Alpha-carotene v death etc.

The new anti-oxidant on the block is alpha-carotene, which has been found in a study to cut the risk of all causes of death, of death from cardiovascular disease (CVD), and death from cancer.

Alpha-carotene, like beta-carotene, is a precursor to vitamin A in the human body, and is found in many types of fruit and vegetables.  However, it is likely that it impact here is as an anti-oxidant, where it is thought to be much more potent than beta-carotene.

The researchers followed up on over 15,000 US adults who had taken part in the Third National Health and Nutrition Examination Survey (NHANES) for an average of 14 years. They compared death risks against the level of alpha-carotene in the blood at the start of the study.

They compared the risks to those with a level 0 to 1 micrograms of alpha-carotene per litre of blood. Those on 2-3 micrograms cut their risk of death from all causes by 23%. At 4-5 micrograms, the cut was 27%. At 6-8 micrograms, the cut was 34%. Those on the highest level of 9 or more micrograms were 39% less likely to die from all causes.

The researchers did not tie up the amount of alpha-carotene in the blood with levels of fruit and vegetable consumption required to produce this.

Alpha-carotene is found most in carrots, sweet potatoes, squash, broccoli, kale, cantaloupe, brussels sprouts, kiwi fruit, spinach, mangos and spinach. Alpha-carotene is fat soluble, so dietary fat is required for proper uptake. Cooking may break down plant cell walls and improve absorption. 

Supplements containing alpha-carotene are dunaliella and palm oil/fruit. These also contain beta-carotene. Beta-carotene in supplement form is thought to be associated with an increased risk of lung cancer in those at risk (smokers, ex-smokers and those exposed to asbestos).

In the Archives of Internal Medicine the researchers concluded “Serum alpha-carotene concentrations were inversely associated with risk of death from all causes, CVD, cancer, and all other causes. These findings support increasing fruit and vegetable consumption as a means of preventing premature death.^“