The December 12 issue of the British Medical Journal (BMJ) contains a study by Moman A Mohammad and several colleagues in Sweden who examined the risk of myocardial infarctions (heart attacks) in relation to various national holidays, sporting events along with the time of day.1 https://www.bmj.com/content/363/bmj.k4811
This study has received significant press attention over the past few days because of one reported observation, the risk for heart attacks is highest on Christmas Eve. Given that most people are counting the days until Christmas with anticipation rather than dread, we want to look at these new data carefully and ponder if there may be an antidote we might employ.
This was a retrospective observational study using a nationwide (Sweden) coronary registry known as SWEDEHEART. The researchers examined 283,014 heart attack cases reported between 1998 and 2013. Time of the heart attack was recorded to the nearest minute in 88% of these cases.
Heart attacks that occurred on Christmas, New Year, Easter, Midsummer holiday along with the FIFA World Cup, UEFA European Championship, and winter and summer Olympics were identified. There were a great many other details about statistics and timing that we won’t share here. The bottom line is that there is about a 15% higher risk both during Christmas and Midsummer (incidence rate ratio 1.15, 95% confidence interval 1.12 to 1.19, P<0.001, and 1.12, 1.07 to 1.18, P<0.001, respectively). The highest risk occurred on Christmas Eve, 37% higher than average (1.37, 1.29 to 1.46, P<0.001). No change in risk happened at Easter or during these major sporting events. Risk was also higher early in the morning and on Mondays. Risks were worse for people older than 75 and those with diabetes, along with those who already had heart disease.
This information should get our attention as this year Christmas is on a Tuesday and Christmas Eve is on a Monday.
What do these researchers think is going on? Heart attacks are more common in the morning, either at or about 9 am, or during the first four hours after waking, which is pretty much the same thing.
There are multiple acute triggers that have been identified. Such triggers include emotional stress, heavy physical activity, cold weather exposure and air pollution. External stressors are also associated with increased risk, such as earthquakes, hurricanes, wars, and stock market drops or jumps. Numerous studies have pointed out this Christmas spike in incidence. Winston Churchill is reported to have had a heart attack during a visit to the White House in 1941.2 Another bit of trivia regarding Churchill that recently came to our attention: About 20% of teens in the UK think Churchill is a fictional character while nearly 50% believe Sherlock Holmes was a real person.3
We should mention that Midsummer is the most important holiday in Sweden after Christmas. It’s that whole dance around the Maypole thing with lots of eating, drinking etc. It’s held on June 24, the Feast Day of St John the Baptist.
While normally heart disease risk peaks in the morning, on Christmas Eve risk peaks at night, about 10 pm to be exact.
The study authors put forth various theories to explain their observations but none seem to ring quite true. It may be that family members that they don’t see regularly notice how poorly they look and drag them into the hospital. Yet there is no sharp decline after Christmas as one would predict after all the ‘vulnerable people’ were dragged into hospital. Some patients might hold off admitting how bad they feel until after the holiday festivities are over but if that were the case there would be a decline in heart attacks in the days leading up to Christmas, and there aren’t. The researchers want to blame the increase on some sort of emotional stress but at this point they do not present a comprehensive or believable theory.
My own theory is that this spike in myocardial infarctions results from a deficiency in Christmas pudding. My primary justification for this idea is that I have a large container of candied fruit in the cupboard that has been soaking in rum since Midsummer. My sister-in-law Sarah shared her family’s recipe for Christmas Pudding with me last winter, and I need an excuse to try making it. Sarah makes the best Christmas Pudding that I have ever tasted.
Sarah is originally from Tasmania. For that matter so are Blundstone Boots. Thus, if you are going to follow this recipe, do so while wearing your Blundstones in the kitchen. Sarah calls this recipe Nana Cox’s Christmas Pudding, though of course, I think of it as Sarah’s Pudding.
You might think that I am hard pressed to find an argument that this pudding will really lower the Christmas peak in infarction incidence, but it unquestionably might. To date there is no evidence heart attack rates increase in Tasmania on Christmas Eve. At least none that I have found.
There is certainly some indication that dried fruit and nuts have a beneficial impact on health. A 2017 review reminds us nuts and dried fruit “… consumption has been associated with the prevention and/or the management of such metabolic conditions as type 2 diabetes (T2D), metabolic syndrome and cardiovascular diseases.”4 A 2017 report from researchers in Australia (almost Tasmania) examined the potential mechanisms as to why nuts are so good for our health, that is in fancy talk, “…. to examine the potential mechanisms of action of nuts addressing effects on glycemic control, weight management, energy balance, appetite, gut microbiota modification, lipid metabolism, oxidative stress, inflammation, endothelial function and blood pressure with a focus on data from both animal and human studies. The favourable effects of nuts could be explained by the unique nutrient composition and bioactive compounds in nuts.”5
A fresh paper that was published last week in Nutrition & Diabetes reported that eating dried fruits lowers the glycemic index of white bread.6
In reality we are going to amend this recipe, cutting down the sugar and being more generous when measuring the nuts. For the sake of historical accuracy though, the recipe below is probably Nana Cox’s original.
- 1 kg mixed dried fruit (currants, sultanas, raisins (900 gms total) and 100 gms of citrus peel
- 2 tsp each of lemon, almond and vanilla essence
- ½ cup sherry
- ½ cup brandy
- 8 oz salted butter (room temperature)
- 10 oz brown sugar
- 4 eggs
- 8 oz flour (fine white or whole wheat)
- 8 oz fine breadcrumbs
- ½ tsp each of allspice, cinnamon and nutmeg
- 1 tsp bicarbonate (baking) soda
- 3 small, 2 medium or 1 large sized oven cooking bags (like those used for poultry)
- Dice the dried fruit and place in an airtight container. Add 1 tsp of the lemon, almond and vanilla essences, as well as the sherry and brandy, and mix well. Ideally complete this step one month or more (Sarah starts this about New Years for the following Christmas) before you want to make the pudding and mix the fruit from time to time to ensure it is moist. If the fruit is getting dry just add a splash more brandy and sherry and mix well. You can complete this step a day or two before you make this recipe, but the flavors will not be as well developed.
- Bring a large pot of water to boil on the stove with a small grate or frame in the bottom of the pot to keep the pudding from directly resting on the pot bottom. Reduce to a simmer.
- In a large mixing bowl cream the butter and sugar until a smooth golden, and then add and blend eggs, one at a time.
- Sift the flour together with bicarbonate soda and spices.
- Add ¼ of the flour, breadcrumbs, fruit and essences into the butter mixture and mix to combine, repeat until all ingredients are added. (You can use a hand or stand mixer, just be careful not to overbeat with each addition).
- Place mixture into cellophane oven cooking bag(s) depending on the number of puddings you are making, and seal well. Wrap with pudding cloth (or old tea towel) to shape into ball, and place in water to cook. A large pudding will take 3-4 hours to cook, each medium pudding will take 1½ -2 hours, and the small puddings will need 1 hour each. If you prefer to use a pudding steamer, grease the pan thoroughly with butter, and then cook according to the pudding sizes listed above.
- Mohammad MA, Karlsson S, Haddad J, et al. Christmas, national holidays, sport events, and time factors as triggers of acute myocardial infarction: SWEDEHEART observational study 1998-2013. BMJ. 2018 Dec 12;363:k4811. doi: 10.1136/bmj.k4811.
- Vale JA, Scadding JW. Did Winston Churchill suffer a myocardial infarction in the White House at Christmas 1941? J R Soc Med 2017;110:483 92.
- Hernández-Alonso P, Camacho-Barcia L, Bulló M, Salas-Salvadó J. Nuts and Dried Fruits: An Update of Their Beneficial Effects on Type 2 Diabetes. Nutrients. 2017 Jun 28;9(7). pii: E673.
- Kim Y, Keogh JB, Clifton PM. Benefits of Nut Consumption on Insulin Resistance and Cardiovascular Risk Factors: Multiple Potential Mechanisms of Actions. Nutrients. 2017 Nov 22;9(11). pii: E1271.
- Viguiliouk E, Jenkins AL, Blanco Mejia S, Sievenpiper JL, Kendall CWC. Effect of dried fruit on postprandial glycemia: a randomized acute-feeding trial. Nutr Diabetes. 2018 Dec 11;8(1):59.