Walnuts make bad cholesterol harmless
Walnuts protect against cardiovascular disease, and thanks to a small human study published by Ella Haddad in Nutrition Journal we better understand why. Walnuts prevent 'bad cholesterol' LDL from oxidising and thus reduce the chance of LDL causing damage to blood vessels.
Nuts & longevity
People who eat lots of nuts live longer than people who don't. This is mainly because nuts reduce the chance of developing fatal cardiovascular disease. Nutritionists agree on this, but how and why nuts have this effect remains an unknown quantity.
Researchers at Loma Linda University in the US tried to find out more about how walnuts work by doing an experiment on 16 adults. On one occasion the subjects were given breakfast that consisted of 90 g walnuts [Walnut] and on another occasion a breakfast based on oil, white bread and egg protein [Control].
After consuming the control meal, the amount of oxidised LDL in the blood rose. LDL is a bit like a molecular oil tanker, which transports cholesterol through your blood vessels. Oxidised LDL is like a leaking oil tanker. A small oil leak means that the blood vessel walls have to absorb lots of cholesterol and bad fats, and as a result the vessels become narrower.
After consuming walnuts the amount of oxidised LDL did not increase. The researchers believe that this was partly due to the vitamin E analogue gamma tocopherol. Walnuts contain large amounts of gamma tocopherol, and after eating walnuts the concentration of this protective vitamin rose in the subjects' blood.
Nuts also contain catechins. Together with the gamma tocopherol these reduce the effect of aggressive molecules, free radicals, the researchers believe. And as a result gamma tocopherol and catechins also protect LDL against oxidation.
The researchers base this theory on other observations: they found a higher antioxidant effect [ORAC] in the blood after the walnut meal and also less malondialdehyde. Malondialdehyde is a marker for free radical activity.
Nutr J. 2014 Jan 10;13:4.
The DNP effect of anacardic acid in cashew nuts 22.02.2014
Handful of almonds in the afternoon improves body composition 29.12.2013
Eat nuts or peanuts and live longer 28.12.2013