Editing Fat (section)

==={{anchor|Monounsaturated fat}}{{anchor|Polyunsaturated fat}}Monounsaturated vs. polyunsaturated fat===
<!--Merged from [[monounsaturated fat]] -->
<!--Merged from [p[olyunsaturated fat]]-->

[[File:Fat triglyceride shorthand formula.PNG|thumb|300px|Schematic diagram of a triglyceride with a saturated fatty acid (top), a monounsaturated one (middle) and a polyunsaturated one (bottom).]]

The most common fatty acids in human diet are unsaturated or mono-unsaturated. Monounsaturated fats are found in animal flesh such as red [[meat]], whole milk products, nuts, and high fat fruits such as olives and avocados. Olive oil is about 75% monounsaturated fat.<ref name="abdu2017" /> The high oleic variety [[sunflower oil]] contains at least 70% monounsaturated fat.<ref name="huth2015" /> [[Canola oil]] and [[cashew]]s are both about 58% monounsaturated fat.<ref>{{Cite news |last=Shute |first=Nancy |date=2012-05-02 |title=Lard Is Back In The Larder, But Hold The Health Claims |language=en |work=NPR |url=https://www.npr.org/sections/thesalt/2012/05/02/151868208/lard-is-back-in-the-larder-but-hold-the-health-claims |access-date=2022-06-29}}</ref> [[Tallow]] (beef fat) is about 50% monounsaturated fat,<ref name="nrc1974" /> and [[lard]] is about 40% monounsaturated fat.<ref>{{Cite web |date=2015-04-13 |title=Ask the Expert: Concerns about canola oil |url=https://www.hsph.harvard.edu/nutritionsource/2015/04/13/ask-the-expert-concerns-about-canola-oil/ |access-date=2022-06-29 |website=The Nutrition Source |language=en-us}}</ref> Other sources include [[hazelnut]], [[avocado oil]], [[macadamia nut oil]], [[Grape seed oil|grapeseed oil]], groundnut oil ([[peanut oil]]), [[sesame oil]], [[corn oil]], [[popcorn]], [[whole grain]] [[wheat]], [[cereal]], [[oatmeal]], [[almond oil]], [[hemp oil]], and [[tea-oil camellia]].<ref name="aizp2015" />

Polyunsaturated fatty acids can be found mostly in nuts, seeds, fish, seed oils, and [[oyster]]s.<ref name="osu2014" />

Food sources of polyunsaturated fats include:<ref name="osu2014" /><ref name="usda2011a" />
{| class="wikitable sortable"
|-
! Food source (100g) !! Polyunsaturated fat (g)
|-
| [[Walnuts]] || 47
|-
| [[Canola oil]] || 34
|-
| [[Sunflower seed]]s || 33
|-
| [[Sesame seed]]s || 26
|-
| [[Salvia hispanica|Chia seeds]] || 23.7
|-
| [[Peanut#Dry roasted peanuts|Unsalted peanuts]] || 16
|-
| [[Peanut butter]] || 14.2
|-
| [[Avocado oil]] || 13.5<ref name="self0000" />
|-
| [[Olive oil]] || 11
|-
|[[Safflower oil]]
|12.82<ref name="usda2015b" />
|-
| [[Seaweed]] || 11
|-
| [[Sardines]] || 5
|-
| [[Soybeans]] || 7
|-
| [[Tuna]] || 14
|-
| [[Salmon as food|Wild salmon]] || 17.3
|-
| [[Whole grain]] [[wheat]] || 9.7
|}

==== Insulin resistance and sensitivity ====

MUFAs (especially oleic acid) have been found to lower the incidence of [[insulin resistance]]; PUFAs (especially large amounts of [[arachidonic acid]]) and SFAs (such as [[arachidic acid]]) increased it. These ratios can be indexed in the [[phospholipid]]s of human [[skeletal muscle]] and in other tissues as well. This relationship between dietary fats and insulin resistance is presumed secondary to the relationship between insulin resistance and [[inflammation]], which is partially modulated by dietary fat ratios ([[Omega-3 fatty acids|omega−3]]/[[Omega-6 fatty acids|6]]/[[Omega-9 fatty acids|9]]) with both omega−3 and −9 thought to be anti-inflammatory, and omega−6 pro-inflammatory (as well as by numerous other dietary components, particularly [[Health effects of polyphenols|polyphenols]] and exercise, with both of these anti-inflammatory). Although both pro- and anti-inflammatory types of fat are [[biology|biologically]] necessary, fat dietary ratios in most US diets are skewed towards omega−6, with subsequent disinhibition of inflammation and potentiation of insulin resistance.<ref name="stor1996" /> This is contrary to the suggestion that polyunsaturated fats are shown to be protective against insulin resistance.{{cn|date=January 2023}}

The large scale KANWU study found that increasing MUFA and decreasing SFA intake could improve insulin sensitivity, but only when the overall fat intake of the diet was low.<ref name="vess2001" /> However, some MUFAs may promote [[insulin resistance]] (like the SFAs), whereas PUFAs may protect against it.<ref name="love2002" /><ref name="fuku2004" />{{clarify|date=August 2020}}

====Cancer====
Levels of oleic acid along with other MUFAs in red blood cell membranes were positively associated with breast cancer risk. The [[saturation index]] (SI) of the same membranes was inversely associated with breast cancer risk. MUFAs and low SI in erythrocyte membranes are predictors of postmenopausal breast cancer. Both of these variables depend on the activity of the enzyme [[delta-9 desaturase]] (Δ9-d).<ref name="pala2001" />

Results from [[observational study|observational clinical trials]] on PUFA intake and cancer have been inconsistent and vary by numerous factors of cancer incidence, including gender and genetic risk.<ref name="nihw2016" /> Some studies have shown associations between higher intakes and/or blood levels of omega-3 PUFAs and a decreased risk of certain cancers, including breast and colorectal cancer, while other studies found no associations with cancer risk.<ref name="nihw2016" /><ref name="patt2011xk" />

====Pregnancy disorders====
Polyunsaturated fat supplementation was found to have no effect on the incidence of pregnancy-related disorders, such as [[hypertension]] or [[preeclampsia]], but may increase the length of [[gestation]] slightly and decreased the incidence of early premature births.<ref name="osu2014" />

Expert panels in the United States and Europe recommend that pregnant and lactating women consume higher amounts of polyunsaturated fats than the general population to enhance the DHA status of the fetus and newborn.<ref name="osu2014" />