The Journal of nutrition
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The Journal of nutrition · May 1998
Comparative StudyAscorbic acid deficiency changes hepatic gene expression of acute phase proteins in scurvy-prone ODS rats.
The ODS rat (genotype od/od), which has a hereditary defect in ascorbic acid biosynthesis, was used to investigate the effects of ascorbic acid deficiency on the hepatic gene expression of both the positive acute phase proteins, haptoglobin and alpha1-acid glycoprotein, and the negative acute phase proteins, apolipoprotein A-I and albumin. Male ODS rats (6 wk old, body weight approximately 140 g) were fed a basal diet containing ascorbic acid (300 mg/kg diet) or a diet without ascorbic acid for 14 d. Ascorbic acid deficiency significantly elevated the serum concentration of haptoglobin and significantly lowered those of apolipoprotein A-I and albumin. ⋯ Although ascorbic acid deficiency significantly elevated the serum corticosterone concentration on d 14, the changes in mRNA levels of haptoglobin, alpha1-acid glycoprotein, apolipoprotein A-I and albumin due to ascorbic acid deficiency were not affected by adrenalectomy, as assessed in a separate experiment. The serum concentration of interleukin-6, an inflammatory cytokine that stimulates gene expression of some acute phase proteins, was significantly higher in the ascorbic acid-deficient rats on d 14 than in the control rats. These results suggest that ascorbic acid deficiency causes physiologic changes similar to those that occur in the acute phase response.
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The Journal of nutrition · Mar 1998
Randomized Controlled Trial Clinical TrialTolerance and breath hydrogen excretion following ingestion of maltitol incorporated at two levels into milk chocolate consumed by healthy young adults with and without fasting.
Little is known about the gastrointestinal effects of ingesting maltitol in chocolate. This study was designed to determine whether it leads to increased gastrointestinal symptomatology and if that symptomatology is dose related. It was also designed to discover whether breath hydrogen excretion in response to maltitol is dose related. ⋯ This dose-related response was consistent with the lower symptomatology after ingestion of 30 vs. 40 g maltitol. We have shown that 30 g maltitol in chocolate causes no significant symptomatology in young adults; however, 40 g caused mild borborygmi and flatus but no increased laxation. An increased breath H2 response indicates colonic fermentation of this polyol.
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The Journal of nutrition · Feb 1998
Review Comparative StudyToxicity considerations when revising the Nordic nutrition recommendations.
The Nordic countries have issued common nutrition recommendations since 1980. In connection with the 3rd revision, a joint working group of nutritionists and toxicologists assessed the toxicology of selected trace elements. ⋯ The safety factors between the lowest intakes at which adverse effects had been reported and the suggested upper limits of intake were small. In the toxicological evaluation of upper safe intake levels of essential trace elements, interactions between trace elements as well as long-term exposure to moderately elevated trace element intakes have to be considered.
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The Journal of nutrition · Feb 1998
ReviewEffects of maternal caloric restriction and exercise during lactation.
In affluent populations, breast-feeding women often wish to return to their prepregnancy weight as soon as possible postpartum and may restrict energy intake or increase exercise to achieve this goal. Gradual weight loss (< or = 2 kg/mo) seems to have no adverse effect on milk volume or composition, provided that the mother is not undernourished and is breast-feeding her infant on demand. Aerobic exercise improves cardiovascular fitness and does not affect milk energy transfer to the infant, but exercise alone is not likely to increase the rate of weight loss unless dietary intake is controlled. ⋯ Exercise enhances maintenance of lean body mass and is therefore a recommended component of any weight loss program. Maternal plasma prolactin concentration generally increases under conditions of negative energy balance, which may serve to protect lactation. Further research is required on the longer-term effect of energy restriction and on the effects of energy balance in lactating women with low fat reserves.
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The Journal of nutrition · Dec 1997
Comparative Study Clinical TrialRaising milk energy content retards gastric emptying of lactose in lactose-intolerant humans with little effect on lactose digestion.
Lactose digestion improves when the energy content of a meal is raised, perhaps due to delayed gastric emptying; however, this has not been demonstrated directly. It is not known whether lactose-intolerant subjects should consume full-fat or high energy milk instead of half-skimmed milk. In this study, breath 13CO2 and hydrogen (H2) measurements were combined to assess simultaneously the effect of increasing milk energy content on gastric emptying, digestion, and tolerance of lactose. ⋯ Mean symptom scores did not differ after ingestion of the two milks, but only two subjects experienced disturbing symptoms after high energy milk ingestion compared with five subjects after ingestion of half-skimmed milk (P = 0.56). Although ingestion of high energy milk delayed the gastric emptying of lactose for significantly longer than the ingestion of half-skimmed milk (P < 0.01), it did not lead to significant improvement in symptoms and reflected only a trend toward improved lactose digestion (P = 0.07), as measured by the area under the breath H2 excretion curve. These results indicate that it is not beneficial for most lactose-intolerant subjects to replace consumption of half-skimmed milk by milk with a higher energy content.