Vitamin B3 is making you fat.....

This one caught my eye today.

If you pick up any packet of cereal you find it is enriched with vitamins:

Ingredients

Maize, Brown Sugar (Sugar, Molasses), Peanuts (7%), Sugar, Honey (2%), Barley Malt Flavouring, Salt, Niacin, Iron, Vitamin B6, Riboflavin (B2), Thiamin (B1), Folic Acid, Vitamin B12.

Some Chinese scientists have just done a study indicating that Niacin can mess up insulin sensitivity....and make you fat

A research team from China examined the role of excess nicotinamide in glucose metabolism using co-loading of glucose and nicotinamide test. They proved that excess niacin intake-induced biphasic response, i.e., insulin resistance in the early phase and hypoglycemia in the late phase, may be a primary cause for the increased appetite in obesity. Their study will be published on May 21, 2010 in the World Journal of Gastroenterology.

The study also revealed for the first time that the obesity prevalence among US children and adolescents increased in parallel with the increase of the per capita niacin consumption with a 10-year lag, in which niacin fortification-induced sharp increase in niacin contents in grain products may play a major role. Reducing niacin intake and facilitating niacin elimination through sweat-inducing physical activity may be a key factor in the prevention and treatment of obesity.

I've not been able to access the full article yet but I certainly think there are some interesting implications there. Especially the last bit - exercise and sweating is healthy too in that it gets rid of excess niacin.

Keep your veggies in the light?

Here is an interesting little report:

Far from being a food spoiler, the fluorescent lighting in supermarkets actually can boost the nutritional value of fresh spinach, scientists are reporting. The finding could lead to improved ways of preserving and enhancing the nutritional value of spinach and perhaps other veggies, they suggest in a study in ACS' bi-weekly Journal of Agricultural and Food Chemistry.

The full text of the study is available. Here is the abstract:

Current retail marketing conditions allow produce to receive artificial light 24 h per day during its displayed shelf life. Essential human-health vitamins [ascorbic acid (vit C), folate (vit B9), phylloquinone (vit K1), α-tocopherol (vit E), and the carotenoids lutein, violaxanthin, zeaxanthin, and β-carotene (provit A)] also are essential for photosynthesis and are biosynthesized in plants by light conditions even under chilling temperatures. Spinach leaves, notably abundant in the aforementioned human-health compounds, were harvested from flat-leaf 'Lazio' and crinkle-leafed 'Samish' cultivars at peak whole-plant maturity as baby (top- and midcanopy) and larger (lower-canopy) leaves. Leaves were placed as a single layer in commercial, clear-polymer retail boxes and stored at 4 °C for up to 9 days under continuous light (26.9 μmol·m2 ·s) or dark. Top-canopy, baby-leaf spinach generally had higher concentrations of all bioactive compounds, on a dry weight basis, with the exception of carotenoids, than bottom-canopy leaves. All leaves stored under continuous light generally had higher levels of all bioactive compounds, except β-carotene and violaxanthin, and were more prone to wilting, especially the flat-leafed cultivar. All leaves stored under continuous darkness had declining or unchanged levels of the aforementioned bioactive compounds. Findings from this study revealed that spinach leaves exposed to simulated retail continuous light at 4 °C, in clear plastic containers, were overall more nutritionally dense (enriched) than leaves exposed to continuous darkness.

Supplementation with vitamin C, vitamin E, or beta carotene doesn't do much to prevent cancer

Antioxidant supplements do not help much! In fact there have been studies that indicate they might do more harm than good.


Vitamins C and E and Beta Carotene Supplementation and Cancer Risk: A Randomized Controlled Trial.

Observational studies suggest that a diet high in fruits and vegetables, both of which are rich with antioxidants, may prevent cancer development. However, findings from randomized trials of the association between antioxidant use and cancer risk have been mostly negative....

Conclusions Supplementation with vitamin C, vitamin E, or beta carotene offers no overall benefits in the primary prevention of total cancer incidence or cancer mortality.

synthetic vitamins and carbs bad....fat good....

Here is just a quick couple of tit-bits for the weekend:


Serious Dangers of Synthetic & Unnatural Vitamins (pdf) - Phil Maffetone looks at the same issue that I have pointed to recently. I really like Dr Maffetone. While I do not always agree with him, especially with respect to exercise, I think he was ahead of his time on things like shoes (simple, cheap and flat) and diet (low carb, higher fat).

Animal foods linked with reduced risk of breast cancer, while starch found to be associated with enhanced risk - Dr Briffa highlights "a piece of research which supports the notion that animal foods, even those rich in saturated fat, are not the dietary spectres they are so often made out to be. In addition, and I do think this is very important, it again supports the notion that the oh-so-health starchy carbs we are generally encouraged to have are fill of may have serious negative consequences for our health."

Antioxidants - do more harm than good?

This one is really going to sound heretical.

While we are often told to eat lots of veggies, red tea, green tea and chocolate to benefit from their antioxidants. In the past I've pointed to a couple of studies (here and here) that raised some questions about the supposed benefits of antioxidants in the diet.

This week I've spotted two new studies that indicate that taking supplementary antioxidants - including the popular Vitamin C - can actually interfere with your body's own antioxidant processes - especially in the context of exercise. Maybe chalk up another one for the high fat, low carb boys?

Here are the abstracts:

Oral administration of vitamin C decreases muscle mitochondrial biogenesis and hampers training-induced adaptations in endurance performance
Background: Exercise practitioners often take vitamin C supplements because intense muscular contractile activity can result in oxidative stress, as indicated by altered muscle and blood glutathione concentrations and increases in protein, DNA, and lipid peroxidation. There is, however, considerable debate regarding the beneficial health effects of vitamin C supplementation.

Objective: This study was designed to study the effect of vitamin C on training efficiency in rats and in humans.

Design: The human study was double-blind and randomized. Fourteen men (27–36 y old) were trained for 8 wk. Five of the men were supplemented daily with an oral dose of 1 g vitamin C. In the animal study, 24 male Wistar rats were exercised under 2 different protocols for 3 and 6 wk. Twelve of the rats were treated with a daily dose of vitamin C (0.24 mg/cm2 body surface area).

Results: The administration of vitamin C significantly (P = 0.014) hampered endurance capacity. The adverse effects of vitamin C may result from its capacity to reduce the exercise-induced expression of key transcription factors involved in mitochondrial biogenesis. These factors are peroxisome proliferator–activated receptor co-activator 1, nuclear respiratory factor 1, and mitochondrial transcription factor A. Vitamin C also prevented the exercise-induced expression of cytochrome C (a marker of mitochondrial content) and of the antioxidant enzymes superoxide dismutase and glutathione peroxidase.

Conclusion: Vitamin C supplementation decreases training efficiency because it prevents some cellular adaptations to exercise.



Moderate exercise is an antioxidant: Upregulation of antioxidant genes by training.

Exercise causes oxidative stress only when exhaustive. Strenuous exercise causes oxidation of glutathione, release of cytosolic enzymes, and other signs of cell damage. However, there is increasing evidence that reactive oxygen species (ROS) not only are toxic but also play an important role in cell signaling and in the regulation of gene expression.

Xanthine oxidase is involved in the generation of superoxide associated with exhaustive exercise. Allopurinol (an inhibitor of this enzyme) prevents muscle damage after exhaustive exercise, but also modifies cell signaling pathways associated with both moderate and exhaustive exercise in rats and humans.

In gastrocnemius muscle from rats, exercise caused an activation of MAP kinases. This in turn activated the NF-kappaB pathway and consequently the expression of important enzymes associated with defense against ROS (superoxide dismutase) and adaptation to exercise (eNOS and iNOS). All these changes were abolished when ROS production was prevented by allopurinol.

Thus ROS act as signals in exercise because decreasing their formation prevents activation of important signaling pathways that cause useful adaptations in cells. Because these signals result in an upregulation of powerful antioxidant enzymes, exercise itself can be considered an antioxidant. We have found that interfering with free radical metabolism with antioxidants may hamper useful adaptations to training.


So don't take that Vitamin C - exercise itself is an antioxidant and taking antioxidants prevents useful benefits to training! I told you it was heresy!

I have said before that:

It is also worth pointing out that Vilhjalmur Stefansson lived for years on the traditional Eskimo diet of fat and meat....no veggies.......and was, like the Eskimos he was living with, exceptionally healthy. Gary Taubes in his new and excellent book Good Calories, Bad Calories suggests that scurvy and other vitamin deficiency diseases are actually only found when people are eating diets low in meat, eggs and dairy. It seems to be the high levels of carbs that prompt the need for all the vitamins in the veggies.....

Supplements - do you really need all those pills?

Vitamin Pills - a waste of money?

As I look back over my years of weight-training, body-building, running and the more general fitness / conditioning stuff that I do now, I must have spent hundreds of pounds on supplements: vitamins, minerals, amino-acids, protein powders, creatine, ornithine, dessicated liver, brewers' yeast.....whatever was in vogue....whatever I thought could make me fitter, stronger, bigger leaner. Nowadays I take a multivitamin once in a while but not a lot. Rarely was it based on science or medical opinion. I was motivated to be better, and so on the basis of a magazine article, an advert, hearsay or rumour I would shell out the cash for the latest potion. Looking back maybe it was daft, but I was always looking for that which would make me a little better and always suspicious that the scientists didn't really know much about "performance" enhancement.

It was the same attitude to training I suppose - you didn't seek the scientifically based protocols, you looked to what the superstars were doing and copied that, wilfully ignoring their superior genetics and ingestion of less legal "supplements".

One one level I think there is an excuse - the scientists often have their own dogma which isn't always consistent with what actually works "in the trenches". For example low carb diets work for fat loss......but the scientists - with some exceptions - do not admit or promote this.

On another level though there is a problem that we athletes do not look at the science (and actually in this context I'd look at the science more broadly, be pragmatic and include a little bit of learning from others' experiences and experimenting on yourself a bit) and critically examine what we do or eat. Too often we rely on rumour or advertising or hearsay and as such we waste money and time. As in the discussions about water and shoes, there are powerful marketing forces at work here!

A study that I came across yesterday made me reflect on this. Basically the scientists reckon that athletes do not generally base their supplement use on any science or medical advice. Plus, given what they want to achieve/the thing that motivates their supplement use, they are often taking the wrong things anyway.

We always need to think. This may not just be academic either - there can be health risks to taking too many supplements. Even the much promoted antioxidants may not be without their risks.


Limited agreement exists between rationale and practice in athletes' supplement use for maintenance of health: a retrospective study

Background

The widespread use of nutritional supplements among athletes is poorly understood. The prevalence of supplement intake and users' knowledge have been researched independently leading to useful, but disconnected, information on supplement use.

Methods

The 'UK Sport 2005 Drug Free Survey' data (n = 874) were re-analysed using association [chi-square] and 'strength of association' tests [phi], to discover observed incongruencies between self-reported supplement use and the underlying motives. Results are given for test pairs between 'motive for use' [doctors advice, avoiding sickness, overcoming injuries and enhancement of diet] and each supplement used and these were categorized as strong (phi > .7), intermediate (.7 <> .3) and weak (phi < .3).

Results

The use of selected supplements varied widely as follows: multivitamin (72.7%), vitamin C (70.4%), echinacea (30.8%), iron (29.8%), magnesium (11.0%) and ginseng (8.3%). Associations with motive were found in 8 of the 10 test pairs which were expected from literature precedents, however only weak associations exist. Of these, four were associated with avoidance of sickness [iron (chi-square = 11.94, p < .001; phi = .15, p = .001), multivitamin (chi-square = 6.43, p < .001; phi = .11, p = .011), vitamin C (chi-square = 54.67, p < .001; phi = .32, p < .001) and echinacea (chi-square = 40.34, p < .001; phi = .28, p < .001)]. The remaining 4 associations were: no time to prepare meals with ginseng (chi-square = 7.64, p = .006; phi = .12, p = .006) and multivitamin (chi-square = 9.103, p = .003; phi = .13, p = .003); overcoming injuries with magnesium (chi-square = 6.99, p = .008; phi = .11, p = .008); doctors' advice and iron (chi-square = 35.00, p < .001; phi = .25, p = .001).

Conclusion

These results suggest a lack of understanding regarding supplements and health maintenance, except for vitamin C and echinacea. Furthermore, supplement use is apparently independent of physicians/dieticians' advice, except for iron. This may suggest a widespread circumvention of expert advice in the growing area of supplement use and therefore should be addressed to underscore potential health risks.