They show that healthy aging is possible with dietary changes, but without the need for caloric restriction, and that poor health is not an inevitable part of the aging process.
Life expectancy has increased significantly in recent decades, but many older people live for years with health problems that deteriorate their quality of life. Changing certain habits can prevent disease, and scientists have long known that caloric restriction—reducing calorie intake without leading to malnutrition—is beneficial to health in old age, and may even increase longevity.
However, studies in mice have shown that lifelong calorie restriction is necessary to achieve these effects, and that the health benefits disappear as soon as a normal diet is returned. Now, a group of scientists from the Babraham Institute at the University of Cambridge (UK) have found an alternative link between diet and aging that may lead to better health throughout the life cycle based on studies with yeast.
Dr. Jon Houseley and his team have shown that healthy aging is possible with unrestricted dietary changes, potentially optimizing eating, and that poor health is not an inevitable part of the aging process. Their findings have been published in PLoS Biology.
“All these studies point to the same trend: to live a long and healthy life, a healthy diet from an early age makes all the difference”
“We show that diet early in life can set yeast on a healthier trajectory. By giving yeast a different diet without restricting calories, we were able to suppress senescence, when cells no longer divide, and the loss of fitness in aging cells,” said Dr. Dorottya Horkai, the study’s principal investigator.
Healthy aging through diet
Yeasts are a good model organism for studying aging because they share much of the cellular machinery found in animals and humans. This avenue of yeast research helps to find a way to promote healthy aging through diet that is easier to carry out than severe and sustained caloric restriction, although more research is needed.
Instead of growing yeast on their usual glucose-rich diet, the researchers switched their diet to galactose and found that many molecular changes that normally occur during aging did not occur. The galactose-grown cells remained as fit as young cells, even late in life, despite not living longer, showing that the period of ill-health towards the end of life was dramatically decreased.
“Most importantly, the change in diet only works when the cells are young, and the diet actually has little influence on the old yeast. It is difficult to translate what youth means between yeast and humans, but all these studies point to the same trend: to live a long and healthy life, a healthy diet from an early age makes all the difference” concludes Dr. Houseley.
