A friend has suggested you try a low carb diet as they have seen amazing results- she has dropped weight, her skin is clearer and she feels great! However you give it a go and you don’t appear to have anywhere near as much luck. If you are having trouble shifting the weight on a low carb diet here are a few reasons as to why that could be the case:
By Cliff Harvey
Low-carb diets have received criticism due to their perceived effects on thyroid function, and the belief that this will have a negative effect on general health, along with performance and fat-loss. But the real picture may be less than clear-cut.
By Cliff Harvey
Dietary medium chain triglycerides (MCTs) are a class of triglycerides in which two-to-three of the fatty acid chains attached to a glycerol backbone are medium in length. Medium-chain fatty acids (MCFAs) are fatty acids comprised of 6–12 carbons in chain. The MCTs are: caproic (C:6), caprylic (C:8), capric (C:10) and lauric acid (C:12) (1). So how do these particular fatty acids aid ketogenic and low carb high fat diets?
Post by Cliff Harvey
Due to the high-fat nature of a ketogenic or LCHF diet they have been considered to be potentially hazardous for those with cardiovascular disease (CVD).
Publicly available information (i.e. position statements and general patient information) from public health groups often include cautions against the use of VLCDs due to these perceived risks. Diabetes New Zealand states in their article on Low Carbohydrate Diets that “Eating more protein and fat may increase your risk of heart disease in the long term.” (1).
So are ketogenic diets dangerous for heart health?
By Cliff Harvey
Dietary guidelines for health are still heavily weighted (excuse the pun!) in favour of high-carbohydrate diets.
Nutrient Reference Values (NRV) for New Zealand and Australia for example state that the diet should contain a minimum of 45% of its calories from carbohydrate (1) and New Zealand Heart Foundation position statements on carbohydrate (currently being updated) suggest a range of 55%-65% caloric intake should be obtained from carbohydrate along with reducing intake of total and saturated fat (2).
Why is this the case?
Post by Cliff Harvey
There has been a lot in the media recently slamming the high fat, low carb diet suggesting that it is not safe and could put you at increased risk of disease.
Individual results to different diets will vary and a ketogenic diet may not be applicable to everyone, but nutritional ketosis is generally considered to be safe by most researchers in the field.
By Cliff Harvey
There is no universally accepted definition of a low-carbohydrate diet (LCD) and so it can be very confusing for the public (and researchers) to know exactly what is being spoken about when people use terms like ‘LCHF’ and low-carb.
By Cliff Harvey
There is a lot of confusion about the term nutritional ketosis amongst people. It is important to understand when and why nutritional ketosis occurs, and the basis of a ketogenic diet.
Post by Emily White
Full fat or low fat? In regards to dairy products it appears to be the question on everyone's mind. Stumble across any health blog and you will no doubt be bombarded with many contrasting opinions.
Until recently, low fat dairy was all the rage. We were told that consuming glass after glass of low fat milk would make us big and strong without the calories. Cheese, Greek yoghurt and butter were the devil and the ‘experts’ said they should be replaced with their lower fat counterparts, such as margarine.
By Cliff Harvey
At a Glance:
The Bottom Line: Coconut oil is a healthy addition to a balanced diet.
Is Coconut Oil used traditionally?
The contention has been made in popular media (example: http://www.nzherald.co.nz/lifestyle/news/article.cfm?c_id=6&objectid=11347584b) that Coconut Oil (CO) has limited traditional use.
This is characterised by attention on Pacific populations using expressed coconut fluid (cream) from coconut flesh, and coconut flesh itself. Not withstanding that these traditional foods contain high amounts of coconut oils (14% and 33% by weight respectively) (USDA SR-27, 2014) thereby justifying their inclusion as a traditional food by proxy, there is also ample evidence for consistent, long term use of coconut oil as a traditional food.
Tribal authorities in outlying islands in Fiji (working with the New Zealand based company Pure Coco) have this to say: “Fijians like most other pacific islanders (and inhabitants of South east Asia) have used coconut for centuries. We use coconuts in all forms, both raw and cooked, as coconut flesh, coconut milk, coconut oil, coconut water, we even make sugar and alcohol from the coconut sap.”
They go on to elucidate the traditional extraction methods: “Traditionally, coconut oil was made from fresh coconut cream (i.e the fatty liquid squeezed from grated coconut flesh) in two different ways. You can heat the coconut cream until the milk solids and fats separate out (similar to making clarified butter or ghee from butter), you strain off the milk solids and what you are left with is coconut oil. Alternately you can leave the coconut cream in a cool dark place for about 48 hours, until it naturally ferments, and the coconut oil separates out.”
Coconut oil has also been used extensively in the Indian sub-continent. The traditional use of coconut and all it’s related products stretches back over 4000 years in Indian tradition and the coconut palm is often referred to in Sanskrit texts as the ‘Tree of Life’ due to the abundance of manufacturing, medicinal and culinary and edible uses for the plant. In traditional Indian medicine coconut oil is commonly used as a topical medicinal compound and base (Muthu, Ayyanar, Raja & Ignacimuthu, 2006; Jeeva, Jeeva & Kingston, 2007; Kumar, Ayyanar, Ignacimuthu, 2007; Gupta, Vairale, Deshmukh, Chaudhary & Wate, 2010; Rajakumar & Shivanna, 2010) and as an oral medicine (Revathi & Parimelazhagan, 2010) (Note: these are only a small selection of myriad relevant studies and texts showing the extensive use of coconut oil in traditional medicines in India).
Many other areas in South East Asia have a tradition and high use of Coconut Oil and Coconut food products.
Is Traditionally Used Coconut Oil Detrimental to Health?
In a comparison of Pacific peoples using differing amounts of CO, Prior and colleagues (1981) evaluated diets of atoll dwellers in Pukapuka and Tokelau in which coconut is the chief source of energy for both groups. Tokelauans exhibited higher saturated fat intake (63% of energy derived from coconut) than Pukapukans (34% energy derived from coconut) and had higher cholesterol levels. But in spite of this, cardiovascular diseases were uncommon in both groups, with no evidence that higher saturated fat intake, and higher coconut intake provide a harmful effect (Prior, Davidson, Salmond, & Czochanska, 1981).
According to Dr Sridhar Maddela, head of medical sciences at Auckland’s Wellpark College of Natural Therapies, Coconut Oil has been used extensively and traditionally as a cooking oil in the Southern Indian province of Kerala. In this province in particular the traditional and common use of CO has been implicated as a reason for high Coronary Heart Disease (CHD) rates. However a study comparing 16 age and sex matched controls performed in Kerala (Kumar, 1997) to explore this presumed link between coconut oil and heart disease risk found that CO consumption was similar in both groups (with and without CHD). The groups did not differ in fat, saturated fat nor cholesterol consumption, implying no specific role for coconut oil or coconut consumption in this population for CHD risk. It has been further noted (in this population) that the lipid composition of arterial plaques is not altered by either coconut oil or sunflower oil (which is often suggested as a replacement cooking medium) (Palazhy et al., 2012).
Indeed there has been an alarming rise in the prevalence of CHD and Type-2 Diabetes in India attributed in part to the replacement of traditional cooking fats condemned to be atherogenic, with refined vegetable oils—resulting in calls to switch ‘back’ to a combination of different types of fats including the traditional cooking fats like ghee, coconut oil and mustard oil to reduce the risk of CHD and diabetes (Sircar & Kansra, 1998).
A community based longitudinal study in Cebu, Phillipines found a positive, albeit small correlation between CO and HDL cholesterol, with no worseing of HDL-Total Cholesterol ratio or triglycerides (Feranil, Duazo, Kuzawa, & Adair, 2011).
The Food and Agriculture Organisation of the United Nations has stated: “All available population studies show that dietary coconut oil does not lead to high serum cholesterol nor to high coronary heart disease mortality or morbidity rate.”(Kaunitz, N.D)
Do the Fats in Coconut Oil Increase Risk of Heart Disease?
A meta-analysis of 60 selected trials calculated the effects of the amount and type of fat on total:HDL cholesterol and on other lipids suggests that lauric acid (the primary fatty acid found in coconut oil) does increase total cholesterol, but much of the effect is on HDL cholesterol, favourably influencing HDL to Total Cholesterol ratios (Mensink, Zock, Kester, & Katan, 2003). The antiartherogenic acitivities of HDL-C are a function not just of quanitity but quality of HDL (Sviridov, Mukhamedova, Remaley, Chin-Dusting, & Nestel, 2008) in which glycation, oxidation and other nutritional factors (influenced for example by excessive sugar and n-6 fatty acid intake) may also play critical roles .
A randomised, double-blind, clinical trial involving 40 women aged 20–40 years, over a 12 week intervention period compared supplementation of 30 mL of either coconut oil or soy bean oil. There were no differences in biochemical or anthropometric markers at the beginning of the study. After 12 weeks the coconut oil treated group exhibited higher levels of HDL (48.7 ± 2.4 vs. 45.00 ± 5.6; P = 0.01) and a lower LDL:HDL ratio (2.41 ± 0.8 vs. 3.1 ± 0.8; P = 0.04). Reductions in BMI were observed in both groups but only the group taking coconut oil reduced waist circumference, The soybean oil treated group demonstrated reduced HDL, increased cholesterol and LDL cholesterol. This suggests coconut oil does not cause dyslipidemia and may promote reduced abdominal obesity (Assunção, Ferreira, dos Santos, Cabral, & Florêncio, 2009). Further, it has been indicated that that a coconut oil-based, high saturated fatty-acid diet may favourbaly affect post-prandial lipoprotein-a concentration compared with a high polyunsaturated fat diet (Müller, Lindman, Blomfeldt, Seljeflot, & Pedersen, 2003).
A study was performed to investigate effects of coconut milk and soya milk supplementation on the lipid profile of free living healthy subjects. In this trial sixty volunteers aged 18–57 years were given coconut milk porridge (CMP) for 5 days of the week for 8 weeks, followed by a 2-week washout period, subsequent to which they received isoenergetic soya milk porridge (SMP) for 8 weeks. LDL levels decreased with CMP whilst HDL rose. They study authors concluded that “coconut fat in the form of CM does not cause a detrimental effect on the lipid profile in the general population and in fact is beneficial due to the decrease in LDL and rise in HDL” (Ekanayaka, Ekanayaka, Perera, & De Silva, 2013).
In rat studies Virgin Coconut Oil (VCO) reduces total cholesterol, triglycerides, LDL, VLDL and increased HDL. It also appears to reduce or prevent oxidation of LDL and reduce carbonyl formation. These properties are thought to result at least partially from the antioxidant polyphenols present in CO (Nevin & Rajamohan, 2004). Virgin coconut oil appears to be superior in its antioxidant action, including increased antioxidant status of animals treated with VCO, and provides a greater reduction in lipid peroxidation when compared to both Copra oil and groundnut oil treated animals (Nevin & Rajamohan, 2006, 2008). It also exhibits significant antithrombotic effects (Nevin & Rajamohan, 2008).
Arunima, S., & Rajamohan, T. (2014). Influence of virgin coconut oil-enriched diet on the transcriptional regulation of fatty acid synthesis and oxidation in rats – a comparative study. British Journal of Nutrition, 111(10), 1782-1790. doi: doi:10.1017/S000711451400004X
Assunção, M., Ferreira, H., dos Santos, A., Cabral, C., Jr., & Florêncio, T. M. T. (2009). Effects of Dietary Coconut Oil on the Biochemical and Anthropometric Profiles of Women Presenting Abdominal Obesity. Lipids, 44(7), 593-601. doi: 10.1007/s11745-009-3306-6
Ekanayaka, R. A. I., Ekanayaka, N. K., Perera, B., & De Silva, P. G. S. M. (2013). Impact of a Traditional Dietary Supplement with Coconut Milk and Soya Milk on the Lipid Profile in Normal Free Living Subjects. Journal of Nutrition and Metabolism, 2013, 11. doi: 10.1155/2013/481068
Feranil, A. B., Duazo, P. L., Kuzawa, C. W., & Adair, L. S. (2011). Coconut oil is associated with a beneficial lipid profile in pre-menopausal women in the Philippines. Asia Pac J Clin Nutr, 20(2), 190-195.
Gupta, R., Vairale, M. G., Deshmukh, R. R., Chaudhary, P. R., & Wate, S. R. (2010). Ethnomedicinal uses of some plants used by Gond tribe of Bhandara district, Maharashtra. Indian Journal of Traditional Knowledge, 9(4), 713-717.
Jeeva, G. M., Jeeva, S., & Kingston, C. (2007). Traditional treatment of skin diseases in South Travancore, southern peninsular India. Indian J Traditional Knowledge, 6(3), 498-501.
Kaunitz, H., Dayrit, C.S. . (N.D). Coconut Oil Consumption and Coronary Heart Disease.
Kumar, P. D. (1997). The Role of Coconut and Coconut Oil in Coronary Heart Disease in Kerala, South India. Tropical Doctor, 27(4), 215-217. doi: 10.1177/004947559702700409
Kumar, P. P., Ayyanar, M., & Ignacimuthu, S. (2007). Medicinal plants used by Malasar tribes of Coimbatore district, Tamilnadu. Indian journal of traditional Knowledge, 6(4), 579-582.
Lemieux, H., Bulteau, A. L., Friguet, B., Tardif, J.-C., & Blier, P. U. (2011). Dietary fatty acids and oxidative stress in the heart mitochondria. Mitochondrion, 11(1), 97-103. doi: http://dx.doi.org/10.1016/j.mito.2010.07.014
Mensink, R. P., Zock, P. L., Kester, A. D., & Katan, M. B. (2003). Effects of dietary fatty acids and carbohydrates on the ratio of serum total to HDL cholesterol and on serum lipids and apolipoproteins: a meta-analysis of 60 controlled trials. Am J Clin Nutr, 77(5), 1146-1155.
Müller, H., Lindman, A. S., Blomfeldt, A., Seljeflot, I., & Pedersen, J. I. (2003). A Diet Rich in Coconut Oil Reduces Diurnal Postprandial Variations in Circulating Tissue Plasminogen Activator Antigen and Fasting Lipoprotein (a) Compared with a Diet Rich in Unsaturated Fat in Women. The Journal of Nutrition, 133(11), 3422-3427.
Muthu, C., Ayyanar, M., Raja, N., & Ignacimuthu, S. (2006). Journal of Ethnobiology and Ethnomedicine. Journal of Ethnobiology and Ethnomedicine,2, 43.
Nevin, K. G., & Rajamohan, T. (2004). Beneficial effects of virgin coconut oil on lipid parameters and in vitro LDL oxidation. Clinical Biochemistry, 37(9), 830-835. doi: http://dx.doi.org/10.1016/j.clinbiochem.2004.04.010
Nevin, K. G., & Rajamohan, T. (2006). Virgin coconut oil supplemented diet increases the antioxidant status in rats. Food Chemistry, 99(2), 260-266. doi: http://dx.doi.org/10.1016/j.foodchem.2005.06.056
Nevin, K. G., & Rajamohan, T. (2008). Influence of virgin coconut oil on blood coagulation factors, lipid levels and LDL oxidation in cholesterol fed Sprague–Dawley rats. e-SPEN, the European e-Journal of Clinical Nutrition and Metabolism, 3(1), e1-e8. doi: http://dx.doi.org/10.1016/j.eclnm.2007.09.003
Palazhy, S., Kamath, P., Rajesh, P. C., Vaidyanathan, K., Nair, S. K., & Vasudevan, D. M. (2012). Composition of Plasma and Atheromatous Plaque among Coronary Artery Disease Subjects Consuming Coconut Oil or Sunflower Oil as the Cooking Medium. Journal of the American College of Nutrition, 31(6), 392-396. doi: 10.1080/07315724.2012.10720464
Prior, I. A., Davidson, F., Salmond, C. E., & Czochanska, Z. (1981). Cholesterol, coconuts, and diet on Polynesian atolls: a natural experiment: the Pukapuka and Tokelau island studies. The American journal of clinical nutrition, 34(8), 1552-1561.
Rajakumar, N., & Shivanna, M. B. (2010). Traditional herbal medicinal knowledge in Sagar taluk of Shimoga district, Karnataka, India. Indian Journal of Natural Products and Resources, 1(1), 102-108.
Sircar, S., & Kansra, U. (1998). Choice of cooking oils--myths and realities. Journal of the Indian Medical Association, 96(10), 304-307.
Revathi, P., & Parimelazhagan, T. (2010). Traditional knowledge on medicinal plants used by the Irula tribe of Hasanur hills, Erode District, Tamil Nadu, India.Ethnobotanical Leaflets, 2010(2), 4.
Sviridov, D., Mukhamedova, N., Remaley, A. T., Chin-Dusting, J., & Nestel, P. (2008). Antiatherogenic functionality of high density lipoprotein: how much versus how good. J Atheroscler Thromb, 15(2), 52-62.
U.S. Department of Agriculture, Agricultural Research Service. 2014. USDA National Nutrient Database for Standard Reference, Release 27. Nutrient Data Laboratory Home Page, http://www.ars.usda.gov/ba/bhnrc/ndl
By Cliff Harvey ND
A recent article in the New Zealand Herald: 'Choice! Food goodness at a glance' tells of the proposed (soon to be implemented) Government initiative to label foods according to a 'star rating', similar to that used to show energy efficiency in appliances. In this system a rating of anywhere between half and five stars will be given according to how (supposedly) 'healthy' a food is.