Hello,
To continue the perennial debate on saturated fat vs polyunsaturated fats (I personnally think it's a matter of nuances, with benefits and dangers from both sides, depending on details and the context).
Here is some intervention studies on humans showing that nuts consumption reduce oxidized LDL and the dreaded MDA (malondialdehyde), which are both recognized markers of lipid peroxidation.
We talk about whole foods here, not isolated oils or roasted and salted nuts, which can become rancid during these processes.
Almond consumption reduces oxidative DNA damage and lipid peroxidation in male smokers - PubMed
"
Abstract
Smoking increases the risk of several chronic diseases associated with elevated oxidative stress status. Almonds are a good source of antioxidant nutrients and may diminish smoking-related biomarkers of oxidative stress. We investigated whether almond consumption decreases biomarkers of oxidative stress in young male smokers. We conducted a randomized, crossover clinical trial with 60 healthy male soldiers (18-25 y) who were habitual smokers (5-20 cigarettes/d) and supplemented their diet with 84 g almonds or 120 g pork (to control for calories) daily for 4 wk with a 4-wk washout period between treatment periods. In addition, 30 healthy nonsmoking men were provided the same daily serving of pork as reference comparison. Blood and urine were collected and assessed for biomarkers of oxidative stress"
"Baseline values of urinary 8-hydroxy-deoxyguanosine (8-OHdG) and malondialdehyde (MDA) and peripheral lymphocyte DNA strand breaks were significantly higher by 185, 64, and 97% in smokers than nonsmokers, whereas activities of plasma superoxide dismutase (SOD), glutathione peroxidase (GPX), and catalase were significantly lower by 15, 10, and 9%, respectively. After the almond intervention, serum alpha-tocopherol, SOD, and GPX increased significantly in smokers by 10, 35, and 16%, respectively and 8-OHdG, MDA, and DNA strand breaks decreased significantly by 28, 34, and 23%. In smokers, after almond supplementation, the concentration of 8-OHdG remained significantly greater than in nonsmokers by 98%. These results suggest almond intake can enhance antioxidant defenses and diminish biomarkers of oxidative stress in smokers."
Effects of pistachio nuts consumption on plasma lipid profile and oxidative status in healthy volunteers - PubMed
"
Abstract
Background and aim: Effects of pistachio nuts consumption on plasma lipid profile and oxidative status were investigated in healthy volunteers with normal lipid levels.
Methods and results: The study was conducted in 24 healthy men and 20 healthy women. All subjects consumed their regular diets during a 1-week period. After this period, half of the subjects (12 men and 10 women, mean age 32.8 +/- 6.7 years) were randomized to a regular diet group and the other half (12 men and 10 women, mean age 33.4 +/- 7.2 years) were randomized to a pistachio group which involved substituting pistachio nuts for 20% of their daily caloric intake for 3 weeks. Plasma total cholesterol, low-density lipoprotein (LDL), high-density lipoprotein (HDL), triglyceride, malondialdehyde (MDA) and antioxidant potential (AOP) were measured before and after the dietary modification from all the subjects."
"
After 3 weeks, with the pistachio diet, the mean plasma total cholesterol, MDA levels and, total cholesterol/HDL and LDL/HDL ratios were found to be significantly decreased (P < 0.05, P < 0.05, P < 0.001 and P < 0.01, respectively); on the contrary, HDL and AOP levels, and AOP/MDA ratios were significantly increased (P < 0.001, P < 0.05 and P < 0.01, respectively). Triglyceride and LDL levels also decreased but this was not statistically significant (P > 0.05).
Conclusion: These results indicated that consumption of pistachio nuts decreased oxidative stress, and improved total cholesterol and HDL levels in healthy volunteers."
Acute effect of nut consumption on plasma total polyphenols, antioxidant capacity and lipid peroxidation - PubMed
"
Background: Nuts have been shown to have beneficial effects on human health due to the healthy fat content; however, the effect of antioxidants (i.e. polyphenols) in nuts have not been fully investigated. The present study aimed to assess the immediate effect of a polyphenol-rich meal (75% of energy from nuts: walnuts or almonds) and a polyphenol-free meal on plasma polyphenol content, antioxidant capacity and lipid peroxidation in healthy volunteers.
Methods: Thirteen subjects participated in a randomized, crossover, intervention study. After an overnight fast, walnuts, almonds or a control meal in the form of smoothies were consumed by study subjects. Each subject participated on three occasions, 1 week apart, consuming one of the smoothies each time. Blood samples were obtained at fasting and then at intervals up to 3.5 h after consumption of the smoothies."
"
Results: There was a significant increase in plasma polyphenol concentration following both nut meals, with peak concentrations being achieved at 90 min, and with a walnut meal having a more sustained higher concentration than an almond meal. The plasma total antioxidant capacity reached its highest point at 150 min postconsumption of the nut meals, and was higher after the almond compared to walnut meal. A gradual significant (P < 0.05) reduction in the susceptibility of plasma to lipid peroxidation was observed 90 min after ingestion of the nut meals. No changes were observed following consumption of control meal.
Conclusions: Consumption of both nuts increased plasma polyphenol concentrations, increased the total antioxidant capacity and reduced plasma lipid peroxidation."
Pecans Acutely Increase Plasma Postprandial Antioxidant Capacity and Catechins and Decrease LDL Oxidation in Humans
"Study design.
In a placebo-controlled, 3-way crossover design with a 1-wk washout period between treatments, participants were randomly assigned to consume a test meal of 90 g (∼3 servings) whole pecans plus water, 90 g pecans blended with water, or a test meal with an energy, macronutrient, and fluid content equivalent to that of the pecan meals as control. Bioactive constituents of pecan nuts such as γ-tocopherol and flavan-3-ol monomers show antioxidant properties in vitro, but bioavailability in humans is not known. We examined postprandial changes in plasma oxygen radical absorbance capacity (ORAC) and in concentrations of tocopherols, catechins, oxidized LDL, and malondialdehyde (MDA) in response to pecan test meals. Sixteen healthy men and women (23-44 y, BMI 22.7 ± 3.4) were randomly assigned to 3 sequences of test meals composed of whole pecans, blended pecans, or an isocaloric meal of equivalent macronutrient composition but formulated of refined ingredients in a crossover design with a 1-wk washout period between treatments."
"
Results
Following the whole and blended pecan test meals, plasma concentrations of γ-tocopherols doubled at 8 h (P < 0.001) and hydrophilic- and lipophilic-ORAC increased 12 and 10% at 2 h, respectively. Post whole pecan consumption, oxidized LDL decreased 30, 33, and 26% at 2, 3, and 8 h, respectively (P < 0.05), and epigallocatechin-3-gallate concentrations at 1 h (mean ± SEM; 95.1 ± 30.6 nmol/L) and 2 h (116.3 ± 80.5 nmol/L) were higher than at baseline (0 h) and after the control test meal at 1 h (P < 0.05). The postprandial molar ratio of MDA:triglycerides decreased by 37, 36, and 40% at 3, 5, and 8 h, respectively (P < 0.05), only when whole and blended pecan data were pooled. These results show that bioactive constituent of pecans are absorbable and contribute to postprandial antioxidant defenses.
In summary, this randomized crossover trial showed that when pecans are consumed, their catechin monomers, of which EGCG is the most available, are absorbed. The plasma concentration of γ-tocopherol and ORAC activity increased, whereas oxidized LDL and the ratio of MDA:triglycerides decreased following pecan consumption. Whether the improvement in antioxidant status is due to γ-tocopherol, catechins, or both acting in synergy remains to be determined."
There is also a lot of positives studies with whole seeds like flaxseed or sesame seeds, on humans and animals models, even for soy (which contains a good amount of PUFA if not processed), and these studies have been reproduced several times for walnuts, almonds...
I'm not saying that nuts are the panacea in every circumstances and for everyone, I'm just saying that they are not the devil because of their PUFA content, and they can be great for health, even beyond lipid peroxidation to control blood sugar, antioxidant status, magnesium status, some diseases...
Like every whole food finally.
If you want to incorporate them, it will be wise to choose them in their raw state, not roasted of salted, not already processed in nut butter or worst in oil...
The best way would be to buy them in their shell, and to crack your nuts when you eat them.
Thanks for reading, it's a pleasure to speak to it.
To continue the perennial debate on saturated fat vs polyunsaturated fats (I personnally think it's a matter of nuances, with benefits and dangers from both sides, depending on details and the context).
Here is some intervention studies on humans showing that nuts consumption reduce oxidized LDL and the dreaded MDA (malondialdehyde), which are both recognized markers of lipid peroxidation.
We talk about whole foods here, not isolated oils or roasted and salted nuts, which can become rancid during these processes.
Almond consumption reduces oxidative DNA damage and lipid peroxidation in male smokers - PubMed
"
Abstract
Smoking increases the risk of several chronic diseases associated with elevated oxidative stress status. Almonds are a good source of antioxidant nutrients and may diminish smoking-related biomarkers of oxidative stress. We investigated whether almond consumption decreases biomarkers of oxidative stress in young male smokers. We conducted a randomized, crossover clinical trial with 60 healthy male soldiers (18-25 y) who were habitual smokers (5-20 cigarettes/d) and supplemented their diet with 84 g almonds or 120 g pork (to control for calories) daily for 4 wk with a 4-wk washout period between treatment periods. In addition, 30 healthy nonsmoking men were provided the same daily serving of pork as reference comparison. Blood and urine were collected and assessed for biomarkers of oxidative stress"
"Baseline values of urinary 8-hydroxy-deoxyguanosine (8-OHdG) and malondialdehyde (MDA) and peripheral lymphocyte DNA strand breaks were significantly higher by 185, 64, and 97% in smokers than nonsmokers, whereas activities of plasma superoxide dismutase (SOD), glutathione peroxidase (GPX), and catalase were significantly lower by 15, 10, and 9%, respectively. After the almond intervention, serum alpha-tocopherol, SOD, and GPX increased significantly in smokers by 10, 35, and 16%, respectively and 8-OHdG, MDA, and DNA strand breaks decreased significantly by 28, 34, and 23%. In smokers, after almond supplementation, the concentration of 8-OHdG remained significantly greater than in nonsmokers by 98%. These results suggest almond intake can enhance antioxidant defenses and diminish biomarkers of oxidative stress in smokers."
Effects of pistachio nuts consumption on plasma lipid profile and oxidative status in healthy volunteers - PubMed
"
Abstract
Background and aim: Effects of pistachio nuts consumption on plasma lipid profile and oxidative status were investigated in healthy volunteers with normal lipid levels.
Methods and results: The study was conducted in 24 healthy men and 20 healthy women. All subjects consumed their regular diets during a 1-week period. After this period, half of the subjects (12 men and 10 women, mean age 32.8 +/- 6.7 years) were randomized to a regular diet group and the other half (12 men and 10 women, mean age 33.4 +/- 7.2 years) were randomized to a pistachio group which involved substituting pistachio nuts for 20% of their daily caloric intake for 3 weeks. Plasma total cholesterol, low-density lipoprotein (LDL), high-density lipoprotein (HDL), triglyceride, malondialdehyde (MDA) and antioxidant potential (AOP) were measured before and after the dietary modification from all the subjects."
"
After 3 weeks, with the pistachio diet, the mean plasma total cholesterol, MDA levels and, total cholesterol/HDL and LDL/HDL ratios were found to be significantly decreased (P < 0.05, P < 0.05, P < 0.001 and P < 0.01, respectively); on the contrary, HDL and AOP levels, and AOP/MDA ratios were significantly increased (P < 0.001, P < 0.05 and P < 0.01, respectively). Triglyceride and LDL levels also decreased but this was not statistically significant (P > 0.05).
Conclusion: These results indicated that consumption of pistachio nuts decreased oxidative stress, and improved total cholesterol and HDL levels in healthy volunteers."
Acute effect of nut consumption on plasma total polyphenols, antioxidant capacity and lipid peroxidation - PubMed
"
Background: Nuts have been shown to have beneficial effects on human health due to the healthy fat content; however, the effect of antioxidants (i.e. polyphenols) in nuts have not been fully investigated. The present study aimed to assess the immediate effect of a polyphenol-rich meal (75% of energy from nuts: walnuts or almonds) and a polyphenol-free meal on plasma polyphenol content, antioxidant capacity and lipid peroxidation in healthy volunteers.
Methods: Thirteen subjects participated in a randomized, crossover, intervention study. After an overnight fast, walnuts, almonds or a control meal in the form of smoothies were consumed by study subjects. Each subject participated on three occasions, 1 week apart, consuming one of the smoothies each time. Blood samples were obtained at fasting and then at intervals up to 3.5 h after consumption of the smoothies."
"
Results: There was a significant increase in plasma polyphenol concentration following both nut meals, with peak concentrations being achieved at 90 min, and with a walnut meal having a more sustained higher concentration than an almond meal. The plasma total antioxidant capacity reached its highest point at 150 min postconsumption of the nut meals, and was higher after the almond compared to walnut meal. A gradual significant (P < 0.05) reduction in the susceptibility of plasma to lipid peroxidation was observed 90 min after ingestion of the nut meals. No changes were observed following consumption of control meal.
Conclusions: Consumption of both nuts increased plasma polyphenol concentrations, increased the total antioxidant capacity and reduced plasma lipid peroxidation."
Pecans Acutely Increase Plasma Postprandial Antioxidant Capacity and Catechins and Decrease LDL Oxidation in Humans
"Study design.
In a placebo-controlled, 3-way crossover design with a 1-wk washout period between treatments, participants were randomly assigned to consume a test meal of 90 g (∼3 servings) whole pecans plus water, 90 g pecans blended with water, or a test meal with an energy, macronutrient, and fluid content equivalent to that of the pecan meals as control. Bioactive constituents of pecan nuts such as γ-tocopherol and flavan-3-ol monomers show antioxidant properties in vitro, but bioavailability in humans is not known. We examined postprandial changes in plasma oxygen radical absorbance capacity (ORAC) and in concentrations of tocopherols, catechins, oxidized LDL, and malondialdehyde (MDA) in response to pecan test meals. Sixteen healthy men and women (23-44 y, BMI 22.7 ± 3.4) were randomly assigned to 3 sequences of test meals composed of whole pecans, blended pecans, or an isocaloric meal of equivalent macronutrient composition but formulated of refined ingredients in a crossover design with a 1-wk washout period between treatments."
"
Results
Following the whole and blended pecan test meals, plasma concentrations of γ-tocopherols doubled at 8 h (P < 0.001) and hydrophilic- and lipophilic-ORAC increased 12 and 10% at 2 h, respectively. Post whole pecan consumption, oxidized LDL decreased 30, 33, and 26% at 2, 3, and 8 h, respectively (P < 0.05), and epigallocatechin-3-gallate concentrations at 1 h (mean ± SEM; 95.1 ± 30.6 nmol/L) and 2 h (116.3 ± 80.5 nmol/L) were higher than at baseline (0 h) and after the control test meal at 1 h (P < 0.05). The postprandial molar ratio of MDA:triglycerides decreased by 37, 36, and 40% at 3, 5, and 8 h, respectively (P < 0.05), only when whole and blended pecan data were pooled. These results show that bioactive constituent of pecans are absorbable and contribute to postprandial antioxidant defenses.
In summary, this randomized crossover trial showed that when pecans are consumed, their catechin monomers, of which EGCG is the most available, are absorbed. The plasma concentration of γ-tocopherol and ORAC activity increased, whereas oxidized LDL and the ratio of MDA:triglycerides decreased following pecan consumption. Whether the improvement in antioxidant status is due to γ-tocopherol, catechins, or both acting in synergy remains to be determined."
There is also a lot of positives studies with whole seeds like flaxseed or sesame seeds, on humans and animals models, even for soy (which contains a good amount of PUFA if not processed), and these studies have been reproduced several times for walnuts, almonds...
I'm not saying that nuts are the panacea in every circumstances and for everyone, I'm just saying that they are not the devil because of their PUFA content, and they can be great for health, even beyond lipid peroxidation to control blood sugar, antioxidant status, magnesium status, some diseases...
Like every whole food finally.
If you want to incorporate them, it will be wise to choose them in their raw state, not roasted of salted, not already processed in nut butter or worst in oil...
The best way would be to buy them in their shell, and to crack your nuts when you eat them.
Thanks for reading, it's a pleasure to speak to it.