Dark Chocolate is Good for Endurance!

Yes, yes I’m going with an unfounded and sensational headline. But its justified – there’s been a study that has shown some promising results that small amounts of dark chocolate is beneficial or specifically the flavional epicatechin (the principle component of cocoa). As reported in the New York Times

By and large, the animals that had been drinking water were the first to give out during the treadmill test. They became exhausted more quickly than the animals that had received epicatechin. Even the control mice that had lightly exercised grew tired more quickly than the nonexercising mice that had been given epicatechin. The fittest rodents, however, were those that had combined epicatechin and exercise. They covered about 50 percent more distance than the control animals.

The muscle biopsies offered some explanation for their dominance. The muscles of all of the animals that had been given epicatechin contained new capillaries, as well as biochemical markers indicating that their cells were making new mitochondria. Mitochondria are structures in cells that produce cellular energy. The more functioning mitochondria a muscle contains, the healthier and more fatigue-resistant it is.

The leg muscles of the mice that had been given epicatechin and exercised displayed far more mitochondrial activity than the leg muscles of the control mice. Even the mice that had drunk epicatechin and not exercised contained markers of increased mitochondrial health, suggesting that the flavonol prompts a physiological reaction even among the sedentary. But that response is greatly heightened by exercise, no matter how slight.

So eating small amounts of dark chocolate helps you if you don’t exercise, and even more if you do? I’m not sure I want to see any further studies that might negate this. However, epicatechin  is closely related to the green tea extract (epigallocatechin-3-gallate; EGCG) which some studies have investigated for endurance enhancement and found lacking (here and here). What I’d like to take from that is that clearly its only chocolate, and not green tea that will help.

Low-Carbohydrate and High Protein to slow Tumour Growth

A new study has been published providing evidence that a diet low in carbohydrates and high in protein may help slow tumour growth.

Our study, herein, shows that a high amylose containing low CHO, high protein diet reduces BG, insulin, and glycolysis, slows tumor growth, reduces tumor incidence, and works additively with existing therapies without weight loss or kidney failure. Such a diet, therefore, has the potential of being both a novel cancer prophylactic and treatment, warranting further investigation of its applicability in the clinic, especially in combination with existing therapies.

 

Previous studies have also suggested a link between a carbohydrate-rich diet and prostate cancer.

• A Low-carb Diet May Stunt Prostate Tumor Growth.
• Carbohydrate Restriction May Slow Prostate Tumor Growth.
• High Carb Diet Linked to Prostate Tumor Growth.

Do we start advocating the prostate cancer diet?

 

Potatoes vs Yoghurt and other Diet Correlations.

A study was reported a month ago that looked at the correlations between people’s diet and weight gain. The key findings were reported as:

Within each 4-year period, participants gained an average of 3.35 lb (5th to 95th percentile, −4.1 to 12.4). On the basis of increased daily servings of individual dietary components, 4-year weight change was most strongly associated with the intake of potato chips (1.69 lb), potatoes (1.28 lb), sugar-sweetened beverages (1.00 lb), unprocessed red meats (0.95 lb), and processed meats (0.93 lb) and was inversely associated with the intake of vegetables (−0.22 lb), whole grains (−0.37 lb), fruits (−0.49 lb), nuts (−0.57 lb), and yogurt (−0.82 lb) (P≤0.005 for each comparison). Aggregate dietary changes were associated with substantial differences in weight change (3.93 lb across quintiles of dietary change). Other lifestyle factors were also independently associated with weight change (P<0.001), including physical activity (−1.76 lb across quintiles); alcohol use (0.41 lb per drink per day), smoking (new quitters, 5.17 lb; former smokers, 0.14 lb), sleep (more weight gain with <6 or >8 hours of sleep), and television watching (0.31 lb per hour per day).

 

Unsurprisingly this had been picked up by a lot of the media with headlines screaming Potatoes Make You Fat. While eating potato crisps and hot chips is associated with weight gain hasn’t surprised many, the fact that potato in any form is strongly correlated to weight gain seems to the big surprise. From the Washington Post

Every additional serving of potatoes people added to their regular diet each day made them gain about a pound over four years.

Although the study did not evaluate why potatoes would be particularly fattening, other research shows that starches and refined carbohydrates such as potatoes cause blood sugar and insulin to surge, which makes people feel less satisfied and eat more as a result, Mozaffarian said.

As an observational study, it is problematic to try and draw conclusions. Are potatoes inherently fattening, or do people who eat a lot of them unhealthy with their whole lives. Are whole grains correlated with lower weight-gain because they are objectively healthier, or because people who eat them are particularly health conscious. The same question could be asked for why yoghurt is apparently the dieters friend. The lifestyle factors also raise questions:

Lifestyle factors were clearly important. Those who exercised more gained nearly 2 pounds less than those who increased their physical activity the least. People who slept less than six hours a night — or more than eight hours — were more likely to gain weight, possibly by unbalancing hunger hormones such as ghrelin. Every extra hour per day of television watching added about a third of a pound, perhaps by encouraging snacking.