A recent study in the British Journal of Nutrition [1] has found that dark chocolate contains antioxidants that are protective to DNA, but this effect only lasts for a day. Researchers in Milan, Italy, measured plasma epicatechin levels, DNA damage in mononuclear blood cells, and plasma total antioxidant activity in 20 volunteers on a balanced diet with standardised levels of antioxidants. After a washout period the subjects were given 45g of either dark chocolate (DC, containing 860 mg polyphenols, of which 58 mg epicatechin) or white chocolate (WC, no epicatechin).

The results found that increased levels of epicatechin in the blood of those who had eaten the dark chocolate lasted for nearly a day; between 2 hours and 22 hours after DC intake. This corresponded with lower levels of DNA damage to the blood cells, but eating the dark chocolate did not affect total antioxidant activity. Eating WC did not make any difference to the factors measured. The researchers conclude: "DC may transiently improve DNA resistance to oxidative stress." They add: “the present results are clinically encouraging especially in the field of the diet therapy of obesity, pathology related to greater incidence of cardiovascular disease and cancer”. Unfortunately regular consumption of dark chocolate does not increase long-term epicatechin levels, so according to this study, dark chocolate must be consumed daily to get these benefits.

Chocolate has long been known to be an important part of a healthy diet According to Donatella Lippi of the Department of Anatomy, Histology and Legal Medicine, University of Florence, Italy [2]:

The Aztecs believed that cocoa pods symbolized life and fertility, and that eating the fruit of the cocoa tree allowed them to acquire wisdom and power. Cocoa was said to have nourishing, fortifying, and aphrodisiac qualities.

One well-researched benefit of chocolate is improving the health of the heart. In a Data from The Stockholm Heart Epidemiology Study showed how of 1169 non-diabetic patients having their first heart attack, those who were regular consumers of chocolate were more likely to survive. [3] A study on dark chocolate published in the International Journal of Cardiology [4] measured the effect of 45g of dark chocolate on blood circulation in the coronary arteries as measured by doppler ultrasound. After two weeks of daily intake the researchers conclude:

Flavonoid-rich dark chocolate intake significantly improved coronary circulation in healthy adults, independent of changes in oxidative stress parameters, blood pressure and lipid profile, whereas non-flavonoid white chocolate had no such effects.

Epicatechins are a type of polyphenol antioxidant in the catechin family. Catechins are found in tea, wine, fruits and vegetables as well as dark chocolate. However it is the bitter principles in the chocolate that contain the beneficial antioxidants: An editorial in The Lancet [5] points out that some chocolate manufacturers may darken the natural cocoa solids and remove the bitter flavanols, "so even a dark-looking chocolate can have no flavanol". In addition, cacao colouring can contain more than the maximum EU permitted level of mercury (1 mcg/g). [6] Manufacturers rarely label their products with this information. In addition, 45g of dark chocolate contains about 200 calories, so calorific intake must be taken into account as part of the risk/benefit calculation. One way round that might be to use raw cacao nibs which contain no sugar and are also unheated, thereby likely to have a higher catechin content, although the consumer may not see the benefit of this over drinking red wine, for example.

Therefore the amount of chocolate consumed is not necessarily proportionate to it's health benefits: Another paper from the British Journal of Nutrition [7] demonstrated that even doubling the the polyphenol content in the same size dose of chocolate had no significant dose-related benefits:

It was observed that the 500 mg polyphenol dose was equally effective in reducing fasting blood glucose levels, systolic BP and diastolic BP as the 1000 mg polyphenol dose suggesting that a saturation effect might occur with increasing dose of polyphenols.

Dark chocolate is suitable for individuals of all blood groups. [8] However, a recent paper in the Journal of Cardiovascular Pharmacology [9] suggests that in addition to the well-known antioxidant effects, one way chocolate may directly help cardiovascular system is by improving nitric oxide function. Nitric oxide recycling is an important function that can sometimes be inadequate in those with the B antigen (blood groups B and AB), probably due to genetic linkage of the argininosuccinate synthase enzyme. [10]

When giving the gift of chocolate to loved ones it may be prudent to ensure adequate polyphenol content, absence of colouring, and to draw attention to the health benefits of both moderation and regular consumption.

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References:

1. Spadafranca A, Martinez Conesa C, Sirini S, Testolin G. "Effect of dark chocolate on plasma epicatechin levels, DNA resistance to oxidative stress and total antioxidant activity in healthy subjects." Br J Nutr. 2009 Nov 5:1-7. PMID: 19889244
doi: 10.1017/S0007114509992698

2. Lippi D. "Chocolate and medicine: dangerous liaisons?" Nutrition. 2009 Nov-Dec;25(11-12):1100-3.
PMID: 19818277

3. Janszky I, Mukamal KJ, Ljung R, Ahnve S, Ahlbom A, Hallqvist J. "Chocolate consumption and mortality following a first acute myocardial infarction: the Stockholm Heart Epidemiology Program." J Intern Med. 2009 Sep;266(3):248-57. PMID: 19711504

4. Shiina Y, Funabashi N, Lee K, et. al. "Acute effect of oral flavonoid-rich dark chocolate intake on coronary circulation, as compared with non-flavonoid white chocolate, by transthoracic Doppler echocardiography in healthy adults." Int J Cardiol. 2009 Jan 24;131(3):424-9. PubMed PMID: 18045712.

5. Lancet. 2007 Dec 22;370(9605):2070. "The devil in the dark chocolate." [No authors listed] PMID: 18156011
doi:10.1016/S0140-6736(07)61873-X

6. Ogimoto M, Uematsu Y, Suzuki K, Kabashima J, Nakazato M. ["Survey of toxic heavy metals and arsenic in existing food additives (natural colors)"]. Shokuhin Eiseigaku Zasshi (Journal of the Food Hygienic Society of Japan). 2009 Oct;50(5):256-60. PMID: 19897953

7. Almoosawi S, Fyfe L, Ho C, Al-Dujaili E. "The effect of polyphenol-rich dark chocolate on fasting capillary whole blood glucose, total cholesterol, blood pressure and glucocorticoids in healthy overweight and obese subjects." Br J Nutr. 2009 Oct 13:1-9. PMID: 19825207

8. Blood Type Diet/ Nutrient Value Encyclopedia: TypeBase 4 - Chocolate

9. Galleano M, Oteiza PI, Fraga CG. "Cocoa, chocolate, and cardiovascular disease." J Cardiovasc Pharmacol. 2009 Dec;54(6):483-90. PMID: 19701098

10. Website - The Individualist: Nitric Oxide

Breaking News:

From today, unpasteurised, raw or 'green' milk is now commercially available in the UK for the first time in a vending machine-style dispenser. The milk is being dispensed in a farmers' market in Canterbury, Kent, The Goods Shed, so called because it is housed in a disused railway shed. The milk comes from a small local herd at Badlesmere Farm, and the machine must carry the advisory notice: "Warning: This milk has not been heat treated & may therefore contain organisms harmful to health." [1]

Pasteurised milk and milk products are generally thought to be a healthier option due to the possibility of infection, although proponents of raw milk claim that if a small dairy herd is well managed then the milk produced can be safe. The Weston A Price Foundation promotes the use of raw milk over pasteurised, although they suggest that soya milk is unsafe. [2] As a generalised dietary theory this does not take into account individual differences in requirements, metabolism and disease susceptibility, as detailed in the Blood Type Diet. Francis Pottenger MD conducted a famous series of experiments on generations of cats between 1932 and 1942, one of them focussed on the dramatic differences in health effects between raw and pasteurised milk. [3] This is often used as evidence of health benefits by proponents of raw food.

In Italy, green milk is available from similar vending machines in hundreds of farmers' markets throughout the country. The dispensers keep the milk at a suitable temperature, constantly stirring the cream into the milk, and cleaning the dispensing area. Buyers place a coin in the slot and a bottle under the spout, and the milk is dispensed at the amount requested.

Although unpasteurised cheeses are still available, the law in the UK is restrictive on the sale of green milk, generally being sold only by the producers (there are 102 registered producers in the UK in 2009):

The milk may only be sold direct to consumers by registered milk production holdings (at the farm gate or in a farmhouse catering operation) or through milk roundsmen. Sales through other outlets have been banned since 1985 (although sales by the farmer at farmers markets are allowed). [1]

Raw milk has been illegal in Scotland since 1983 following a number of milk-related illnesses and 12 potentially associated deaths.

References:
1. UK Food Standards Agency, Raw drinking milk and raw cream control requirements in the different countries of the UK. 11 May 2009.
2. Weston A Price Foundation Campaign for Real Milk Website accessed 16th Dec 2009
3. Pottenger, F. Pottenger's Cats: A Study in Nutrition Pub. Cancer Book House, 1983, p.15 ISBN 0916764060

A marker on the fingertips present at birth may predict adult-onset diabetes, according to a study published in the International Journal of Epidemiology [1].

Dermatoglyphics, the study of skin markings made by ridges on hands and feet, is used as a way of measuring gene expression determined by the early pre-birth environment. On each fingertip, the number of dermal ridges (the ridge count) provides a measure of fingertip growth activity during the early foetal period. These dermal ridges are formed during gestational weeks 12–19, and the resulting fingertip ridge appearance (i.e., the fingerprint) is fixed permanently.

Changes in the uterine environment can influence the activity of genes which either stimulate or inhibit growth of specific areas of the body. According to the study by Kahn and colleagues, those with specific dermatoglyphic patterns were more likely to develop type 2 diabetes after the age of 50, even when other influencing factors were taken into account. The ratio of the difference between the number of ridges on the thumb and 5th finger is one way of predicting the probability of an individual developing diabetes in later life:

Fingerprints may provide a useful tool to investigate prenatal developmental plasticity.

Epigenetics, or the influence of environment on gene expression, has become recognised as an influencing factor in type 2 diabetes [2]. Other body measurements predicting similar disease risk, such as the waist-to-thigh ratio, are also correlated with fingertip ridge counts [3]. Evidence for the significance of epigenetic influences during early prenatal life is compelling, and should be used as the basis for a preventive strategy starting before conception. Dermatoglyphics is used in The GenoType Diet, along with other markers of gene expression, not only to predict future disease risks, but to target specific prevention strategies.

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References:

1. Kahn HS, Graff M, Stein AD, Lumey LH. "A fingerprint marker from early gestation associated with diabetes in middle age: the Dutch Hunger Winter Families Study." Int J Epidemiol. 2009 Feb;38(1):101-9.
PMID: 18684786

2. Ling C, Groop L. "Epigenetics: a molecular link between environmental factors and type 2 diabetes." Diabetes. 2009 Dec;58(12):2718-25.
PMID: 19940235

3. Kahn HS, Graff M, Stein AD, Zybert PA, McKeague IW, Lumey LH. "A fingerprint characteristic associated with the early prenatal environment." Am J Hum Biol. 2008 Jan-Feb;20(1):59-65.
PMID: 17929242

Hello, My son is blood type A non-secretor. I know that sucanat is an avoid. In many different organic products we find sweeteners like evaporated cane juice, dehydrated cane juice, granulated cane juice, invert cane juice, are they all like sucanat, an avoid for type A non-secretor? Is cane juice different from the raw form of cane sugar? I would appreciate any information about this type of sweetener.
I have started following the BTD for about one month. Thank you.

Marie Claire

Evaporated cane juice is often described as a healthy alternative to refined sugar, as it retains more of the nutrients found in sugar cane. Sucanat® (a contraction of SUgar CAne NATural) is a type of evaporated cane juice[1], which unlike blackstrap molasses, has a relatively high sugar content.

For an individual of blood type A who is a non-secretor of their blood type, foods high in sugar are not a good food choice, due in part to the fact that ABH non-secretors have a greater risk of both metabolic syndrome and also of diseases due to lower levels of immunoglobulin antibodies[2].

References:

1. Ashley. Evaporated Cane Juice & Unrefined Powdered Sugar, in: Blog: Sweet & Natural Published December 17, 2008
2. Secretor Status, in The Individualist Wiki.

Dear Dr. Greenfield,

I have decided to try the blood type diet (A). I am aware that Dr. D'Adamo suggests avoiding smoked meat and seafood. I am assuming this is due to the nitrate/nitrite added to the food. However, I shop at Whole Foods Market and they smoke their seafood in house, naturally, without any preservatives. Would this be okay to eat on the blood type diet?

Thank you,

Jennifer

Smoking is a way of preserving foods using smoke typically from hardwood burnt at low temperatures: Certain compounds given off by burning wood have a preservative or antimicrobial effect on the food, and add flavour. Other compounds, such as polycyclic aromatic hydrocarbons (PAHs) may have a detrimental effect on human health at levels found in cooked foods, they are certainly a risk for workers occupationally exposed to PAHs, and also for cigarette smokers. Certain PAHs may become more toxic when metabolised, and metabolism can be dependent on individual polymorphisms. For example, cytochrome P450 1A1 (CYP1A1) is the primary cytochrome P-450 isoenzyme that biologically activates benzopyrene, a tetracyclic hydrocarbon present in smoked food, and the main carcinogen in cigarette smoke. Charbroiled and smoked meats and fish contain more PAHs than uncooked products, with up to 2.0 µg/kg of benzopyrene detected in smoked fish.[1]

Some people may be more at risk from eating smoked foods or other exposure to PAHs: Genetic polymorphisms in CYP1A1 inducibility has been implicated as a factor for susceptibility to lung and laryngeal cancer. CYP1A1 may be induced by other substances. The mechanism by which PAH causes cancer is thought to be via the binding of metabolites to DNA. Infants may be at risk for exposure to PAHs: Animal studies have shown that PAHs and metabolites cross the placenta; Because PAHs are excreted in breast milk, nursing infants of exposed mothers can be exposed through breastfeeding. Polymorphisms causing glutathione transferase deficiencies (GSTM1) may result in elevated breast cancer risk from PAHs.[2] Other risk factors may include blood group, with type A individuals having a greater risk of certain types of cancer, although this can be masked by other genetic factors overriding the blood group phenotype.[3]

Sodium nitrite (E250) is a preservative added to meats, which can form carcinogenic nitrosamines when exposed to high temperatures. Nitrosamine formation can be inhibited by the addition of vitamin C.[4]

The Blood Type Diet™ is based on naturopathic principles, and as such advocates avoiding or minimising consumption of foods that may enhance disease risk either for the individual or for the population in general.

References:
1. Grimmer G. 1968. "Carcinogenic hydrocarbons in the human environment". Dtsch Apoth Ztg 108:529.
2. van der Hel OL, Peeters PH, Hein DW, Doll MA, Grobbee DE, et al. "NAT2 slow acetylation and GSTM1 null genotypes may increase postmenopausal breast cancer risk in long-term smoking women." Pharmacogenetics. 2003 Jul;13(7):399-407. Pubmed.
3. Anderson DE, Haas C. "Blood type A and familial breast cancer." Cancer. 1984 Nov 1;54(9):1845-9. PubMed.
4. Mackerness CW, Leach SA, Thompson MH, Hill MJ. "The inhibition of bacterially mediated N-nitrosation by vitamin C: relevance to the inhibition of endogenous N-nitrosation in the achlorhydric stomach." Carcinogenesis 1989; 10(2) 397-399. PubMed.