How Does What We Eat Affect How We Age?

The results of the study highlight the importance of thinking about nutrition holistically.

According to recent research from the Butler Columbia Aging Center at Columbia University Mailman School of Public Health, the answer to a seemingly simple question – how does what we eat impact how we age – is unavoidably complex.

While the majority of analyses had focused on the effects of a single nutrient on a single outcome, a conventional, unidimensional approach to understanding the effects of diet on health and aging no longer gives us the full picture. A healthy diet needs to be thought of based on the balance of ensembles of nutrients, rather than by optimizing a series of nutrients one at a time. Up until recently, little was understood about how dietary variation that occurs naturally in humans impacts aging. The findings were recently published in the journal BMC Biology.

“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.

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“This study, therefore, 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.”

Cohen also notes that the findings are consistent with other studies demonstrating the need for higher protein consumption in older people, in particular, to counter sarcopenia and decreased physical performance associated with aging.

The researchers identified key patterns of particular nutrients related to minimal biological aging by using multidimensional modeling tools to investigate the impact of nutrient intake on physiological dysregulation in older adults.

“Our approach presents a roadmap for future studies to explore the full complexity of the nutrition-aging landscape,” observed Cohen, who is also affiliated with the Butler Columbia Aging Center.

The researchers analyzed data from 1560 older men and women, aged 67-84 years selected randomly between November 2003 and June 2005 from the Montreal, Laval, or Sherbrooke areas in Quebec, Canada, who were re-examined annually for 3 years and followed over four years to assess on a large-scale how nutrient intake associates with the aging process.

Aging and age-related loss of homeostasis (physiological dysregulation) were quantified via the integration of blood biomarkers. The effects of diet used the geometric framework for nutrition, applied to macronutrients and 19 micronutrients/nutrient subclasses. Researchers fitted a series of eight models exploring different nutritional predictors and adjusted for income, education level, age, physical activity, number of comorbidities, sex, and current smoking status.

Four broad patterns were observed:

• The optimal level of nutrient intake was dependent on the aging metric used. Elevated protein intake improved/depressed some aging parameters, whereas elevated carbohydrate levels improved/depressed others;
• There were cases 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 (‘homeostatic plateaus’).
• Optimal levels of one nutrient often depend on levels of another (e.g. vitamin E and vitamin C). Simpler analytical approaches are insufficient to capture such associations.

The research team also developed an interactive tool to allow users to explore how different combinations of micronutrients affect different aspects of aging.

The results of this study are consistent with earlier experimental work in mice showing that high-protein diets may accelerate aging earlier in life, but are beneficial at older ages.

“These results are not experimental and will need to be validated in other contexts. Specific findings, such as the salience of the combination of vitamin E and vitamin C, may well not replicate in other studies. But 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,” said Cohen.

Reference: “Multidimensional associations between nutrient intake and healthy ageing in humans” by Alistair M. Senior, Véronique Legault, Francis B. Lavoie, Nancy Presse, Pierrette Gaudreau, Valérie Turcot, David Raubenheimer, David G. Le Couteur, Stephen J. Simpson and Alan A. Cohen, 1 September 2022, BMC Biology.
DOI: 10.1186/s12915-022-01395-z

The study was funded by the Australian Research Council, the Canadian Institutes of Health Research, the Quebec Research Fund (FRQ), and the Quebec Network for Research on Aging.