It is a question that middle-aged people trying to live longer might ponder – what diet is best – low-fat or low-carbohydrate?
According to researchers from China’s Peking University, the overall winner is a low-fat diet with lots of plant protein and some high-quality carbs, while some low-carb diets also tick the box.
Writing in the Journal of Internal Medicine, they said healthy low-fat diets and some low-carb diets could prolong the lives of middle-aged and older adults, while unhealthy low carb-diets could do the opposite.
The study looked at more than 370,000 people aged 50-71 over 23 years. It found that eating a healthy low-fat diet with lots of plant protein and high-quality carbs was related to fewer deaths from all causes, cardiovascular disease, and cancers.
In contrast, an overall low-carb diet and an unhealthy low-carb diet were associated with significantly higher total, cardiovascular and cancer mortality rates. A healthy low-carb diet was associated with slightly lower death rates.
Which diets can prolong life?
In the past, various short-term clinical trials have demonstrated the health benefits of low-carb and low-fat diets for weight loss and heart protection.
This latest study looked at the effects of the diets on mortality in middle-aged and older adults, by studying 371,159 people aged 50 to 71 years and the 165,698 deaths which occurred over a median follow-up of 23.5 years.
A healthy low-fat diet – characterised by a low intake of saturated fat and high intakes of plant protein and high-quality carbohydrates — was the overall winner, with it related to fewer deaths from all causes, from cardiovascular diseases and from cancers.
“Our results support the importance of maintaining a healthy low-fat diet with less saturated fat in preventing all-cause and cause-specific mortality among middle-aged and older people,” the authors wrote.
Med diet dementia link
Meanwhile other Chinese research released this week shows that sticking to a Mediterranean-style diet can reduce the risk of dementia risk.
Writing in JAMA Psychiatry, researchers from Zhejiang University School of Medicine looked at the dementia benefits of a particular Mediterranean-style diet, known as the MIND diet (Mediterranean–Dietary Approaches to Stop Hypertension (DASH) Intervention for Neurodegenerative Delay).
The diet emphasises natural plant-based foods, limits the intake of animal foods and foods high in saturated fat, and encourages people to eat berries and green leafy vegetables rich in vitamins and antioxidants.
The study, which looked at 200,000 people, found that those who stuck to the diet the best had a 17% lower risk of dementia compared with people with the worst adherence to the diet.