Longevity and nutrition: How do carbs, fats affect life expectancy?

Evan Walker
Evan Walker TheMediTary.Com |
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Extreme dietary habits related to carbohydrate and fat consumption may affect longevity, a new study suggests. Image credit: GraphicaArtis/Getty Images.
  • When it comes to longevity, consuming too little in the way of carbohydrates and fats can shorten one’s lifespan, according to a new Japanese study.
  • The study finds that men who eat too few carbohydrates daily may increase their risk of dying, while women who consume insufficient quantities of fat may do the same.
  • The researchers studied people in Japan, so the findings may or may not apply as well to Western populations.

A new study from Nagoya University Graduate School of Medicine in Japan finds that going to extremes with carbohydrates and fats can shorten one’s lifespan. However, the hazard differed for men and women. All the study participants were in fit condition at recruitment.

The study found that men who ate too few carbohydrates significantly increased their risk of all-cause mortality. At the same time, women who consumed too little fat had a marginally higher risk of all-cause and cancer-related mortality.

The authors of the study paint a complex picture of Healthy eating in terms of carbohydrates and fats, overall suggesting that going to any extreme may negatively affect longevity.

The study appears in The Journal of Nutrition.

If men require at least 40% of their calories from carbohydrates to avoid reducing their longevity, why might that be, and why might they struggle to obtain the necessary carbs?

Prof. Van Horn suggested that “[i]n this study, [this is] likely due to poor dietary quality, poverty-related lack of adequate healthy care, smoking, [and] alcohol.“

“Diets low in carbohydrates, lack dietary fiber, and nutrients such as magnesium, potassium, vitamin C, and B vitamins, which are essential for our bodies to thrive. When we lack these protective nutrients, it can increase the risk of some cancers.”

– Michelle Routhenstein

The study suggests a shortfall in bioactive dietary components may be at play. Specifically, the authors mention fiber, heme iron, vitamins, minerals, branched-chain amino acids, fatty acids, and phytochemicals as being in short supply.

The authors of the study also mention that a diet lacking in plant sources — particularly when animal products make up the difference — has been seen to encourage inflammatory pathways, cause more rapid biological aging, and produce oxidative stress.

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