What’s Best for Aging: Patterns of Nutrients or Specific Ones Only?
How does food, and the nutrients it provides, affect our health and lifespan? That’s a pretty complicated question because there’s so much variation in what we eat that it’s hard just to isolate the intake of one nutrient and explain how it affects aging. Yet, most research on this issue has concentrated on the effects of a particular nutrient on a single result.
A recent study by the University of Sydney researchers identified key patterns of specific nutrients associated with biological aging. In a survey of nutrition data on biological aging from 1560 older adults followed over four years, biological aging was minimized on relatively high carbohydrate and lower to moderate protein intakes. Also, combinations of nutrients with the most significant effects on minimizing biological aging included α-tocopherol, vitamin C, and trans-fatty acids. This approach presents a roadmap for future studies to explore the full complexity of the nutrition-aging landscape.
Diets Are Crazy Complex
Traditional methods for analyzing diet effects on health and aging have concentrated on a single nutrient or a small number of dietary characteristics. But nutrients have both individual and group effects. And key classes — such as proteins, carbohydrates, and fat energy sources — interact at the macro-level to influence metabolic, physiological, and cognitive performance.
As a result, rather than being the result of isolated processes, the seemingly different aspects of aging represent a more general loss of homeostasis in a complex dynamic system. The interpretation of the effects of a single nutrient or diet is likely to be pretty context-dependent, making the results of studies looking at just one dietary component suspect or more challenging to replicate and resulting in inconsistent findings across studies.
“Our ability to understand the problem has been complicated by the fact that both nutrition and the physiology of aging are highly complex and multidimensional, involving a high number of functional interactions,” said Alan Cohen, Ph.D., associate professor of environmental health sciences at Columbia Mailman School.
Are Nutrient Patterns Linked with Aging?
In this study, lead author Alistair M. Senior and colleagues dissected the effect of nutrition on biological aging from 1560 older adults followed over four years. The University of Sydney researchers looked at macronutrients and 19 micronutrient subclasses. They observed four broad patterns:
- The optimal level of nutrient intake was dependent on the aging metric used. Elevated protein and carbohydrate intake differentially altered aging parameters;
- There were non-linearities where intermediate levels of nutrients performed well for many outcomes (i.e., arguing against a simple more/less is better perspective);
- There is broad tolerance for nutrient intake patterns that don’t deviate too much from norms.
- Optimal levels of one nutrient often depend on levels of another (e.g., vitamin E and vitamin C).
Vital Vitamin E
In addition to these broad strokes, Senior and colleagues found that consuming high levels of α-tocopherol — a type of vitamin E — is associated with benefits. In the subject population, this level corresponds to 10.21 mg/day of α-tocopherol. The World Health Organisation recommended intake of α-tocopherol for those aged 65+ is 7.5 mg/day in females and 10 mg/day in males. So, the value highlighted in this study is not substantially beyond current guidelines.
One Size Doesn’t Fit All
These results advocate against the widespread practice of eating to maximize or minimize certain nutrients. “This study … provides further support to the importance of looking beyond ‘a single nutrient at a time’ as the one size fits all response to the age-old question of how to live a long and healthy life,” said Cohen. “The qualitative finding that there are no simple answers to optimal nutrition is likely to hold up: it was evident in nearly all our analyses, from a wide variety of approaches, and is consistent with evolutionary principles and much previous work.”
Future applications could include personalized approaches to aid in healthy aging and screening at-risk older adults to ensure they do not fall off the ‘dietary cliff’. Cohen also points out that the results are concordant with numerous studies highlighting the need for increased protein intake in older people, particularly to offset muscle decline and decreased physical performance associated with aging. The research team also developed an interactive tool to allow users to explore how different combinations of micronutrients affect various aspects of aging.
It is important to note that these results are not causal. They are only correlative. Experimental studies controlling diets for extended periods are necessary to validate these findings.
Senior, A.M., Legault, V., Lavoie, F.B. et al. Multidimensional associations between nutrient intake and healthy ageing in humans. BMC Biol 20, 196 (2022). https://doi.org/10.1186/s12915-022-01395-z