Overall, I’m not a fan of taking too many supplements, as I think you can get most of what you need from a healthy diet.
But I make an exception for vitamin D. And with recent studies showing that high doses can not only reduce the risk of colon Cancerbut also dementia, now I’m taking a higher dose than normal – and I’m also taking it all year round.
During the winter months, when the sun is weak, I always follow National Health Service I advise and swallow a daily tablet, because I know that vitamin D is very important for a number of reasons.
But usually this time of year, when the sun is out and summer is coming, I stop taking it. After all, I eat a lot of oily fish and eggs, both of which are rich in vitamin D, and I also go for a lot of walks, so my vitamin D levels must be well up.
However, this year I will continue taking these supplements.
Studies show that our bodies become less effective at absorbing vitamin D from food and sunlight as we age, which is why Dr. Michael Mosley says he takes supplements year-round.
This happens in part because, surprise surprise, every year that passes I get older and studies show that as we age our bodies become less effective at absorbing vitamin D from food and our skin also becomes less efficient at absorbing vitamin D from food. conversion of sunlight into this nutrient.
This, and the fact that older people tend to spend more time indoors or in the shade, means that vitamin D deficiency is very common in people over 60, even in the summer months, especially if you have the darker skin.
But what dose should you take? This is where things get more controversial. Although the NHS suggests you limit yourself to 10 micrograms (mcg) – or 400 international units (IU) of vitamin D per day, the US National Institutes of Health recommends 15 mcg – and 20 mcg if you’re over 70.
I take 25 mcg (1,000 IU), which is within the limits of what’s considered safe (anything below 100 mcg a day for adults or 50 mcg for children, according to the NHS), but closer to the type of dose that studies show you need. take to avoid infections, cancer and perhaps even dementia.
Since its discovery in the 1920s, vitamin D’s best-known role has been keeping bones healthy by increasing the body’s absorption of calcium.
In recent years, scientists have discovered that there are vitamin D receptors in almost all of our cells, suggesting that its usefulness extends far beyond our bones.
But there is growing evidence that to enjoy benefits in these areas, such as preventing colon cancer and maintaining brain health, larger doses than are routinely recommended are needed.
For example, when it comes to cancer, a very recent study published in the journal Science showed that one of the ways in which taking large doses of vitamin D may work is by stimulating the type of gut bacteria that are particularly good at preventing growth. . of intestinal cancers. When researchers at the Francis Crick Institute in London gave mice a diet rich in vitamin D, they increased levels of Bacteroides fragilis – and higher levels of this bacteria better protected them against colon cancer.
Although there is currently no clear evidence that taking high doses of vitamin D has the same impact on the human gut, there are ongoing studies looking at its use in the treatment of colon cancer.
In 2017, for example, a trial of 139 patients with advanced colon cancer who were undergoing chemotherapy found that those who took a high dose of vitamin D (100 mcg) were 36 percent less likely to die or see death. your disease progresses. over the course of the two-year study than those who received a low dose (10 mcg). Encouraged, the team is carrying out a larger, longer study to see whether high doses of vitamin D can help slow or even prevent the spread of the disease.
However, evidence of the impact of vitamin D in delaying dementia is also increasing.
Last year there was a fascinating study from the University of Exeter where they analyzed the brains of more than 12,000 people who participated in the US National Alzheimer’s Coordinating Center (a project that collects data on the disease).
At the start of the study, patients had an average age of 71 and did not have dementia – and just over a third (37 percent) said they took vitamin D supplements regularly. Vitamin D fans will be pleased to know that over the next ten years, those who took the supplements were 40% less likely to develop dementia.
This may be because vitamin D has been shown to help prevent the accumulation of two proteins in the brain, amyloid and tau, which have been linked to dementia. It also helps reduce inflammation, another trigger for dementia.
Although convincing, this was not a randomized, controlled clinical trial – where people taking the supplement would be compared with a placebo group – and the patients were all on very different doses, which makes these results difficult to interpret.
But the same researchers have been conducting a trial of patients at risk of developing dementia that will include random assignment of a high-dose vitamin D supplement (100 mcg) or a placebo. I will let you know when the results are published.
In the meantime, take a supplement if you need it (obviously ask your doctor about the appropriate dose, especially if you already have health problems) and make the most of the vitamin D boost you get in the summer months by spending at least ten minutes a day outdoors – with your sleeves rolled up.
Walking down stairs can help your heart
When I’m at an airport or a shopping center I’m always surprised (and disappointed) by the number of people who get on the escalator, even when it’s going down.
All I can say is that you are missing out on the chance to exercise your heart and potentially prolong your life. That was the conclusion of a recent review presented at a European Society of Cardiology conference.
Based on data from 480,000 people, it was found that those who regularly climbed stairs were 39% less likely to die from a heart attack or stroke and 24% less likely to die from any cause. This is because it is a relatively intense exercise that quickly speeds up the heart.
It’s even more beneficial to take the stairs – in a 2017 study from Edith Cowan University in Australia, overweight women took the elevator to the sixth floor and then went down, or went up and down in the elevator, twice a week. After two weeks, those who went down saw the biggest benefits in balance, bone strength and blood pressure – probably because going down stairs means their muscles have to work harder to stop the fall.
What to do with that persistent cough
You may have noticed that there is an annoying and persistent cough going around. I got it a few weeks ago from my brother-in-law, who had it for at least three weeks, and who in turn got it from his wife.
This one keeps me up at night and shows no signs of improving. The problem is that I don’t really believe in the effectiveness of over-the-counter medicines (there is no adequate evidence that cough medicines work) – but in desperation I turned to cough syrup and a zinc supplement. Neither of them have done anything good so far. I was particularly disappointed with zinc, as studies have suggested that supplements can reduce colds and coughs by up to 46%. (Although this only seems to apply if you take them within 24 hours of developing symptoms, I probably missed that boat.)
If you have a similar cough, I suggest drinking plenty of water and, from time to time, warm lemon and honey (honey helps soothe your throat, while lemon has anti-inflammatory properties). The NHS recommends seeing your doctor if your cough persists for more than three weeks.
Tell one thief to catch another is a well-known saying that, fortunately for us, also seems to apply to bacteria. A new study from the University of Bonn in Germany has found that a common type of skin bacteria, Staphylococcus, kills other bacteria by injecting a chemical that dissolves their cell membranes.
The idea is that this could be harnessed to create a new antibiotic, which is exciting given that many bacteria are now resistant to antibiotics – including the first truly effective antibiotic, penicillin, which saved my life as a baby, when I got pneumonia.