This article contains findings obtained from research on animals:
- The results from animal research studies should not be directly applied to humans and the results may not generalise to the human population.
- There may be significant differences between species in terms of physiology, physiology, and pharmacology, as well as differences in the way diseases and treatments are modelled in animals.
- Any conclusions drawn from animal research should be considered with caution and in the context of other types of research studies such as observational studies, clinical trials, and reviews of the literature.
Insights & Discussion
Tiger nut and walnut supplementation in diets can improve testosterone levels and help control vasoconstriction, potentially benefiting hypertensive individuals.
Rats were used in the experiment, placed into seven distinct groups with various diet and medicinal intake combinations including basal diet controls, supplemented processed and raw tiger nut (TN) and walnut (WN) diets, and more. Before hypertension was induced with L-NAME, the rats were given their regular diet for two weeks. After this period, they began receiving L-NAME for ten subsequent days. The scientists then measured the impacts on the rats' platelet androgen levels, ectonucleotidases, and adenosine deaminase (ADA).
The L-NAME treatment resulted in a considerable decline in testosterone levels in the rats. However, the groups that were fed diets supplemented with TN and WN exhibited improved testosterone levels compared to the control group, yet their luteinizing hormone levels remained unchanged.
The L-NAME-treated group also saw an increase in ATP hydrolysis and ADA activity, alongside a reduction in ADP and AMP hydrolysis. These effects were substantially reversed in the groups that were fed supplemented TN and WN diets. This suggests that TN and WN could enhance testosterone levels and modulate the purinergic system in platelets, which might be a potential mechanism through which they contribute to the control of vasoconstriction.
Discover Related Insights
Walnut consumption coupled with concurrent training improves lipid profile, steroid hormone levels, and systematic inflammation in elderly men.
2021 Biology of Sport Moderate walnut consumption improved lipid profile, steroid hormones and inflammation in trained elderly men: a pilot study with a randomized controlled trial Kamoun A, Hammouda O, Turki M, Maaloul R, Chtourou M, Bouaziz M, et al.
Randomised Controlled Trial Cholesterol Cortisol CRP
The study created two matched groups of fit elderly men and placed one on a diet inclusive of walnuts (15g/day for six weeks) alongside their concurrent (resistance and endurance) training. The other group did the concurrent training without the walnut-supplemented diet. The study then took fasting blood samples from the participants 48 hours before and after the intervention for biochemical assessments.
The group consuming walnuts saw a significant improvement in their lipid profiles with increased high-density lipoprotein levels and decreased total cholesterol, low-density lipoprotein and triglyceride levels. The walnut-eating participants also saw an increase in testosterone levels after the training, which was significantly higher than the group not consuming walnuts. Additionally, the walnut-consuming group experienced lowered cortisol levels and decreased C-reactive protein compared to the group not consuming walnuts. It is plausible the results could be attributed to the presence of polyunsaturated fatty acids in walnuts.
Consuming walnuts daily can reduce cardiovascular risk factors in chronic kidney disease patients without altering significant physiological levels.
2019 Nutrients A Pilot Randomized Crossover Trial Assessing the Safety and Short-Term Effects of Walnut Consumption by Patients with Chronic Kidney Disease Sanchis P, Molina M, Berga F, Muñoz E, Fortuny R, Costa-Bauzá A, et al.
Randomised Controlled Trial Cardiovascular Disease Chronic Kidney Disease High Blood Pressure
In this prospective, randomized, crossover, pilot clinical trial, 13 patients suffering from chronic kidney disease were selected as subjects. They were randomly divided into two groups, one of which was assigned a diet including 30 grams of walnuts each day while the other followed a control diet. After a duration of 30 days, a washout period of an additional 30 days was allowed, following which the groups were switched to the alternate diet. Key markers such as urinary and serum levels of phosphorous and potassium, multiple vascular risk factors, and urinary inositol phosphates were measured before initiating the trial and post the intervention period.
The study indicated that a dietary supplement of walnuts resulted in reduced blood pressure, lower LDL cholesterol, and decreased albumin excretion. Interestingly, despite these changes, it had no impact on the physiological levels of phosphorous, potassium, parathyroid hormone, and fibroblast growth factor 23. This indicates that daily consumption of walnuts, when incorporated in a sodium, protein, phosphate, and potassium controlled diet, has the potential to be an effective strategy in reducing cardiovascular risk among chronic kidney disease patients without perturbing key physiological levels.