Many dietary factors have been studied for their role in longevity, including dietary composition (the types and proportions of different foods and macronutrients in the diet), energy intake and fasting. In a recent narrative review published in the scientific journal Cell, well known longevity researcher Dr Volter Longo and colleague Rozalyn Anderson provide an overview of nutrition research in both animals and humans looking at the role of diet in longevity, ageing and age-related disease. The review discusses the role of energy (Calories or kilojoules) restriction and fasting, including time restricted eating and periodic fasting. They also discuss dietary macronutrient composition, including low-carbohydrate and ketogenic diets, diets low in protein and specific amino acids, and low fat and high fat diets. Lastly, they discuss vegan, vegetarian and pesco-vegetarian diets and their role in ageing. Based on the findings from all the studies discussed in their review, the authors suggest that the research to date points towards the following eating patterns to achieve healthy longevity:
- Moderate-to-high carbohydrate intake (45-60% of energy), coming mainly from minimally-refined carbohydrate-containing foods including fruits, vegetables, legumes and wholegrains.
- For those under the age of 65, a relatively low but sufficient protein intake (10-15% of energy) that is mostly plant-based, including a high intake of legumes (they are low in methionine which has been shown to promote ageing) and which may also include regular consumption of fish and other seafood. However, for those aged over 65 years, a higher protein intake may be needed to avoid loss of lean body mass and frailty, particularly as total energy intake decreases.
- A fat intake of around 25-35% of energy, mostly from plant-based sources. This would include foods such as avocado, nuts, seeds and olives, and oils made from these foods.
- Eating within a 11-12 hour time period each day. For example, having your first meal at 7am and finishing your last meal before 6–7pm.
They also suggest that some individuals aged 18 to 70 years may benefit from periodic fasting, up to 3-4 times per year. The Fasting Mimicking Diet (FMD), designed and studied by Dr Longo, is a plant-based low energy diet which is low in protein and carbohydrate and high in healthy fats. It is designed to replace water-only fasting but still provide the beneficial metabolic responses seen with traditional fasting. The FMD diet has been shown to lower insulin-like growth factor 1 (IGF-1), blood pressure, total cholesterol, and inflammation, particularly in at-risk individuals, such as those with insulin resistance. IGF-1 plays an important role in growth and has been found to be a major regulator of the ageing process.
However, they also caution that the longevity diet should be personalized based on an individuals characteristics including their genome, body size, level of adiposity, biological age, sex, and health status in order to prevent the person from becoming malnourished, and to prevent frailty and diseases that may result from reduced bone or muscle mass or low blood cell counts. This is particularly important for those who are 65 years or older.
- Longo VD, Anderson RM. Nutrition, longevity and disease: From molecular mechanisms to interventions. Cell. 2022
Dr Kate Marsh is an is an Advanced Accredited Practising Dietitian, Credentialled Diabetes Educator and health and medical writer with a particular interest in plant-based eating and the dietary management of diabetes and polycystic ovary syndrome (PCOS).
Contact: Via her website www.drkatemarsh.com.au