Nature, in her infinite intelligence, has gifted us millions of different proteins that supply the music and instruments of the body’s orchestra. These proteins are assembled from twenty amino acids joined in fifty to tens of thousands of different combinations.
Proteins carry most of the trillions of body cells’ workload. Proteins provide bodily tissues and organs, from the executive brain and mighty muscle to the modest skin, hair and nails, with structure and regulate their activities—including thousands of chemical reactions, enzyme production, signal transmission, and physical movement.
Amino acids can’t be stored, so need to regularly come from food. If consulting recommended daily allowances (RDAs), or recommended daily intakes (RDIs—Australian version), popular discourse claims we eat too much protein. Nutrition experts who congregated for two Protein Summits in Washington, US, disagree.
The RDA, or RDI, is calculated to estimate how much of a nutrient will fulfil the body’s basic nutritional needs. Recommended protein intakes average 0.8 grams per kilogram of body weight per day in healthy adults, equating to 10% of most people’s daily calories.
The average person consumes 16% of their daily calories as protein. Although this exceeds the RDA, the Protein Summit consensus, published in the American Journal of Clinical Nutrition in 2015, suggests people should eat at least double that, or around 15% to 25% of daily calories from protein depending on age and activity levels for optimal health—particularly preservation of muscle mass, strength and fat-burning capacity.
Every year, a third of Australians over 65 fall at least once—that’s around a million older adults falling over, potentially increasing to 2.7 million by 2050 as the population ages. Not only can falls cause cuts, bruises, broken bones, disability and even death, costs are estimated to blow out to $1.4 billion by 2051.
That muscles need protein is well-known—less well appreciated is that 50% of bone volume and about a third of bone mass is made from protein. Dietary protein is critical for making and maintaining bones throughout life, but this has not been considered in recommended intakes.
Protein’s importance for bone health is further suggested by its ability to increase insulin-like growth factor (IGF-1; a growth hormone), calcium absorption and muscle mass.
A systematic review and meta-analysis, April 2017, found high compared to low protein intake was associated with 16% reduced incidence of hip fractures. They reported correlations between protein intake and bone mineral density, warranting further investigation. Also meriting research is whether increased protein can prevent or treat osteoporosis.
All in all, the review supports protein intakes above the RDA for preventing hip fractures and bone mineral density loss, concluding “This is the first systematic review of its kind that shows consuming protein above current recommended levels is beneficial for bone health.”
The review did not find any difference between plant and animal protein sources for preventing bone loss, but noted a dearth of data from which to draw definitive recommendations. However, protein quality matters.
Posted by ProPortion Foods Blog on Jan 15, 2018 in Nutrition
Most people are aware that nutrition plays a key role in maintaining good health. But the age-old question remains: what constitutes ‘good nutrition’ and what should we be eating?
There is no doubt that many people are confused about what to eat. Statistics support this:
Much research has been published based on the health impact of different diets, macro and micronutrients, food intake timing and other nutrition and health related aspects. Studies based on similar parameters often lead researchers to draw different conclusions from one another, or to identify differing cause/effect relationships.
However, few ordinary people read scientific papers or reviews in technical journals. The masses become aware of this type of information via the media, whether formal or social. Information that attracts most media attention tends to be either radical in nature, different, or of popular interest and is filtered for their specific audiences. This can lead to deletions and distortions and an emphasis that may only partially reflect the relevant study.
The media tends to offer information in bite-sized chunks, with headlines designed to attract attention. This lends itself to over-simplification and speculation. It can also follow or create fads and trends (for example, today focusing on the ‘evils’ of sugar, tomorrow on the benefit of dark chocolate).
Apart from the media, one of the biggest influencers on the average person is their friends and family. More people cite their friends and family as an influence on food choices than their healthcare practitioner. That means that we’re more likely to believe someone with no nutritional education than a qualified expert in the field.
People tend to believe that more expensive food options are healthier, even when the nutritional content of comparable foods is identical. Similarly, fresh foods are generally considered healthier than their canned or frozen counterparts.
It’s clear that many people are confused about how to eat a generally healthy diet .
In an ideal world, an individual’s food intake should be tailored to meet their specific needs, taking into account their life stage, lifestyle and preferences. Older adults, as an example, have a greater need for calcium and vitamin D for bone health. They also need to consume sufficient energy and protein to maintain optimal health.
But no matter what an individual’s needs, some things are generally accepted by dietitians and nutritionists as promoting good health:
As regards what constitutes a ‘best diet’, it is interesting to note the observation from the World Health Organization that any diet approach that works for one person will not necessarily work for someone else .
When all is said and done, it’s easy to understand why consumers are so confused about nutrition and what constitutes a healthy, or balanced, diet. There is no ‘one size fits all’ definition and the plethora of information and diversity of opinion (often ill-informed) makes it challenging for most people to know what to believe and how to act. There is most definitely a role here for better consumer education but the question remains: by whom and how?
Animal protein – particularly whey powder – is popularly endorsed as the best source of amino acids for boosting muscle strength. But a closer look at the research suggests that plant proteins could be just as effective for building and maintaining lean muscle mass.
Whey protein contains more of the amino acid leucine than plant proteins. Extensive research shows that leucine activates muscle protein synthesis – i.e. helps muscle to use the protein. This is thought to explain its superior benefits for building lean muscle and strength after resistance training.
However, the evidence derives from studies of whey protein’s short-term impact over 3 to 4 hours. A recent meta-analysis combined nine studies that compared soy protein with various animal proteins over 6 weeks or more (5 studies tested whey and 4 used beef, milk or dairy protein).
Overall, the analysis found that combining protein supplementation with resistance training exercises (bench press and squat) increased muscle strength. But the effects of soy protein did not differ from whey powder or the other animal proteins.
Looking at whole dietary patterns, the Framingham Third Generation Study found last year that people with lower protein intakes had lower lean mass and muscle strength. But they also found no difference between the different types of protein.
According to Health.com, lead author Kelsey Mangano says, “As long as a person is exceeding the recommended daily allowance for protein, no matter the source in their diet, they can improve their muscle health.”
Losing muscle mass is one of the biggest health challenges of aging. Lean muscle does so much more than endow our bodies with a shapely physique.
Older adults need to maintain lean muscle mass to prevent falls, a major problem in aging that results in physical injury, reduced quality of life, and death.
Muscles store glucose to provide energy and can protect against diabetes and heart disease. Age-related loss of muscle mass can lead to sarcopenia, also associated with reduced quality of life, hospital admissions and chronic conditions like poor lung function and breast cancer risk.
Proteins are made from 20 amino acids arranged in thousands of different combinations. Nine amino acids are “essential” – i.e. we need to get them through dietary sources.
Animal proteins include meat, fish, chicken, eggs, and dairy foods. Protein also derives from abundant plant foods including nuts, legumes, seeds, lentils, grains, and even hemp.
Most plant protein sources are incomplete – i.e. they don’t contain all essential amino acids. Proteins derived from animal sources are complete; hence animal protein was deemed to be superior.
However, eating combinations of plant sources provides a complete protein, and it’s now established that the body can store amino acids, so a whole amino acid contingent doesn’t need to be eaten in one meal.
Most importantly, regardless of the source, research suggests that older adults who eat 1 gram of protein per kg of body weight each day are less likely to suffer disability. Combining this with regular physical movement will yield the greatest benefits.