Hey, so I revisited my post on milk and decided to change a few things. The end result is a much shorter, more fully referenced article that is just better to read in totality. If you haven't read it I strongly suggest you do so. Peace.
[For purposes of unneeded repetition, please note when I say 'milk' I mean, bovine 3.25% full-fat/full-cream whole milk]
There is growing debate about the efficacy of milk in a 'bodybuilding' regimen. Some avoid it like the plague, others deem it so beneficial they recommend over 15 glasses per day. This article is not necessarily out to prove any one of those positions correct, but to rather present an argument for the consumption of milk; how much exactly is purely reliant on reader discretion. The general consensus amongst the scientific evidence suggests milk is conducive to strength and muscular augmentation and beneficial to other athletic applications1.
1) Milk boasts a wholesome macronutrient profile.
The table above summarizes the important nutritional values from 1 cup of milk2. This data makes it clear that the macronutrient composition of milk compares most handsomely to other foods. Fats, carbohydrates and protein are all quantified relatively high.
Many would immediately point the finger at the saturated fat and cholesterol numbers and begin to spew endless rhetoric about the dangers of these substances. This for the most part is an unfounded indictiment3.
Fat has been shown in numerous studies to have an association with sex hormones, namely testosterone. When fat consumption is reduced, testosterone is reduced similarly 6,7,8. The contrary is also equally true4,5,.
Let us move on to carbohydrate. Milk sugar is a disaccharide called lactose which is formed from the condensation of glucose and galactose molecules9. Lactose is the same type of sugar found in mammalian breast milk10.
With a Glycemic Index (GI) of merely 25, milk does not evoke erratic fluctuations in blood-sugar11.
Other critics often turn to the Insulinemic Index (II) and condemn the highly insulinotrophic nature of milk. There have been many studies that have shown milk, other dairy and protein foods to induce an acute spike in insulin irrespective of their GI12,13,14,15,16,17. Firstly, what causes this violent spike? The answer is the amino acid, leucine18,19,20,21. So why does this happen? Well an insulin spike becomes incredibly beneficial as a role of insulin is to stimulate the uptake of amino acids into muscle cells22,23. Moreover, all protein foods are known to increase glucagon production24,25,26,27,28, the supposed antithesis of insulin. What is the purpose of both an insulin and glucagon secretion following the ingestion of amino acids? It has to do with blood-sugar homeostasis, amino acid efficiency and muscle protein synthesis optimization29. Worth noting here is that insulin is one of most powerful anabolic agents. It is demonstrable then that the insulinogenic nature of milk can greatly assist strength and muscle growth through this method30.
The third and last macronutrient is protein. Milk is known for it's rather unique protein blend of 20% whey and 80% casein31. Casein is a slow digesting protein which creates a gel clot in the stomach and can take up to 8 hours to fully absorb32, and even longer when co-ingested with fat as it slows gastric emptying33,34.
2) Milk has superior protein and amino acid quality
Protein, whether derived from your own tissues or from whole foods, supplement etc. all consist of amino acids. They are integral to bodily function, being the building blocks of protein and the intermediates in metabolism35 amongst many other biochemical functions. Milk has a complete amino acid profile containing all 9 essential amino acids36.
Biological value of protein is a measure of the proportion of absorbed protein from a food which becomes incorporated into the proteins of the organism's body37. Suffice it to say, different proteins from different foods have different protein quality. Protein from a certain food will be absorbed better than a protein from a different food source, even if both are given in the same quantity, gram for gram. Milk is amongst the top 5 foods with the highest biological value with a scoring of 90, rating higher than egg-whites, beef and chicken38.
Another measure of protein quality (considered the best by the FAO39) is the Protein Digestibility Corrected Amino Acid Score (PDCAAS). It is essentially a method of evaluating the protein quality based on both the amino acid requirements of humans and their ability to digest it40. PDCAAS supersedes other methods that determine protein quality that include (but is not limited to) Net Protein Utilization (NPU) and the Protein Efficiency Ratio (PER). PDCAAS is measured from a scale from 0 (inferior) to 1 (superior). Casein (milk protein) is rated at 1.00, the absolute very best41,42.
3) Milk is rich in micronutrients and offers a plethora of health benefits.
There is no argument that milk contains an abundance of micronutrients such as vitamins and minerals needed to sustain and promote healthy living.
Vitamins have many roles in the body, including metabolism co-factors, oxygen transport and antioxidants. Moreover they facilitate the usage of macronutrients. Minerals have many roles in the body including enzyme functions, bone formation, water balance maintenance, and oxygen transport43. Milk (Unfortified) contains over 14 vitamins. Just one cup (250ml) provides nearly half of ones Recommended Daily Intake (RDI) of B12, more than a third of ones B2, phosphorus and calcium intake44. Vitamin A, B1, B6, Magnesium and Potassium are also plentiful in milk. And not to mention the all important sterols such as Cholesterol45.
The scientific literature shows there are no deleterious effects of moderate milk consumption, and conversely, there are a myriad of health benefits to be gained46.
4) Milk is economical, satiating, convenient and palatable.
Several pragmatic arguments can be raised as well. It is understood that the actual price of milk may differ between countries, however milk has traditionally been a cheap product across the world. It is an absolute comparative bargain when contrasted against other foods of the same nutritional quality. The palatability of milk remains entirely anecdotal although a large population no doubt enjoy the beverage. Its versatility in culinary applications is also noteworthy. And finally, milk scores well with satiety probably due to its protein content47,48,49.
Overview
Milk comprises of a complete macronutrient profile, complete amino acid profile, a superb micronutrient profile and extraordinary biological value, moreover milk offers health benefits, is favorably palatable, economical, convenient and is thoroughly satiable.
At 8g of quality protein per cup, milk can successfully contribute to meeting ones protein requirements, help stay in a positive nitrogen balance and facilitate the creation of an anabolic environment. Carbohydrates for sustained energy and glycogen storage are self-explanatory in their role to fuel workouts and recovery.
These are not merely perceived benefits, they are inherent within milk and few other foods can compare. There are few reasons to exclude it from your diet. A superficial analysis of milk and it's respective profiles have elucidated the nutritional superiority it boasts in the face of many other foods and food-groups entirely. Milk is a cornerstone food for successful development in muscularity and strength. I will end with a quote.
"Milk is quite literally better than steroids for a novice lifter to grow on, and no supplement produces the same effect." - Mark Rippetoe
No comments:
Post a Comment