Saturday, July 28, 2012

Vitamin D, Testosterone, & Coffee

Vitamin D increases Testosterone levels - 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 -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 -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) - 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 - 10 year randomized trial of 1621 participants showed a 50% reduction in Melanoma in the group that applied sunscreen daily. - 4 year randomized trial of 1621 participants showed a 24% reduction in Keratoses in the group that applied sunscreen daily. - 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.