Diet Friendly Fast Food

Red (meat) breast cancer alert!

Its not the first study and I am pretty sure its not going to be the last study to link red meat and cancer, but in view of the fact that I am pretty sure that the results Maryam S Farvid and colleagues present in their latest paper in the British Journal of Medicine are going to be all over the place this week, I feel that its worth to give you an unbiased overview of the results before you are confronted with the sensational press release celebrating the newest "Harvard science" - a source people trust, one that "propagates the truth" and one that is (ab-)used by press release writers to generate the impression that each and every word they write is true.

Well the truth is that we are dealing with yet another prospective epidemiological study which does not have the power to reveal causal links between parameter (a), in this case the dietary protein sources in early adulthood and parameter (b), which is the incidence of breast cancer.
The average ignoramus will still read the headlines as "red meat" causes cancer and think of poultry, fish, eggs, legumes, and nuts as "the cure". In contrast to the red meat intake which was associated with a 22% risk increase in the 2830 documented cases of breast cancer the scientists had been collecting and following for 20 years, the a higher intake of poultry, fish, eggs, legumes, and nuts was
not just unrelated to breast cancer, in postmenopausal women, a high poultry intake was even associated with a -27% reduced breast cancer risk.

Energy intake and cancer risk expressed relative to lowest intake quintile for red meat (Farvid. 2014)

The latter observation gives rise to one of the (imho) hilarious substitute this for that equations, where the "estimating the effects of exchanging different protein sources, substituting one serving/day of legumes for one serving/day of red meat was associated with a 15% lower risk of breast cancer among all women (0.85, 0.73 to 0.98) and a 19% lower risk among premenopausal women (0.81, 0.66 to 0.99). Substituting poultry for red meat was even associated with 17% and 24% lower breast cancer risk in all and postmenopausal women.

Unlike the fooled readers of the press release, the researchers are obviously aware of the weaknesses of the study, in the discussion of the results, Farvid et al. point out that "potential limitations need to be considered":

• participants were predominantly white, educated US adults, they cannot determine whether our findings are generalizable to other race or ethnic groups
• dietary intake was assessed by food frequency questionnaires, some degree of measurement error is inevitably present, and thus to reduce measurement error they used the cumulative average of
  multiple measurements in a sensitivity analysis
• residual confounders are always of concern in any observational studies; although they adjusted for a wide range of potential confounders for breast cancer, they still could not rule out the possibility that other unmeasured or inadequately measured factors have confounded the true association
• they only estimated the effects of substitution of legumes, poultry, and other protein sources for red meat on risk of breast cancer, when trials on dietary modification would be ideal to support these substitutions

In addition, the scientists made multiple comparisons (different food groups and nutrients, premenopausal and postmenopausal subgroups, and subtype of tumors) in this analysis, and can thus not exclude the possibility of type I errors. But (sarcasm) this is not so much of concern, "the central finding of an association with red meat was [after all] a prior hypothesis." (Farvid. 2014) - In other words: What do you want people, weve just made sure we confirm our hypothesis.
Reference:

• Farvid, et al. "Dietary protein sources in early adulthood and breast cancer incidence: prospective cohort study." BMJ 2014;348:g3437 doi: 10.1136/bmj.g3437

What could be better than starting your day with the first rays of the sun? Doing this with a person you love, I suppose.

If you have listened to Super Human Radio earlier this week (download episode), you will have heard that Carl "caught" me off guard calling me without prior notice during the live show. We ended up talking about the use of melatonin and my beloved "daylight lamp" (light therapy lamp), which kept my energy levels up even at the darkest winter mornings over the past couple of months.

If you listened to the show, you may also remember that Carl mentioned that it would be great to have a light-based alarm clock - something like a light therapy lamp that increases its intensity gradually at a given time and will thus wake you up from a deep slumber.
Well, I already mentioned during the show that a corresponding device is already available, but pretty useless for someone who usually uses blindfolds to get a good nights sleep. For the rest of you, who are sleeping in a pitch black room without covering their eyes with a blindfold, on the other hand, Carls suggestion could be a viable means to "improve both cognitive and physical performance after waking." (Thompson. 2014).

This is at least what a recent study from the University College London would suggest. For the corresponding experiment, the researchers from the Department of Epidemiology and Public Health recruited 8 young adults (four males; four females) with a mean age of 24 ± 9 years who had not been involved in nocturnal shift work or undertaken transmeridian travel during the past 30 days (thats important to ensure that their circadian rhythm was not messed up in the first place).
The trials themselves were ordered in a counterbalanced fashion and were separated by 5–9 days. In the two days leading up to the tests, the participants were asked to sleep the exact times in their own homes that they would in the laboratory. to monitor compliance wrist accelerometers were issued.

Did you know that previous studies support the use of dawn simulations to tread seasonal effective disorder, where it was on top of that associated with lower remission rates than regular light therapy (Avery. 1993 & 2001). In addition, dawn simulations have been shown to have beneficial effects on the necessary and natural and healthy (Clow. 2010) early morning increase in cortisol (Thorn. 2004)?

"The experimental trials were identical with the exception of the 30 min prior to waking. During this time par ticipants either slept normally in complete darkness, the control condition (c), or were exposed to dawn simulation (DS).

Each night’s sleep ended with an audible alarm. At the same moment, a researcher entered the room to ensure that the participant was awake. Participants were then allowed to attend the bathroom if required.

After waking, a 75 min testing protocol commenced which consisted of: three bouts of cognitive assessment, one physical performance test and monitoring of physiological and subjective variables." (Thompson. 2014)

In view of the fact that I already gave away the results, its probably not really surprising that the data in Figure 1 confirms that being waken up by artificial sunlight had significant beneficial effects on the cognitive and physical performance of the subjects.

Figure 1: Changes in number of total additions and reaction time in cognitive tests (Thompson. 2014)

What did not differ, though, were the sleep efficiency, sleep latency, and the total sleep time. In a similar vein, the differences in perceived sleepiness and body temperature were visible, but not statistically significant.
References:

• Avery, David H., et al. "Dawn simulation treatment of winter depression: a controlled study." American Journal of Psychiatry 150 (1993): 113-113.
• Avery, David H., et al. "Dawn simulation and bright light in the treatment of SAD: a controlled study." Biological psychiatry 50.3 (2001): 205-216.
• Clow, Angela, et al. "The cortisol awakening response: more than a measure of HPA axis function." Neuroscience & Biobehavioral Reviews 35.1 (2010): 97-103.
• Thompson, Andrew, et al. "Effects of dawn simulation on markers of sleep inertia and post-waking performance in humans." European journal of applied physiology (2014): 1-8.
• Thorn, Lisa, et al. "The effect of dawn simulation on the cortisol response to awakening in healthy participants." Psychoneuroendocrinology 29.7 (2004): 925-930.