Compounds

Fiber

The longevity nutrient hiding in plain sight.

~95% of Americans do not meet the recommended fiber intake

Why it matters for longevity

Dietary fiber feeds beneficial gut bacteria, regulates blood sugar, lowers cholesterol, and promotes healthy bowel function. A landmark meta-analysis in The Lancet found that people eating 25-29g of fiber daily had a 15-30% lower risk of all-cause mortality, heart disease, stroke, type 2 diabetes, and colorectal cancer compared to low-fiber diets. Every 8g increase in daily fiber was linked to a 5-27% reduction in these conditions.

How much you need

RDA

38g for men, 25g for women (adequate intake)

Optimal

Longevity researchers suggest 30-50g daily, closer to what ancestral diets provided.

Signs you might be low

  • Constipation or irregular bowel movements
  • Blood sugar spikes after meals
  • Feeling hungry soon after eating
  • High LDL cholesterol

Best food sources

FoodPer serving
Lentils, cooked (1 cup)15.6g
Black beans, cooked (1 cup)15g
Avocado (1 whole)10g
Raspberries (1 cup)8g
Oats, cooked (1 cup)4g

Key research

Reynolds A et al. (2019). Carbohydrate quality and human health: a series of systematic reviews and meta-analyses. The Lancet, 393(10170), 434-445.

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