A higher protein diet - alongside exercise - may contribute to reducing the risk of diabetes and cardiovascular disease in older adults, according to new research.
Higher protein diets have soared in popularity across the globe in the past decade.
And whey protein shakes in particular are used by countless gym-goers in an effort to increase strength, gain muscle and to support fat loss.
But now a new study from academics at the School of Health Sciences, Liverpool Hope University and The Department of Medicine, University of Melbourne, Australia, has found that a higher protein diet might also boost inner cardiovascular and metabolic health, as well as helping to sculpt a better body.
The study focused on a group of 100 older adults, men and women, from the UK with an average age of 68 years old.
The researchers suggest that whey protein enriched with ‘Leucine’ - an essential amino acid used in the biosynthesis of proteins which can also help control blood sugar through the hormone insulin - can lower ‘low-density lipoproteins’, or ‘LDL’ cholesterol levels.
That’s the ‘bad’ type of cholesterol - which clings to arterial walls and makes you more likely to have heart problems or a stroke, according to the NHS.
What’s more, some test subjects saw cardiovascular health benefits from protein supplementation alone, without necessarily needing to exercise.
Dr Ben Kirk, writing in the Journal of Cachexia, Sarcopenia and Muscle - a prestigious journal ranked Number 1 in global ranking of Geriatrics and Gerontology and Number 9 in global ranking of Medicine - concludes: “We report that 16 weeks of leucine-enriched whey protein supplementation alone and combined with resistance-based exercise improved cardiometabolic health markers in older adults.
“More specifically, increasing total protein intake by means of supplementation reduced LDL-cholesterol and serum insulin, and improved estimates of insulin resistance when compared with exercise or control groups alone.”
Dr Kirk, a Research Fellow at the Australian Institute for Musculoskeletal Science (AIMSS), worked with Prof Omid Khaiyat and Associate Professor Farzad Amirabdollahian from Liverpool Hope University, as well as other experts from the University of Melbourne
And the team says the findings are particularly important for the world’s ageing population.
Advancing years are, they say, linked to a decline in ‘cardiometabolic’ health, with older adults at risk of developing problems such as insulin resistance, type 2 diabetes, arterial stiffness, and obesity.
Older people also typically suffer from a debilitating loss of muscle mass which increases the risk of disability and frailty.
Hope’s Associate Professor Farzad Amirabdollahian, who has led this work, says the results are ‘fascinating’, explaining: “There are several previous studies demonstrating the musculoskeletal health benefits of exercise and high protein diet.
“But in the current study, we have examined the impact of a high protein diet, with or without exercise, on a range of blood biomarkers associated with risk of diabetes and cardiovascular disease.
“And it is fascinating to see the impact of a high protein diet and exercise on the reduction of risk of these diseases.”
When looking at the test subjects who just received the supplement and weren’t tasked with exercise, he adds: “Subjects randomised to receive protein supplementation alone also saw an improved sensitivity of the body to respond to insulin, a hormone which helps control the amount of sugar in your blood.
The research itself split the test subjects - 52 per cent of which were women - into four groups. Alongside a control, some were just asked to exercise, others tasked with exercise and consuming a popular, well-known whey protein drink three times per day, and the final group purely enjoyed the whey protein shake without exercising.
The amount of the whey protein - a concentrated form of milk protein - which was given to test subjects depended on their individual body weight.
The ‘Exercise’ and the ‘Exercise and Protein’ groups performed one bout of ‘circuit training’ exercises once a week, which included things like lunges, star jumps and a mini obstacle course.
They were also put through resistance-based exercise - including shoulder presses and bicep curls - twice per week, under the watchful eye of qualified exercise scientists.
After 16 weeks, researchers saw ‘significant’ declines in LDL-cholesterol levels in both the ‘Exercise and Protein’ and the solely ‘Protein’ groups.
There were also positive changes in insulin levels for both the ‘Exercise and Protein’ and the ‘Protein’ cohorts.
The University of Melbourne’s Dr Kirk and Hope’s Associate Professor Amirabdollahian say that what’s really driving the positive effects noticed is likely to be the ‘composite of the supplement - and particularly the collective high concentration of leucine - at 3 to 5 g per drink.
The academics also referred to ‘adipokine resistin’- a hormone linked with obesity as well as the production of LDL-cholesterol on the liver - by concluding: “In addition, protein supplementation alone - in the absence of exercise - conferred positive decreases in the adipokine resistin.”
While acknowledging that longer term studies are needed to confirm the findings, they add: “Elucidating this information will enable the efficacy and safety of higher vs. lower protein diets on cardiometabolic health to be further evaluated.”
This is not the first study emanating from Liverpool Hope University which considers the health of older adults.
In February last year, this same research team - including Dr Kate Mooney, Dr Ben Kirk, Associate Professor Amirabdollahian and Prof Khaiyat - revealed how a short four month programme of weight-based exercise saw ‘incredible’ improvements in muscle strength - up to 60 per cent gains - in a group of older adults.
Dr Mooney said at the time: “Our study shows that it’s never too late to start lifting weights.
“The improvement of muscular strength noted in this study is crucial for maintaining older adults’ independence, to enable them to carry out activities of daily living such as climbing stairs, walking to the shop and holding grocery bags.
“Losing mobility is one of the most debilitating issues facing older adults and exercise could help prevent this.
“Muscle weakness is a common cause of falls and fractures in the elderly and can extend hospitalisation and recovery times for older patients. It is also associated with increased risk of mortality in older adults.
“But resistance exercise - designed to increase muscle strength as well as functional ability and physical performance - could have a significant impact on prevention of age-related diseases.
“Older adults should be taking part in a combination of weight based training and aerobic exercise, at least two to three times per week, as per NHS recommendations. And it’s never too late to begin!”