AJCN July, 2009 – SUMMARY
This is another issue packed with wonderful reminders and revelations about the benefits of a healthy diet. To remember why so much is now being discovered, please review the omics revolution. Also please read the longer summaries with links to published articles at http://www.beloit.edu/nutrition/aln/0709ajcn. And if you have questions, please ask Roc at ordman@beloit.edu.
FEATURE THIS MONTH 1. Good nutrition “cures”, slows, and decreases risk of chronic diseases – Early documentation of the importance of good nutrition dates back to the time of Hippocrates (460–377 BC), who is quoted as saying, “Let thy food be thy medicine and thy medicine be thy food.” …We currently have evidence from major clinical trials that show efficacy of nutrition practices in “curing” diseases, slowing disease progression, and markedly decreasing risk of chronic diseases to a similar extent as pharmacologic therapy.
FOR EVERYONE
2. Eat a handful of walnuts (or any nuts) daily – Walnuts resulted in a significantly greater decrease in total cholesterol and in LDL-cholesterol concentrations…
3. Omega-3 and -6 unsaturated fats lower serum triglycerides and raise (beneficial) HDL.
4. Concern about nitrates lowered – The presence of nitrates and nitrites in food is associated with an increased risk of gastrointestinal cancer and, in infants, methemoglobinemia. 5. Nitrates are a struggle for farmers – Nitrate and nitrite are considered hazardous, and there are legal limits to their concentration in food and drinking water…Hord et al… claim that nitrate and nitrite should be considered as nutrients rather than hazardous.
6. Carotenes reduce breast cancer risk
WEIGHT CONCERNS
7. Fruit and veggie intake reduces weight gain
8. Low carb diet raises LDL cholesterol
9. Dietary restraint is effective, while dieting usually is not – Women who reported dieting at study entry were heavier at study entry and gained more weight over time than did nondieters.
10. Skim milk better for diet than fruit juice – Consumption of skim milk, in comparison with a fruit drink, leads to increased perceptions of satiety and to decreased energy intake at a subsequent meal.
11. The importance of getting vitamin supplements after bariatric surgery is clear.
FISH OIL BENEFICIAL, BUT SOME BENEFITS ARE UNCERTAIN
12. Fish oil may not reduce dementia risk (Danish study) – 13. Fish oil may not reduce dementia risk (Canadian study)
14. Study indicates postpartum depression is not due to fish oil deficiency-(See previous study to the contrary )
INFANTS AND MOTHERS
15. Hazard of bottle feeding baby – Our findings support a key role for IGF-I in the partitioning of overall infant weight gain into statural growth compared with adiposity.
16. Kids get needed iron from cereal – Regular provision of medicinal iron or iron-fortified cereal improves the iron status of breastfed infants, but medicinal iron leads to somewhat reduced growth.
DETAILS –1. Good nutrition “cures”, slows, and decreases risk of chronic diseases – Early documentation of the importance of good nutrition dates back to the time of Hippocrates (460–377 BC), who is quoted as saying, “Let thy food be thy medicine and thy medicine be thy food.” Today, diet is the cornerstone of healthy lifestyle recommendations issued by many federal agencies and health organizations. The foundation for healthy lifestyle recommendations is a robust evidence base that has evolved over time.We currently have evidence from major clinical trials that show efficacy of nutrition practices in “curing” diseases, slowing disease progression, and markedly decreasing risk of chronic diseases to a similar extent as pharmacologic therapy. With respect to diabetes, recommended lifestyle behaviors surpass the benefits of drug therapy. (Strongly recommend you follow the link and read the rest of this editorial. Ir documents clinical trials proving the benefits of proper diet compared to conventional medical treatment of chronic disease!)
2. Eat a handful of walnuts (or any nuts) daily – Diets lasted 4–24 wk with walnuts providing 10–24% of total calories. When compared with control diets, diets supplemented with walnuts resulted in a significantly greater decrease in total cholesterol and in LDL-cholesterol concentrations…
3. Omega-3 and -6 unsaturated fats lower serum triglycerides – Marine n–3 PUFAs were significantly inversely associated with triglyceride… n–6 PUFAs were significantly positively associated with HDL cholesterol … Marine n–3 PUFAs were significantly positively associated with HDL choles…Conclusion: Serum n–6 and n–3 PUFAs are inversely associated with triglycerides across populations.
4. Concern about nitrates lowered – The presence of nitrates and nitrites in food is associated with an increased risk of gastrointestinal cancer and, in infants, methemoglobinemia. Despite the physiologic roles for nitrate and nitrite in vascular and immune function, consideration of food sources of nitrates and nitrites as healthful dietary components has received little attention. Approximately 80% of dietary nitrates are derived from vegetable consumption; sources of nitrites include vegetables, fruit, and processed meats. Nitrites are produced endogenously through the oxidation of nitric oxide and through a reduction of nitrate by commensal bacteria in the mouth and gastrointestinal tract. As such, the dietary provision of nitrates and nitrites from vegetables and fruit may contribute to the blood pressure–lowering effects of the Dietary Approaches to Stop Hypertension (DASH) diet…These data call into question the rationale for recommendations to limit nitrate and nitrite consumption from plant foods. 5. Nitrates are a struggle for farmers – Nitrate and nitrite are considered hazardous, and there are legal limits to their concentration in food and drinking water. Nitrate from fertilizer accumulates in vegetables and fruit, and large-scale livestock production yields huge amounts of manure rich in nitrate that seeps into groundwater. Therefore, keeping nitrate concentrations below legal limits is a struggle for farmers. ..Other authors have already pointed out that the evidence for adverse effects of nitrate is inconsistent and that nitrate may actually be beneficial (2, 3). Hord et al (1) go one step further: they claim that nitrate and nitrite should be considered as nutrients.
6. Carotenes reduce breast cancer risk – Conclusions: The present study, which was the first to assess repeated measurements of serum carotenoids and micronutrients in relation to breast cancer, adds to the evidence of an inverse association of {alpha}-carotene and β-carotene with breast cancer. The positive associations observed for lycopene and {gamma}-tocopherol require confirmation.
7. Fruit and veggie intake reduces weight gain – Background: High fruit and vegetable intakes may limit weight gain, particularly in susceptible persons, such as those who stop smoking….Conclusions: Fruit and vegetable intake relates significantly, albeit weakly inversely, to weight change. For persons who stop smoking, high fruit and vegetable intakes may be recommended to reduce the risk of weight gain.
8. Low carb diet raises LDL cholesterol – Background: Long-term weight loss and cardiometabolic effects of a very-low-carbohydrate, high-saturated-fat diet (LC) and a high-carbohydrate, low-fat diet (LF) have not been evaluated under isocaloric conditions…Conclusions: Under planned isoenergetic conditions, as expected, both dietary patterns resulted in similar weight loss and changes in body composition. The LC diet may offer clinical benefits to obese persons with insulin resistance. However, the increase in LDL cholesterol with the LC diet suggests that this measure should be monitored.
9. Dietary restraint is effective, while dieting usually is not – Women who reported dieting at study entry were heavier at study entry and gained more weight over time than did nondieters. ..Conclusions: Increasing levels of dietary restraint may be beneficial in moderating weight by attenuating the positive association between disinhibition and weight in dieting women.
10. Skim milk better for diet than fruit juice – Objective: The objective was to investigate the effects of drinking skim milk in comparison with a fruit drink at breakfast on self-reported postmeal satiety and energy intake at lunch…Conclusion: Consumption of skim milk, in comparison with a fruit drink, leads to increased perceptions of satiety and to decreased energy intake at a subsequent meal.
11. Vitamins A, D, and thiamine deficiencies show need for vitamin supplements after bariatric surgery – Background: Bariatric surgery is widely performed to induce weight loss…Conclusions: Compared with gastric bypass, duodenal switch may be associated with a greater risk of vitamin A and D deficiencies in the first year after surgery and of thiamine deficiency in the initial months after surgery.
12. Fish oil may not reduce dementia risk (Danish study) – Background: Greater fish and omega-3 (n–3) polyunsaturated fatty acid (PUFA) intake may reduce dementia risk…Design: We studied 5395 participants aged ≥55 y …Results: During an average follow-up of 9.6 y, dementia developed in 465 participants…total fish intake was unrelated to dementia risk… 13. Fish oil may not reduce dementia risk (Canadian study) – Conclusions: No associations between n–3 PUFAs and dementia or AD were found. The results regarding mercury may indicate a spurious association.
14. This study indicates postpartum depression is not due to fishoil deficiency – Background: Mothers may be reluctant to receive medical treatment of postpartum depression (PPD), despite the detrimental consequences the disorder can impose on mother and child. Research on alternative methods of prevention and treatment of PPD is warranted. Previous studies have suggested that long-chain n–3 polyunsaturated fatty acids (PUFAs) might have a beneficial effect on depression…Results: Rates of depression were 0.3% (PPD-admission) and 1.6% (PPD-prescription). ..Conclusion: Overall, our data from a large prospective cohort linked with high-quality registers showed little evidence to support an association between intake of fish or n–3 PUFAs and PPD. (See previous study to contrary)
15. Hazard of bottle feeding baby – Background: Formula milk–fed infants show faster rates of growth and weight gain than do breastfed infants, and they have higher concentrations of insulin-like growth factor I (IGF-I)…Conclusions: Our findings support a key role for IGF-I in the partitioning of overall infant weight gain into statural growth compared with adiposity.
16. Kids get needed iron from cereal – Conclusions: Regular provision of medicinal iron or iron-fortified cereal improves the iron status of breastfed infants and may prevent iron deficiency . Both modalities are equally effective, but medicinal iron leads to somewhat reduced growth.
