Nutriton

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Chapter 12: The Antioxidant Nutrients

- start march 4 at ~ 42 mins -

Slide 1
* we produce a lot of reactive oxygen species (ROS) from reactions in the body, especially from energy metabolism * these ROS can damage the molecules in the body, especially in dna and rna molecules and lipids. This can have serious consequences on the health of the individual * one of the ways that the body deals with ROS is by having compounds that can help to neutralize the radicals or protect the body from exposure and getting damaged by them

Slide 2
* there are both vitamins and minerals that function as antioxidants * they quench free radicals which are things that are produced from normal metabolism, especially energy metabolism. Immune cells that fight against bacteria also release a lot of ROS because they help kill those foreign organisms. * minerals mainly function as cofactors for enzymes that are important in free radical prevention, for example the peroxidases and catylases that are involved in detoxifying some of the molecules like hydrogen peroxide that can cause damages in the body * apart from the vitamins and minerals, we have some other compounds called phytochemicals that don't fall in the vitamin or mineral categories. They are present especially in plants and they also help limit the damages that antioxidants can do * oxidation is a part of normal metabolism – so for example during oxidative phosphorylation leading to the generation of ATP you have oxidation and reduction reactions * unpaired electrons are free radicals and they are very reactive species that are present in the body and they can damage lipids, dna, rna and proteins. Dna and rna damages have implications for cancers

Slide 3
* help neutralize free radicals, preventing them from doing the damages that they do * antioxidants are stable whether they’re oxidized or reduced, unlike other compounds which become unstable when you add or remove electrons from them * so…antioxidants needed because they help to prevent damages that would otherwise occurs from free radicals that were exposed to because of normal metabolism and from our environment

Slide 4
* this slide summarizes some of the damages that can happen to the different components of the cells of our body * polyunsaturated fatty acids are more susceptible to oxidative damages compared to saturates fats because they have double bonds * dna and rna get oxidized and it can lead to wrong proteins being produced leading to specific problems * when proteins themselves get oxidized you affect the structure of the protein so the protein cant do what its supposed to do

- end March 4 -

- start march 6 –

Before we get back to antioxidants,

* how is potassium intake beneficial against hypertension? * many of the studies out there linking potassium and hypertension are usually epidemiologically studies arising from the DASH program – diet high in potassium were found to potentially be beneficial * one reason why this might be true is because when you have a lot of potassium in your diet, the body will try to get rid of it by excreting it. The process by which potassium is excreted also leads to an increase in sodium excretion (sodium diuresis or natriuresis). Also when you excrete sodium you remove fluid in the process which will reduce fluid volume/retention which will contribute to helping to reduce blood pressure * another possible link between high potassium intake and decreased blood pressure is the fact that unlike what sodium does, which increases calcium excretion, potassium tends to be protective of calcium and magnesium retention * lastly, potassium can also induce smooth muscle relaxation which will allow the blood vessels to relax and thereby reducing the pressure in the blood vessels * how does an increase in Na intake increase Ca excretion? the transporters in the kidney proximal tubules that take sodium...
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