High protein diets are currently all the rage. This is, in part, due to their effectiveness at producing rapid and immediately observable weight loss. The short term losses seen by the Atkins diet have put high-protein diets back in vogue.
Scientific literature has substantiated that protein has a thermic action superior to that of fat or carbohydrates. Protein also satiates hunger more effectively, leading to the suppression of cravings.
However, literature has also shown that protein is correlated with bone loss when consumed at extremely high levels. This has been shown by examining urine samples of persons on high protein diets. The results demonstrated elevated levels of excreted calcium in urine. Not surprisingly, then, it is common practice that when one increases protein intake, one supplements with a calcium supplement or increases the consumption of dairy products.
A recent study aimed to examine the effects on bone of a high protein diet and high calcium supplementation on overweight adults attempting to lose weight.
The sixty study participants who were between the ages of 28 and 65 embarked on a twelve week phase of energy restriction followed by a four week phase of energy balance. They also attended a clinical research unit every two weeks for consultation with a qualified dietician. The subjects provided 24 hour urine samples, in weeks 0, 12 and 16. In the same weeks, blood samples were collected from subjects who fasted overnight.
Although the diets of individuals were matched in energy and macronutrient composition, the two diets differed in the sources of protein, as well as in the levels of calcium consumed.
The study found that although there were markers of bone turnover in urine samples, a diet high in protein and calcium may protect against bone loss.
Source: Journal of Nutrition 134:568-533, 2004.
CLA has long been used as bodybuilding supplement. It is known to facilitate fat loss. New research is demonstrating that it is also very effective at blocking estrogen signalling in human breast cancer cells.
Researchers in Georgia obtained breast cancer cells and proceeded to grow and maintain them.
A series of tests has shown that, in the presence of these cancer cells, CLA has direct anti-estrogenic activity and can, therefore, interfere with estrogen signalling in breast cancer cells.
This is good news for bodybuilders who suffer from gynocomastia, or who are using prescription anabolics. Not only can CLA help facilitate fat loss, it will also work against estrogen, and help keep you in an anabolic state.
It currently a common practice to consume a simple glucose drink after strenuous physical exercise. This practice has proven efficacious in promoting recovery through the replenishment of glycogen, the spiking of insulin, and the minimization of cortisol.
Insulin spiking prepares the way for fast acting proteins, and helps them to repair muscle tissue by delivering them to their intended destination.
However, a growing body of research suggests that it is beneficial to consume a glucose drink during exercise.
A recent study examined seven wheelchair athletes who regularly participated in wheelchair basketball or racing.
The participants exercised at 65% of peak oxygen uptake for one hour, followed by a twenty minute performance test. The responses of the participants during the one hour test were similar between trials. At this time a baseline glucose reading was obtained.
The plasma glucose concentrations significantly increased after ingestion of the carbohydrate drink, and remained stable during during one trial, but reduced over time in a following trial.
The athletes who consumed the carbohydrate drink during exercise also noted increased productivity and focus, compared to those who did not.
This shows that it may be beneficial to drink a simple carbohydrate drink during exercise.
How efficacious and appropriate this practice is will depend on the type of activity being performed.
Alzheimer's disease is a devastating condition that affects millions of elderly North Americans. In some cases, with early detection the condition can be managed and the reduction in quality of life can be minimized. Other cases can lead to wasting, and ultimately death.
Scientists have known for some time that Alzheimer's disease is a condition that comes about as a result of amyloid plaques in the brain. These neural plaques are tangled proteins, or neurofibrillary tangles, and they interfere with the transmission of neural signals.
A joint study done by American and Italian researchers has demonstrated that the spice curry can have neuroprotective effects. It is believed that the ingredient curcumin oil triggers enzyme activity that enhances antioxidant activity and the elimination of harmful free-radicals.
Bodybuilders who eat clean know that it is a challenge to keep their diets from becoming stale and unappealing. After all, there are only so many choices for meat and ways to prepare it. The addition of spices like curry are a great way to continue to eat clean, while providing for variety and protecting the brain.
For years athletes have been using antioxidants to protect their bodies from free-radicals and oxidative stress. Typically, the bodybuilders diet is rich in fruits and vegetables, and most athletes obtain their antioxidants via this route. Others may obtain their antioxidants from a supplement.
Despite the well known benefits of antioxidants, some still refuse to concede that they are essential, and often advise that it is not necessary to supplement with a vitamin as long as one "eats right."
The only problem with this advice is that agricultural practices have drastically reduced the nutritive contents of food. As a result, eating right may not be enough in the presence of rising pollution levels and newly emerging super-diseases.
A recent controlled-training double-blind study examined triatheletes to see if an antioxidant mixture (Se 150 microg, retinyl acetate mg, ascorbic acid 120 mg, alpha-tocopheryl succinate) would allow the athletes to avoid adaptation in the antioxidant system resulting from overload training.
The researchers recorded the athletes dietary intakes and physical activity levels for a period of eight weeks. During this time the athletes were subject to overload training followed by a four week period of normal training.
Upon testing it was found that the antioxidant mixture helped to preserve the antioxidant system from stress brought about by overload training in subjects with initially low antioxidant intakes. This demonstrates that its important get antioxidants if you lead an active lifestyle.
Source: Palazzetti S, Rousseau AS, Richard MJ, Favier A, Margaritis I. Antioxidant supplementation preserves antioxidant response in physical training and low antioxidant intake. Br J Nutr. 2004 Jan;91(1):91-100.
Soy protein is well known for its beneficial effects. Research has established that soy isoflavones play a role in stunting many cancers, including breast cancer and prostate cancer.
However, as beneficial as soy is, it is also known to have estrogenic properties, and for this reason many bodybuilders and athletes limit their consumption of it. Typically, an athlete will obtain the majority of their soy proteins from vegetable sources, and the remainder will come from various protein powder blends that supplement ones nutritional regimen.
Because of its known estrogenic properties, and because of the bad press given to hormone replacement therapy in recent years, many older female athletes who are in post-menopause have supplemented with soy protein powders, hoping that the supplementation will favourably affect their hormone profiles while simultaneously boosting nitrogen retention and eliminating the side effects associated with HRT.
A study by Australian researchers recruited 50 post-menopausal women and conducted a double-blind, placebo-controlled trial. In this trial the women were assigned into a manipulation group or a placebo group. They received either soy protein isolate (40 g soy protein, 118 mg isoflavones) or casein placebo supplement.
After taking baseline readings, researchers administered the supplements for a period of three months, and repeated the tests. It was noted that there were elevated isoflavone levels in the urine samples of the soy group, but no noted differences in protein synthesis levels.
The study concluded that soy isoflavones have no effect in vivo on estrogen or protein sysnthesis.
This should come as a comfort to bodybuilders who avoid soy for fear of its estrogenic activities. At the dosage administered in this study, no estrogenic effects were noted. Soy should be consumed in limited amounts so that one can benefit from its protective effects.
Source: Teede HJ, Dalais FS, McGrath BP. Dietary soy containing phytoestrogens does not have detectable estrogenic effects on hepatic protein synthesis in postmenopausal women. Am J Clin Nutr. 2004 Mar;79(3):396-401.
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