I used to get sunburn and terrible prickly heat on my arms and on my head, to the point where I had blisters on my scalp under my hair and it was very painful and itched like crazy. It would start around mid-June and stay until the end of August and was getting worse as I aged. I am in Spain, which is no bueno for this condition.
I switched to carnivore one October (lost a lot of weight) and the following summer I had no reaction to the sun at all.
A few years later a friend started making bacon at home, so I ate a lot (it was great) but a few months later the sunburn and prickly heat started to come back. I dropped the bacon and within a few weeks it was gone again.
I took as much omega 6 out my diet as possible but didn’t focus on adding in omega 3. Took about 18 months for me to properly notice that I didn’t burn anymore. I’m naturally “Scottish blue” in colour! I realised I hadn’t burned as a child in the 70s and 80s but then had burned most of my adult life when I had to start cooking for myself when the prevailing wisdom was for low fat/vegetable oil diets. It seems mum did know best cooking with butter and lard and beef dripping!
Mechanism: UV light can initiate photooxidation, a process where linoleic acid reacts with oxygen to form peroxides and other reactive oxygen species (ROS). This reaction typically involves the absorption of UV light, which provides the energy needed to form singlet oxygen (^1O_2) or other reactive intermediates.
Products: Photooxidation of linoleic acid can produce hydroperoxides, aldehydes, ketones, and other secondary oxidation products. These compounds can degrade further into smaller molecules like malondialdehyde (MDA) and 4-hydroxynonenal (4-HNE), both of which are markers of oxidative stress.
Formation of Harmful Compounds
Reactive Aldehydes: One of the significant products of linoleic acid photooxidation is 4-HNE. 4-HNE is a highly reactive aldehyde that can form adducts with proteins, DNA, and phospholipids, potentially leading to cellular damage and contributing to various diseases.
Volatile Compounds: The breakdown of hydroperoxides can also produce volatile compounds such as hexanal and pentanal, which are associated with rancidity and off-flavors in food products.
<snip>
I think it is likely that LA increases skin cancer?
I'm not nearly as strict about not consuming industrial seed oils as you and others are, but I find that avoiding fried food (which is all cooked in canola/soybean oil around me) for 2 weeks before we go on a beach vacation eliminates almost all of the sunburn I would normally get. I didn't see your reply about your estimate on the time frame to see results, but I think 2 weeks is the minimum needed, with longer periods improving things further.
This is something I noticed way back by now...we're talking 2010-ish after a couple of years "Paleo-ish" as it was thought of at the time, generally real food, low to moderate carbs.
I never linked it to n-6, just better diet overall (which of course would subsume lower n-6).
I was never a huge sunburn guy and usually, after I got a bad one early in the season, it seemed to be protective for future ones.
Anyway, it's been 15 years now without a serious burn. I'm very tanned right now (I live in Thailand, so tan in year-round), I try to hit the pool most bright sunny days at high noon. I never bake in the sun. I do stuff. Move around.
The big test was back in 2020, I spent a few months in rural Thailand building a house where it was outside many hours per day, no shirt ever (shorts only), and never caught a burn, not even tops of shoulders which are the most intensely exposed.
... Oh, another thing is my eye's sensitivity to sunlight. Way less. Before, I could not exist without my sunglasses, ever (took them up in earnest as a teen). Now, I wear them for style as much as anything. If I forget them it's no big. I can function fine without.
I'm sure I remember hearing of a study that found increased LA consumption was associated with increased rates of sunburn. I can't seem to find it though. Maybe it was just something discussed in an article about the broader inflammatory/oxidative effects of LA.
I made diet alterations in conjunction with intentionally increasing sun exposure. So I never noticed same clear association with sunburn and Omega-6 that other people seem to. I can spend the entire day in the sun in a high UV area now though without concern of burning, and my diet does happen to be very low in Omega-6. Would be interesting to eat a bunch of LA and see what happens. Don't particularly want to though...
I used to get sunburn and terrible prickly heat on my arms and on my head, to the point where I had blisters on my scalp under my hair and it was very painful and itched like crazy. It would start around mid-June and stay until the end of August and was getting worse as I aged. I am in Spain, which is no bueno for this condition.
I switched to carnivore one October (lost a lot of weight) and the following summer I had no reaction to the sun at all.
A few years later a friend started making bacon at home, so I ate a lot (it was great) but a few months later the sunburn and prickly heat started to come back. I dropped the bacon and within a few weeks it was gone again.
I took as much omega 6 out my diet as possible but didn’t focus on adding in omega 3. Took about 18 months for me to properly notice that I didn’t burn anymore. I’m naturally “Scottish blue” in colour! I realised I hadn’t burned as a child in the 70s and 80s but then had burned most of my adult life when I had to start cooking for myself when the prevailing wisdom was for low fat/vegetable oil diets. It seems mum did know best cooking with butter and lard and beef dripping!
Asking GPT4o - What is the effect of UV on LA?
Effects of UV Light on Linoleic Acid
Photooxidation
Mechanism: UV light can initiate photooxidation, a process where linoleic acid reacts with oxygen to form peroxides and other reactive oxygen species (ROS). This reaction typically involves the absorption of UV light, which provides the energy needed to form singlet oxygen (^1O_2) or other reactive intermediates.
Products: Photooxidation of linoleic acid can produce hydroperoxides, aldehydes, ketones, and other secondary oxidation products. These compounds can degrade further into smaller molecules like malondialdehyde (MDA) and 4-hydroxynonenal (4-HNE), both of which are markers of oxidative stress.
Formation of Harmful Compounds
Reactive Aldehydes: One of the significant products of linoleic acid photooxidation is 4-HNE. 4-HNE is a highly reactive aldehyde that can form adducts with proteins, DNA, and phospholipids, potentially leading to cellular damage and contributing to various diseases.
Volatile Compounds: The breakdown of hydroperoxides can also produce volatile compounds such as hexanal and pentanal, which are associated with rancidity and off-flavors in food products.
<snip>
I think it is likely that LA increases skin cancer?
I'm not nearly as strict about not consuming industrial seed oils as you and others are, but I find that avoiding fried food (which is all cooked in canola/soybean oil around me) for 2 weeks before we go on a beach vacation eliminates almost all of the sunburn I would normally get. I didn't see your reply about your estimate on the time frame to see results, but I think 2 weeks is the minimum needed, with longer periods improving things further.
This is something I noticed way back by now...we're talking 2010-ish after a couple of years "Paleo-ish" as it was thought of at the time, generally real food, low to moderate carbs.
I never linked it to n-6, just better diet overall (which of course would subsume lower n-6).
I was never a huge sunburn guy and usually, after I got a bad one early in the season, it seemed to be protective for future ones.
Anyway, it's been 15 years now without a serious burn. I'm very tanned right now (I live in Thailand, so tan in year-round), I try to hit the pool most bright sunny days at high noon. I never bake in the sun. I do stuff. Move around.
The big test was back in 2020, I spent a few months in rural Thailand building a house where it was outside many hours per day, no shirt ever (shorts only), and never caught a burn, not even tops of shoulders which are the most intensely exposed.
... Oh, another thing is my eye's sensitivity to sunlight. Way less. Before, I could not exist without my sunglasses, ever (took them up in earnest as a teen). Now, I wear them for style as much as anything. If I forget them it's no big. I can function fine without.
I'm sure I remember hearing of a study that found increased LA consumption was associated with increased rates of sunburn. I can't seem to find it though. Maybe it was just something discussed in an article about the broader inflammatory/oxidative effects of LA.
I made diet alterations in conjunction with intentionally increasing sun exposure. So I never noticed same clear association with sunburn and Omega-6 that other people seem to. I can spend the entire day in the sun in a high UV area now though without concern of burning, and my diet does happen to be very low in Omega-6. Would be interesting to eat a bunch of LA and see what happens. Don't particularly want to though...