Dietary supplements and fatigue in patients with breast cancer: a systematic review

Effects of Combined Interventions of Exercise and Diet or Exercise and Supplementation on Breast Cancer Patients: A Systematic Review

This systematic review investigated the effects of exercise interventions combined with diet and/or dietary supplement interventions on anthropometry, body composition, metabolic biomarkers, physical function, healthy lifestyles, quality of life, psychosocial variables and fatigue for women with breast cancer. A systematic search was performed in the PubMed and Web of Science databases (from inception to 1 March 2022). A review was carried out following the Preferred Reporting Items for Systematic review and Meta-Analyses (PRISMA) guidelines. The methodological quality and the risk of bias of the included studies was assessed with the Physiotherapy Evidence Database (PEDro) scale. A total of 13 randomised controlled trial studies were included, comprising 1569 breast cancer patients. The main finding of this systematic review is that groups performing interventions combining exercise plus diet show significant improvements in cardiorespiratory fitness, muscular strength, body composition, quality of life, fatigue, anxiety, depression and sleep compared to control groups. On the other hand, the use of interventions combining exercise plus supplementation does not result in an improvement compared to groups using exercise alone or supplementation alone.

The Role of Complementary and Alternative Medicine on Cancer-Related Fatigue in Adults: An Overview of Systematic Reviews

BACKGROUND

Cancer-related fatigue (CRF) has an enormous adverse impact on quality of life and subsequent therapy of cancer patients. Complementary and alternative medicine (CAM) is reported to improve CRF in many systematic reviews (SRs), but the effects are controversial because of variations in the quality and outcomes.

METHODS

Thirteen databases were searched from inception to September 2022. Only SRs of randomized controlled trials (RCTs) were included. We assessed the quality of included SRs with the AMSTAR-2 tool, the strength of evidence with the GRADE system, the risk of bias with the ROBIS tool, and the integrity of SRs with the PRISMA checklist.

RESULTS

We included 30 eligible SRs (27 meta-analyses). Based on the AMSTAR-2 tool, 29 SRs were rated as "critically low" quality, and only one was rated as "low" quality. With the ROBIS tool, 19 SRs demonstrated a low risk of bias. According to the PRISMA checklist, no SRs reported all the items, and 10 SRs sufficiently reported over 70%. Based on the GRADE system, 7 outcomes were assessed as high-quality evidence.

CONCLUSION

This overview demonstrates promising evidence for the effectiveness of CAM interventions in the treatment of CRF in adults. The roles of qigong, music, auricular point therapy, and dietary supplements in CRF need further evaluation. Although findings are mixed, it is recommend to select appropriate CAM to manage cancer-related fatigue under the guidance of physicians. More studies with rigorous methodological designs and sufficient sample sizes are needed.

Meta-Analysis of Pharmacological, Nutraceutical and Phytopharmaceutical Interventions for the Treatment of Cancer Related Fatigue

Purpose: In this study we aimed to estimate the effectiveness of pharmacological, nutraceutical, and phytopharmaceutical treatments on CRF. Methods: Ovid MEDLINE, Ovid Embase, Ovid Psych info, CINHAHL and Cochrane Library databases were searched up to 30 September 2021. Randomized controlled trials of pharmacological, nutraceutical and phytopharmaceutical interventions for treatment of CRF for at least one week duration and have used valid tool to assess severity of CRF as a primary or secondary outcome were considered. Results: 32 eligible studies (4896 patients) were reviewed. For the overall meta-analysis, the random effect models yielded the treatment effect (95% CI) of −0.29 (−0.48,−0.09), p < 0.001. The meta-analysis did not show significant reduction of CRF with treatment with ginseng (n = 6), guarana (n = 3), megestrol (n = 2), mistletoe (n = 3), psychostimulants (n = 14), SSRI/antidepressants (n = 2). Corticosteroids (n = 2) showed significant reduction in CRF with treatment effects of 0.94 (−1.21, −0.67), p <0.0001, respectively. Conclusions: In this study, overall meta-analysis of all studies demonstrates significant reduction of CRF using Pharmacological, Nutraceutical and Phytopharmaceutical interventions with a pooled standardized treatment effect of −0.29. Metanalysis of Corticosteroids studies showed significant reduction in CRF. Further studies are needed.

The Effect of Dietary Methyl-Donor Intake and Other Lifestyle Factors on Cancer Patients in Hungary

Background: Nutrition is essential to life and can have an indisputable influence on health and prevention of disease development including cancer. Methyl-donors are macronutrients that are important in achieving a healthy balance of metabolic processes. Their deficiency can lead to several symptoms and diseases—even to severe SARS-CoV-2 infection. We aimed to explore the potential protective effect of methyl-donor intake in breast, colorectal and pancreatic cancer by patient follow up. Methods: A food frequency questionnaire and a diet diary were used to evaluate methyl-donor intake and blood samples were taken to evaluate Il-6 and IL-8 cytokine levels as well as MTHFR (C677T) polymorphism in breast, colorectal and pancreatic cancer patients. Results: We found that levels around the recommended daily intake of B6 and B9 were effective in supporting the overall survival of breast and colorectal, and a relatively higher level of pancreatic adenocarcinoma, patients. The total intake of methyl-donors significantly and negatively correlated with smoking in pancreatic cancer, while folate as well as betaine intake significantly and positively correlated with IL-8 in colorectal cancer patients. Conclusions: Our results suggest that the appropriate intake of methyl-donor can be an adjunct of conventional oncotherapy to improve quality of life. Whether methyl-donor intake supports cancer prevention and patient survival needs further confirmation in large patient cohorts.

Acylcarnitines: Nomenclature, Biomarkers, Therapeutic Potential, Drug Targets, and Clinical Trials

Acylcarnitines are fatty acid metabolites that play important roles in many cellular energy metabolism pathways. They have historically been used as important diagnostic markers for inborn errors of fatty acid oxidation and are being intensively studied as markers of energy metabolism, deficits in mitochondrial and peroxisomal β -oxidation activity, insulin resistance, and physical activity. Acylcarnitines are increasingly being identified as important indicators in metabolic studies of many diseases, including metabolic disorders, cardiovascular diseases, diabetes, depression, neurologic disorders, and certain cancers. The US Food and Drug Administration-approved drug L-carnitine, along with short-chain acylcarnitines (acetylcarnitine and propionylcarnitine), is now widely used as a dietary supplement. In light of their growing importance, we have undertaken an extensive review of acylcarnitines and provided a detailed description of their identity, nomenclature, classification, biochemistry, pathophysiology, supplementary use, potential drug targets, and clinical trials. We also summarize these updates in the Human Metabolome Database, which now includes information on the structures, chemical formulae, chemical/spectral properties, descriptions, and pathways for 1240 acylcarnitines. This work lays a solid foundation for identifying, characterizing, and understanding acylcarnitines in human biosamples. We also discuss the emerging opportunities for using acylcarnitines as biomarkers and as dietary interventions or supplements for many wide-ranging indications. The opportunity to identify new drug targets involved in controlling acylcarnitine levels is also discussed. SIGNIFICANCE STATEMENT: This review provides a comprehensive overview of acylcarnitines, including their nomenclature, structure and biochemistry, and use as disease biomarkers and pharmaceutical agents. We present updated information contained in the Human Metabolome Database website as well as substantial mapping of the known biochemical pathways associated with acylcarnitines, thereby providing a strong foundation for further clarification of their physiological roles.

Cancer treatment regimens and their impact on the patient-reported outcome measures health-related quality of life and perceived cognitive function

Background and purpose

Breast cancer can be a significant challenge for those affected. Knowledge of physical function, social-emotional challenges, and perceived cognitive function based on the cancer treatment regimens may help to inform adequate support.

Methods

For this prospective observational pilot study, we collected data of seventy-nine women (mean age 54.6 ± 9.5 years) before (T0) and after (T1) initial breast cancer treatment. Functional Assessment of Cancer Therapy-Breast (FACT-B) and Functional Assessment of Cancer Therapy–Cognitive-Function (FACT-Cog) were used to collect data of four treatment subgroups: SCR = Surgery + Chemotherapy + Radiation Therapy; SC = Surgery + Chemotherapy; SR = Surgery + Radiation Therapy; S = Surgery. A mixed ANOVA and posthoc analysis (Tukey, Games-Howell) were used to detect interactions (group by time) and the main effect. A repeated-measures ANOVA displayed individual group differences (time).

Results

Significant interaction showed more deterioration was experienced with SC and SCR than SR and S for FACT-B (p < 0.01) and FACT-Cog (p < 0.001). The longitudinal comparison between T0 and T1 indicated a significant group main effect on all subscales (p < 0.001) except for Emotional Well-Being. Significant reductions (p < 0.05) in FACT-B, (− 19%); FACT-Cog, (− 21%) with most pronounced effect in Physical Well-Being (− 30%), Functional Well-Being (− 20%), Breast Cancer Subscale (− 20%), Perceived Cognitive Impairments (− 18%) and Impact of Cognitive Impairments on Quality of Life (− 39%) were detected for SCR.

Conclusion

Our study showed that the extent of change in health-related quality of life (HRQoL) and perceived cognitive function (PCF) depends on the treatment regimen. Multidisciplinary support initiated early in breast cancer therapy is needed, especially for women undergoing combined cancer treatment. Routine assessment of patient-reported outcomes (PROs) in oncology practice may increase the transparency of patients’ perceived circumstances, leading to personalized and optimized acute and survivorship care.

Routine cancer treatments and their impact on physical function, symptoms of cancer-related fatigue, anxiety, and depression

Background and purpose

Breast cancer can be a major challenge for affected women. Knowledge of the physical function, symptoms of cancer-related fatigue, anxiety, and depression based on the cancer treatment may help to guide adequate support.

Methods

For this prospective observational study, we collected data from seventy-nine women with a mean age 54.6 ± 9.5 years prior to the onset of breast cancer treatment (T0) and after (T1/T2). Handgrip strength test (HGS), six-minute walk test (6MWT), the phase angle (PhA), the hospital anxiety and depression scale (HADS), and functional assessment of chronic illness therapy-fatigue (FACIT-F) were used to collect data from four treatment subgroups SC, surgery + chemotherapy; SCR, surgery + chemotherapy + radiation therapy; SR, surgery + radiation therapy; and S, surgery.

Results

A mixed ANOVA revealed a significant interaction between time and group for PhA, F = 8.55, p < 0.01; HGS, F = 3.59, p < 0.01; 6MWT, F = 4.47, p < 0.01; and FACIT-F, F = 2.77, p < 0.05 with most pronounced deterioration seen in group SCR (PhA 4.8°; HGS 27.5 kg, 6MWT 453.4 m, FACIT-F 33.8 points). HADS data displayed moderate anxiety and depression predominantly after treatment.

Conclusion

Our study showed that the extent of change in physical function, symptoms of fatigue, anxiety, and depression depends on the treatment conditions. The potentially higher risk of impaired function due to the prevalence of values below a critical threshold requires early initiated multidisciplinary support.

Observational study on the benefit of a nutritional supplement, supporting immune function and energy metabolism, on chronic fatigue associated with the SARS-CoV-2 post-infection progress

Background & aims

Recent studies have verified that the SARS-CoV-2 infection (from December 2019 has affected 123 million people throughout the world and more than 3 million people in Italy), can have medium-term and long-term effects, collectively referred to as “post-Covid syndrome” or “long-Covid” characterized by chronic fatigue, followed by muscle weakness, dyspnea and headache. Chronic fatigue or chronic tiredness is a persistent symptom both in patients who have experienced a severe infection and in those who have experienced a mild form of infection. Studies conducted on both patients discharged from hospital and patients managed at home showed that there was no association between the severity of the Coronavirus disease (Covid-19) and the subsequent chronic fatigue symptom. The aim of this study was to evaluate the ability of a nutritional supplement based on vitamins, minerals, amino acids and plant extracts (Apportal®) intake, to ameliorate the general health status in particular the chronic fatigue symptom in subjects after SARS-CoV-2 negativity.

Methods

Participants were advised to take one sachet daily of Apportal® for 28 consecutive days. At the beginning (T0), after 14 days (T1) and after 28 days (T2) of supplementation, general fatigue, mental fatigue and Quality of Life indexes were evaluated through specific questionnaires. The assessment of quality of life and health status were measured through the EuroQoL-5D questionnaire, chronic fatigue using the FACIT-Fatigue questionnaire and mental fatigue using the modified Chalder questionnaire.

Results

201 subjects were enrolled for the study; results showed a significant improvement in all indexes analyzed after 14 and 28 days of supplementation. The main significant improvement was observed after the first 14 days and it was further confirmed at 28 days as well. The RTE (Relative Treatment Effect) trend about quality of life, health status, FACIT-Fatigue and mental fatigue in the three questionnaires was statistically significant (Wald Statistic, p < 0.0001). The data of FACIT-questionnaire showed an improvement of at least 1 unit in 76.62% of subjects after 14 days and in 90.05% of subjects after 28 days. An improvement of 10-unit was found in about one third of subjects after 14 days and in half of the subjects after 28 days.

Conclusions

This study shows that Apportal® can reduce chronic fatigue and improve quality of life and health status in subjects after SARS-CoV-2 negativity due to the synergistic effect of its components.

An update on cancer-related fatigue in older adults: A narrative review

Up to 70% of older adults report fatigue after a cancer diagnosis. For many of these patients, cancer-related fatigue (CRF) persists for years after cancer treatment and is associated with significant disability. Despite this, little has been written on the diagnosis and management of CRF in older adults. To address this gap, we performed a narrative review of the literature on CRF in older adults and used literature from the general population when evidence was lacking to provide guidance to clinical providers on how to tailor care to this population. We recommend evidence-based options for evaluating CRF and address their limitations in the assessment of older adults. We also provide guidance and a treatment algorithm on evaluating CRF using the Comprehensive Geriatrics Assessment. Lastly, we present evidence for the use of non-pharmacologic and pharmacologic therapies in the management of CRF in older adults.

The use of guarana (Paullinia cupana) as a dietary supplement for fatigue in cancer patients: a systematic review with a meta-analysis

OBJECTIVE

The objective of the present study was to carry out a systematic review with a meta-analysis to assess evidence about the use of guarana fruit to manage fatigue in cancer patients.

METHODOLOGY

The data were extracted from the EMBASE, Scopus, MEDLINE, CENTRAL, and CINAHL databases, in any language, using the descriptors "neoplasms" and "Paullinia" or "guarana powder" and "placebos" and "fatigue". Searches were also conducted to identify any grey literature. Clinical studies with patients who presented cancer-related fatigue as a primary outcome and who used guarana as a dietary supplement were included. The risk of bias in randomized clinical trials was analyzed according to the Cochrane recommendations. The quality of the evidence was assessed using the GRADE system. For studies with the same types of tumors and treatments, meta-analysis was also conducted.

RESULTS

A total of 383 studies were found and, of these, seven were included in the review, for a total of 427 cancer patients. The instruments used to analyze fatigue were the Brief Fatigue Inventory (BFI), the Chalder Fatigue Scale, the Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-FATIGUE), and the Piper Scale. Some studies presented a low risk of bias for all the categories. Meta-analysis was conducted for three studies about breast cancer, which presented sufficient data. The use of guarana did not reduce cancer-related fatigue compared with placebo groups (mean of - 0.02 [95% CI - 1.54, 1.50]; p = 0.98) and the quality of evidence according to GRADE was very low.

CONCLUSION

Dietary supplements are used to improve cancer-related fatigue. The results of this review showed that the use of guarana was not superior to the placebo groups, pointing to the need for further studies with better methodological quality.

Methyl-Donors Can Induce Apoptosis and Attenuate Both the Akt and the Erk1/2 Mediated Proliferation Pathways in Breast and Lung Cancer Cell Lines

Dietary methyl-donors play important roles in physiological processes catalyzed by B vitamins as coenzymes, and are used for complementary support in oncotherapy. Our hypothesis was that methyl-donors can not only assist in tolerating cancer treatment but may also directly interfere with tumor growth and proliferation. Therefore, we investigated the proposed cancer inhibitory effects of methyl-donors (in a mixture of L-methionine, choline chloride, folic acid, and vitamin B12) on MCF7 and T47D breast cancer as well as A549 and H1650 lung cancer cell lines. Indeed, methyl-donor treatment significantly reduced the proliferation in all cell lines, possibly through the downregulation of MAPK/ERK and AKT signaling. These were accompanied by the upregulation of the pro-apoptotic Bak and Bax, both in MCF7 and H1650 cells, at reduced anti-apoptotic Mcl-1 and Bcl-2 levels in MCF7 and H1650 cells, respectively. The treatment-induced downregulation of p-p53(Thr55) was likely to contribute to protecting the nuclear localization and apoptosis inducing functions of p53. The presented features are known to improve the sensitivity of cancer therapy. Therefore, these data support the hypothesis, i.e., that methyl-donors may promote apoptotic signaling by protecting p53 functions through downregulating both the MAPK/ERK and the AKT pathways both in breast and lung adenocarcinoma cell lines. Our results can emphasize the importance and benefits of the appropriate dietary supports in cancer treatments. However, further studies are required to confirm these effects without any adverse outcome in clinical settings.

Fatigue in Cancer Patients in Palliative Care-A Review on Pharmacological Interventions

Simple Summary

Cancer related fatigue is a common and distressing symptom for patients with cancer during and after primary treatment, and also in the palliative phase of the disease trajectory. This review focuses on the pharmacological treatment of cancer related fatigue in patients with advanced or metastatic cancer. There are few high-quality studies performed in this setting, but both methylphenidate and corticosteroids might be used to relieve fatigue.

Abstract

Fatigue is one of the most distressing symptoms experienced by cancer patients. The suggested biological mechanism for cancer related fatigue (CRF) includes immune activation triggered by tumor tissue or by anticancer treatment but other mechanisms have also been proposed. Previous large meta-analysis of interventions on fatigue focuses mostly on patients early in the disease trajectory, with only one tenth of included studies performed in palliative cohorts. The aim of this narrative review is therefore to present a background on CRF with focus on the palliative setting. A summary of recent randomized, controlled trials on pharmacological interventions on CRF in palliative care is presented, including studies on psychostimulants, corticosteroids, testosterone and melatonin. Interestingly, in several of these studies there was a positive and similar effect on fatigue in both the intervention and the placebo arm—indicating an important placebo effect for any pharmacological treatment. In addition, studies on dietary supplements and on pharmacological complementary medicines are discussed. To conclude, the evidence is still weak for using pharmacological treatments on CRF in palliative care patients—although methylphenidate and corticosteroids might be considered.

Cancer-Related Fatigue: Causes and Current Treatment Options

Cancer-related fatigue (CRF) is a problem for a significant proportion of cancer survivors during and after active cancer treatment. However, CRF is underdiagnosed and undertreated. Interventions are available for CRF although there is no gold standard. Based on current level of evidence, exercise seems to be most effective in preventing or ameliorating CRF during the active- and posttreatment phases.

Complementary and Alternative Medicine in Patients With Breast Cancer: Exploratory Study of Social Network Forum Data

Background

Patients and health care professionals are becoming increasingly preoccupied in complementary and alternative medicine (CAM) that can also be called nonpharmacological interventions (NPIs). In just a few years, this supportive care has gone from solutions aimed at improving the quality of life to solutions intended to reduce symptoms, supplement oncological treatments, and prevent recurrences. Digital social networks are a major vector for disseminating these practices that are not always disclosed to doctors by patients. An exploration of the content of exchanges on social networks by patients suffering from breast cancer can help to better identify the extent and diversity of these practices.

Objective

This study aimed to explore the interest of patients with breast cancer in CAM from posts published in health forums and French-language social media groups.

Methods

The retrospective study was based on a French database of 2 forums and 4 Facebook groups between June 3, 2006, and November 17, 2015. The extracted, anonymized, and compiled data (264,249 posts) were analyzed according to the occurrences associated with the NPI categories and NPI subcategories, their synonyms, and their related terms.

Results

The results showed that patients with breast cancer use mainly physical (37.6%) and nutritional (31.3%) interventions. Herbal medicine is a subcategory that was cited frequently. However, the patients did not mention digital interventions.

Conclusions

This exploratory study of the main French forums and discussion groups indicates a significant interest in CAM during and after treatments for breast cancer, with primarily physical and nutritional interventions complementing approved treatments. This study highlights the importance of accurate information (vs fake medicine), prescription and monitoring of these interventions, and the mediating role that health professionals must play in this regard.

Anti-Inflammatory Diets and Fatigue

Accumulating data indicates a link between a pro-inflammatory status and occurrence of chronic disease-related fatigue. The questions are whether the observed inflammatory profile can be (a) improved by anti-inflammatory diets, and (b) if this improvement can in turn be translated into a significant fatigue reduction. The aim of this narrative review was to investigate the effect of anti-inflammatory nutrients, foods, and diets on inflammatory markers and fatigue in various patient populations. Next to observational and epidemiological studies, a total of 21 human trials have been evaluated in this work. Current available research is indicative, rather than evident, regarding the effectiveness of individuals’ use of single nutrients with anti-inflammatory and fatigue-reducing effects. In contrast, clinical studies demonstrate that a balanced diet with whole grains high in fibers, polyphenol-rich vegetables, and omega-3 fatty acid-rich foods might be able to improve disease-related fatigue symptoms. Nonetheless, further research is needed to clarify conflicting results in the literature and substantiate the promising results from human trials on fatigue.

Use of biologically based complementary medicines in patients with neuroendocrine tumors

Background: Biologically based complementary medicines (BB-CMs) are popular in patients with cancer. However, there are only limited data for BB-CMs in patients with neuroendocrine tumors (NET). We aimed to identify the prevalence and type of BB-CM use and the association to the nutritional risk score (NRS-2002) in NET patients. Methods: We performed a cross-sectional questionnaire study in NET outpatients at the Department of Hepatology and Gastroenterology at Aarhus University Hospital. The nutritional risk was determined by the NRS-2002. Results: We included 186 patients (51% women, median age 66 years). Sixty-six percent were regular BB-CM users. Forty-two percent used at least two supplements. The most popular BB-CMs were vitamin and mineral supplements (47%), calcium and vitamin D (34%). One-third used non-vitamin non-mineral supplements such as fish oil, herbs, Ginger, Q-10, garlic and probiotics. The use of BB-CMs was associated with female gender (48% vs. 37%, p < .05). Intake was significantly more frequent among patients with an NRS score ≥ 3, (60% vs. 76%) and in patients with change in performance status (58% vs. 76%), (p < .05, all). Patients reporting dietary changes used BB-CMs more frequently than patients without dietary changes (61% vs. 77%) (p < .05). Conclusions: In our study, 66% percent of NET patients use BB-CM and 42% used two or more supplements. Vitamins with and without herbal ingredients, minerals, calcium, vitamin D, and fish oil were the most popular supplements. The use of BB-CMs was associated with an NRS score ≥ 3, change in dietary intake, female gender, and change in ECOG performance status.

Enhancing Omega-3 Long-Chain Polyunsaturated Fatty Acid Content of Dairy-Derived Foods for Human Consumption

Omega-3 polyunsaturated fatty acids (n-3 PUFA) are termed essential fatty acids because they cannot be synthesized de novo by humans due to the lack of delta-12 and delta-15 desaturase enzymes and must therefore be acquired from the diet. n-3 PUFA include α-linolenic acid (ALA, 18:3n-3), eicosapentaenoic (EPA, 20:5n-3), docosahexaenoic (DHA, 22:6n-3), and the less recognized docosapentaenoic acid (DPA, 22:5n-3). The three long-chain (≥C20) n-3 PUFA (n-3 LC-PUFA), EPA, DHA, and DPA play an important role in human health by reducing the risk of chronic diseases. Up to the present time, seafood, and in particular, fish oil-derived products, have been the richest sources of n-3 LC-PUFA. The human diet generally contains insufficient amounts of these essential FA due largely to the low consumption of seafood. This issue provides opportunities to enrich the content of n-3 PUFA in other common food groups. Milk and milk products have traditionally been a major component of human diets, but are also among some of the poorest sources of n-3 PUFA. Consideration of the high consumption of milk and its processed products worldwide and the human health benefits has led to a large number of studies targeting the enhancement of n-3 PUFA content in dairy products. The main objective of this review was to evaluate the major strategies that have been employed to enhance n-3 PUFA content in dairy products and to unravel potential knowledge gaps for further research on this topic. Nutritional manipulation to date has been the main approach for altering milk fatty acids (FA) in ruminants. However, the main challenge is ruminal biohydrogenation in which dietary PUFA are hydrogenated into monounsaturated FA and/or ultimately, saturated FA, due to rumen microbial activities. The inclusion of oil seed and vegetable oil in dairy animal diets significantly elevates ALA content, while the addition of rumen-protected marine-derived supplements is the most effective way to increase the concentration of EPA, DHA, and DPA in dairy products. In our view, the mechanisms of n-3 LC-PUFA biosynthesis pathway from ALA and the biohydrogenation of individual n-3 LC-PUFA in ruminants need to be better elucidated. Identified knowledge gaps regarding the activities of candidate genes regulating the concentrations of n-3 PUFA and the responses of ruminants to specific lipid supplementation regimes are also critical to a greater understanding of nutrition-genetics interactions driving lipid metabolism.