A study comparing the impact of diet versus drugs on the inner workings of cells has found nutrition has a much stronger impact.
The pre-clinical study by
the University of Sydney's Charles Perkins Centre suggests the makeup
of our diet could be more powerful than drugs in keeping conditions like
diabetes, stroke and heart disease at bay.
Conducted
in mice, the research showed nutrition (including overall calories and
macronutrient balance) had a greater impact on aging and metabolic
health than three drugs commonly used to treat diabetes and slow down
aging.
The findings are published in Cell Metabolism.
The
research builds on the team's pioneering work in mice and humans
demonstrating the protective role of diet and specific combinations of
proteins, fats and carbohydrates against aging, obesity, heart disease,
immune dysfunction and risk of metabolic diseases, such as type 2
diabetes.
Senior
author and academic director of the Charles Perkins Centre, Professor
Stephen Simpson, said drugs can also target the same biochemical pathways as
nutrients. There has been a huge effort to discover drugs aimed at
improving metabolic health and aging without requiring a change in diet,
he said.
"Diet
is a powerful medicine. However, presently drugs are administered
without consideration of whether and how they might interact with our
diet composition—even when these drugs are designed to act in the same
way, and on the same nutrient-signaling pathways as diet," said
Professor Simpson.
The
researchers set out to discover whether drugs or diet were more
powerful in remodeling nutrient-sensing and other metabolic pathways, as
well as whether drugs and diet interacted in ways that made them more
or less effective.
"We
discovered dietary composition had a far more powerful effect than
drugs, which largely dampened responses to diet rather than reshaped
them," said Professor Simpson.
"Given
humans share essentially the same nutrient-signaling pathways as mice,
the research suggests people would get better value from changing their
diet to improve metabolic health rather than taking the drugs we studied."
The study explained
The
research team designed a complex mouse study, involving 40 different
treatments, each with varying levels of protein, fat and carbohydrate
balance, calories and drug content.
The
study was designed to examine the impact of three anti-aging drugs on
the liver, which is a key organ in the regulation of metabolism.
A
key strength of the study was the use of the geometric framework for
nutrition developed by Professors Stephen Simpson and David
Raubenheimer. The framework made it possible for the team to consider
how mixtures and interactions of different nutrients influence health
and disease, rather than focusing on any one nutrient in isolation,
which is a limitation in other nutrition studies.
What did they find?
The results add another piece to the puzzle in our understanding of the mechanisms that link 'what we eat' with 'how we age."
The
researchers found calorie intake and the balance of macronutrients
(protein, fats and carbohydrates) in the diet had a strong impact on the
liver.
Protein
and total calorie intake had a particularly powerful effect not just on
metabolic pathways, but also on fundamental processes that control the
way our cells function.
For
example, the amount of protein eaten influenced activity in the
mitochondria, which are the part of cells that produce energy.
This
creates a downstream effect, as the amount of protein and dietary
energy eaten influences how accurately cells translate their genes into
the different proteins needed to help cells function properly and to
make new cells.
These two fundamental processes are linked to aging.
In
comparison, the drugs mainly acted to dampen the cell's metabolic
response to diet, rather than fundamentally re-shaping them.
However,
the researchers also found some more specific interactions between the
biochemical effects of the drugs and diet composition.
One
anti-aging drug had a bigger effect on changes in the cells caused by
dietary fat and carbohydrates, while a cancer and another diabetes drug both blocked the effects of dietary protein on the energy-producing mitochondria.
Lead
author Professor David Le Couteur of the Charles Perkins Centre and
Faculty of Medicine and Health said although the study was very complex,
it shows how important it is to study many different diets at the same
time, rather than just comparing a few different diets.
"This
approach is the only way we can get an overview of the interaction
between diet, our health and physiology," said Professor Le Couteur.
"We
all know what we eat influences our health, but this study showed how
food can dramatically influence many of the processes operating in our
cells. This gives us insights into how diet impacts on health and aging."