DEEP DIVE

A three-year study from the DO-HEALTH trial has provided some of the strongest evidence yet that a simple supplement might influence biological aging.

Researchers followed 777 adults aged 70 and over, randomly assigning them to take daily omega-3, vitamin D, both, or placebos. They also took part in either a simple exercise programme or a control activity. Blood samples collected at the beginning and end of the trial were used to measure four different biological aging clocks.

Omega-3 produced the clearest result. Taking 1 gram a day was linked to slower changes on three of the four clocks: PhenoAge, GrimAge2 and DunedinPACE. The researchers estimated that the effect amounted to roughly three to four months less biological aging over the three-year study period.

The study has some important strengths. It was randomized and placebo-controlled, lasted three years, and tested several different aging measures rather than relying on a single clock. That makes the finding more interesting than results from small, short-term studies.

The researchers were measuring biological changes rather than lifespan, so the study cannot show that omega-3 makes people live longer. But the results suggest that something as simple as adding omega-3 to the daily routine could help preserve a younger biological profile as we age. If future research confirms the finding and links it to better health outcomes, it could become another useful tool for supporting healthy aging.

Match the study dose: The DO-HEALTH trial used about 1 gram of EPA and DHA per day — the two main types of omega-3. The daily dose was 330 mg of EPA plus 660 mg of DHA, sourced from marine algae.

If you’re comparing supplements, look for the amount of EPA + DHA on the label. Don’t rely on the larger “total fish oil” or “total omega-3” number, as it may include other oils that were not used in the study.

Make It Daily And Boring: The signal took three years to measure. Consistency matters more than cycling mega doses. If you already eat oily fish several times a week, that covers a lot of the same ground.

MYTH BUSTER

The famous advice to drink eight glasses of water a day is much less scientific than it sounds. The closest original source is a 1945 US Food and Nutrition Board recommendation of around 2 to 2.5 litres of water a day, but it also pointed out that much of that water comes from food. Somewhere along the way, that important detail disappeared.

A much larger study published in 2022 measured water turnover in 5,604 people from 23 countries, ranging from newborns to people aged 96. The researchers found that water needs vary enormously depending on body size, activity, climate, age and pregnancy. Two people can need very different amounts of water on the same day.

And water turnover isn't the same as how much you need to drink. Food provides a significant amount of your daily water, as does the water produced naturally by your metabolism.

So rather than counting glasses, use your body as a guide. Drink when you're thirsty, increase your intake when you're exercising or in hot weather, and aim for urine that's a pale straw colour rather than dark yellow.

QUICK HITS

A three-year omega-3 signal across several aging clocks, the quiet collapse of the eight glasses rule, and three quick reads for the weekend. Useful health decisions are usually smaller and slower than the headlines suggest.

Take care of yourself,
The Vitality Club