Zinc nutrition and dietary zinc supplements

As the second most abundant trace element in the human body, zinc nutrition is constantly a hot topic. More than one-third population is suffering zinc deficiency, which results in various types of diseases or nutritional deficiencies. Traditional ways of zinc supplementation seem with low absorption rates and significant side effects. Zinc supplements with dietary components are easily accessible and improve zinc utilization rate significantly. Also, mechanisms of maintaining zinc homeostasis are of broad interest. The present review focuses on zinc nutrition in human health in inductive methods. Mainly elaborate on different diseases relating to zinc disorder, highlighting the impact on the immune system and the recent COVID-19. Then raise food-derived zinc-binding compounds, including protein, peptide, polysaccharide, and polyphenol, and also analyze their possibilities to serve as zinc complementary. Finally, illustrate the way to maintain zinc homeostasis and the corresponding mechanisms. The review provides data information for maintaining zinc homeostasis with the food-derived matrix.

Fibromyalgia Syndrome: A Metabolic Approach Grounded in Biochemistry for the Remission of Symptoms

Fibromyalgia syndrome (FMS) is a chronic, complex, and heterogeneous disorder of still poorly understood etiopathophysiology associated with important musculoskeletal widespread pain, fatigue, non-restorative sleep, and mood disturbances. It is estimated to afflict 2–3% of the worldwide population, with clean prevalence among women. The objective of this paper is to propose a novel treatment for symptomatic remission of FMS, grounded in biochemistry and consisting in the withdrawal from the diet of molecules that can indirectly trigger the symptoms. The hypothesis develops from the evidence that low serotonin levels are involved in FMS. Serotonin is synthesized starting from the essential amino acid tryptophan. The presence of non-absorbed molecules in the gut, primarily fructose, reduces tryptophan absorption. Low tryptophan absorption leads to low serotonin synthesis that triggers FMS symptoms. Moreover not-absorbed sugars could also produce a microbiota deterioration activating a positive feedback loop: the increasing microbiota deterioration reduces the functionality of absorption both of fructose and tryptophan in the gut, entering a vicious circle. The therapeutic idea is to sustain serotonin synthesis allowing the proper tryptophan absorption. The core of the cure treatment is the exclusion from the diet of some carbohydrates and the marked reduction of some others. The main target is the limitation of total dietary fructose as marked as possible. It could be an effective strategy to get the remission of symptoms acting on the impaired biochemical pathways. The straying from the treatment is expected to cause the reappear of the symptoms.

Evidence of impaired carbohydrate assimilation in euthyroid patients with Hashimoto's thyroiditis

BACKGROUND/OBJECTIVES

Hashimoto's thyroiditis (HT) represents a wide-spread autoimmune disease. In euthyroid patients with HT, an impaired assimilation of common carbohydrates has been observed. Our objectives were to compare the frequency of (1) fructose (FM), lactose (LM) and sorbitol malassimilation (SM), (2) gastrointestinal symptoms (GS) following carbohydrate ingestion and (3) recurrent GS relevant to the participants' daily lives.

SUBJECTS/METHODS

We conducted a prospective case-control study of 45 ambulatory patients with HT and 38 healthy volunteers, matched with regard to age, gender and area of origin. Hydrogen breath tests with fructose, lactose, sorbitol and glucose were performed, the lactose testing additionally comprising measurements of capillary blood glucose (cBG). GS during the tests and recurrent GS concerning the participants' daily lives were assessed. A food-frequency questionnaire was administered.

RESULTS

FM was diagnosed in 48.9% of patients compared with 26.3% of the control group (P=0.035). In all, 42.2% of patients with HT and 21.1% of healthy controls showed LM (P=0.04). FM and/or LM was present in 73.3% of the patients and in 42.1% of healthy controls (P=0.004). GS after the ingestion of fructose (P=0.003) or lactose (P=0.025) and recurrent GS were significantly more prevalent in the case group. The consumption of free fructose, lactose or sorbitol did not differ.

CONCLUSIONS

Carbohydrate malassimilation and gastrointestinal complaints are frequent in euthyroid patients with HT, leading to novel clinical and pathophysiological considerations and concepts.

Fructose and lactose intolerance and malabsorption testing: the relationship with symptoms in functional gastrointestinal disorders

BACKGROUND

The association of fructose and lactose intolerance and malabsorption with the symptoms of different functional gastrointestinal disorders (FGID) remains unclear.

AIM

To investigate the prevalence of fructose and lactose intolerance (symptom induction) and malabsorption and their association with clinical gastrointestinal (GI) as well as non-GI symptoms in FGID and the outcome of dietary intervention.

METHODS

Fructose and lactose intolerance (defined by positive symptom index) and malabsorption (defined by increased hydrogen/methane) were determined in 1372 FGID patients in a single centre using breath testing. Results were correlated with clinical symptoms in different FGID Rome III subgroups. The effectiveness of a targeted saccharide-reduced diet was assessed after 6-8 weeks.

RESULTS

Intolerance prevalence across all FGIDs was 60% to fructose, 51% to lactose and 33% to both. Malabsorption occurred in 45%, 32% and 16% respectively. There were no differences in intolerance or malabsorption prevalence between FGID subgroups. FGID symptoms correlated with symptoms evoked during testing (r = 0.35-0.61. P < 0.0001), but not with malabsorption. Non-GI symptoms occurred more commonly in patients with intolerances. Methane breath levels were not associated with constipation using several cut-off thresholds. Adequate symptom relief was achieved in >80% of intolerant patients, irrespective of malabsorption.

CONCLUSIONS

Fructose and lactose intolerances are common in FGID and associated with increased non-GI symptoms, but not with specific FGID subtypes. Symptoms experienced during breath testing, but not malabsorption, correlate with FGID symptoms. Effective symptom relief with dietary adaptation is not associated with malabsorption. Mechanisms relating to the generation of GI and non-GI symptoms due to lactose and fructose in FGID need to be explored further.