Nut Consumption 

• The ability of nuts to improve the blood lipid profile and reduce the risk of CAD is now well established. ¹ Nuts are  powerhouse of healthy fats and nutrients: Extensive studies during the past decade have transformed the image of nuts from fattening snacks to a wholesome and heart-healthy food to be consumed daily but in small quantities.¹

• Nuts are rich sources of protein, antioxidants, fiber, phytosterols, carotenoids, phenols, vitamins and minerals (especially potassium and magnesium).^{1, 2} Nuts also yield 5-10% fiber and 12-25% protein. Yet, nuts are not generally recommended as snacks because of their high fat content.

• Although nuts contain 45-80% fat, most of the fats are the highly beneficial monounsaturated fat and polyunsaturated fat.^{1, 3} Incorporation of nuts in the diet may therefore improve the overall nutritional quality of the diet.⁴ Various nuts with demonstrated beneficial effects on lipids and CAD risks include walnuts, Macadamia nuts, peanuts and almonds (See Table 114 A).^5-12

Table 114 A. MUFA, PUFA, and SAFA content (in gm) in Tree Nuts and Fruit (All nuts are dry roasted without salt except coconut) 1, 13
Nuts	Calories per 100 gm	Fat content per 100 gm	MUFA	PUFA	SAFA
Macadamia nuts	718	76	59	1	12
Hazelnuts	646	62	47	8	5
Pecans	710	74	44	21	6
Almonds	597	53	34	13	4
Cashew nuts	574	46	27	8	9
Pistachio nuts	570	46	24	14	6
Walnuts	607	57	13	37	4
Flax Seed	492	34	7	22	3
Coconut meat, creamed	684	69	3	1	61
Coconut meat, sweetened, shredded	501	35	2	0	31
Fruits
Avocados, California	177	17	11	2	3
Olives	115	11	8	1	1
Avocados, Florida	112	9	5	1	2
MUFA =monounsaturated fatty acids; PUFA = polyunsaturated fatty acids; SAFA= saturated fatty acids

 

•  Elevated serum LDL levels have been consistently shown to be an important risk factor in the development of coronary artery disease (CAD). While statin therapy has been shown to be very effective in reducing one’s serum lipid levels, dietary therapeutic approaches are continually being assessed for their potentially beneficial effects on serum lipid levels. ¹⁴

•  Randomised-controlled trials (RCT) have become the gold standard for scientific evidence.^{15, 16} The results of a large pooled analysis of all RCTs (until 2010) suggest that increased consumption of nuts, most commonly walnuts and almonds, can significantly reduce LDL-C. The daily nut consumption in these trials ranged from 0.8 to 4.8 ounces (average = 2.4 ounces/day) and the effects of different nuts including walnuts, almonds, pecans, macadamia nuts, and pistachios were assessed in these trials.¹⁴

• The estimated effects of nut consumption on blood lipid levels were dose related. For example, when approximately 20% of the  dietary energy was obtained from nuts, average decrease in LDL-cholesterol is  10 mg/dl (approximate 5% decline); when approximately 10% of dietary energy was obtained from nuts, blood lipid levels of total cholesterol and LDL-cholesterol were reduced by approximately 6 mg/dl or 3%.¹⁴

•  Consumption of a handful of nuts a day (around 60g) reduces LDL cholesterol levels by around 6%.─An effect identical in magnitude to doubling the dose of any statin including atorvastatin or rosuvastatin from 20 mg to 40 mg/d.^17-19

• A 1% reduction in LDL occurs for every 7 g/d of almonds.¹⁶ Consumption of other nuts (except coconuts) is equally beneficial. For example, a 10% reduction in LDL can be achieved by the daily consumption of 40 g of walnuts, peanuts or pistachios, 70 g almonds, 100 g of macadamia nuts, or110 g of  pecans.¹ But quantities of this magnitude are not recommended unless the total energy intake from other foods is reduced, since excess caloric intake can lead to obesity with all its attendant problems.

• Nuts also have beneficial effects on diabetes, metabolic syndrome, cancer and cardiovascular disease (CVD).^{2, 20-23} Nuts have minimal effects on increasing blood glucose levels after a meal when eaten alone. More importantly, nuts diminish the blood sugar increase after a meal when consumed with high-glycemic index carbohydrate foods in people with and without  diabetes.²⁰

• Regular  almond consumption  reduces hemoglobin A(1c) in individuals with diabetes.²⁴ Nuts also improve insulin sensitivity and >5 oz/wk of nuts reduce the risk of  diabetes by 27%.¹

• Nut consumption also improves HDL cholesterol.  Nuts are as effective as increasing physical activity and trimming calories to increase HDL. Adding 2 oz or 60 g of nuts to a diet is a delicious way to decrease TC/HDL ratio and CAD risk.¹

• The   inclusion of nuts in the diet is warranted, in view of their potential to reduce CAD risk of individuals with and without diabetes and the metabolic syndrome.^{21, 23}The proscription of nuts can no longer be justified. In fact, regular nut consumption as replacement for refined grains and high-fat meats is strongly recommended.¹

• Nuts are an energy dense food source and must be eaten as part of a balanced diet.²⁵ Nuts contain 160-200 calories/oz. It cannot be overemphasized that energy from nuts should replace the unhealthy calories from saturated fat and refined grains to prevent  unwarranted weight gain.¹12 almonds or 11 cashew nuts or 56 peanuts will provide you with 100 calories on an average and hence over-consumption of nuts must be limited to prevent excess calories and resultant weight gain.

• All nuts are not created equal. Betel nut chewing was independently associated with a greater risk of CVD and all-cause mortality in Taiwanese men²⁶ and consumption of coconut significantly increases LDL-C.²⁷

Sources

1. Enas EA. Indian diet and cardiovascular disease: An update. In: Chatterjee SS, ed. Update in Cardiology Hyderabad: Cardiology Society of India.; 2007.

2. Chen CY, Blumberg JB. Phytochemical composition of nuts. Asia Pac J Clin Nutr. 2008;17 Suppl 1:329-332.

3. www.nal.usda.gov/fnic/cgi-bin. USDA nutrient database for standard reference. Accessed June 22, 2011.

4. O’Neil CE, Keast DR, Fulgoni VL, 3rd, Nicklas TA. Tree nut consumption improves nutrient intake and diet quality in US adults: an analysis of National Health and Nutrition Examination Survey (NHANES) 1999-2004. Asia Pac J Clin Nutr. 2010;19(1):142-150.

5. Garg ML, Blake RJ, Wills RB, Clayton EH. Macadamia nut consumption modulates favourably risk factors for coronary artery disease in hypercholesterolemic subjects. Lipids. Jun 2007;42(6):583-587.

6. Ellsworth JL, Kushi LH, Folsom AR. Frequent nut intake and risk of death from coronary heart disease and all causes in postmenopausal women: the Iowa Women’s Health Study. Nutr Metab Cardiovasc Dis. Dec 2001;11(6):372-377.

7. Hu FB, Stampfer MJ. Nut consumption and risk of coronary heart disease: a review of epidemiologic evidence. Curr Atheroscler Rep. Nov 1999;1(3):204-209.

8. Fraser GE. Nut consumption, lipids, and risk of a coronary event. Clin Cardiol. Jul 1999;22(7 Suppl):III11-15.

9. Hu FB, Stampfer MJ, Manson JE, et al. Frequent nut consumption and risk of coronary heart disease in women: prospective cohort study. BMJ. Nov 14 1998;317(7169):1341-1345.

10. Fraser GE, Sabate J, Beeson WL, Strahan TM. A possible protective effect of nut consumption on risk of coronary heart disease. The Adventist Health Study. Arch Intern Med. Jul 1992;152(7):1416-1424.

11. Albert CM, Gaziano JM, Willett WC, Manson JE. Nut consumption and decreased risk of sudden cardiac death in the physicians’ health study. Arch Intern Med. 2002;162(12):1382-1387.

12. Hu FB, Stampfer M, Manson J, et al. Frequent nut consumption and risk of coronary heart disease in women: Prospective cohort study. BMJ. 1998;317(7169):1341-1345.

13. Enas EA, Senthilkumar A, Chennikkara H, Bjurlin MA. Prudent diet and preventive nutrition from pediatrics to geriatrics: current knowledge and practical recommendations. Indian heart journal. Jul-Aug 2003;55(4):310-338.

14. Sabate J, Oda K, Ros E. Nut consumption and blood lipid levels: a pooled analysis of 25 intervention trials. Arch Intern Med. May 10 2010;170(9):821-827.

15. Sabate J, Haddad E, Tanzman JS, Jambazian P, Rajaram S. Serum lipid response to the graduated enrichment of a Step I diet with almonds: a randomized feeding trial. Am J Clin Nutr. Jun 2003;77(6):1379-1384.

16. Jenkins DJ, Kendall CW, Marchie A, et al. Dose response of almonds on coronary heart disease risk factors: blood lipids, oxidized low-density lipoproteins, lipoprotein(a), homocysteine, and pulmonary nitric oxide: a randomized, controlled, crossover trial. Circulation. Sep 10 2002;106(11):1327-1332.

17. Jenkins DJ, Kendall CW, Marchie A, et al. Effects of a dietary portfolio of cholesterol-lowering foods vs lovastatin on serum lipids and C-reactive protein. Jama. Jul 23 2003;290(4):502-510.

18. Sabate J. Nut consumption and body weight. Am J Clin Nutr. Sep 2003;78(3 Suppl):647S-650S.

19. Roberts WC. The rule of 5 and the rule of 7 in lipid-lowering by statin drugs. Am J Cardiol. 1997;80(1):106-107.

20. Kendall CW, Josse AR, Esfahani A, Jenkins DJ. Nuts, metabolic syndrome and diabetes. Br J Nutr. Aug 2010;104(4):465-473.

21. Li TY, Brennan AM, Wedick NM, Mantzoros C, Rifai N, Hu FB. Regular consumption of nuts is associated with a lower risk of cardiovascular disease in women with type 2 diabetes. J Nutr. Jul 2009;139(7):1333-1338.

22. Jiang R, Manson JE, Stampfer MJ, Liu S, Willett WC, Hu FB. Nut and peanut butter consumption and risk of type 2 diabetes in women. JAMA. Nov 27 2002;288(20):2554-2560.

23. Jenkins DJ, Hu FB, Tapsell LC, Josse AR, Kendall CW. Possible benefit of nuts in type 2 diabetes. J Nutr. Sep 2008;138(9):1752S-1756S.

24.  Cohen AE, Johnston CS. Almond ingestion at mealtime reduces postprandial glycemia and chronic ingestion reduces hemoglobin A(1c) in individuals with well-controlled type 2 diabetes mellitus. Metabolism. Apr 11 2011.

25. Joint WHO/FAO Expert Consultation. WHO Technical Report Series 916: Diet, Nutrition and the Prevention of Chronic Diseases Geneva: World Health Organization 2003.

26. Lin WY, Chiu TY, Lee LT, Lin CC, Huang CY, Huang KC. Betel nut chewing is associated with increased risk of cardiovascular disease and all-cause mortality in Taiwanese men. Am J Clin Nutr. May 2008;87(5):1204-1211.

27. Joseph A, Kutty VR, Soman CR. High risk for coronary heart disease in Thiruvananthapuram City: A study of serum lipids and other risk factors. Indian Heart J. 2000;52(1):29-35.