Three findings that predict how you age. Two you can check yourself this weekend.

Three things we learned this week. One worth doing before Monday.

The numbers that best predict how you age are mostly not the ones on your annual physical. Three of them surfaced this week. Here is each, where it came from, and what it asks of you.

1. Grip strength predicts death better than blood pressure.

The PURE study, Leong et al, The Lancet 2015, measured grip strength in 139,691 adults across 17 countries. Each 5 kilogram drop in grip strength was associated with a 16 percent higher risk of dying from any cause. Grip outpredicted systolic blood pressure. It is not that your hands matter in themselves. Grip is a cheap proxy for total muscle, and muscle is what the body spends to stay alive. This is cohort data, an association rather than proof, but it is large, global, and consistent.

2. When you sleep beats how long you sleep.

A 2024 study in SLEEP, Windred et al, put wrist sensors on 60,977 UK Biobank adults and scored sleep regularity, the day-to-day consistency of when sleep starts and ends. Regularity predicted all-cause mortality better than sleep duration did. The most regular sleepers had 20 to 48 percent lower mortality risk than the least regular. Eight ragged hours lose to seven steady ones. The lever here is not a longer night. It is a fixed wake time.

3. Omega-3 is the supplement that earned its place.

Most of the supplement aisle is noise. Omega-3 is the exception. A 2021 pooled analysis in Nature Communications, Harris et al, combined 17 cohorts and 42,466 people. Those with the highest blood levels of EPA and DHA had 15 to 18 percent lower all-cause mortality than those with the lowest. Most Western adults sit near the bottom of that range. Monday's issue covered the test, the Omega-3 Index, that tells you where you stand. This is the supplement worth taking on the strength of the data alone.

Your Weekend Action

Two of these three you can check yourself, for free, before Monday. The third is a decision, not a test.

Of the three numbers above, which is the one you have never actually measured?