Assuming that you have no idea what this "evidence" is for, I would suspect that you missed the live show yesterday and also did not find the time to download and listen to the podcast, yet -- right? Well, you should either download and listen to the show now and digest the Seconds later, or you read the following paragraphs first and download the podcast later.
What is not an option, however, is to miss one or another - I mean you can hardly want to eat the seconds if you have not had the main dish yet... and after listening to the podcast, I cannot imagine you don't want at least some seconds. Apropos seconds, here are today's seconds...
- Wheat gluten hydrolysate is not the new goto protein supplement - certainly not for female distance runners and probably not for anyone else, either! These are the kinds of studies that really annoy me. Studies that start out with blatant statements like "WGH [Wheat gluten hydrolysate] has been reported to suppress post-exercise rises in serum creatine kinase in male distance runners" (Hirao. 2012).
So, even if you are not afraid of the evil in gluten (which I believe not everyone has to), I strongly caution against making the switch from a high EAA protein with ton's of GSH boosting cysteine in it like whey to a mediocre grain protein, which is a potential allergen and contains tons of glutamine your body will readily turn into glucose, once it passes through the portal veign into the liver (I bet a large part won't even make it into systemic circulation).
And as far as the purported "gender difference" goes the study at hand tries to blame the null result on (Hiriao. 2012), I suspect that it is rather the indisputable difference between the long-distance running at a continuous pace the women in the study at hand did, versus the totally different strains the guys in the previous study were exposed to during a soccer training + mini-match, which made the difference.
- Working out next to a street takes away some of the beneficial cognitive effects due to ultrafine particulate matter (UFPM) exposure. "Working out in the fresh air will promote weight loss more than working out inside." You heard me state that in one of the previous installments of the SuppVersity Science Round Up on Super Human Radio. Now this is still correct and based on sientific evidence, but at least as far as the cognitive benefits are concerned, working out outside does also have its downsides - at least for those of you who live in the inner city area.
During a 12-week program the researchers from the Universiteit Brussel, the Hasselt University and the Royal Military Academy measured the improvements in physical performance, changes in serum markers and corresponding ultrafine particulate matter (UFPM) concentrations in the enviromnent in which their 15 previously untrained subjects conducted their aerobic training program thrice a week (Bos. 2012). What Bos et al. found was that the UFPM levels were signfificantly higher in the urban compared to the rural environment and that the higher UFPM exposures correlated with increases in leukocyte counts (p = 0.02), neutrophil counts (p = 0.04), and eNO levels (p = 0.002) that were exclusively observed in the group that trained in the urban environment.
You better watch what you breath while you run.
With the latter being markers of inflammation which exert their effects systemically, i.e. not just in the lung or musculature of which you may be thinking now, but also in the brain, it is no wonder that
"reaction times on the Stroop task improved in the rural group (p = 0.001), but not in the urban group" (Bos. 2012).What's comforting, though, is that the physical fitness did increase to a similar extend in both arms of the study.
- Homocysteine levels, mortality, cognitive impairment and which nutrients can offer some protection. I am not sure about what your impression is, but for whatever reason homocystein seems to be 'out of vogue' -- probably no room for it on the research agenda with all the hype surrounding vitamin D. It used to be all the rage in CVD risk research and today's news item is actually ain't about cardiovascular health, either.
What the researchers from China and Taiwan actually were interested in was the correlation of high and low homocysteine levels with cognitive impairment and the corresponding nutrient intakes. In that Xiu et al. paid particular attention to the "B-vitamins" and found the following correlations between the mortality, cognitive status, homocystein levels and nutrient intake of their 1412 study participants (Xiu. 2012):
if you go by the unadjusted data in figure 2, it's plain obvious that the all-cause mortality increases linearly from one quartile to the other
Figure 2: Unadjusted mortality in the four quartiles of homocysteine levels (top); mortality according to homocysteine levels in subjects with different degrees of cognitive impairment (based on Xiu. 2012)
- this relation between plasma homocysteine levels and all mortality remained statistically significant after adjustments for age, sex, smoking status, BMI, physical function and general health were made
- of the general foods, the scientists assessed, only regular fish intake had a statistically significant effect on homocysteine levels, with higher intakes being associated with lower homocysteine levels
- of the b-vitamins choline was the only one with a significant association with plasma homocysteine levels (suggested read "Old School Supplement Choline Could Save Your Live and Liver!")
- neither betaine, nor vitamin B1, B2, B3 or B6 intakes did show statistically significant correlations with plasma homocysteine (not even "borderline significant; p > 0.15 for all, most way hither)
- of the plasma markers, folate showed a highly significant correlation with homocysteine (14.4 nmol/L in the lowest HCY and 8.70 nnmol/L in the highest HCY group)
- PLP, the active form of vitamin B6, came in close second with 70.3 nmol/l in the lowest HCY quantile and only 44.4 nmol / l in the highest quantile.
Actually if you follow this rationale you can almost answer the question yourself. If you have low homocysteine and severe cognitive decline, the severe cognitive decline can hardly be from high homocysteine levels, so it must have another obviously pathological reason, or as the scientists have it
"The joint effects of the 2 variables [homocysteine and cognitive decline] were most pronounced with severe cognitive impairment where mortality HRs ranged from 5- to 18-fold across a wide range of homocysteine concentrations. The findings with hypohomocysteinemia provide some insight into what might be an optimal range for this analyte in peripheral blood and tissues. The low concentrations may be seen with severe illness and malnutrition, and our study population comprises the health-vulnerable aged. For these reasons, we adjusted these associations for BMI (using the World Health Organization chronic energy deficiency category of, 18.5 kg/m 2 ), and we excluded those who died in the first year of follow-up. The findings were unchanged. Because mortality among the very old may have skewed the joint effects, these are presented for those ≤75 years and over, but again with similar findings." (A sarcastic person would now probably say: "We all have to go some time!" and just wave his hands at these results. True! And I am the last to advice you to become over-anxious. Yet in the mean time it would appear prudent to make sure to get your homocysteine levels checked from time to time, not to forget that choline is a b-vitamin as well and not to fall for the idea that you cannot overdose on B-vitamins - I don't have to remind you of the negative effects, specifically folic acid supplementation can have on all sorts of cancer (e.g. breast cancer, where a high folic acid intake from foods and supplements is associated with a +30% risk of cancerous growth; cf. Kim. 2006).
- Aoki K, Kohmura Y, Suzuki Y, Koikawa N, Yoshimura M, Aoba Y, Fukushi N, Sakuraba K, Nagaoka I, Sawaki K. Post-training consumption of wheat gluten hydrolysate suppresses the delayed onset of muscle injury in soccer players. Exp Ther Med. 2012 Jun;3(6):969-972. Epub 2012 Apr 3.
- Bos I, De Boever P, Vanparijs J, Pattyn N, Panis LI, Meeusen R. Subclinical Effects of Aerobic Training in Urban Environment. Med Sci Sports Exerc. 2012 Oct 15.
- Cankurtaran M, Yesil Y, Kuyumcu ME, Oztürk ZA, Yavuz BB, Halil M, Ulger Z, Cankurtaran ES, Arıoğul S. Altered Levels of Homocysteine and Serum Natural Antioxidants Links Oxidative Damage to Alzheimer's Disease. J Alzheimers Dis. 2012 Oct 29.
- Guest PC, Urday S, Ma D, Stelzhammer V, Harris LW, Amess B, Pietsch S, Oheim C, Ozanne SE, Bahn S. Proteomic analysis of the maternal protein restriction rat model for schizophrenia: Identification of translational changes in hormonal signalling pathways and glutamate neurotransmission. Proteomics. 2012 Oct 16.
- Hirao T, Koikawa N, Aoki K, Sakuraba K, Shimmura Y, Suzuki Y, Sawaki K. Female distance runners show a different response to post-workout consumption of wheat gluten hydrolysate compared to their male counterparts. Exp Ther Med. 2012 Apr;3(4):641-644.
- Kim YI. Does a high folate intake increase the risk of breast cancer? Nutr Rev. 2006 Oct;64(10 Pt 1):468-75.
- Vijgen GH, Bouvy ND, Teule GJ, Brans B, Hoeks J, Schrauwen P, van Marken Lichtenbelt WD. Increase in brown adipose tissue activity after weight loss in morbidly obese subjects. J Clin Endocrinol Metab. 2012 Jul;97(7):E1229-33. Epub 2012 Apr 24.
- Xiu LL, Lee MS, Wahlqvist ML, Chia-Yu Chen R, Huang YC, Chen KJ, Li D. Low and high homocysteine are associated with mortality independent of B group vitamins but interactive with cognitive status in a free-living elderly cohort. Nutr Res. 2012. Ahead of print.