WIL Weekly Review #26
Butter protects from seed oil damage, phytonutrients in meat and more...
This is my free weekly newsletter covering 5 interesting points from the week. Subscribe (if you haven’t already) if you’d like to get it in your inbox each week!
1. Grass-fed meat and milk has as many healthy “phytonutrients” as plants
According to a 2021 study titled Health-Promoting Phytonutrients Are Higher in Grass-Fed Meat and Milk
“Meat and milk, irrespective of rearing practices, provide many essential nutrients including bioavailable protein, zinc, iron, selenium, calcium, and/or B12. Emerging data indicate that when livestock are eating a diverse array of plants on pasture, additional health-promoting phytonutrients—terpenoids, phenols, carotenoids, and anti-oxidants—become concentrated in their meat and milk. Several phytochemicals found in grass-fed meat and milk are in quantities comparable to those found in plant foods known to have anti-inflammatory, anti-carcinogenic, and cardioprotective effects. …Several studies have found increased anti-oxidant activity in meat and milk of grass-fed vs. grain-fed animals.”
2. Are Vegetable Oils the primary driver of modern diseases?
Another interesting video by Dr. Chris Knobbe just dropped. He makes another compelling case against seed oils here. Great watch. Two interesting he didn’t mention about seed oils are…
3. You NEED vegetable oil to damage your liver with alcohol? (Study on absolute binge-drinking rats)
Linoleic acid is the main omega-6 fat in vegetable oils. The linoleic acid content of butter is under 1%. The common vegetable oil, canola oil, is 20% linoleic acid.
Let me share with you a totally wild study.
According to an old 1989 study titled Dietary linoleic acid is required for development of experimentally induced alcoholic liver injury:
We had previously hypothesized that linoleic acid (LA) was essential for development of alcoholic induced liver injury in our rat model. Male Wistar rats were fed a nutritionally adequate diet (25% calories as fat) with ethanol (8–17 g/kg/day). The source of fat was tallow (0.7% LA), lard (2.5% LA) or tallow supplemented with linoleic acid (2.5%). Liver damage was followed monthly by obtaining blood for alanine aminotransferase assay and liver biopsy for assessment of morphologic changes. Enzyme and histologic changes (fatty liver, necrosis and inflammation) in the tallow-linoleic acid-ethanol fed animals were more severe than in the lard-ethanol group. The tallow ethanol group did not show any evidence of liver injury. Our results strongly support our hypothesis that LA is essential for development of alcoholic liver disease in our rat model.
A standard drink has 14 grams of ethanol. These rats were getting 8-17 grams of ethanol PER KILOGRAM PER DAY. 8-17 grams of ethanol per kilogram per day for an 82 kilogram (181 pounds) human like me would be 47-99 drinks PER DAY.*
*That is completely insane but note that this clearly doesn’t translate directly to humans because apparently only 25 standard drinks puts you at risk of coma or death. Male Winstar rats weigh 135 to 170g so they’re only getting about 1/7th of a drink. To get a proper understanding of how that equates to humans, you’ll need to put that through a human equivalent dose conversion. Though, on a per kg basis, 8-17g/kg/day is wild.
They were checking the level of liver damage in the rats on a monthly basis. They found that they could induce liver damage only if they gave the rats linoleic acid. If the rats only ate tallow, there was no discernible liver damage.
4. Saturated fat cures alcoholic liver disease?
No, this isn’t a clickbait title, that’s straight up the title of a 1995 rat study. They found that a saturated-fat rich diet reversed alcoholic liver injury. Unsaturated fats were not able to provide this benefit. From Dietary saturated fatty acids: a novel treatment for alcoholic liver disease:
Lipid peroxidation may be important in the pathogenesis of alcoholic liver injury. The purpose of this study was to determine whether a saturated fatty acid-based therapy (palm oil) could decrease lipid peroxidation and alcoholic liver injury during ethanol withdrawal.
Methods: Three groups of male Wistar rats (5 rats/group) were studied. Rats in group 1 were fed a fish oil-ethanol diet for 6 weeks; rats in groups 2 and 3 were fed a fish oil-ethanol diet for 6 weeks before treatment with fish oil-dextrose (group 2) or palm oil-dextrose (group 3) for 2 weeks. …
Results: By 6 weeks, all rats had developed fatty liver, inflammation, and necrosis. Group 2 showed minimal histological improvement, whereas group 3 showed near normalization of the histology. …
Conclusions: A diet enriched in saturated but not unsaturated fatty acids reversed alcoholic liver injury. This effect may be explained by down-regulation of lipid peroxidation.
5. Soy has negative effects on men?
A 2010 review on soy’s effect on men concluded that soy doesn’t have negative effects on androgens, but personally I’m still suspicious of soy. This topic is controversial and there are multiple studies showing soy doesn’t cause significant changes in testosterone, however…
・A 2000 clinical trial had 42 men consume 150g lean meat or 290g tofu daily for 4 weeks. The tofu reduced androgen activity. Mean testosterone-estradiol ratio was 10% lower, SHBG was 9% higher, and the free androgen index was 7% lower after tofu consumption.
・A 2001 rat study found soy isoflavones significantly reduce testosterone.
・A 2002 feeding study on infant marmosets found “[Standard cow milk based formula]-fed males had mean testosterone levels of 2.8–3.1 ng/ml, typical of the ‘neonatal testosterone rise’, whereas [soy formula]-fed males exhibited consistently lower mean levels (1.2–2.6 ng/ml)”
・A 2003 paper found that soya supplementation “reduces serum testosterone and improves markers of oxidative stress.”
・A 2007 paper found that in 12 subjects being given soy powder, “serum testosterone decreased 19%(+/-22%) during the 4-week use of soy protein powder (P = 0.021) and increased within 2 weeks after we discontinued soy protein powder.”
・A 2008 case report documents “an Unusual Case of Gynecomastia Associated with Soy Product Consumption”
・A 2008 article on men at an infertility clinic noted that “there was an inverse association between soy food intake and sperm concentration that remained significant after accounting for age, abstinence time, body mass index, caffeine and alcohol intake and smoking. …These data suggest that higher intake of soy foods and soy isoflavones is associated with lower sperm concentration.”
・A 2010 review stated that “there are some indications that phyto-oestrogens, alone or in combination with other endocrine disruptors, may alter reproductive hormones, spermatogenesis, sperm capacitation and fertility.”
・A 2011 case report found a 19-y-old type 1 diabetic “but otherwise healthy man with sudden onset of loss of libido and erectile dysfunction after the ingestion of large quantities of soy-based products in a vegan-style diet.” His testosterone and free testosterone were decreased but returned to normal after stopping the vegan diet for 1 year. He was eating a massive amount of soy.
・A 2013 paper found that “14 days of supplementation with soy protein does appear to partially blunt serum testosterone.”
・A 2022 case report out of Japan noted that “A 54-year-old man had been drinking approximately 1.2 L of soy milk (equivalent to approximately 310 mg of isoflavones) per day for the previous 3 years. He then developed erectile dysfunction and gynecomastia.” This makes me wonder if the trials finding no negative effects from soy are too short.
I love to read all your nutrition articles. The best part of them is that they are full of data that you can check for yourself online.
As a lover of wine, I often defend my rather significant daily consumption with the phrase 'it's the 'worst' and only 'bad' thing I consume - otherwise I'm whole / organic ketovore, sat animal fats or our own extra virgin olive oil. The response to people who say to me 'aren't you concerned' I respond, well, I'm aware and fortunately these are testable concerns - my annual liver function tests are amazing. I'm 61.