Let鈥檚 face it, running on a treadmill isn鈥檛 one of life鈥檚 most exciting activities, but it does provide time to contemplate life and think about what is likely to extend it. There鈥檚 plenty of evidence that exercise will, which is why one plods away on the treadmill in the first place.
But should one gear up for short bursts of high-intensity exercise or scamper along at a slower pace for a longer time? The scientific literature is ambivalent on the issue, but it is one that I follow closely because I am sort of addicted to the treadmill. That鈥檚 why a New York Times blog with the headline 鈥淔or Fitness, Push Yourself鈥� accompanied by a photo of competitive runners obviously at full tilt got my attention.
鈥淚ntense exercise changes the body and muscles at a molecular level in ways that milder physical activity doesn鈥檛 match, according to an enlightening new study,鈥� the article began.
Was there finally an answer to the exercise conundrum?
The study was enlightening all right, if you are a mouse. This is not a criticism of the research, which was carried out by a very reputable group at the Scripps Research Institute in Florida. But it is a criticism of the interpretation of the study, not only by the New York Times blog, but by many other media reports that concluded 鈥渢o realize the greatest benefits from workouts, we probably need to push ourselves.鈥� There were also quotes from one of the researchers involved in the study about 鈥渘o pain, no gain.鈥� Coming to such a conclusion based on a study involving specially-bred mice scuttling on a treadmill is way too adventurous.
The study鈥檚 basic goal was to examine how the hormones adrenalin and noradrenaline affect muscle structure. These hormones are released under stressful conditions and are known to prime muscles for 鈥渇light or fight.鈥� Since intense exercise is also known to release these chemicals, it is reasonable to explore its potential to increase muscle strength. The effects of the stress hormones are thought to be manifested through the activation of a specific protein termed CRTC2, present in mice as well as in people. The Scripps researchers therefore bred mice that were genetically programmed to produce more of this protein, put them on a program of strenuous treadmill exercise and found that they developed larger muscles and were more efficient at releasing fat for use as fuel than control animals. Interesting, but genetically modified mice are a long way from humans and the study does not justify giving any sort of advice to people.
The researchers also talk about 鈥渟earching for molecular therapeutics that will activate the CRTC2 protein so that even an average exercise routine could potentially be enhanced and made more beneficial.鈥� Sounds like an attractive research project, but I suspect it won鈥檛 be long before an inventive marketer puts the cart before the horse and starts promoting some sort of 鈥淐RTC2 enhancer.鈥�
In the anti-aging business, making more of reputable science than is warranted is par for the course. Consider these headlines: 鈥淐ocoa Extract Highly Effective in Protecting Against Alzheimer鈥檚 disease, Says New Study鈥� or 鈥淲orried About Alzheimer鈥檚? Go on a Chocolate Binge, Study Says.鈥� Well, no. The study doesn鈥檛 say anything like that. The grossly exuberant headlines were prompted by a paper published in the Journal of Alzheimer鈥檚 disease titled 鈥淐ocoa extracts Reduce Oligomerization of Amyloid-beta: Implications for Cognitive Improvement in Alzheimer鈥檚 disease.鈥�
Did the researchers from the Mount Sinai School of Medicine in New York carry out experiments with cocoa on Alzheimer鈥檚 patients? No. Did they feed cocoa to animals? No. What they did was study the effects of a specific type of cocoa extract on the activity of nerve cells in mouse brain tissue dosed with synthetic compounds thought to model Alzheimer鈥檚 disease.
One of the hallmarks of Alzheimer鈥檚 disease, which affects an estimated 36 million people worldwide and is expected to double by 2030, is the deposition of a protein known as amyloid-beta between nerve cells. This virtually gums up the workings of the brain by preventing neurotransmitters, the chemicals nerve cells use to communicate with each other, from crossing the synapse, the gap between nerve cells. Since amyloid proteins are formed from smaller fragments called peptides, any interference with the ability of peptides to aggregate into the troublesome proteins is worthy of investigation.
Flavanols are a class of compounds found in cocoa that have been proposed as candidates for interfering with the formation of the amyloid proteins. The Mount Sinai researchers decided to use an unfermented, lightly processed cocoa known as 鈥淟avado鈥� in their investigation because of its high flavanol content. Most commercial cocoa is 鈥淒utched鈥� and has undergone alkali treatment to reduce bitterness, a treatment that also significantly reduces flavanol content. As far as chocolates go, their flavanol content is minimal.
The experiment that generated all the publicity consisted of bathing brain slices from mice specially bred to be prone to Alzheimer鈥檚 disease in solutions of the amyloid precursor peptides mixed with different cocoa extracts. When the nerve cells in these tissues were electrically stimulated, transmission of information between them was enhanced with Lavado cocoa extracts.
While this is interesting research, it cannot be used to draw any conclusion about people consuming cocoa. There is no way to know how the amount of the cocoa extracts used in these experiments relate to amounts of flavanol that may make it to the brain from eating chocolate or drinking cocoa. And mouse brain slices in a lab are a long way from a functioning human brain. Although maybe not so far from the human brains that clutter the media implications for human health based on preliminary laboratory or animal experiments.
Needless to say, I won鈥檛 go out searching for Lavado cocoa, at least not until a proper randomized trial in humans shows a benefit. And as far as the treadmill goes, I have no idea what 鈥渋ntense鈥� mouse exercise means in human terms, but on looking into the issue, I did come across a scientific paper that added some pep to my treadmilling. The title was 鈥淧hysical Exercise Protects Against Alzheimer鈥檚 disease.鈥� I won鈥檛 be shouting about it from rooftops, though. The study was on mice genetically modified to develop the disease.
