Maclean's Interview: neurologist Martin Samuels

By Kate Fillion - Thursday, April 15, 2010 at 12:10 PM - 5 Comments

Photographs by Jodi Hilton/Getty Images

Dr. Martin Samuels heads the Harvard Medical School Department of Neurology at Brigham and Women’s Hospital in Boston, where he is also neurologist-in-chief, and has received dozens of international honours, including numerous teaching awards. On April 15, he will deliver the inaugural lecture of the Scienta Health Series in Toronto. His topic is “Successful aging: important advances in protecting your brain.”

Q: What are the big controversies in neurology regarding cognitive impairment associated with aging?
A: There are thousands. One is that nobody really knows the causes of Alzheimer’s disease. One hypothesis, invented by a colleague of mine, is that something called the amyloid precursor protein is the cause. Most people think he’s right, but a strong minority think it’s something completely different. A second controversy concerns treatment of Alzheimer’s. The FDA has approved four drugs that act indirectly, on memory systems, and some people think they should be used freely, while others question the benefit-to-cost ratio. Double-blind studies show that families can’t even tell whether the patient is taking the drugs or not, but families still want whatever is available. The question becomes whether it’s worth it, given the high cost and the side effects, like making people nauseated.

Q: Is memory loss inevitable?
A: An aspect of memory is lost, predictably, with aging: it becomes more difficult to think of the names of things and people. If you give people the Boston naming test—a standardized test of 60 objects that starts with easy words like “house” and ends with low frequency words like “protractor”—and you force them to go fast, you can predict age quite accurately. A normal 30-year-old would get over 57 correct, a normal 60-year-old would be more like 50 out of 60, and a 90-year-old, more like 40 correct. If you have Alzheimer’s disease, or a stroke that interferes with language in a pathological way, you might get only 10 right.

Q: Why does word retrieval diminish with age?
A: Neurons are dying; the brain is actually shrinking. If you took a perfectly normal 90-year-old who everybody in the family says is sharp as a tack, even if he was still the president of IBM, his brain would be lighter than it was when he was 80, and so on, all the way back to the peak weight of the brain, which is around 17 or 18 years old.

Q: Does intelligence protect against cognitive decline because you have a larger cognitive reserve?
A: It’s very hard to measure cognitive reserve. You hear stuff like “Einstein used just 38 per cent of his brain,” but there’s no evidence that’s the case. As far as we know, we are all using all of our brain, the neurons are firing and making electrical connections. What makes for fast cognition—intelligence, quick thinking—is the microscopic complexity of the network. It’s like a radio: it’s about the number of wires and the number of connections and, of course, they have to be connected correctly to work. The evidence we have is that if you start with very high cognition it doesn’t mean you’re less likely to get Alzheimer’s, but it does mean it takes more brain loss before it becomes obvious to the outside world that anything’s wrong.

Q: Is there any good news about our brains and aging?
A: Oh yes. Given the same basic intelligence, old people know way more than young people. They’ve forgotten more because they’ve lived so much longer, but what’s left is probably an order of magnitude greater than what a young person has, even though young people know things that some old people don’t, like how to text on a cellphone. It’s important to realize that forgetting is fine, in fact it’s critical for normal brain function. There are very good rememberers, idiot savants, who can tell you whether the 20th of April 1908 was a Wednesday, but they can’t do anything creative or that requires new thoughts because every circuit is completely jammed with useless old data.

Q: What can we do to protect our brains as we age?
A: There are no magical pills, vitamins or tricks which prevent aging. Aging cannot be prevented. But what one can do is make the environment for the nervous system as amenable as possible, so that as it ages, it can still function at a pretty high level, and cognition can be maintained well into late life, provided there isn’t a disease. More than anything else, there are things to avoid: smoking cigarettes, which is bad for the brain’s blood vessels, and getting morbidly obese and getting Type 2 diabetes, which is bad for your blood vessels, heart and your kidneys—when those don’t work, the brain doesn’t work well either. Very high levels of bad cholesterol: not good. Very low good cholesterol: also probably not good. A lot of alcohol—not one or two drinks a day, but a lot—is probably bad. And there’s the potential that there are toxins in a lot of herbs and spices that are sold as anti-aging cures. You don’t know what’s in them or how they’re made, because they’re not regulated by the FDA or the corresponding agency in other countries. A lot of these anti-aging teas, for instance, actually have neurotoxins in them.

Q: That’s it?
A: There are a few tricks, too. Tricks don’t prevent disease, and if you get a brain tumour or Alzheimer’s, tricks don’t work, but a good one is to sleep. Sleep is a very important part of memory consolidation—many of us believe that’s its function—and if you don’t sleep well, you put an extra stress on your aging nervous system.

Q: How much is enough?
A: I don’t think it matters exactly how much. One of the key things about sleeping is not to obsess about it, just do the right things. Don’t take stimulants—caffeine, diet pills, or things that contain caffeine, like chocolate— or exercise within a few hours of bedtime. You want an hour of downtime if possible before going to bed, and it’s good to dim the lights; it has a direct effect on the pineal gland, which secretes melatonin, a pro-sleeping hormone.

Q: As you get older, isn’t it harder to sleep?
A: Many reasons people don’t sleep well have nothing to do with aging. Drinking is the biggest problem, I would say. People think a drink will help them fall asleep, and it does, but as the alcohol level in the blood falls, they wake up two or three hours after going to bed. You shouldn’t drink significantly—a small glass doesn’t bother some people—within a couple of hours of going to bed. It’s very disruptive to sleep.

Q: We keep hearing about sudoku, ballroom dancing—don’t any of those things help our brains?
A: Well, ballroom dancing isn’t bad, it combines exercise and socialization. Physical exercise is associated with a lower risk of Alzheimer’s disease, and to the extent that Alzheimer’s is an analogy for normal aging—which isn’t necessarily true—that’s a reasonable thing to do. People should exercise about 20 minutes, if they can, at least five times a week. It’s the one thing that really works but we don’t know why.

Q: What about those brain games on the computer—just marketing scams?
A: “Scam” is a little strong, but they’re marketing efforts, no question about it. The basis is a famous study of nuns who did crossword puzzles and had a low incidence of Alzheimer’s disease. The problem with the study, and subsequent studies, is that there’s a pre-selection bias: if you’re a person who does crossword puzzles and you’re still doing them when you’re 90, you probably have a genetic background of high cognitive skills, so even if you get Alzheimer’s disease, it’s going to take longer before anybody notices. There’s no evidence that doing the New York Times crossword puzzle prevents Alzheimer’s.

Q: What do you personally do to protect your brain?
A: Nothing.

Q: Not even exercise?
A: Well, my wife and I run every morning, 1.5 to 2 miles—no more because I don’t want to wreck my knees—but that’s for general well-being. It’s more a psychological thing.

Q: You don’t take vitamins or supplements?
A: No. Dietary supplements are just a waste of money.

Q: What about this claim that omega-3 maintains the flexibility of the cell wall of the neuron?
A: What you can show about a cell wall in a lab doesn’t necessarily have any effect on the physiological system in vivo. There’s no benefit for omega-3 with regard to maintaining cognition or treating Alzheimer’s.

Q: What about a special diet?
A: I don’t believe in that at all. I personally enjoy everything and encourage my patients to do the same. Eating is one of the great pleasures of life. I’ve seen way, way more problems in people who’ve gone on diets or decided to take megavitamins than in people who have a normal diet.

Q: What kinds of problems?
A: There are all sorts of neurological complications of different vitamins. I had a man recently who decided he was going to take zinc, which is advertised in health food stores as being good for your memory and your libido. What he didn’t know is that zinc induces a protein in the gut which causes a loss of copper. He became very weak in the legs, numb and unable to walk, basically, and people thought he had a spinal cord tumour or some other horrible thing. But all it was was a profound copper deficiency.

Q: Why, if they don’t work, do the media keep telling us about vitamins and other things “proven” to enhance cognitive functioning?
A: Over the years, journalists have interviewed me about one thing or another, and they always want to put in their article what somebody or other can do about a problem. It’s the obsession of advanced societies: having too much confidence in technology, to the point where people believe everything can be prevented if you just do the right things. Well, there isn’t always something to do.

Q: When you were in med school, was anti-aging even a focus in neurology?
A: I finished medical school in ’71, and there was no talk about neuroprotection or anything of the kind. It’s become a focus because of the public’s interest in it, primarily. Successful aging is an aspect of neurological medicine that I would say is analogous to cosmetic dermatology: it’s nice to have, but it isn’t really the important thing. Neurology is a medical field, and what we’re really worried about are the diseases that can disable or kill you: brain tumours, strokes, epilepsy. Normal aging is not a disease, even though people who are 90 walk slower and their memory is not what it once was, and neither are their joints, or their faces. Successful aging is [a concept] that has come along in societies where people have a lot of resources and leisure time. In Africa, where people are falling down on the street and dying of brain infections caused by parasites, they don’t worry about successful cognitive aging. It’s a luxury.

Inside McLuhan’s head

By macleans.ca - Wednesday, March 17, 2010 at 9:00 AM - 10 Comments

Photograph by P.J. Salkovitch/ Canadian Press

“I knew going into it that this wasn’t going to be a straight biography,” says Douglas Coupland about his new study of Marshall McLuhan. What the Vancouver-based author has concocted instead is a historical mosaic that borrows heavily from McLuhan’s inimitable riffing style—that is, to dance non-linearly around ideas as a means of forming a distinct theory. Coupland also adds a healthy dose of his own literary signature to the mix—asides, like copies of online user-reviews of McLuhan’s works that appear in between chapters, seem at first glance peripheral to the subject at hand but later turn out to speak a distinct truth about it.

To be sure, this is still a biographical work. It’s just that, for Coupland, the things people already know about McLuhan—his famous phrases “global village” and “the medium is the message,” plus his cameo in Annie Hall—aren’t as interesting as, say, the great thinker’s biological and genetic makeup. And so, instead of analyzing McLuhan’s 1962 masterwork The Gutenberg Galaxy, Coupland investigates the brain that composed it.

Marshall McLuhan’s brain was fuelled by fresh blood from the heart through not one but two arteries at the base of his skull, a trait in the mammalian world found mostly in cats and rarely in human beings. As well, people in Marshall’s family tended to die of strokes. Marshall himself had countless small strokes during his lifetime—sometimes in front of a classroom of students, where he’d suddenly gap out for a few minutes and then return to the world.

Continue…

Going to work on smart drugs

By Jason Kirby - Thursday, October 2, 2008 at 12:00 AM - 1 Comment

While most people start their day with a cup of coffee, Jeremy Cole, an operations manager at an aviation company in Denver, Colo., ingests a little white pill called modafinil. For those with debilitating sleep disorders such as narcolepsy, which can cause individuals to pass out at all hours of the day, the drug’s energizing qualities offer a ray of hope for a normal life. But the thing is, Cole doesn’t suffer from narcolepsy. Instead, he’s part of a growing throng of otherwise healthy individuals popping high-powered pharmaceuticals to add some zing to their grey matter. “It’s not like coffee, it doesn’t make you feel buzzed or amped up,” says Cole, who began to take the drug 10 months ago. “It’s as if a fog has been lifted off your brain.”

By now, many have heard the stories of university students popping Ritalin to help them cram for exams. But in recent months there have been signs the phenomenon has spread to scientists, academics and even office workers. This past spring the journal Nature conducted an informal survey of its readers to gauge how many of them have used so-called smart drugs. The survey found that one in five respondents had turned to pharmaceuticals to enhance their concentration, focus and memory. Then, in July, a popular technology blog in Silicon Valley proclaimed Provigil (the brand name for modafinil) to be the “entrepreneur’s drug of choice.” The blog cited executives at upstart tech companies who rely on it to keep them energized through 20-hour workdays.

Now a report entitled “When the Boss Turns Pusher” in last month’s issue of the Journal of Medical Ethics warns that some employers may soon pressure workers to take brain boosters as a way to improve their performance. The report argues legislation is urgently needed to protect workers’ rights before the practice of healthy people using smart drugs becomes more common. “I’m a strong supporter of individual autonomy and I think people should be able to enhance themselves all they want,” Dr. Jacob Appel, a bioethics lecturer at Brown University in Rhode Island and the report’s author, told Maclean’s. “But my concern is that employers will try to compel individuals to do that.”

It’s hard to know exactly how many healthy adults are doping their brains. Anecdotal evidence on the Internet suggests an underground enhancement culture is taking shape not unlike what occurred in the early days of steroid use in bodybuilding. In online forums devoted to cognition enhancement, participants rhyme off their pharmaceutical regimens the same way other people swap cocktail recipes. Except in this case, the ingredients are some of the most powerful compounds on the market, approved to treat not just narcolepsy and attention deficit disorder, but also Parkinson’s disease, Alzheimer’s and depression.

Obesity: a "brain disease"?

By Kate Lunau - Tuesday, May 6, 2008 at 4:10 PM - 2 Comments

Have you ever been grocery shopping when you’re hungry, and bought way more stuff than you intended? Understanding the reasons for this may give us some clues to the obesity epidemic, new research suggests.

People generally eat for two reasons: because they’re hungry (hormones in the brain tell us to eat to maintain a constant body weight), or because we’re tempted by delicious food (so-called “hedonistic consumption”). But it could be these two urges are more interconnected than we previously thought: researchers at the Montreal Neurological Institute, McGill University say they’ve discovered that ghrelin (one of the hormones that prompts us to eat when we need more calories) might also make us want to consume food for pleasure.

“Our study demonstrates that ghrelin actually activates certain regions of the brain to be more responsive to visual food cues, thereby enhancing the hedonic and incentive responses to food-related cues,” neurologist Dr. Alain Dagher, principal investigator in the study, says in a press release. “Ghrelin is a hormone that triggers hunger, and is secreted by the stomach [when it is empty].”

This supports the view, the press release notes, that “obesity must be understood as a brain disease and that hunger should also be looked at as a kind of food addiction,” as obese people might be overeating largely due to an uncontrollable hunger.

Researchers found ghrelin actually acts on the same reward and motivation areas of the brain implicated in drug addiction, which could potentially have profound implications: “If food is thought of as potentially ‘addictive,’” the press release says, “this would support action to limit or ban fast food from schools and junk food advertisements geared towards children, in the same way that results proving nicotine to be addictive spurred the current public policy towards nicotine.”