overweight The incidence of obesity and obesity has been associated with the development of atherosclerotic cardiovascular disease (CVD). However, several studies have shown that consuming certain types of nuts reduces the risk of cardiovascular disease.
Recently, A.J Nutrition, metabolism and cardiovascular disease The study examined the effect of daily consumption of mixed nuts on low-density lipoprotein (LDL-C) and lipoprotein (a) cholesterol. [Lp(a)]and markers of inflammation in overweight or obese individuals.
Stady: Effects of mixed hazelnut consumption on low-density lipoprotein (LDL) cholesterol and other cardiac risk factors in overweight and obese adults. Image credit: Aleksandr Grechanyuk / Shutterstock.com
An overview of atherosclerosis
Atherosclerosis is a type of cardiovascular disease in which fatty plaques form in the walls of the arteries. Cholesterol deposition in the damaged endothelium occurs through the circulation of cholesterol-rich apolipoprotein B (ApoB) containing lipoprotein particles, such as LDL-C (VLDL-C), LDL-C or Lp(a).
After deposition, cholesterol undergoes oxidation, which leads to initiation of an inflammatory response through monocyte infiltration, foam cell formation, plaque formation, and arterial occlusion reducing blood flow to major organs. Previous studies have suggested that high levels of LDL-C and Lp(a) increase the risk of cardiovascular disease, including the development of atherosclerosis, while low LDL-C leads to lower Lp(a) levels.
Health benefits of nuts
Usually, unhealthy eating habits cause an increase in LDL-C; Therefore, effective dietary modifications can prevent cardiovascular disease. Consuming walnuts, for example, has been shown to reduce some of the risk factors associated with cardiovascular disease.
Nuts contain unsaturated fats, antioxidants, phytochemicals, and soluble fiber that are useful for blood lipids and lipoproteins. In fact, almonds, walnuts, macadamia nuts, pistachios, and Brazil nuts have been shown to significantly reduce total cholesterol (TC) and LDL-C levels and increase HDL-C. Similarly, hyperlipidemia patients exposed to 73 g/day of almonds showed decreased Lp(a) levels.
The current randomized controlled trial (RCT) evaluated the effect of mixed nut consumption on lipid profiles, Lp(a), and inflammation. Here, the researchers hypothesized that diets supplementing with 42.5 grams/day of mixed nuts would reduce LDL-C and Lp(a) levels and inflammation in obese and overweight subjects.
Both men and women who were obese or overweight were recruited. All study participants ranged from 20 to 55 years oldAnd Non-pregnant, non-smokers and not taking nutritional supplements. In addition, none of the participants had a history of metabolic disorders or chronic infections and were not allergic to nuts.
Twenty-nine participants were randomly assigned to consume either an unsalted cracker (control) or a mixed nut intervention for a period of sixteen weeks. Each study participant had three laboratory visits indicating a fasting state (baseline), week eight, and week 16.
Participants assigned to the intervention groups were provided with 42.5 g/day packets of mixed nuts that included cashews, almonds, macadamia nuts, Brazil nuts, pecan nuts (25.5 g), pistachios (5 g), walnuts (5 g), and peanuts (7 g). Each individual was asked to eat one serving of the mixed nuts per day and to continue with their usual diet and physical activity.
Mixed nut supplementation significantly reduced some cardiovascular disease risk factors, including body fat percentage, glucose, diastolic blood pressure, and adiponectin in overweight and obese adults. In addition, a decreased propensity for 8-oxodG and C-reactive protein (CRP), as well as a non-significant increased propensity for total antioxidant capacity (TAC), was observed in the mixed nut group.
Mixed nut consumption did not affect Lp(a), insulin, plasma lipids, HMGB1, and liver function enzymes. This result was consistent with previous studies that revealed that increased consumption of nuts or vegetable oils and decreased consumption of saturated fats did not lead to significant changes in Lp(a) after six weeks. However, several studies have contradicted these findings, suggesting that Lp(a) levels may be altered by dietary interventions.
These contradictory results can be attributed to the diverse protocols used to measure Lp(a). Moreover, since circulating Lp(a) levels may be genetically determined, discrepancies can also be influenced by genetic factors.
Genotyping is needed to better understand the underlying mechanisms affecting Lp(a) concentrations. In addition, more research is needed to elucidate specific dietary interventions, including macronutrient and fatty acid composition, that can reduce Lp(a) concentrations.
A decrease in body fat was observed in the mixed nuts group, while an increase in body weight was observed in the pretzel group. This may be due to the ability of nut consumption to increase fat oxidation, which may help mitigate body fat accumulation over time. Decreased obesity has been documented with nut consumption, which may be attributed to the lower biological accessibility and metabolizable energy associated with nuts.
The bioactive components in nuts, such as antioxidants, dietary fiber, magnesium, L-arginine, and vitamins, play an important role in reducing oxidative stress, inflammation, and the risk of cardiovascular disease. In addition, nut consumption improves dyslipidemia and obesity, thus reducing the risk of cardiovascular disease.
Previous studies have shown that nut consumption reduces body fat percentage and increases lean body mass. Weight loss improves fasting blood glucose levels, which relieves risk of atherosclerosis and CVD.
The current study provided new insights into how long-term mixed nut consumption affects overweight and obese adults.
- Nora CL, Chang L, Castro RG, et al. (2023) Effects of mixed hazelnut consumption on low-density lipoprotein (LDL) cholesterol and other cardiac risk factors in overweight and obese adults. Nutrition, metabolism and cardiovascular disease. doi: 10.1016/j.numecd.2023.05.013