Sydney: Low protein, high carbohydrate diets could be just as effective as
low calorie diets at promoting a long life and good heart and digestive
health. New research from the University of Sydney's Charles Perkins Centre
shows the long-reported benefits associated with caloric restriction
diets could also be reached with a low protein, high carbohydrate diet. Published in Cell Reports,
the research marks 80 years since the publication of a seminal paper
showing that restricting calorie intake in rats by around 40 per cent
prolonged their lives. Since that time, caloric restriction without
starvation has been found to extend lifespan and improve metabolic
health in organisms from yeast cells and worms to mice and monkeys.
"We have known for many years that caloric restriction diets increase lifespan in all manner of organisms," said Professor Stephen Simpson, Academic Director of the Charles Perkins Centre and corresponding author of the paper, published in Cell Reports.
"However,
except for the fanatical few, no one can maintain a 40 per cent caloric
reduction in the long term, and doing so can risk loss of bone mass,
libido and fertility."
The research showed in mice that a low
protein, high carbohydrate diet provides the same benefits as caloric
restriction - a result researchers believe may also hold true in humans.
"There
is one downside. While a low protein, high carb diet is likely to have
beneficial effects later in life, it is also associated with an
increased food intake driven by protein appetite, which poses the risk
of weight gain.
"It still holds true that reducing food intake and
body weight improves metabolic health and reduces the risk of diseases
like type-2 diabetes, obesity and fatty liver disease.
"However,
according to these mouse data and emerging human research, it appears
that including modest intakes of high quality protein and plenty of
healthy carbohydrates in the diet will be beneficial for health as we
age."
"We've shown that when compared head-to-head, mice got the
same benefits from a low protein, high carbohydrate as a 40 per cent
caloric restriction diet. If the same applies to us, this would mean
healthier ageing, with more pleasure and less pain than caloric
restriction."
The results follow research
from the Charles Perkins Centre that showed a low protein, high
carbohydrate diet promotes longevity and good cardiometabolic health,
while a high protein, low carbohydrate diet leads to leaner body mass
and better measures of reproductive function, but also shortened
lifespan and poor cardiometabolic health.
The game-changing body
of work points to the balance and quality of macronutrients (protein,
carbohydrates and fat) - rather than caloric intake or the role of any
one nutrient - as the major factor in nutritional health.
"We have
again shown that changing the macronutrient composition of a diet is
vitally important, and in this case is a more feasible intervention than
caloric restriction for managing human health," Professor Simpson said.