Does avocado help you absorb vitamins?
Avocado measurably helps with the absorption of fat-soluble vitamins and carotenoids from other vegetables. A few slices on your salad or alongside your carrot dish is already enough to make a difference.
Avocado is rich in monounsaturated fat, and it is precisely that fat which drives the absorption of fat-soluble compounds. Vitamins A, D, E and K, and pigments such as beta-carotene and lutein, barely reach your bloodstream without a little fat in the same meal. As little as 3 to 5 grams of fat per meal helps, and half an avocado (68 grams) already delivers around 6 to 7 grams.
The effects measured in people are strikingly large. Adding avocado to salsa increased the absorption of lycopene 4.4 times and of beta-carotene 2.6 times compared with avocado-free salsa. With salad the effect was even greater: beta-carotene rose 15.3 times, alpha-carotene 7.2 times and lutein 5.1 times. These figures come from small studies with around ten participants each, but the mechanism is clear and the effects are biologically plausible.
With carrots and tomato sauce, the conversion to vitamin A was also measured. Avocado alongside tomato sauce increased the conversion to vitamin A 4.6 times. With raw carrot it was as much as 12.6 times. This means that avocado not only helps with absorbing carotenoids from other vegetables, but also with converting them into a form the body can use directly.
Lutein is a compound that accumulates in the retina and is linked to healthy eyes. Older adults who ate one avocado every day for six months had 25% more lutein in their blood afterwards, compared with 15% in the control group. That study was funded by an avocado industry organisation, which is worth bearing in mind, but the finding fits well with the other evidence. Half a Hass avocado (68 grams) also provides 185 micrograms of lutein on its own.
In short: if you eat vegetables rich in beta-carotene (carrots, spinach, tomato), avocado is a practical way to absorb far more of them. You do not need a whole avocado for this: even a few slices or a drizzle of avocado oil over your salad makes a measurable difference.
The findings on absorption come from several randomised studies with small groups of 11 to 12 participants. Because the comparisons are neatly controlled (same meal, with or without avocado), cause and effect can be reasonably assumed, even though the groups are small. The study on lutein and eyes (forty older adults, six months) was funded by an avocado industry organisation; the finding is consistent with the rest of the evidence but warrants a little extra caution. The underlying mechanism of fat-soluble vitamins is also supported by multiple review articles; the precise optimal fat dose for humans has not yet been fully established.