cancer, fasting Blood glucose, Insulin concentrations, Total cholesterol, Blood pressure, & response to Myocardial infarction (Heart attack).

Saturday, August 4, 2012

Lying & Health

The study is not yet peer reviewed or published, but the headline caught my eye:

Study finds that avoiding lies can improve your health
http://www.usatoday.com/news/health/story/2012-08-04/honesty-beneficial-to-health/56782648/1?csp=34news - 1 group was instructed not to lie, the other served as the control. Researchers found that decreased lying was associated with better mental & physical health. Participants also reported that their social interactions went more smoothly.

... when participants in the no-lie group told three fewer white lies than they did in other weeks, they experienced, on average, approximately four fewer mental-health complaints and about three fewer physical complaints.
Personally, I seldom lie. If I do find myself wanting to lie, it prompts me to ask myself some questions. Why do I want to lie? Am I ashamed of what I'm doing? Am I trying to avoid some kind of conflict? If I am ashamed of what I'm doing, why am I doing it? Or maybe, how can I hide it better so that I don't feel the need to lie about it in the future? Why avoid conflict? Maybe conflict is the better option. Maybe through conflict I can test my beliefs & convictions or even convince the other party of something.

An example that comes to mind is lying about my eating habits. My wife's mother is always trying to get me to eat Fruit, but my currently favored hypothesis is that Fruit is not good for you. Rather than arguing with her & having her disappointed or frustrated, it might be easier to just take the Fruit & give it to someone at work or throw it away when I'm out of her sight.

Perhaps trying not to offend her is harmful, though. Maybe what I should do is to convince her. Sort of like yanking out a bad tooth, a brief, painful conflict will prevent greater amounts of stress & strife down the line.

Thursday, August 2, 2012

LDL & Mortality

So I stumbled on this interesting bit today & it got me researching:

This is in reference to Primary prevention (i.e. trying to reduce the risk of Cardiovascular disease in patients that don't have it yet). The Party Line is that Cholesterol is evil & lowering Cholesterol will save lives. So if a patient doesn't tolerate a Statin, why not just put them on some other drug that lowers Cholesterol? Any drug that lowers Cholesterol should save lives, shouldn't it?

Well, no.

As it turns out, there are a slew of studies showing that various other Cholesterol lowering drugs have either Neutral or Harmful effects:

Clofibrate lowered Cholesterol, but increased Mortality
http://www.ncbi.nlm.nih.gov/pubmed?term=6105515 - Lancet 1980

Explanation of the excess mortality is not apparent: a long term toxic effect of clofibrate, the possible consequences of reducing body cholesterol pools and, remotely, chance have all to be considered.” [emphasis mine]
Cholestyramine reduced Total cholesterol & LDL, but had no effect on All-cause mortality
http://www.ncbi.nlm.nih.gov/pubmed?term=6361300  - JAMA 1984

Clofibrate reduced Cholesterol by 9% but increased All-cause mortality (77 deaths vs. 47 deaths, P less than 0 .01)
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC483536/pdf/brheartj00224-0001.pdf - Br Heart J 1978

Gemfibrozil reduced Total cholesterol, LDL, Non-HDL cholesterol, & Triglycerides, but had no effect on All-cause mortality
http://www.ncbi.nlm.nih.gov/pubmed?term=3313041 - Frick MH in N Engl J Med 1987

So apparently none of these Non-statin interventions save lives, so they aren't recommended.

What about Statins themselves?


Meta-analysis: Statins have no effect on All-cause mortality
http://www.ncbi.nlm.nih.gov/pubmed?term=20585067 - Ray KK in Arch Intern Med 2010

Okay, okay. So we have pretty strong evidence that lowering LDL doesn't save lives, but lowering LDL prevents Cardiovascular events, so THAT is why we need to get everyone scared of Cholesterol.

Actually, no.

Pravastatin reduced CHD (Coronary heart disease) but did not reduce All-cause mortality; reduced CHD was NOT correlated with LDL reduction
http://www.ncbi.nlm.nih.gov/pubmed?term=9576423 - WOSCOPS trial in Circulation 1998

Did you get that? The reduction in CHD caused by Pravastatin was independent of LDL.

Here's another one:

Analysis of AFCAPS/TexCAPS data: Lovastatin prevented CHD in subjects with low Total:HDL ratios AND high CRP levels, but did not in subjects with low Total:HDL ratios and LOW CRP levels
http://www.ncbi.nlm.nih.gov/pubmed?term=11430324 - Ridker PM in N Engl J Med 2001

This seems to suggest that the reduction in CHD caused by Statins might be due to some kind of Anti-inflammatory effect, NOT due to effects on Cholesterol.

The next study didn't look at CHD or Mortality, but looked at Carotid-artery intima thickness (CIMT):

Simvastatin plus Ezetimibe lowers LDL more than Simvastatin alone, but has no greater effect on CIMT than Simvastatin alone
www.ncbi.nlm.nih.gov/pubmed/18376000 - Kastelein JJ in N Engl J Med 2008

In this study average LDL was 192.7 in the Simvastatin-only group & 141.3 in the Simvastatin-plus-Ezetimibe group. If lowering LDL is what improves Carotid-artery disease, why doesn't lowering LDL another 51 points give us any improvement?

To summarize:

  • Non-statin Lipid-lowering drugs aren't recommended for Primary prevention because they don't reduce All-cause mortality.
  • Statin drugs for Primary prevention don't reduce All-cause mortality.
  • Statin drugs DO reduce some forms of CVD, but this effect seems to be independent of their effects on LDL.

Wednesday, August 1, 2012

Fructose, Metabolic syndrome, & Fatty liver

Fructose induces Metabolic syndrome via increasing Uric acid in Rats
http://www.ncbi.nlm.nih.gov/pubmed/16234313 - Researchers performed several experiments. 1st, they saw that Fructose feeding induces Hyperinsulinemia, Hypertriglyceridemia, & Hyperuricemia. 2nd, they gave Fructose-fed Rats drugs to lower Uric acid levels & found that these drugs prevented or reversed the symptoms of Metabolic syndrome. Finally, they showed that Uric acid inhibits Endothelial function in a dose-dependent fashion.

Consumption of Fructose-sweetened drinks induces Metabolic syndrome in Humans
http://www.ncbi.nlm.nih.gov/pubmed/22828276 - 32 subjects were divided into 2 groups, with 1 receiving 25% of their calories from a Fructose-sweetened beverage & the other from a Glucose-sweetened beverage. The group who consumed the Fructose-sweetened beverages had significantly elevated levels of Uric acid, RBP4 (Retinol-binding protein 4, associated with Insulin resistance), & GGT (Gamma-glutamyl transferase or transpeptidase, also associated with Metabolic syndrome and/or Non-alcoholic fatty liver disease [NAFLD]).

Fructose causes Dyslipidemia & Fat deposition in the Liver & Muscle in Healthy Humans
http://www.ncbi.nlm.nih.gov/pubmed/19403641 - 24 subjects were given either an isocaloric diet or hypercaloric Fructose diet for 7 days. The Fructose diet caused an increase in Fat in the Liver, Fat in the Muscle, VLDL (sometimes referred to as "very bad" Cholesterol), & fasting hepatic glucose output. Some of the patients were children of people with Diabetes, and in this subgroup, the effects of Fructose were worse.

Saturday, July 28, 2012

Vitamin D, Testosterone, & Coffee

Vitamin D increases Testosterone levels
http://www.ncbi.nlm.nih.gov/pubmed/21154195 - 54 overweight, non-diabetic men with deficient Vitamin D levels (<50 nmol/L) undergoing a weight reduction program were randomized to ~3000IU Vitamin D daily for 1 year or Placebo. Vitamin D levels increased by ~50 nmol/L & Total testosterone levels increased by ~11 to 13 nmol/L in the Treatment group, with no change seen in the Placebo group.

For reference, hormone therapy is usually started for men with Total testosterone < ~12 nmol/L.

Testosterone improves Metabolic syndrome
http://www.medscape.com/viewarticle/755673 -147 men with Total testosterone levels <~12 nmol/L were given 1000 mg Testosterone undecanoate injections every 3 months for at least 4 years. The average waist reduction was 8 cm; average weight loss was 12.9 kg. During the 1st year of treatment the average Lean body mass increase was 4.5 - 5 kg & average Fat loss was 5 to 6 kg. Total cholesterol, LDL, & Triglycerides were all significantly reduced; C-reactive protein levels (a marker of Inflammation) dropped from 7.1 to 1.6 mg/L.

Testosterone aids Weight loss & Waist-size reduction

http://www.medscape.com/viewarticle/767696 -130 men with Total testosterone levels <~12 nmol/L were given 1000mg Testosterone undecanoate injections on Day 1, 6 weeks later, then every 3 months. Average weight loss was 14.3 kg; average waist reduction was 11 cm.

Coffee may help prevent Atherosclerosis (hardening of the arteries)
http://www.ajcn.org/content/86/3/604.long - 10 healthy volunteers were given 200mL of Filtered coffee after an overnight fast; researchers measured the resistance of the volunteers' LDL to oxidation; LDL had increased resistance to oxidation, presumably due to increased incorporation of Phenolic acids (found in the Coffee) within the LDL particles.

Oxidation of LDL is considered to be a major initiating factor in the development of Atherosclerosis (hardening of the arteries), as can be read about here.

Monday, July 16, 2012

Sunscreen, Cancer, & Vitamin D

http://www.ncbi.nlm.nih.gov/pubmed/21135266 - 10 year randomized trial of 1621 participants showed a 50% reduction in Melanoma in the group that applied sunscreen daily.

http://www.ncbi.nlm.nih.gov/pubmed/12707092 - 4 year randomized trial of 1621 participants showed a 24% reduction in Keratoses in the group that applied sunscreen daily.

http://www.ncbi.nlm.nih.gov/pubmed/7726582 - Randomized trial during 1 Australian summer of 113 participants showed daily use of sunscreen did not result in Vitamin D levels outside of the normal range.

Tentative conclusion:  daily sunscreen use might lower Vitamin D levels, but maybe not to the point of clinical significance. Oral supplementation is cheap & easy, and the benefits of sunscreen use on Cancer prevention seem well-established.

Saturday, July 14, 2012

Meditation, Exercise, & Immunity

Meditation & Exercise (individually) both prevent illness & lessen illness severity
149 participants were randomized into 1 of 3 groups: no intervention, 8 weeks of exercise, or 8 weeks of meditation. The control group got sick 40 times and had 453 days of illness, the exercise group got sick 26 times and had 241 days of illness, while the meditation group got sick 27 times and had 257 days of illness. The participants were also surveyed to assess the severity of their illness, with a higher score indicating more severe symptoms. The control group had a mean severity score of 358, exercise 248, and meditation 144. In terms of days of work missed: the control group missed 67 days, exercise 32, and meditation only 16.

Sunday, July 8, 2012

Exercise, Cognition, Strength & Immunity

Intense exercise increases BDNF & improves cognitive function
Participants cycled at 2 different intensities. Those who cycled at higher intensity had significant increases in BDNF in the blood. Increased BDNF levels correlated with increasing Lactate levels (Lactate levels increase when exercise becomes Anaerobic). Cognitive function improved after both forms of exercise.

BDNF is Brain-derived neurotrophic factor. It helps to "support the survival of existing neurons, and encourage the growth and differentiation of new neurons and synapses."

Lifting speed matters for strength progression
In short, experienced lifters were divided into one group who lifted at their preferred speed and one group that sped up the concentric portion of their lift (the push in the bench press in this example). The group that focused on lifting faster had about a 10% increase in strength while the other group showed no change.

Parents have stronger immune systems
Researchers infected adults with cold viruses and found that those with children were less likely to develop colds as a result. The effect was greater in older parents and not seen in parents aged 18-23.